Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels usin...Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.展开更多
Synthesizing high-density fuel from lignocellulose can not only achieve green and low-carbon development,but also expand the feedstock source of hydrocarbon fuel.Here,we reported a route of producing high-density fuel...Synthesizing high-density fuel from lignocellulose can not only achieve green and low-carbon development,but also expand the feedstock source of hydrocarbon fuel.Here,we reported a route of producing high-density fuel from lignin oil and hemicellulose derivative cyclopentanol through alkylation and hydrodeoxygenation,HY with SiO_(2)/Al_(2)O_(3) molar ratio of 5.3 was screened as the alkylation catalyst in the reaction of model phenolic compounds and mixtures,and the reaction conditions were optimized to achieve conversion of phenolic compounds higher than 87%and selectivity of bicyclic and tricyclic products higher than 99%.Then two phenolic pools simulating the composition of two typic lignin oils were studied to validate the alkylation and analyze the competition mechanism of phenolic compounds in mixture system.Finally,real lignin oil from depolymerized of beech powder was tested,and notably80%of phenolic monomers in the oil were converted into fuel precursor.After hydrodeoxygenation,the alkylated product was converted to fuel blend with a density of 0.91 g/mL at 20℃and a freezing point lower than-60℃,very promising as high density fuel.This work provides a facile and energyefficient way of synthesizing high-performance jet fuel directly from lignocellulosic derivatives,which decreases processing energy consumption and improve the utilization rate of feedstock.展开更多
During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil d...During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.展开更多
Grape berry shape is an important agricultural trait.Clarifying its genetic basis is significant for cultivating grape varieties that meet market demands.However,the current study by forward genetics has not achieved ...Grape berry shape is an important agricultural trait.Clarifying its genetic basis is significant for cultivating grape varieties that meet market demands.However,the current study by forward genetics has not achieved in-depth results.Here,a high-density map was constructed to identify quantitative trait loci(QTLs)for berry shape.A total of 358709 polymorphic SNPs were obtained using whole-genome resequencing(WGS)based on 208 F2 individuals derived from round grape‘E42-6’and oblong grape‘Rizamat’.The 1635.65 cM high-density map was divided into 19 linkage groups with an average distance of 0.37 cM.Using this map,three significant QTLs for fruit shape index(ShI:ratio of berry length to berry width)identified over three years were mapped onto LG4 and LG5,including one stable QTL on Chr5 with the genomic region of 0.47–1.94 Mb.Combining with gene annotation and expression patterns based on RNA-seq data from two contrasting F2 individuals with round and oblong berry(their average ShI was 1.89 and 1.10,respectively)at four developmental stages,four candidate genes were selected from the above QTLs.They were mainly involved in DNA replication,cell wall modification,and phytohormone biosynthesis.Further analysis of RNA-seq data revealed that several important phytohormone synthesis and metabolic pathways were enriched based on differentially expressed genes(DEGs),which was consistent with the results of QTL mapping for genes related to plant hormone biosynthesis in the F2 population.Furthermore,a comparison of plant hormone content showed that there were significant differences in IAA and tZ content between the two contrasting F2 individuals at different developmental stages.Our findings provide molecular insights into the genetic variation in grape berry shape.Stable QTLs and their tightly linked markers offer the possibility of marker-assisted selection to accelerate berry shape breeding.展开更多
BACKGROUND Left atrial flutter without prior cardiac interventions is uncommon,especially dual-loop macro-reentry atrial flutter.The critical step to ablate dual-loop macroreentry atrial flutter is to identify the dom...BACKGROUND Left atrial flutter without prior cardiac interventions is uncommon,especially dual-loop macro-reentry atrial flutter.The critical step to ablate dual-loop macroreentry atrial flutter is to identify the dominant loop and key isthmus.Although entrainment mapping could help identify the dominant loop and key isthmus,it may alter or terminate tachycardia.High-density mapping allows the generation of electroanatomic maps without altering or terminating tachycardia.CASE SUMMARY Here,we report a case of symptomatic left atrial flutter without prior intervention.In this case,high-density mapping revealed a dual-loop macro-reentry around the mitral annulus and central scar of the anterior wall.The propagation result showed that the dominant loop was around the mitral annulus,and the key isthmus was between the central scar and mitral annulus.The atrial flutter terminated successfully after ablation was performed.CONCLUSION In this case,we demonstrate that high-density mapping technology may help identify the dominant loop of dual-loop atrial flutter without entrainment,which makes ablation easier.展开更多
The disaster of seawater intrusion seriously affects people's lives and restricts economic development,so the detection and treatment of seawater intrusion is a long-term task.On the basis of field investigation a...The disaster of seawater intrusion seriously affects people's lives and restricts economic development,so the detection and treatment of seawater intrusion is a long-term task.On the basis of field investigation and water quality analysis,according to the change characteristics of apparent resistivity of groundwater after Cl-reaches 250 mg/L,the theoretical basis for the application of high-density resistivity method was determined,and the characteristic values of apparent resistivity for seawater intrusion interfaces in different geological characteristic regions in Laizhou Bay area were determined by typical profile tests.Combined with water quality investigation and other means,profiles for the high-density resistivity method were arranged,and the interfaces between saline and fresh water were accurately divided.展开更多
