[Objectives]This study was conducted to clarify the differences of volatile components in fresh fruit of Morinda citrifolia L.from different origins.[Methods]The method of HS-SPME-GC/MS detection was used to determine...[Objectives]This study was conducted to clarify the differences of volatile components in fresh fruit of Morinda citrifolia L.from different origins.[Methods]The method of HS-SPME-GC/MS detection was used to determine the volatile chemical components in fresh fruit of M.citrifolia.[Results]52,52 and 45 volatile components were identified from the fresh fruit of M.citrifolia from Xisha,Wanning and Haikou,respectively.Among them,the number and content of the identified esters were relatively high,mainly methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbuten-2-enyl caprylate,methyl caproate,and ethyl caproate.There were also fatty acids,alcohols,phenols,ketones,aldehydes and other substances.There were 33 common ingredients in the fruit from the three origins,mainly including caprylic acid,caproic acid,capric acid,methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbutene-2-enyl caprylate,methyl caproate,ethyl caproate,methyl caprate and hexyl caproate.[Conclusions]The types and contents of volatile components in fresh fruit of M.citrifolia from different origins were significantly different.展开更多
Characteristics of ore forming fluids as inferred from detailed studies of inclusions indicate that pegmatites may have different origins. For example, the granitic pegmatite at Mufushan is originated from magma diffe...Characteristics of ore forming fluids as inferred from detailed studies of inclusions indicate that pegmatites may have different origins. For example, the granitic pegmatite at Mufushan is originated from magma differentiation at 1100-200℃, while the No.3 Pegmatite Vein in Xinjiang may owe its origin to a pegmatitic magma produced via metamorphic anatexis at 1140-200℃. Pegmatite fluids of the above two types are a melt liquid system and may evolve into a solid melt or solid liquid system that would have a critical bearing on metasomatism and intergranular solutions. The Minxi pegmatite, on the other hand, resulted from metamorphic differentiation, with its fluid (formed at 400-180℃) exhibiting many features of metamorphism. Pegmatites of different origins are distributed in tectonic units of different characters and are different both in the nature of ore forming fluid and in the source of ore metals. This concept of polygene launches a challenge to the traditional belief that pegmatite is exclusively originated from magma differentiation and may be helpful for the establishment of a new theory of pegmatite genesis.展开更多
The genetic similarity and genetic difference among improved japonica rice varieties from different countries (or regions and organizations) were detected. The aim is to provide genetic basis to the breeding of japoni...The genetic similarity and genetic difference among improved japonica rice varieties from different countries (or regions and organizations) were detected. The aim is to provide genetic basis to the breeding of japonica rice varieties. The genetic similarity and cluster of 313 improved japonica varieties from 20 countries (or regions and organizations) were analyzed using the SSR marker. With 34 SSR primers which were polymorphic and uniformly distributed in rice genome, totally 198 alleles were detected among these improved varieties with the average number of alleles per pair of primers of 5.8235. RM320, RM531, RM1, RM21, and RM336 located more alleles, which were 16, 13, 12, 10, and 10 respectively. RM320, RM336, RM286, RM531, and RM21 showed higher genetic diversity indexes, which were 2.3668, 2.0041, 1.9684, 1.9508, and 1.7203, respectively. The genetic similarity for improved japonica varieties among different countries (or regions and organizations) were ranged from 0.279 to 0.918, and the mean value was 0.653. The rice varieties from countries whose latitude and geography position were all nearer were clustered together with higher genetic similarity indexes. The rice varieties from countries who had more different latitude and far geography position were clustered separately with lower genetic similarity indexes. The results indicated the genetic similarity indexes among improved japonica varieties had a close relationship with the geographical position, especially with the latitude.展开更多
Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermen...Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.展开更多
An autonomous altitude adjustment system for a stratospheric satellite(StratoSat)platform is proposed.This platform consists of a helium balloon,a ballonet,and a two-way blower.The helium balloon generates lift to bal...An autonomous altitude adjustment system for a stratospheric satellite(StratoSat)platform is proposed.This platform consists of a helium balloon,a ballonet,and a two-way blower.The helium balloon generates lift to balance the platform gravity.The two-way blower inflates and deflates the ballonet to regulate the buoyancy.Altitude adjustment is achieved by tracking the differential pressure difference(DPD),and a threshold switching strategy is used to achieve blower flow control.The vertical acceleration regulation ability is decided not only by the blower flow rate,but also by the designed margin of pressure difference(MPD).Pressure difference is a slow-varying variable compared with altitude,and it is adopted as the control variable.The response speed of the actuator to disturbance can be delayed,and the overshoot caused by the large inertia of the platform is inhibited.This method can maintain a high tracking accuracy and reduce the complexity of model calculation,thus improving the robustness of controller design.展开更多
Hester Prynne and Tess Durbeyfield were two eminent female figures in the world by Thomas Hardy and Nathaniel Hawthone.Although the two female leading characters were in different time and place,their tragic experienc...Hester Prynne and Tess Durbeyfield were two eminent female figures in the world by Thomas Hardy and Nathaniel Hawthone.Although the two female leading characters were in different time and place,their tragic experiences were almost the same.However,they were separated in the end.From the comparison of their personalities and the social situation they involved in,we would try to explore the origins of their similarity and ending by this article with the aim of alerting the world.展开更多
THE crystalline-fluid melt inclusions in aquamarines in pegmatites from Mufushan (Hunan Prov.) andAilaoshan (Yunnan Prov.) have been studied. The research shows that there are obvious differences inthe chemical compos...THE crystalline-fluid melt inclusions in aquamarines in pegmatites from Mufushan (Hunan Prov.) andAilaoshan (Yunnan Prov.) have been studied. The research shows that there are obvious differences inthe chemical composition of the inclusions in the aquamarines, which is of great importance for studyingthe forming mechanism and origin of pegmatites. 1 General geology of pegmatites Mufushan is situated in the middle sector of the Jiangnan Ancient Land. The granitic pegmatitesmainly outcrop in granite mass of late Yanshanian (105-145 Ma) which was intruded in middle sector ofthe middle Proterozoic strata. Part of the pegmatites occur in the contact zone of the granite and the metamorphic rocks. The pegmatite veins may be divided into four types, all of them were originated from mag-展开更多