A profile of shallow crustal velocity structure(1–2 km) may greatly enhance interpretation of the sedimentary environment and shallow tectonic deformation.Recent advances in surface wave tomography, using ambient noi...A profile of shallow crustal velocity structure(1–2 km) may greatly enhance interpretation of the sedimentary environment and shallow tectonic deformation.Recent advances in surface wave tomography, using ambient noise data recorded with high-density seismic arrays, have improved the understanding of regional crustal structure. As the interest in detailed shallow crustal structure imaging has increased, dense seismic array methods have become increasingly efficient. This study used a high-density seismic array deployed in the Xinjiang basin in southeastern China, to record seismic data, which was then processed with the ambient noise tomography method. The high-density seismic array contained 203 short-period seismometers, spaced at short intervals(～ 400 m). The array collected continuous records of ambient noise for 32 days. Data preprocessing,cross correlation calculation, and Rayleigh surface wave phase-velocity dispersion curve extraction, yielded more than 16,000 Rayleigh surface wave phase-velocity dispersion curves, which were then analyzed using the direct-inversion method. Checkerboard tests indicate that the shear wave velocity is recovered in the study area, at depths of 0–1.4 km,with a lateral image resolution of ～ 400 m. Model test results show that the seismic array effectively images a 50 m thick slab at a depth of 0–300 m, a 150 m thick anomalous body at a depth of 300–600 m, and a 400 m thick anomalous body at a depth of 0.6–1.4 km. The shear wave velocity profile reveals features very similar to those detected by a deep seismic reflection profile across the study area. This demonstrates that analysis of shallow crustal velocity structure provides high-resolution imaging of crustal features.Thus, ambient noise tomography with a high-density seismic array may play an important role in imaging shallow crustal structure.展开更多
Various previous studies have found a negative cor-relation between the risk of cardiovascular events and serum high-density lipoprotein(HDL) cholesterol levels. The reverse cholesterol transport, a pathway of choles-...Various previous studies have found a negative cor-relation between the risk of cardiovascular events and serum high-density lipoprotein(HDL) cholesterol levels. The reverse cholesterol transport, a pathway of choles-terol from peripheral tissue to liver which has several potent antiatherogenic properties. For instance, the particles of HDL mediate to transport cholesterol from cells in arterial tissues, particularly from atherosclerotic plaques, to the liver. Both ATP-binding cassette trans-porters(ABC) A1 and ABCG1 are membrane cholesterol transporters and have been implicated in mediating cholesterol effluxes from cells in the presence of HDL and apolipoprotein A-I, a major protein constituent of HDL. Previous studies demonstrated that ABCA1 and ABCG1 or the interaction between ABCA1 and ABCG1 exerted antiatherosclerotic effects. As a therapeutic approach for increasing HDL cholesterol levels, much focus has been placed on increasing HDL cholesterol levels as well as enhancing HDL biochemical functions. HDL therapies that use injections of reconstituted HDL, apoA-I mimetics, or full-length apoA-I have shown dramatic effectiveness. In particular, a novel apoA-I mi-metic peptide, Fukuoka University ApoA-I Mimetic Pep-tide, effectively removes cholesterol via specific ABCA1 and other transporters, such as ABCG1, and has an an-tiatherosclerotic effect by enhancing the biological func-tions of HDL without changing circulating HDL choles-terol levels. Thus, HDL-targeting therapy has significant atheroprotective potential, as it uses lipid transporter-targeting agents, and may prove to be a therapeutic tool for atherosclerotic cardiovascular diseases.展开更多
BACKGROUND:An increase in high-density lipoprotein(HDL)is well associated with a decreased cardiovascular risk,especially atherosclerosis.Recent studies suggest that lower levels of HDL may also be associated with an ...BACKGROUND:An increase in high-density lipoprotein(HDL)is well associated with a decreased cardiovascular risk,especially atherosclerosis.Recent studies suggest that lower levels of HDL may also be associated with an increased risk of sepsis and an increased rate of mortality in septic patients.However,this conclusion remains controversial.METHODS:MEDLINE,EMBASE,and CENTRAL databases were searched from inception to September 30,2019.All studies were conducted to evaluate the correlation of lipoprotein levels and the risk and outcomes of sepsis in adult patients.The primary outcomes were the risk and mortality of sepsis.RESULTS:Seven studies comprising 791 patients were included.Lower levels of HDL had no marked relevance with the risk of sepsis(odds radio[OR]for each 1 mg/dL increase,0.94;95%CI 0.86–1.02;P=0.078),whereas lower HDL levels were related to an increased mortality rate in septic patients(OR for below about median HDL levels,2.00;95%CI 1.23–3.24;P=0.005).CONCLUSION:This meta-analysis did not reveal a signifi cant association between lower HDL levels and an increase in the risk of sepsis,whereas it showed that lower HDL levels are associated with a higher mortality rate in septic adult patients.These findings suggest that HDL may be considered as a promising factor for the prevention and treatment of sepsis in the future.展开更多
Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from...Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from which the reference genome assembly of bread wheat was obtained.Both parents and the recombinant inbred lines were genotyped using the wheat 55K single nucleotide polymorphism(SNP) array.A high-density genetic map containing 21,197 SNPs was obtained.These markers covered each of the 21 chromosomes with a total linkage distance of 3792.71 c M.Locations of these markers in this linkage map were highly consistent with their physical locations in the genome assembly of Chinese Spring.The two parents and the whole RIL population were assessed for GNS in two consecutive years at two different locations.Based on multi-environment phenotype data and best liner unbiased prediction values,three quantitative trait loci (QTL) for GNS were identified.One of them located on chromosomes 2B and the other two on 2D.Phenotypic variation explained by these loci varied from 3.07%to26.57%.One of these QTL,QGns.sicau-2D-2,was identified in each of all trials conducted.Based on the best linear unbiased prediction values,this locus explained 19.59%–26.57%of phenotypic variation.A KASP(Kompetitive Allele-Specific PCR) marker closely linked with this locus was generated and used to validate the effects of this locus in three different genetic backgrounds.The identified QTL and the KASP marker developed for it will be highly valuable in fine-mapping the locus and in exploiting it for markerassisted selection in wheat breeding programs.展开更多