Well-developed pores and cracks in coal reservoirs are the main venues for gas storage and migration.To investigate the multi-scale pore fractal characteristics,six coal samples of different rankings were studied usin...Well-developed pores and cracks in coal reservoirs are the main venues for gas storage and migration.To investigate the multi-scale pore fractal characteristics,six coal samples of different rankings were studied using high-pressure mercury injection(HPMI),low-pressure nitrogen adsorption(LPGA-N2),and scanning electron microscopy(SEM)test methods.Based on the Frankel,Halsey and Hill(FHH)fractal theory,the Menger sponge model,Pores and Cracks Analysis System(PCAS),pore volume complexity(D_(v)),coal surface irregularity(Ds)and pore distribution heterogeneity(D_(p))were studied and evaluated,respectively.The effect of three fractal dimensions on the gas adsorption ability was also analyzed with high-pressure isothermal gas adsorption experiments.Results show that pore structures within these coal samples have obvious fractal characteristics.A noticeable segmentation effect appears in the Dv1and Dv2fitting process,with the boundary size ranging from 36.00 to 182.95 nm,which helps differentiate diffusion pores and seepage fractures.The D values show an asymmetric U-shaped trend as the coal metamorphism increases,demonstrating that coalification greatly affects the pore fractal dimensions.The three fractal dimensions can characterize the difference in coal microstructure and reflect their influence on gas adsorption ability.Langmuir volume(V_(L))has an evident and positive correlation with Dsvalues,whereas Langmuir pressure(P_(L))is mainly affected by the combined action of Dvand Dp.This study will provide valuable knowledge for the appraisal of coal seam gas reservoirs of differently ranked coals.展开更多
Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb.(DTTP).The influences of 4 extraction methods,namely hot water extraction(W),acidic extraction(HA),hot-com...Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb.(DTTP).The influences of 4 extraction methods,namely hot water extraction(W),acidic extraction(HA),hot-compressed water extraction(HCW)and enzyme-assisted extraction(EAE),on the yields,physicochemical properties,hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared.Among these DTTP polysaccharides,DTTP-HA was outstanding in several respects.DTTP-HA was the most water soluble;it had the highest total carbohydrate content(85.08%),the highest uronic acid(13.20%)and the highest thermal stability.DTTP-HA and DTTP-W possessed a triple-helix structure.These 4 kinds of polysaccharides have the same types of monosaccharides,but in different molar percentages.Extraction method had a significant impact on the microstructures of the extracted polysaccharides.DTT-HA exhibited irregular structure with many holes.Among the 4 extracted methods,the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities.The better bioactivities of DTTP-HA may be related to the above factors.The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.展开更多
The goal of the study was to quantify the genetic diversity of different potato varieties. Five groups were named to classify the 25 genres of potatoes as: Cluster I (Lalpakri, Diamond), Cluster II (Hagrai, Green Moun...The goal of the study was to quantify the genetic diversity of different potato varieties. Five groups were named to classify the 25 genres of potatoes as: Cluster I (Lalpakri, Diamond), Cluster II (Hagrai, Green Mountain, G.M.O., Elvera), Cluster III (Atlantic, Shepody, Raja, Fundy, Multa, Granulla, Shibilati, Japanese Red), Cluster IV (Atlas, Brondy, Yucon Gold, Monona, Petrones, Cheroki), and Cluster V (Calwhite, Prelude, Allblue, Russet, Burbank, TPS-67). The highest and lowest genotypes are found in Clusters III and I, respectively. The two groups’ maximum inter-cluster distance (the cluster’s distance between them) demonstrates the enormous diversity between Clusters II & III. Cluster III had the greatest intra-cluster distance (distance within a set), whereas Cluster V had the smallest. In most cases, the distance between gaps was more significant than the distance within the holes, showing greater genetic diversity between different groups’ genotypes. The highest, second highest, and third highest eigenvalues, accompanying the positive canonical values for Vectors I and II of three characteristics: average tuber weight in each plant, the tubers number in each plant, and the eyes number in each tuber, showed the most outstanding contribution to the complete difference between genotypes. Of the nine features, the smaller leaves number in each plant, the shorter plant height, the more minor genotypes, the fewer eyes per tube generated from Cluster I, the maximum height of the plants, the high-quality tubers in each plant, the tubers number in each plant, the fresh weight in each plant, and the leaf number in each plant from Cluster II could be chosen in the role of parents in this program for hybridization. Given the size of the genetic distance, the various characteristics that contribute to the overall difference, and the average population size, Hagrai, Green Mountain, O.M.G., Elvera Cluster II and Cluster I, Lalpakri, and Diamond genotypes can be regarded as parents of hybridization programs in the future. Thus, producers can get guidance to enhance genetic diversity by selecting materials from different relatives and reducing their vulnerability to diseases and climate change.展开更多
Overpressure is significant to the exploration and exploitation of petroleum due to its influence on hydrocarbon accumulation and drilling strategies.The deep-burial hydrocarbon reservoirs of Jurassic strata in the ce...Overpressure is significant to the exploration and exploitation of petroleum due to its influence on hydrocarbon accumulation and drilling strategies.The deep-burial hydrocarbon reservoirs of Jurassic strata in the central Junggar Basin are characterized by intensive overpressure,whose origins are complex and still unclear.In this study,Bowers'method and sonic velocity-density crossplot method based on well logging data were used as a combination for overpressure judgements in geophysics.Furthermore,the corresponding geological processes were analysed in quality and quantity to provide a rational comprehension of the overpressure origins and the model of overpressure evolution and hy-drocarbon accumulation processes.The results showed that hydrocarbon generation in the Jurassic source rocks led to overpressure in the mudstones,while hydrocarbon generation in Permian source rocks led to overpressure in the sandstone reservoirs in Jurassic strata by vertical pressure transfer.The burial and thermal history indicated that the aquathermal effect of pore fluids by temperature increase in deep strata is also an important origin of overpressure,while disequilibrium compaction may not be the dominant cause for the overpressure in deep-buried strata.Furthermore,the continuous tectonic compression in both the north-south and west-east trends from the Jurassic period to the present may also have enhanced the overpressure in deep strata.Meanwhile,the developed faults formed by intensive tectonic compression led to pressure transfer from source rocks to the Jurassic reservoirs.Overpressured geofluids with hydrocarbons migrated to sandstone reservoirs and aggravated the over-pressure in the Jurassic strata.To conclude,the intensive overpressure in the central Junggar Basin is attributed to the combination of multiple mechanisms,including hydrocarbon generation,the aqua-thermal effect,tectonic compression and pressure transfer.Furthermore,the developed overpressure indicated hydrocarbon migration and accumulation processes and the potential of oil and gas reservoirs in deeply buried strata.We hope this study will provide a systematic research concept for overpressure origin analysis and provide guidance for petroleum exploration and exploitation in deep-buried strata.展开更多