The reverse cholesterol transport mediated by highdensity lipoprotein(HDL)is an important mechanism for maintaining body cholesterol,and hence,the crucial anti-atherogenic action of the lipoprotein.Recent studies,howe...The reverse cholesterol transport mediated by highdensity lipoprotein(HDL)is an important mechanism for maintaining body cholesterol,and hence,the crucial anti-atherogenic action of the lipoprotein.Recent studies,however,have shown that HDL exerts a variety of anti-inflammatory and anti-atherogenic actions independently of cholesterol metabolism.The present review provides an overview of the roles of sphingosine 1-phosphate(S1P)/S1P receptor and apolipoprotein A-I/ scavenger receptor class B typeⅠsystems in the antiatherogenic HDL actions.In addition,the physiological significance of the existence of S1P in the HDL particles is discussed.展开更多
There is a tight link between bone and lipid metabolic pathways.In this vein,several studies focused on the exploration of high-density lipoprotein(HDL)in the pathobiology of bone diseases,with emphasis to the osteoar...There is a tight link between bone and lipid metabolic pathways.In this vein,several studies focused on the exploration of high-density lipoprotein(HDL)in the pathobiology of bone diseases,with emphasis to the osteoarthritis(OA)and osteoporosis,the most common bone pathologies.Indeed,epidemiological and in vitro data have connected reduced HDL levels or dysfunctional HDL with cartilage destruction and OA development.Recent studies uncovered functional links between HDL and OA fueling the interesting hypothesis that OA could be a chronic element of the metabolic syndrome.Other studies have linked HDL to bone mineral density.Even though at epidemiological levels the results are conflicting,studies in animals as well as in vitro experiments have shown that HDL facilitates osteoblastogensis and bone synthesis and most probably affects osteoclastogenesis and osteoclast bone resorption.Notably,reduced HDL levels result in increased bone marrow adiposity affecting bone cells function.Unveiling the mechanisms that connect HDL and bone/cartilage homeostasis may contribute to the design of novel therapeutic agents for the improvement of bone and cartilage quality and thus for the treatment of related pathological conditions.展开更多
A helicon wave plasma source in a tube of ring permanent magnets(PMs)has been constructed to study the effect of the conflguration of the magnetic fleld with zero magnetic points on plasma parameters.This device also ...A helicon wave plasma source in a tube of ring permanent magnets(PMs)has been constructed to study the effect of the conflguration of the magnetic fleld with zero magnetic points on plasma parameters.This device also serves as an exploration platform for a simple,compact helicon wave plasma source adaptable to engineering applications.A small-diameter(26 mm)highdensity(~10^(18)m^(-3))blue core plasma is produced in~1 Pa argon by helicon RF(radiofrequency)discharge using a NagoyaⅢantenna under magnetic fleld(~2 k G)of compact ring PMs(length~204 mm).Operational parameters,i.e.RF power and neutral gas pressure are scanned and plasma density is measured by an RF compensated probe to explore the operating characteristics of the device.Iconic feature of a helicon discharge,such as blue core plasmas and E-H-W mode transitions are well observed in the device,despite the wavelength calculated using the conventional dispersion relation of a bounded whistler waves(Chen 1991 Plasma Phys.Control.Fusion 33339)is order of magnitudes longer than the length of the plasma in this device which seems to suggest that such helicon device is impossible.Surprisingly,the wavelength calculated by the unbounded whistle wave dispersion formula in turn suggests the occurrence of a half wavelength resonance.展开更多
Impact behavior of polymers has received considerable attention in recent years,and much work based on fracture mechanic approaches has been carried out.In this paper,fracture behavior in large deformation of a high d...Impact behavior of polymers has received considerable attention in recent years,and much work based on fracture mechanic approaches has been carried out.In this paper,fracture behavior in large deformation of a high density polyethylene(HDPE)materials was investigated through experimental impact testing on single edge notched specimen(SENB)and by using theoretical and analytical fracture criteria concepts.Moreover,a review of the main fracture criteria is given in order to characterize the toughness of this polymer in the both cases(static and dynamic).The fractured specimens obtained from the Charpy impact test were characterized with respect to their fracture surfaces.Characteristic zones of the fracture surface can be assigned to different stages and mechanisms of the fracture process.Finally,for a better understanding of fracture and damage mechanisms and to provide the best estimation of fracture toughness in impact,an experimental approach based on microscopic observations(SEM)was used.展开更多
Ancherythroculter nigrocauda is a fish endemic to the upper areas of the Changjiang(Yangtze)River in China.Quantitative trait locus(QTL)mapping is a powerful tool to identify potential genes affecting traits of econom...Ancherythroculter nigrocauda is a fish endemic to the upper areas of the Changjiang(Yangtze)River in China.Quantitative trait locus(QTL)mapping is a powerful tool to identify potential genes affecting traits of economic importance in domestic animals.In this study,a high-density genetic map was constructed with 5901 single nucleotide polymorphism(SNP)makers by sequencing 92 individual fish from a F1 family using the specific-locus amplified fragment sequencing approach.Initially,48 QTLs for total length,body length,body height,and body weight were identified according to the high density of the genetic map with 24 LGs,a total length of 3839.4 cM,and marker spacing of about 0.82 cM.These QTLs explained 27.1%-49.9%of phenotypic variance.The results of this study suggest that major QTLs are responsible for the growth of A.nigrocauda,and these are potentially useful in comparative genomics research,genome assembly,and marker-assisted breeding programs for this species.展开更多
In this research,the tensile properties'performance of compression moulded discontinuous randomized zalacca fibre/high-density polyethylene under critical fibre length was analysed by means of experimental method ...In this research,the tensile properties'performance of compression moulded discontinuous randomized zalacca fibre/high-density polyethylene under critical fibre length was analysed by means of experimental method and micromechanical models.These investigations were used to verify the tensile properties models toward the effect of fibre length and volume fraction on the composites.The experimental results showed that the tensile properties of composites had significantly increased due to the enhancement of fibre length.On the contrary,a decline in the tensile properties was observed with the increase of volume fraction.A comparison was made between the available experimental results and the performances of Tsai-Pagano,Christensen and Cox-Krechel models in their prediction of composites elastic modulus.The results showed that the consideration of fibre's elastic anisotropy in the Cox-Krenchel model had yielded a good prediction of the composites modulus,nevertheless the models could not accurately predict the composites modulus for fibre length study.展开更多