The main geolocation technology currently used in COSPAS-SARSAT system is TDOA/FDOA or three-star TDOA,the principle is to determine the location of the signal source by using the difference in arrival time and freque...The main geolocation technology currently used in COSPAS-SARSAT system is TDOA/FDOA or three-star TDOA,the principle is to determine the location of the signal source by using the difference in arrival time and frequency of the wireless signal between different receivers.Therefore,ground monitoring stations need to be equipped with more than two antenna receiving stations,and multiple satellites should be able to simultaneously relay the distress signal from the target source in order to achieve the geolocation function.However,when the ground receiving system has only one antenna receiving station,or the target source is in a heavily obscured environment,the ground side is unable to receive the forwarded signals from multiple satellites at the same time,which will make it impossible to locate.To address these problems,in this paper,a time-sharing single satellite geolocations method based on different orbits is proposed for the first time.This method uses one or several low-earth orbit satellites(LEO)and mediumearth orbit satellites(MEO)in the visible area,and the receiving station only needs one pair of receiving antennas to complete the positioning.It can effectively compensate for the shortcomings of the traditional TDOA using the same moment and have better positioning accuracy compared with the single satellite in the same orbit.Due to the limited experimental conditions,this paper tests the navigation satellite using different orbit time-sharing single satellite geolocations,and proves that the positioning method has high positioning accuracy and has certain promotion and application value.展开更多
In the financial sector, data are highly confidential and sensitive,and ensuring data privacy is critical. Sample fusion is the basis of horizontalfederation learning, but it is suitable only for scenarios where custo...In the financial sector, data are highly confidential and sensitive,and ensuring data privacy is critical. Sample fusion is the basis of horizontalfederation learning, but it is suitable only for scenarios where customershave the same format but different targets, namely for scenarios with strongfeature overlapping and weak user overlapping. To solve this limitation, thispaper proposes a federated learning-based model with local data sharing anddifferential privacy. The indexing mechanism of differential privacy is used toobtain different degrees of privacy budgets, which are applied to the gradientaccording to the contribution degree to ensure privacy without affectingaccuracy. In addition, data sharing is performed to improve the utility ofthe global model. Further, the distributed prediction model is used to predictcustomers’ loan propensity on the premise of protecting user privacy. Usingan aggregation mechanism based on federated learning can help to train themodel on distributed data without exposing local data. The proposed methodis verified by experiments, and experimental results show that for non-iiddata, the proposed method can effectively improve data accuracy and reducethe impact of sample tilt. The proposed method can be extended to edgecomputing, blockchain, and the Industrial Internet of Things (IIoT) fields.The theoretical analysis and experimental results show that the proposedmethod can ensure the privacy and accuracy of the federated learning processand can also improve the model utility for non-iid data by 7% compared tothe federated averaging method (FedAvg).展开更多
In the present paper,the numerical solution of It?type stochastic parabolic equation with a timewhite noise process is imparted based on a stochastic finite difference scheme.At the beginning,an implicit stochastic fi...In the present paper,the numerical solution of It?type stochastic parabolic equation with a timewhite noise process is imparted based on a stochastic finite difference scheme.At the beginning,an implicit stochastic finite difference scheme is presented for this equation.Some mathematical analyses of the scheme are then discussed.Lastly,to ascertain the efficacy and accuracy of the suggested technique,the numerical results are discussed and compared with the exact solution.展开更多
In the context of global emission reduction, the low-carbon sustainable development of the construction industry has become an important research content. With the vigorous development of new industrial technologies, ...In the context of global emission reduction, the low-carbon sustainable development of the construction industry has become an important research content. With the vigorous development of new industrial technologies, the application of prefabrication technology to buildings had become a mainstream. However, the research on the role of prefabricated technology in reducing building carbon emissions was not yet comprehensive, and the research on the relationship between prefabricated structure types and carbon emissions in the construction stage was not yet thorough. Guided by life cycle assessment (LCA), this paper used the scenario analysis method to set different working conditions for five different structural systems, and used SimaPro software to evaluate the carbon emissions of prefabricated buildings in order to clarify the carbon emissions of prefabricated buildings under different structural systems, and explore their impact mechanisms in depth. Finally, take the existing buildings in China as an empirical study, the results showed that: 1) The carbon emissions produced by the four common prefabricated structural systems were almost the same. Different structures had different requirements for the combination of components. The carbon emissions of individual buildings would be superimposed according to the carbon emission characteristics of various individual components to form the final total carbon emissions. 2) When the building structure system requires more combinations of components, the greater the amount of transportation invested in the transportation process, the more carbon emissions would be caused. In the calculation of all individual building construction stages, the carbon emissions generated by tower cranes almost exceed the sum of the carbon emissions of all mobile machinery. 3) Prefabricated shear wall structures and prefabricated frame-shear wall structures require a large amount of hoisting of prefabricated shear walls, so the carbon emissions of their mechanical equipment were also the highest.展开更多