BACKGROUND Colorectal cancer(CRC)is a common malignant tumor of the gastrointestinal tract.Lipid metabolism,as an important part of material and energy circulation,is well known to play a crucial role in CRC.AIM To ex...BACKGROUND Colorectal cancer(CRC)is a common malignant tumor of the gastrointestinal tract.Lipid metabolism,as an important part of material and energy circulation,is well known to play a crucial role in CRC.AIM To explore the relationship between serum lipids and CRC development and identify aberrantly expressed cholesterol metabolism genes in CRC.METHODS We retrospectively collected 843 patients who had confirmed CRC and received surgical resection from 2013 to 2015 at the Cancer Hospital of the Chinese Academy of Medical Sciences as our research subjects.The levels of serum total cholesterol(TC),triglycerides,low-density lipoprotein cholesterol(LDL-C),highdensity lipoprotein cholesterol(HDL-C),LDL-C/HDL-C and clinical features were collected and statistically analyzed by SPSS.Then,we used the data from Oncomine to screen the differentially expressed genes(DEGs)of the cholesterol metabolism pathway in CRC and used Gene Expression Profiling Interactive Analysis to confirm the candidate DEGs.PrognoScan was used to analyze the prognostic value of the DEGs,and Search Tool for the Retrieval of Interacting Genes was used to construct the protein-protein interaction network of DEGs.RESULTS The serum HDL-C level in CRC patients was significantly correlated with tumor size,and patients whose tumor size was more than 5 cm had a lower serum HDL-C level(1.18±0.41 mmol/L vs 1.25±0.35 mmol/L,P<0.01)than their counterparts.In addition,TC/HDL(4.19±1.33 vs 3.93±1.26,P<0.01)and LDL-C/HDL-C(2.83±1.10 vs 2.61±0.96,P<0.01)were higher in patients with larger tumors.The levels of HDL-C(P<0.05),TC/HDL-C(P<0.01)and LDL-C/HDL-C(P<0.05)varied in different stages of CRC patients,and the differences were significant.We screened 14 differentially expressed genes(DEGs)of the cholesterol metabolism pathway in CRC and confirmed that lipoprotein receptor-related protein 8(LRP8),PCSK9,low-density lipoprotein receptor(LDLR),MBTPS2 and FDXR are upregulated,while ABCA1 and OSBPL1A are downregulated in cancer tissue.Higher expression of LDLR(HR=3.12,95%CI:1.77-5.49,P<0.001),ABCA1(HR=1.66,95%CI:1.11-2.48,P=0.012)and OSBPL1A(HR=1.38,95%CI:1.01-1.89,P=0.041)all yielded significantly poorer DFS outcomes.Higher expression of FDXR(HR=0.7,95%CI:0.47-1.05,P=0.002)was correlated with longer DFS.LDLR,ABCA1,OSBPL1A and FDXR were involved in many important cellular function pathways.CONCLUSION Serum HDL-C levels are associated with tumor size and stage in CRC patients.LRP8,PCSK9,LDLR,MBTPS2 and FDXR are upregulated,while ABCA1 and OSBPL1A are downregulated in CRC.Among them,LDLR,ABCA1,OSBPL1A and FDXR were valuable prognostic factors of DFS and were involved in important cellular function pathways.展开更多
The authors employ the high-density resistivity method to image the subsurface structure of a mountain in Erdaojiang District,Tonghua City,Jilin Province,China,to evaluate the potential risk of slope failure on surrou...The authors employ the high-density resistivity method to image the subsurface structure of a mountain in Erdaojiang District,Tonghua City,Jilin Province,China,to evaluate the potential risk of slope failure on surrounding residential areas and infrastructure,and identify a shallow fault that extends across the center of the mountain and is perpendicular to the mountain slope and accurately locate the spatial position and depth of another fault on the southern side of the mountain.The results provide an important basis for evaluating mountain slope stability.This study also demonstrates that the high-density resistivity method is effective for detecting mountain faults.展开更多
By determining the distribution and extent of geological structures surrounding the Mingyan Tunnel,Xicheng Town,Helong City,Jilin Province,we can evaluate the stability of the rock mass and assess potential hazards du...By determining the distribution and extent of geological structures surrounding the Mingyan Tunnel,Xicheng Town,Helong City,Jilin Province,we can evaluate the stability of the rock mass and assess potential hazards during tunnel construction.We use the high-density resistivity method to analyze the subsurface structure of the study area.Conductive anomalies are likely to represent joint and fissure systems within strongly weathered host rocks,and the bedrock surrounding the tunnel is relatively stable and does not contain well-developed faults.High-density resistivity analysis can provide valuable information in the context of tunnel engineering and safety.展开更多
The rheological behavior of composites made with high-density polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF), Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100...The rheological behavior of composites made with high-density polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF), Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100 mesh were studied. The experimental results were obtained from samples containing 65 vol.% agro fiber and 3 wt.% lubricant. Particle sizes distribution of the agro fibers was in the range of 0.295 mm to ?0.125 mm. SEM showed evidence of complete matrix/fiber impregnation or wetting. The melt rheological data in terms of complex viscosity (η*), storage modulus (G'), loss modulus (G"), and loss tangent (tanδ) were evaluated and compared for different samples. Due to higher probability of agglomeration formation in the samples containing 65 vol.% of agro fillers, the storage modulus, loss modulus and complex viscosity of these samples were high. The unique change in all the samples is due to the particle size distribution of the agro fibers. The storage and loss modulus increased with increasing shear rates for all the composites, except for Walnut shell composite which exhibited unusual decrease in storage modulus with increasing shear rate. Damping factor (tanδ) decreased with increasing shear rate for all the composites at 65 vol.% filler load although there were differences among the composites. Maximum torque tended to increase at the 65 vol.% agro fiber load for all composites. Corncob and Walnut shell composites gave higher torque and steady state torque values in comparison with Flax shives and Rice hull composites due to differences in particle sizes distribution of the agro fibers.展开更多
基金the support from National Key Research and Development Program of China(2021YFC2104400)the Tianjin Science and Technology Plan Project(21JCQNJC00340)the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.