Based on the hourly precipitation data from 4 observation stations of Xining City from June to September during 2005-2011,the temporal and spatial distribution characteristics of short-time precipitation were analyzed...Based on the hourly precipitation data from 4 observation stations of Xining City from June to September during 2005-2011,the temporal and spatial distribution characteristics of short-time precipitation were analyzed.The results show that the precipitation distribution in Xining region exhibited the less-more-less trend from southwest to northeast,while the torrential rain gradually increased from the northwest and southwest to the middle.The hourly general precipitation in Xining region had obviously seasonal characteristics,and its annual distribution showed wavy changes,but the annual variation of short-time heavy precipitation and rainstorm was very obvious.Furthermore,short-time heavy precipitation was concentrated from 18:00 to 24:00,followed by 03:00-07:00 on the following day.The occurrence time of short-time rainstorm accorded with short-time heavy precipitation.It offers a useful reference for the accurate and timely short-term forecast.展开更多
Inflammation-mediated carcinogenesis develops in the context of chronic inflammation and is a significant cause of cancer within the digestive system.In the chronic inflammation microenvironment,the metabolic activity...Inflammation-mediated carcinogenesis develops in the context of chronic inflammation and is a significant cause of cancer within the digestive system.In the chronic inflammation microenvironment,the metabolic activity of tissue cells undergoes extensive changes,which interfere with the normal function of immune cells.Dysregulation of cell metabolism and immune function has been identified as a key factor contributing to inflammation-mediated carcinogenesis within the major digestive organs,such as the stomach,liver,and colorectum.This metabolic-immune imbalance also corresponds to traditional Chinese medicine(TCM)theories of“yin-yang disharmony”and“disharmony between Ying-nutrients and Wei-defense.”The metabolic-immune imbalance has also been regarded as the key factor supporting“treatment of different diseases with the same method”,in which the same approach is adopted in the treatment of different conditions.In the TCM treatment process,it is necessary to first identify TCM patterns and then apply the corresponding TCM to correct the dysregulated metabolic and immune function,thereby blocking the progression from inflammation to malignancy.Our study findings deepen the TCM understanding of metabolic-immune dysregulation and the relationship between metabolic-immune dysregulation,pattern identification,and treatment method.They also provide new insights for the treatment of inflammation-mediated carcinogenesis in major digestive organs and help us further explore the scientific connotation of the TCM strategy of“treating different diseases with the same method”.展开更多
The resorption of nutrients from senescent leaves allows plants to conserve and recycle nutrients. To explore the adaptation strategies of desert plants to nutrient-limited environments, we selected four typical deser...The resorption of nutrients from senescent leaves allows plants to conserve and recycle nutrients. To explore the adaptation strategies of desert plants to nutrient-limited environments, we selected four typical desert plants(Populus euphratica Oliv., Tamarix ramosissima Ledeb., Glycyrrhiza inflata Batal., and Alhagi camelorum Fisch.) growing in the desert area of the northern margin of the Tarim Basin,China. The contents of nitrogen(N), phosphorus(P), potassium(K), calcium(Ca), magnesium(Mg), and Ferrum(Fe) in the leaves of these four typical desert plants and their resorption characteristics were analyzed. The relationship of nutrient resorption efficiency with leaf functional traits and soil physical-chemical properties in two different habitats(saline-alkali land and sandy land) was discussed.The results showed that the four plants resorbed most of the elements. Ca was enriched in the leaves of P.euphratica, G. inflate, and A. camelorum;Mg was enriched in the leaves of G. inflata;and Fe was enriched in the leaves of the four plants. The results of the redundancy analysis showed that leaf thickness, soil electrical conductivity, and soil P content were the major factors affecting the nutrient resorption efficiency of the four plants. Leaf thickness was negatively correlated with N resorption efficiency(NRE),P resorption efficiency, and Fe resorption efficiency;soil electrical conductivity was positively correlated with the resorption efficiency of most elements;and soil P content was negatively correlated with the resorption efficiency of most elements in the plant leaves. The results showed that soil physical-chemical properties and soil nutrient contents had an important impact on the nutrient resorption of plant leaves.The same species growing in different habitats also differed in their resorption of different elements. The soil environment of plants and the biological characteristics of plant leaves affected the resorption of nutrient elements in different plants. The purpose of this study is to provide small-scale data support for the protection of ecosystems in nutrient-deficient areas by studying leaf functional strategies and nutrient conservation mechanisms of several typical desert plants.展开更多
In this study,we estimated the weekly Gravity Recovery and Climate Experiment(GRACE)spherical harmonic(SH)solutions and regional mascon solutions using GRACE-based Geopotential Difference(GPD)data and investigated the...In this study,we estimated the weekly Gravity Recovery and Climate Experiment(GRACE)spherical harmonic(SH)solutions and regional mascon solutions using GRACE-based Geopotential Difference(GPD)data and investigated their abilities in retrieving terrestrial water storage(TWS)changes over the Amazon River Basin(ARB)from January 2003 to February 2013.The performance of the weekly GPD-SH and GPDmascon solutions was evaluated by comparing them with the weekly GFZ-SH solutions,Global Land Data Assimilation Systems(GLDAS)-NOAH hydrological model outputs,and monthly GFZ-SH,GPD-SH,and CSRmascon solutions in the spatio-temporal and spectral domains.The results demonstrate that the weekly GPD-SH and GPD-mascon present good consistency with the weekly GFZ-SH solutions and GLDAS-NOAH estimates in the spatio-temporal domains,but GPD-mascon presents stronger signal amplitudes and more spatial details.The comparison of the monthly average of weekly estimates and monthly solutions demonstrates that the weekly GPD-mascon and GFZ-SH with DDK1 filtering are close to the monthly CSRmascon and GFZ-SH solutions,respectively.However,the signal amplitudes of TWS changes from GPD-SH and GFZ-SH with 650 km Gaussian filtering are smaller than the monthly solutions,and the corresponding Root Mean Square Errors between the TWS change time series from the monthly average of weekly solutions and monthly estimates are 18.12 mm(GPD-mascon),18.81 mm(GFZ-SH-DDK1),24.93 mm(GPDSH-G650km),and 33.07 mm(GFZ-SH-G650km),respectively.Additionally,the TWS change time series derived from weekly solutions present more high-frequency time-varying information than monthly solutions.Furthermore,the 300 km Gaussian filtering can improve the signal amplitudes of TWS changes from the weekly GPD-SH solutions more than those with 650 km Gaussian filtering,but the corresponding noise level is higher.The weekly GPD-SH and GPD-mascon solutions can extend the application scopes of GRACE and provide good complements to the current GRACE monthly solutions.展开更多
Through the theoretical analysis of overburden destabilization mechanism, FLAC 3D simplified plane numerical simulation method and field measurement method, we compared the relationship of overburden support pressure ...Through the theoretical analysis of overburden destabilization mechanism, FLAC 3D simplified plane numerical simulation method and field measurement method, we compared the relationship of overburden support pressure at 35 m of workface recovery, and the peak overburden support pressure decreased from 13.85 Mpa to 11.97 Mpa from 1:1 to 1:3. With the increase of mining ratio, the peak over-supporting pressure decreases: with the increase of top coal recovery thickness, the peak over-supporting pressure and the influence range will be further expanded, and the distance between the peak over-supporting pressure and the coal wall of the working face will be further increased and the high stress zone of the peak area will be expanded simultaneously.展开更多
基金Supported by Hainan Province Basic and Applied Basic Research Program(Natural Science)High-level Talents(No.2019RC318)Nanfeng Special Phase III:Investigation and Protection of Cultivated Land and Fishery Water Resources(NFZX2021)the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(No.1630032022022)。
文摘[Objectives]This study was conducted to clarify the differences of volatile components in fresh fruit of Morinda citrifolia L.from different origins.[Methods]The method of HS-SPME-GC/MS detection was used to determine the volatile chemical components in fresh fruit of M.citrifolia.[Results]52,52 and 45 volatile components were identified from the fresh fruit of M.citrifolia from Xisha,Wanning and Haikou,respectively.Among them,the number and content of the identified esters were relatively high,mainly methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbuten-2-enyl caprylate,methyl caproate,and ethyl caproate.There were also fatty acids,alcohols,phenols,ketones,aldehydes and other substances.There were 33 common ingredients in the fruit from the three origins,mainly including caprylic acid,caproic acid,capric acid,methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbutene-2-enyl caprylate,methyl caproate,ethyl caproate,methyl caprate and hexyl caproate.[Conclusions]The types and contents of volatile components in fresh fruit of M.citrifolia from different origins were significantly different.
文摘Characteristics of ore forming fluids as inferred from detailed studies of inclusions indicate that pegmatites may have different origins. For example, the granitic pegmatite at Mufushan is originated from magma differentiation at 1100-200℃, while the No.3 Pegmatite Vein in Xinjiang may owe its origin to a pegmatitic magma produced via metamorphic anatexis at 1140-200℃. Pegmatite fluids of the above two types are a melt liquid system and may evolve into a solid melt or solid liquid system that would have a critical bearing on metasomatism and intergranular solutions. The Minxi pegmatite, on the other hand, resulted from metamorphic differentiation, with its fluid (formed at 400-180℃) exhibiting many features of metamorphism. Pegmatites of different origins are distributed in tectonic units of different characters and are different both in the nature of ore forming fluid and in the source of ore metals. This concept of polygene launches a challenge to the traditional belief that pegmatite is exclusively originated from magma differentiation and may be helpful for the establishment of a new theory of pegmatite genesis.
基金supported by the National Key Tech-nology Research and Development Program of China(2006BAD13B01)the Protective Program of Crop Germpalsm of China (NB05-070401-22-01)the Cooperative Research between China and Korea (2004-2007)
文摘The genetic similarity and genetic difference among improved japonica rice varieties from different countries (or regions and organizations) were detected. The aim is to provide genetic basis to the breeding of japonica rice varieties. The genetic similarity and cluster of 313 improved japonica varieties from 20 countries (or regions and organizations) were analyzed using the SSR marker. With 34 SSR primers which were polymorphic and uniformly distributed in rice genome, totally 198 alleles were detected among these improved varieties with the average number of alleles per pair of primers of 5.8235. RM320, RM531, RM1, RM21, and RM336 located more alleles, which were 16, 13, 12, 10, and 10 respectively. RM320, RM336, RM286, RM531, and RM21 showed higher genetic diversity indexes, which were 2.3668, 2.0041, 1.9684, 1.9508, and 1.7203, respectively. The genetic similarity for improved japonica varieties among different countries (or regions and organizations) were ranged from 0.279 to 0.918, and the mean value was 0.653. The rice varieties from countries whose latitude and geography position were all nearer were clustered together with higher genetic similarity indexes. The rice varieties from countries who had more different latitude and far geography position were clustered separately with lower genetic similarity indexes. The results indicated the genetic similarity indexes among improved japonica varieties had a close relationship with the geographical position, especially with the latitude.
基金the financial support received from The Key Project of R&D Program of Ningxia Hui Autonomous Region,China(2022BBF01003)China Agriculture Research System of MOF and MARA(CARS-29).
文摘Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.
基金the National Natural Science Foundation of China(No.52175103)。
文摘An autonomous altitude adjustment system for a stratospheric satellite(StratoSat)platform is proposed.This platform consists of a helium balloon,a ballonet,and a two-way blower.The helium balloon generates lift to balance the platform gravity.The two-way blower inflates and deflates the ballonet to regulate the buoyancy.Altitude adjustment is achieved by tracking the differential pressure difference(DPD),and a threshold switching strategy is used to achieve blower flow control.The vertical acceleration regulation ability is decided not only by the blower flow rate,but also by the designed margin of pressure difference(MPD).Pressure difference is a slow-varying variable compared with altitude,and it is adopted as the control variable.The response speed of the actuator to disturbance can be delayed,and the overshoot caused by the large inertia of the platform is inhibited.This method can maintain a high tracking accuracy and reduce the complexity of model calculation,thus improving the robustness of controller design.
文摘Hester Prynne and Tess Durbeyfield were two eminent female figures in the world by Thomas Hardy and Nathaniel Hawthone.Although the two female leading characters were in different time and place,their tragic experiences were almost the same.However,they were separated in the end.From the comparison of their personalities and the social situation they involved in,we would try to explore the origins of their similarity and ending by this article with the aim of alerting the world.