基金supported by the National Key Research and Development Program(2021YFC2104400)the Tianjin Science and Technology Plan Project(21JCQNJC00340)the Haihe Laboratory of Sustainable Chemical Transformations。
文摘Synthesizing high-density fuel from lignocellulose can not only achieve green and low-carbon development,but also expand the feedstock source of hydrocarbon fuel.Here,we reported a route of producing high-density fuel from lignin oil and hemicellulose derivative cyclopentanol through alkylation and hydrodeoxygenation,HY with SiO_(2)/Al_(2)O_(3) molar ratio of 5.3 was screened as the alkylation catalyst in the reaction of model phenolic compounds and mixtures,and the reaction conditions were optimized to achieve conversion of phenolic compounds higher than 87%and selectivity of bicyclic and tricyclic products higher than 99%.Then two phenolic pools simulating the composition of two typic lignin oils were studied to validate the alkylation and analyze the competition mechanism of phenolic compounds in mixture system.Finally,real lignin oil from depolymerized of beech powder was tested,and notably80%of phenolic monomers in the oil were converted into fuel precursor.After hydrodeoxygenation,the alkylated product was converted to fuel blend with a density of 0.91 g/mL at 20℃and a freezing point lower than-60℃,very promising as high density fuel.This work provides a facile and energyefficient way of synthesizing high-performance jet fuel directly from lignocellulosic derivatives,which decreases processing energy consumption and improve the utilization rate of feedstock.
基金financial supports for this research project by the National Natural Science Foundation of China(Nos.41602308,41967037)supported by Zhejiang Provincial Natural Science Foundation of China under Grant No.LY20E080005+1 种基金funded by National Key Research and Development Projects of China(No.2019YFC507502)Guangxi Science and Technology Plan Project(No.RZ2100000161).
文摘During subway operation,various factors will cause long-term land subsidence,such as the vibration subsidence of foundation soil caused by train vibration load,incomplete consolidation deformation of foundation soil during tunnel construction,dense buildings and structures in the vicinity of the tunnel,and changes in water level in the stratum where the tunnel is located.The monitoring of long-term land subsidence during subway operation in high-density urban areas differs from that in low-density urban construction areas.The former is the gathering point of the entire urban population.There are many complex buildings around the project,busy road traffic,high pedestrian flow,and less vegetation cover.Several existing items requiremonitoring.However,monitoring distance is long,and providing early warning is difficult.This study uses the 2.8 km operation line between Wulin Square station and Ding’an Road station of Hangzhou Subway Line 1 as an example to propose the integrated method of DInSAR-GPS-GIS technology and the key algorithm for long-term land subsidence deformation.Then,it selects multiscene image data to analyze long-termland subsidence of high-density urban areas during subway operation.Results show that long-term land subsidence caused by the operation of Wulin Square station to Ding’an Road station of Hangzhou Subway Line 1 is small,with maximumsubsidence of 30.64 mm,and minimumsubsidence of 11.45 mm,and average subsidence ranging from 19.27 to 21.33 mm.And FLAC3D software was used to verify the monitoring situation,using the geological conditions of the soil in the study area and the tunnel profile to simulate the settlement under vehicle load,and the simulation results tended to be consistent with the monitoring situation.
基金financially supported by National Key R&D Program of China(Grant No.2019YFD1001401)Project of Construction of Grape Germplasm Resources Sharing Platform(Grant No.PT2029)+2 种基金Zhengzhou Major Scientific and Technological Innovation Projects(Grant No.2020CXZX0082)National Modern Agricultural Industry Technology System Construction Special Project(Grant No.CARS-29-yc-1)Special Project of Science,Technology Innovation Project of Chinese Academy of Agricultural Sciences(Grant No.CAAS-ASTIP-2019-ZFRI).
文摘Grape berry shape is an important agricultural trait.Clarifying its genetic basis is significant for cultivating grape varieties that meet market demands.However,the current study by forward genetics has not achieved in-depth results.Here,a high-density map was constructed to identify quantitative trait loci(QTLs)for berry shape.A total of 358709 polymorphic SNPs were obtained using whole-genome resequencing(WGS)based on 208 F2 individuals derived from round grape‘E42-6’and oblong grape‘Rizamat’.The 1635.65 cM high-density map was divided into 19 linkage groups with an average distance of 0.37 cM.Using this map,three significant QTLs for fruit shape index(ShI:ratio of berry length to berry width)identified over three years were mapped onto LG4 and LG5,including one stable QTL on Chr5 with the genomic region of 0.47–1.94 Mb.Combining with gene annotation and expression patterns based on RNA-seq data from two contrasting F2 individuals with round and oblong berry(their average ShI was 1.89 and 1.10,respectively)at four developmental stages,four candidate genes were selected from the above QTLs.They were mainly involved in DNA replication,cell wall modification,and phytohormone biosynthesis.Further analysis of RNA-seq data revealed that several important phytohormone synthesis and metabolic pathways were enriched based on differentially expressed genes(DEGs),which was consistent with the results of QTL mapping for genes related to plant hormone biosynthesis in the F2 population.Furthermore,a comparison of plant hormone content showed that there were significant differences in IAA and tZ content between the two contrasting F2 individuals at different developmental stages.Our findings provide molecular insights into the genetic variation in grape berry shape.Stable QTLs and their tightly linked markers offer the possibility of marker-assisted selection to accelerate berry shape breeding.
基金the National Science Foundation of China,No.81800292.
文摘BACKGROUND Left atrial flutter without prior cardiac interventions is uncommon,especially dual-loop macro-reentry atrial flutter.The critical step to ablate dual-loop macroreentry atrial flutter is to identify the dominant loop and key isthmus.Although entrainment mapping could help identify the dominant loop and key isthmus,it may alter or terminate tachycardia.High-density mapping allows the generation of electroanatomic maps without altering or terminating tachycardia.CASE SUMMARY Here,we report a case of symptomatic left atrial flutter without prior intervention.In this case,high-density mapping revealed a dual-loop macro-reentry around the mitral annulus and central scar of the anterior wall.The propagation result showed that the dominant loop was around the mitral annulus,and the key isthmus was between the central scar and mitral annulus.The atrial flutter terminated successfully after ablation was performed.CONCLUSION In this case,we demonstrate that high-density mapping technology may help identify the dominant loop of dual-loop atrial flutter without entrainment,which makes ablation easier.