文摘THE crystalline-fluid melt inclusions in aquamarines in pegmatites from Mufushan (Hunan Prov.) andAilaoshan (Yunnan Prov.) have been studied. The research shows that there are obvious differences inthe chemical composition of the inclusions in the aquamarines, which is of great importance for studyingthe forming mechanism and origin of pegmatites. 1 General geology of pegmatites Mufushan is situated in the middle sector of the Jiangnan Ancient Land. The granitic pegmatitesmainly outcrop in granite mass of late Yanshanian (105-145 Ma) which was intruded in middle sector ofthe middle Proterozoic strata. Part of the pegmatites occur in the contact zone of the granite and the metamorphic rocks. The pegmatite veins may be divided into four types, all of them were originated from mag-
基金The first author would like to express sincere appreciation for the scholarship provided by China Scholarship Council(No.202006430006)and University of Wollongongfinancially supported by the ACARP Project C28006+1 种基金the National Key Research and Development Program of China(No.2018YFC0808301)the Natural Science Foundation of Beijing Municipality,China(No.8192036)。
文摘Well-developed pores and cracks in coal reservoirs are the main venues for gas storage and migration.To investigate the multi-scale pore fractal characteristics,six coal samples of different rankings were studied using high-pressure mercury injection(HPMI),low-pressure nitrogen adsorption(LPGA-N2),and scanning electron microscopy(SEM)test methods.Based on the Frankel,Halsey and Hill(FHH)fractal theory,the Menger sponge model,Pores and Cracks Analysis System(PCAS),pore volume complexity(D_(v)),coal surface irregularity(Ds)and pore distribution heterogeneity(D_(p))were studied and evaluated,respectively.The effect of three fractal dimensions on the gas adsorption ability was also analyzed with high-pressure isothermal gas adsorption experiments.Results show that pore structures within these coal samples have obvious fractal characteristics.A noticeable segmentation effect appears in the Dv1and Dv2fitting process,with the boundary size ranging from 36.00 to 182.95 nm,which helps differentiate diffusion pores and seepage fractures.The D values show an asymmetric U-shaped trend as the coal metamorphism increases,demonstrating that coalification greatly affects the pore fractal dimensions.The three fractal dimensions can characterize the difference in coal microstructure and reflect their influence on gas adsorption ability.Langmuir volume(V_(L))has an evident and positive correlation with Dsvalues,whereas Langmuir pressure(P_(L))is mainly affected by the combined action of Dvand Dp.This study will provide valuable knowledge for the appraisal of coal seam gas reservoirs of differently ranked coals.
基金the financial support provided by Zhengzhou 1125 Talents Gathering Project (2018)the Doctor startup fund of Henan Agricultural University (30500431)
文摘Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb.(DTTP).The influences of 4 extraction methods,namely hot water extraction(W),acidic extraction(HA),hot-compressed water extraction(HCW)and enzyme-assisted extraction(EAE),on the yields,physicochemical properties,hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared.Among these DTTP polysaccharides,DTTP-HA was outstanding in several respects.DTTP-HA was the most water soluble;it had the highest total carbohydrate content(85.08%),the highest uronic acid(13.20%)and the highest thermal stability.DTTP-HA and DTTP-W possessed a triple-helix structure.These 4 kinds of polysaccharides have the same types of monosaccharides,but in different molar percentages.Extraction method had a significant impact on the microstructures of the extracted polysaccharides.DTT-HA exhibited irregular structure with many holes.Among the 4 extracted methods,the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities.The better bioactivities of DTTP-HA may be related to the above factors.The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.
文摘The goal of the study was to quantify the genetic diversity of different potato varieties. Five groups were named to classify the 25 genres of potatoes as: Cluster I (Lalpakri, Diamond), Cluster II (Hagrai, Green Mountain, G.M.O., Elvera), Cluster III (Atlantic, Shepody, Raja, Fundy, Multa, Granulla, Shibilati, Japanese Red), Cluster IV (Atlas, Brondy, Yucon Gold, Monona, Petrones, Cheroki), and Cluster V (Calwhite, Prelude, Allblue, Russet, Burbank, TPS-67). The highest and lowest genotypes are found in Clusters III and I, respectively. The two groups’ maximum inter-cluster distance (the cluster’s distance between them) demonstrates the enormous diversity between Clusters II & III. Cluster III had the greatest intra-cluster distance (distance within a set), whereas Cluster V had the smallest. In most cases, the distance between gaps was more significant than the distance within the holes, showing greater genetic diversity between different groups’ genotypes. The highest, second highest, and third highest eigenvalues, accompanying the positive canonical values for Vectors I and II of three characteristics: average tuber weight in each plant, the tubers number in each plant, and the eyes number in each tuber, showed the most outstanding contribution to the complete difference between genotypes. Of the nine features, the smaller leaves number in each plant, the shorter plant height, the more minor genotypes, the fewer eyes per tube generated from Cluster I, the maximum height of the plants, the high-quality tubers in each plant, the tubers number in each plant, the fresh weight in each plant, and the leaf number in each plant from Cluster II could be chosen in the role of parents in this program for hybridization. Given the size of the genetic distance, the various characteristics that contribute to the overall difference, and the average population size, Hagrai, Green Mountain, O.M.G., Elvera Cluster II and Cluster I, Lalpakri, and Diamond genotypes can be regarded as parents of hybridization programs in the future. Thus, producers can get guidance to enhance genetic diversity by selecting materials from different relatives and reducing their vulnerability to diseases and climate change.
基金supported by the National Natural Science Foundation of China(Grant No.41972124)。
文摘Overpressure is significant to the exploration and exploitation of petroleum due to its influence on hydrocarbon accumulation and drilling strategies.The deep-burial hydrocarbon reservoirs of Jurassic strata in the central Junggar Basin are characterized by intensive overpressure,whose origins are complex and still unclear.In this study,Bowers'method and sonic velocity-density crossplot method based on well logging data were used as a combination for overpressure judgements in geophysics.Furthermore,the corresponding geological processes were analysed in quality and quantity to provide a rational comprehension of the overpressure origins and the model of overpressure evolution and hy-drocarbon accumulation processes.The results showed that hydrocarbon generation in the Jurassic source rocks led to overpressure in the mudstones,while hydrocarbon generation in Permian source rocks led to overpressure in the sandstone reservoirs in Jurassic strata by vertical pressure transfer.The burial and thermal history indicated that the aquathermal effect of pore fluids by temperature increase in deep strata is also an important origin of overpressure,while disequilibrium compaction may not be the dominant cause for the overpressure in deep-buried strata.Furthermore,the continuous tectonic compression in both the north-south and west-east trends from the Jurassic period to the present may also have enhanced the overpressure in deep strata.Meanwhile,the developed faults formed by intensive tectonic compression led to pressure transfer from source rocks to the Jurassic reservoirs.Overpressured geofluids with hydrocarbons migrated to sandstone reservoirs and aggravated the over-pressure in the Jurassic strata.To conclude,the intensive overpressure in the central Junggar Basin is attributed to the combination of multiple mechanisms,including hydrocarbon generation,the aqua-thermal effect,tectonic compression and pressure transfer.Furthermore,the developed overpressure indicated hydrocarbon migration and accumulation processes and the potential of oil and gas reservoirs in deeply buried strata.We hope this study will provide a systematic research concept for overpressure origin analysis and provide guidance for petroleum exploration and exploitation in deep-buried strata.
基金supported by National Science Foundation of China(No.91738201,U21A20450)。
文摘The main geolocation technology currently used in COSPAS-SARSAT system is TDOA/FDOA or three-star TDOA,the principle is to determine the location of the signal source by using the difference in arrival time and frequency of the wireless signal between different receivers.Therefore,ground monitoring stations need to be equipped with more than two antenna receiving stations,and multiple satellites should be able to simultaneously relay the distress signal from the target source in order to achieve the geolocation function.However,when the ground receiving system has only one antenna receiving station,or the target source is in a heavily obscured environment,the ground side is unable to receive the forwarded signals from multiple satellites at the same time,which will make it impossible to locate.To address these problems,in this paper,a time-sharing single satellite geolocations method based on different orbits is proposed for the first time.This method uses one or several low-earth orbit satellites(LEO)and mediumearth orbit satellites(MEO)in the visible area,and the receiving station only needs one pair of receiving antennas to complete the positioning.It can effectively compensate for the shortcomings of the traditional TDOA using the same moment and have better positioning accuracy compared with the single satellite in the same orbit.Due to the limited experimental conditions,this paper tests the navigation satellite using different orbit time-sharing single satellite geolocations,and proves that the positioning method has high positioning accuracy and has certain promotion and application value.
基金supported by the National Natural Science Foundation (NSFC),China,under the National Natural Science Foundation Youth Fund program (J.Hao,No.62101275).
文摘In the financial sector, data are highly confidential and sensitive,and ensuring data privacy is critical. Sample fusion is the basis of horizontalfederation learning, but it is suitable only for scenarios where customershave the same format but different targets, namely for scenarios with strongfeature overlapping and weak user overlapping. To solve this limitation, thispaper proposes a federated learning-based model with local data sharing anddifferential privacy. The indexing mechanism of differential privacy is used toobtain different degrees of privacy budgets, which are applied to the gradientaccording to the contribution degree to ensure privacy without affectingaccuracy. In addition, data sharing is performed to improve the utility ofthe global model. Further, the distributed prediction model is used to predictcustomers’ loan propensity on the premise of protecting user privacy. Usingan aggregation mechanism based on federated learning can help to train themodel on distributed data without exposing local data. The proposed methodis verified by experiments, and experimental results show that for non-iiddata, the proposed method can effectively improve data accuracy and reducethe impact of sample tilt. The proposed method can be extended to edgecomputing, blockchain, and the Industrial Internet of Things (IIoT) fields.The theoretical analysis and experimental results show that the proposedmethod can ensure the privacy and accuracy of the federated learning processand can also improve the model utility for non-iid data by 7% compared tothe federated averaging method (FedAvg).
文摘In the present paper,the numerical solution of It?type stochastic parabolic equation with a timewhite noise process is imparted based on a stochastic finite difference scheme.At the beginning,an implicit stochastic finite difference scheme is presented for this equation.Some mathematical analyses of the scheme are then discussed.Lastly,to ascertain the efficacy and accuracy of the suggested technique,the numerical results are discussed and compared with the exact solution.
文摘In the context of global emission reduction, the low-carbon sustainable development of the construction industry has become an important research content. With the vigorous development of new industrial technologies, the application of prefabrication technology to buildings had become a mainstream. However, the research on the role of prefabricated technology in reducing building carbon emissions was not yet comprehensive, and the research on the relationship between prefabricated structure types and carbon emissions in the construction stage was not yet thorough. Guided by life cycle assessment (LCA), this paper used the scenario analysis method to set different working conditions for five different structural systems, and used SimaPro software to evaluate the carbon emissions of prefabricated buildings in order to clarify the carbon emissions of prefabricated buildings under different structural systems, and explore their impact mechanisms in depth. Finally, take the existing buildings in China as an empirical study, the results showed that: 1) The carbon emissions produced by the four common prefabricated structural systems were almost the same. Different structures had different requirements for the combination of components. The carbon emissions of individual buildings would be superimposed according to the carbon emission characteristics of various individual components to form the final total carbon emissions. 2) When the building structure system requires more combinations of components, the greater the amount of transportation invested in the transportation process, the more carbon emissions would be caused. In the calculation of all individual building construction stages, the carbon emissions generated by tower cranes almost exceed the sum of the carbon emissions of all mobile machinery. 3) Prefabricated shear wall structures and prefabricated frame-shear wall structures require a large amount of hoisting of prefabricated shear walls, so the carbon emissions of their mechanical equipment were also the highest.
基金Supported by the Key Research and Development and Transformation Project of Science and Technology Department of Qinghai Province in 2021(2021-SF-141-2).
文摘Based on the hourly precipitation data from 4 observation stations of Xining City from June to September during 2005-2011,the temporal and spatial distribution characteristics of short-time precipitation were analyzed.The results show that the precipitation distribution in Xining region exhibited the less-more-less trend from southwest to northeast,while the torrential rain gradually increased from the northwest and southwest to the middle.The hourly general precipitation in Xining region had obviously seasonal characteristics,and its annual distribution showed wavy changes,but the annual variation of short-time heavy precipitation and rainstorm was very obvious.Furthermore,short-time heavy precipitation was concentrated from 18:00 to 24:00,followed by 03:00-07:00 on the following day.The occurrence time of short-time rainstorm accorded with short-time heavy precipitation.It offers a useful reference for the accurate and timely short-term forecast.