文摘The disaster of seawater intrusion seriously affects people's lives and restricts economic development,so the detection and treatment of seawater intrusion is a long-term task.On the basis of field investigation and water quality analysis,according to the change characteristics of apparent resistivity of groundwater after Cl-reaches 250 mg/L,the theoretical basis for the application of high-density resistivity method was determined,and the characteristic values of apparent resistivity for seawater intrusion interfaces in different geological characteristic regions in Laizhou Bay area were determined by typical profile tests.Combined with water quality investigation and other means,profiles for the high-density resistivity method were arranged,and the interfaces between saline and fresh water were accurately divided.
基金supported by the China Geological Survey Project“Deep Geological Survey of the Qin-Hang Belt”(No.DD20160082)the National Natural Science Foundation of China(No.41574048)
文摘A profile of shallow crustal velocity structure(1–2 km) may greatly enhance interpretation of the sedimentary environment and shallow tectonic deformation.Recent advances in surface wave tomography, using ambient noise data recorded with high-density seismic arrays, have improved the understanding of regional crustal structure. As the interest in detailed shallow crustal structure imaging has increased, dense seismic array methods have become increasingly efficient. This study used a high-density seismic array deployed in the Xinjiang basin in southeastern China, to record seismic data, which was then processed with the ambient noise tomography method. The high-density seismic array contained 203 short-period seismometers, spaced at short intervals(～ 400 m). The array collected continuous records of ambient noise for 32 days. Data preprocessing,cross correlation calculation, and Rayleigh surface wave phase-velocity dispersion curve extraction, yielded more than 16,000 Rayleigh surface wave phase-velocity dispersion curves, which were then analyzed using the direct-inversion method. Checkerboard tests indicate that the shear wave velocity is recovered in the study area, at depths of 0–1.4 km,with a lateral image resolution of ～ 400 m. Model test results show that the seismic array effectively images a 50 m thick slab at a depth of 0–300 m, a 150 m thick anomalous body at a depth of 300–600 m, and a 400 m thick anomalous body at a depth of 0.6–1.4 km. The shear wave velocity profile reveals features very similar to those detected by a deep seismic reflection profile across the study area. This demonstrates that analysis of shallow crustal velocity structure provides high-resolution imaging of crustal features.Thus, ambient noise tomography with a high-density seismic array may play an important role in imaging shallow crustal structure.
文摘Various previous studies have found a negative cor-relation between the risk of cardiovascular events and serum high-density lipoprotein(HDL) cholesterol levels. The reverse cholesterol transport, a pathway of choles-terol from peripheral tissue to liver which has several potent antiatherogenic properties. For instance, the particles of HDL mediate to transport cholesterol from cells in arterial tissues, particularly from atherosclerotic plaques, to the liver. Both ATP-binding cassette trans-porters(ABC) A1 and ABCG1 are membrane cholesterol transporters and have been implicated in mediating cholesterol effluxes from cells in the presence of HDL and apolipoprotein A-I, a major protein constituent of HDL. Previous studies demonstrated that ABCA1 and ABCG1 or the interaction between ABCA1 and ABCG1 exerted antiatherosclerotic effects. As a therapeutic approach for increasing HDL cholesterol levels, much focus has been placed on increasing HDL cholesterol levels as well as enhancing HDL biochemical functions. HDL therapies that use injections of reconstituted HDL, apoA-I mimetics, or full-length apoA-I have shown dramatic effectiveness. In particular, a novel apoA-I mi-metic peptide, Fukuoka University ApoA-I Mimetic Pep-tide, effectively removes cholesterol via specific ABCA1 and other transporters, such as ABCG1, and has an an-tiatherosclerotic effect by enhancing the biological func-tions of HDL without changing circulating HDL choles-terol levels. Thus, HDL-targeting therapy has significant atheroprotective potential, as it uses lipid transporter-targeting agents, and may prove to be a therapeutic tool for atherosclerotic cardiovascular diseases.
文摘BACKGROUND:An increase in high-density lipoprotein(HDL)is well associated with a decreased cardiovascular risk,especially atherosclerosis.Recent studies suggest that lower levels of HDL may also be associated with an increased risk of sepsis and an increased rate of mortality in septic patients.However,this conclusion remains controversial.METHODS:MEDLINE,EMBASE,and CENTRAL databases were searched from inception to September 30,2019.All studies were conducted to evaluate the correlation of lipoprotein levels and the risk and outcomes of sepsis in adult patients.The primary outcomes were the risk and mortality of sepsis.RESULTS:Seven studies comprising 791 patients were included.Lower levels of HDL had no marked relevance with the risk of sepsis(odds radio[OR]for each 1 mg/dL increase,0.94;95%CI 0.86–1.02;P=0.078),whereas lower HDL levels were related to an increased mortality rate in septic patients(OR for below about median HDL levels,2.00;95%CI 1.23–3.24;P=0.005).CONCLUSION:This meta-analysis did not reveal a signifi cant association between lower HDL levels and an increase in the risk of sepsis,whereas it showed that lower HDL levels are associated with a higher mortality rate in septic adult patients.These findings suggest that HDL may be considered as a promising factor for the prevention and treatment of sepsis in the future.