基金supported by National Natural Science Foundation of China(92059102 and 81630080)the National Key Research and Development Plan of China(2018YFC1704106).
文摘Inflammation-mediated carcinogenesis develops in the context of chronic inflammation and is a significant cause of cancer within the digestive system.In the chronic inflammation microenvironment,the metabolic activity of tissue cells undergoes extensive changes,which interfere with the normal function of immune cells.Dysregulation of cell metabolism and immune function has been identified as a key factor contributing to inflammation-mediated carcinogenesis within the major digestive organs,such as the stomach,liver,and colorectum.This metabolic-immune imbalance also corresponds to traditional Chinese medicine(TCM)theories of“yin-yang disharmony”and“disharmony between Ying-nutrients and Wei-defense.”The metabolic-immune imbalance has also been regarded as the key factor supporting“treatment of different diseases with the same method”,in which the same approach is adopted in the treatment of different conditions.In the TCM treatment process,it is necessary to first identify TCM patterns and then apply the corresponding TCM to correct the dysregulated metabolic and immune function,thereby blocking the progression from inflammation to malignancy.Our study findings deepen the TCM understanding of metabolic-immune dysregulation and the relationship between metabolic-immune dysregulation,pattern identification,and treatment method.They also provide new insights for the treatment of inflammation-mediated carcinogenesis in major digestive organs and help us further explore the scientific connotation of the TCM strategy of“treating different diseases with the same method”.
基金supported by the National Natural Science Foundation of China (32001145)。
文摘The resorption of nutrients from senescent leaves allows plants to conserve and recycle nutrients. To explore the adaptation strategies of desert plants to nutrient-limited environments, we selected four typical desert plants(Populus euphratica Oliv., Tamarix ramosissima Ledeb., Glycyrrhiza inflata Batal., and Alhagi camelorum Fisch.) growing in the desert area of the northern margin of the Tarim Basin,China. The contents of nitrogen(N), phosphorus(P), potassium(K), calcium(Ca), magnesium(Mg), and Ferrum(Fe) in the leaves of these four typical desert plants and their resorption characteristics were analyzed. The relationship of nutrient resorption efficiency with leaf functional traits and soil physical-chemical properties in two different habitats(saline-alkali land and sandy land) was discussed.The results showed that the four plants resorbed most of the elements. Ca was enriched in the leaves of P.euphratica, G. inflate, and A. camelorum;Mg was enriched in the leaves of G. inflata;and Fe was enriched in the leaves of the four plants. The results of the redundancy analysis showed that leaf thickness, soil electrical conductivity, and soil P content were the major factors affecting the nutrient resorption efficiency of the four plants. Leaf thickness was negatively correlated with N resorption efficiency(NRE),P resorption efficiency, and Fe resorption efficiency;soil electrical conductivity was positively correlated with the resorption efficiency of most elements;and soil P content was negatively correlated with the resorption efficiency of most elements in the plant leaves. The results showed that soil physical-chemical properties and soil nutrient contents had an important impact on the nutrient resorption of plant leaves.The same species growing in different habitats also differed in their resorption of different elements. The soil environment of plants and the biological characteristics of plant leaves affected the resorption of nutrient elements in different plants. The purpose of this study is to provide small-scale data support for the protection of ecosystems in nutrient-deficient areas by studying leaf functional strategies and nutrient conservation mechanisms of several typical desert plants.
基金funded by the National Natural Science Foundation of China(Nos.41974015,42374002)the Project Supported by the Special Fund of Hubei Luojia Laboratory(No.220100004)。
文摘In this study,we estimated the weekly Gravity Recovery and Climate Experiment(GRACE)spherical harmonic(SH)solutions and regional mascon solutions using GRACE-based Geopotential Difference(GPD)data and investigated their abilities in retrieving terrestrial water storage(TWS)changes over the Amazon River Basin(ARB)from January 2003 to February 2013.The performance of the weekly GPD-SH and GPDmascon solutions was evaluated by comparing them with the weekly GFZ-SH solutions,Global Land Data Assimilation Systems(GLDAS)-NOAH hydrological model outputs,and monthly GFZ-SH,GPD-SH,and CSRmascon solutions in the spatio-temporal and spectral domains.The results demonstrate that the weekly GPD-SH and GPD-mascon present good consistency with the weekly GFZ-SH solutions and GLDAS-NOAH estimates in the spatio-temporal domains,but GPD-mascon presents stronger signal amplitudes and more spatial details.The comparison of the monthly average of weekly estimates and monthly solutions demonstrates that the weekly GPD-mascon and GFZ-SH with DDK1 filtering are close to the monthly CSRmascon and GFZ-SH solutions,respectively.However,the signal amplitudes of TWS changes from GPD-SH and GFZ-SH with 650 km Gaussian filtering are smaller than the monthly solutions,and the corresponding Root Mean Square Errors between the TWS change time series from the monthly average of weekly solutions and monthly estimates are 18.12 mm(GPD-mascon),18.81 mm(GFZ-SH-DDK1),24.93 mm(GPDSH-G650km),and 33.07 mm(GFZ-SH-G650km),respectively.Additionally,the TWS change time series derived from weekly solutions present more high-frequency time-varying information than monthly solutions.Furthermore,the 300 km Gaussian filtering can improve the signal amplitudes of TWS changes from the weekly GPD-SH solutions more than those with 650 km Gaussian filtering,but the corresponding noise level is higher.The weekly GPD-SH and GPD-mascon solutions can extend the application scopes of GRACE and provide good complements to the current GRACE monthly solutions.
文摘Through the theoretical analysis of overburden destabilization mechanism, FLAC 3D simplified plane numerical simulation method and field measurement method, we compared the relationship of overburden support pressure at 35 m of workface recovery, and the peak overburden support pressure decreased from 13.85 Mpa to 11.97 Mpa from 1:1 to 1:3. With the increase of mining ratio, the peak over-supporting pressure decreases: with the increase of top coal recovery thickness, the peak over-supporting pressure and the influence range will be further expanded, and the distance between the peak over-supporting pressure and the coal wall of the working face will be further increased and the high stress zone of the peak area will be expanded simultaneously.