基金supported by the National Natural Science Foundation of China (31771794)the National Key Research and Development Program of China (2016YFD0101004 and 2017YFD0100900)the International Science & Technology Cooperation Program of the Bureau of Science and Technology of Chengdu China (2015DFA306002015-GH03-00008-HZ)。
文摘Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from which the reference genome assembly of bread wheat was obtained.Both parents and the recombinant inbred lines were genotyped using the wheat 55K single nucleotide polymorphism(SNP) array.A high-density genetic map containing 21,197 SNPs was obtained.These markers covered each of the 21 chromosomes with a total linkage distance of 3792.71 c M.Locations of these markers in this linkage map were highly consistent with their physical locations in the genome assembly of Chinese Spring.The two parents and the whole RIL population were assessed for GNS in two consecutive years at two different locations.Based on multi-environment phenotype data and best liner unbiased prediction values,three quantitative trait loci (QTL) for GNS were identified.One of them located on chromosomes 2B and the other two on 2D.Phenotypic variation explained by these loci varied from 3.07%to26.57%.One of these QTL,QGns.sicau-2D-2,was identified in each of all trials conducted.Based on the best linear unbiased prediction values,this locus explained 19.59%–26.57%of phenotypic variation.A KASP(Kompetitive Allele-Specific PCR) marker closely linked with this locus was generated and used to validate the effects of this locus in three different genetic backgrounds.The identified QTL and the KASP marker developed for it will be highly valuable in fine-mapping the locus and in exploiting it for markerassisted selection in wheat breeding programs.
基金Supported by Grants-in-Aid for scientific research from the Japan Society for the Promotion of Science,No.20015008,20054003,and 21390016
文摘The reverse cholesterol transport mediated by highdensity lipoprotein(HDL)is an important mechanism for maintaining body cholesterol,and hence,the crucial anti-atherogenic action of the lipoprotein.Recent studies,however,have shown that HDL exerts a variety of anti-inflammatory and anti-atherogenic actions independently of cholesterol metabolism.The present review provides an overview of the roles of sphingosine 1-phosphate(S1P)/S1P receptor and apolipoprotein A-I/ scavenger receptor class B typeⅠsystems in the antiatherogenic HDL actions.In addition,the physiological significance of the existence of S1P in the HDL particles is discussed.
文摘There is a tight link between bone and lipid metabolic pathways.In this vein,several studies focused on the exploration of high-density lipoprotein(HDL)in the pathobiology of bone diseases,with emphasis to the osteoarthritis(OA)and osteoporosis,the most common bone pathologies.Indeed,epidemiological and in vitro data have connected reduced HDL levels or dysfunctional HDL with cartilage destruction and OA development.Recent studies uncovered functional links between HDL and OA fueling the interesting hypothesis that OA could be a chronic element of the metabolic syndrome.Other studies have linked HDL to bone mineral density.Even though at epidemiological levels the results are conflicting,studies in animals as well as in vitro experiments have shown that HDL facilitates osteoblastogensis and bone synthesis and most probably affects osteoclastogenesis and osteoclast bone resorption.Notably,reduced HDL levels result in increased bone marrow adiposity affecting bone cells function.Unveiling the mechanisms that connect HDL and bone/cartilage homeostasis may contribute to the design of novel therapeutic agents for the improvement of bone and cartilage quality and thus for the treatment of related pathological conditions.
基金supported by National Natural Science Foundation of China(No.U19A20113)。
文摘A helicon wave plasma source in a tube of ring permanent magnets(PMs)has been constructed to study the effect of the conflguration of the magnetic fleld with zero magnetic points on plasma parameters.This device also serves as an exploration platform for a simple,compact helicon wave plasma source adaptable to engineering applications.A small-diameter(26 mm)highdensity(~10^(18)m^(-3))blue core plasma is produced in~1 Pa argon by helicon RF(radiofrequency)discharge using a NagoyaⅢantenna under magnetic fleld(~2 k G)of compact ring PMs(length~204 mm).Operational parameters,i.e.RF power and neutral gas pressure are scanned and plasma density is measured by an RF compensated probe to explore the operating characteristics of the device.Iconic feature of a helicon discharge,such as blue core plasmas and E-H-W mode transitions are well observed in the device,despite the wavelength calculated using the conventional dispersion relation of a bounded whistler waves(Chen 1991 Plasma Phys.Control.Fusion 33339)is order of magnitudes longer than the length of the plasma in this device which seems to suggest that such helicon device is impossible.Surprisingly,the wavelength calculated by the unbounded whistle wave dispersion formula in turn suggests the occurrence of a half wavelength resonance.
文摘Impact behavior of polymers has received considerable attention in recent years,and much work based on fracture mechanic approaches has been carried out.In this paper,fracture behavior in large deformation of a high density polyethylene(HDPE)materials was investigated through experimental impact testing on single edge notched specimen(SENB)and by using theoretical and analytical fracture criteria concepts.Moreover,a review of the main fracture criteria is given in order to characterize the toughness of this polymer in the both cases(static and dynamic).The fractured specimens obtained from the Charpy impact test were characterized with respect to their fracture surfaces.Characteristic zones of the fracture surface can be assigned to different stages and mechanisms of the fracture process.Finally,for a better understanding of fracture and damage mechanisms and to provide the best estimation of fracture toughness in impact,an experimental approach based on microscopic observations(SEM)was used.
基金Supported by the Technical Innovation Project of Hubei Province(No.2018ABA105)the Enterprise Technology Innovation Project of Wuhan(No.39 of 2019 WuKe)。
文摘Ancherythroculter nigrocauda is a fish endemic to the upper areas of the Changjiang(Yangtze)River in China.Quantitative trait locus(QTL)mapping is a powerful tool to identify potential genes affecting traits of economic importance in domestic animals.In this study,a high-density genetic map was constructed with 5901 single nucleotide polymorphism(SNP)makers by sequencing 92 individual fish from a F1 family using the specific-locus amplified fragment sequencing approach.Initially,48 QTLs for total length,body length,body height,and body weight were identified according to the high density of the genetic map with 24 LGs,a total length of 3839.4 cM,and marker spacing of about 0.82 cM.These QTLs explained 27.1%-49.9%of phenotypic variance.The results of this study suggest that major QTLs are responsible for the growth of A.nigrocauda,and these are potentially useful in comparative genomics research,genome assembly,and marker-assisted breeding programs for this species.
文摘In this research,the tensile properties'performance of compression moulded discontinuous randomized zalacca fibre/high-density polyethylene under critical fibre length was analysed by means of experimental method and micromechanical models.These investigations were used to verify the tensile properties models toward the effect of fibre length and volume fraction on the composites.The experimental results showed that the tensile properties of composites had significantly increased due to the enhancement of fibre length.On the contrary,a decline in the tensile properties was observed with the increase of volume fraction.A comparison was made between the available experimental results and the performances of Tsai-Pagano,Christensen and Cox-Krechel models in their prediction of composites elastic modulus.The results showed that the consideration of fibre's elastic anisotropy in the Cox-Krenchel model had yielded a good prediction of the composites modulus,nevertheless the models could not accurately predict the composites modulus for fibre length study.
文摘BACKGROUND Colorectal cancer(CRC)is a common malignant tumor of the gastrointestinal tract.Lipid metabolism,as an important part of material and energy circulation,is well known to play a crucial role in CRC.AIM To explore the relationship between serum lipids and CRC development and identify aberrantly expressed cholesterol metabolism genes in CRC.METHODS We retrospectively collected 843 patients who had confirmed CRC and received surgical resection from 2013 to 2015 at the Cancer Hospital of the Chinese Academy of Medical Sciences as our research subjects.The levels of serum total cholesterol(TC),triglycerides,low-density lipoprotein cholesterol(LDL-C),highdensity lipoprotein cholesterol(HDL-C),LDL-C/HDL-C and clinical features were collected and statistically analyzed by SPSS.Then,we used the data from Oncomine to screen the differentially expressed genes(DEGs)of the cholesterol metabolism pathway in CRC and used Gene Expression Profiling Interactive Analysis to confirm the candidate DEGs.PrognoScan was used to analyze the prognostic value of the DEGs,and Search Tool for the Retrieval of Interacting Genes was used to construct the protein-protein interaction network of DEGs.RESULTS The serum HDL-C level in CRC patients was significantly correlated with tumor size,and patients whose tumor size was more than 5 cm had a lower serum HDL-C level(1.18±0.41 mmol/L vs 1.25±0.35 mmol/L,P<0.01)than their counterparts.In addition,TC/HDL(4.19±1.33 vs 3.93±1.26,P<0.01)and LDL-C/HDL-C(2.83±1.10 vs 2.61±0.96,P<0.01)were higher in patients with larger tumors.The levels of HDL-C(P<0.05),TC/HDL-C(P<0.01)and LDL-C/HDL-C(P<0.05)varied in different stages of CRC patients,and the differences were significant.We screened 14 differentially expressed genes(DEGs)of the cholesterol metabolism pathway in CRC and confirmed that lipoprotein receptor-related protein 8(LRP8),PCSK9,low-density lipoprotein receptor(LDLR),MBTPS2 and FDXR are upregulated,while ABCA1 and OSBPL1A are downregulated in cancer tissue.Higher expression of LDLR(HR=3.12,95%CI:1.77-5.49,P<0.001),ABCA1(HR=1.66,95%CI:1.11-2.48,P=0.012)and OSBPL1A(HR=1.38,95%CI:1.01-1.89,P=0.041)all yielded significantly poorer DFS outcomes.Higher expression of FDXR(HR=0.7,95%CI:0.47-1.05,P=0.002)was correlated with longer DFS.LDLR,ABCA1,OSBPL1A and FDXR were involved in many important cellular function pathways.CONCLUSION Serum HDL-C levels are associated with tumor size and stage in CRC patients.LRP8,PCSK9,LDLR,MBTPS2 and FDXR are upregulated,while ABCA1 and OSBPL1A are downregulated in CRC.Among them,LDLR,ABCA1,OSBPL1A and FDXR were valuable prognostic factors of DFS and were involved in important cellular function pathways.
基金Supported by National Key R&D Program of China and Fundamental Research Funds for the Central Universities(2017YFC0601305)。
文摘The authors employ the high-density resistivity method to image the subsurface structure of a mountain in Erdaojiang District,Tonghua City,Jilin Province,China,to evaluate the potential risk of slope failure on surrounding residential areas and infrastructure,and identify a shallow fault that extends across the center of the mountain and is perpendicular to the mountain slope and accurately locate the spatial position and depth of another fault on the southern side of the mountain.The results provide an important basis for evaluating mountain slope stability.This study also demonstrates that the high-density resistivity method is effective for detecting mountain faults.
基金Supported by The National Natural Science Foundation of China(41504076)Jilin Science and Technological Development Program(20180101093JC)。
文摘By determining the distribution and extent of geological structures surrounding the Mingyan Tunnel,Xicheng Town,Helong City,Jilin Province,we can evaluate the stability of the rock mass and assess potential hazards during tunnel construction.We use the high-density resistivity method to analyze the subsurface structure of the study area.Conductive anomalies are likely to represent joint and fissure systems within strongly weathered host rocks,and the bedrock surrounding the tunnel is relatively stable and does not contain well-developed faults.High-density resistivity analysis can provide valuable information in the context of tunnel engineering and safety.
文摘The rheological behavior of composites made with high-density polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF), Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100 mesh were studied. The experimental results were obtained from samples containing 65 vol.% agro fiber and 3 wt.% lubricant. Particle sizes distribution of the agro fibers was in the range of 0.295 mm to ?0.125 mm. SEM showed evidence of complete matrix/fiber impregnation or wetting. The melt rheological data in terms of complex viscosity (η*), storage modulus (G'), loss modulus (G"), and loss tangent (tanδ) were evaluated and compared for different samples. Due to higher probability of agglomeration formation in the samples containing 65 vol.% of agro fillers, the storage modulus, loss modulus and complex viscosity of these samples were high. The unique change in all the samples is due to the particle size distribution of the agro fibers. The storage and loss modulus increased with increasing shear rates for all the composites, except for Walnut shell composite which exhibited unusual decrease in storage modulus with increasing shear rate. Damping factor (tanδ) decreased with increasing shear rate for all the composites at 65 vol.% filler load although there were differences among the composites. Maximum torque tended to increase at the 65 vol.% agro fiber load for all composites. Corncob and Walnut shell composites gave higher torque and steady state torque values in comparison with Flax shives and Rice hull composites due to differences in particle sizes distribution of the agro fibers.
