Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in ...Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in the world.This study,using multisource datasets(including satellite data and meteorological observations and reanalysis data)revealed the mutual feedback mechanisms between changes in climate(temperature and precipitation)and vegetation coverage in recent decades in the Hengduan Mountains Area(HMA)of the southeastern TP and their influences on climate in the downstream region,the Sichuan Basin(SCB).There is mutual facilitation between rising air temperature and increasing vegetation coverage in the HMA,which is most significant during winter,and then during spring,but insignificant during summer and autumn.Rising temperature significantly enhances local vegetation coverage,and vegetation greening in turn heats the atmosphere via enhancing net heat flux from the surface to the atmosphere.The atmospheric heating anomaly over the HMA thickens the atmospheric column and increases upper air pressure.The high pressure anomaly disperses downstream via the westerly flow,expands across the SCB,and eventually increases the SCB temperature.This effect lasts from winter to the following spring,which may cause the maximum increasing trend of the SCB temperature and vegetation coverage in spring.These results are helpful for estimating future trends in climate and eco-environmental variations in the HMA and SCB under warming scenarios,as well as seasonal forecasting based on the connection between the HMA eco-environment and SCB climate.展开更多
In the context of emerging engineering disciplines,a hybrid teaching reform for the Bioengineering Downstream Technology course,based on ideological and political education and online open courses,is being carried out...In the context of emerging engineering disciplines,a hybrid teaching reform for the Bioengineering Downstream Technology course,based on ideological and political education and online open courses,is being carried out.This reform focuses on aspects such as“building a professional teacher team for ideological and political education,scientifically designing the ideological and political teaching system,innovating classroom teaching methods,and improving both formative and summative evaluation systems.”The“Craftsmanship in Education and Cultivating Soul and Roots”small private online course hybrid teaching reform for the Bioengineering Downstream Technology online open course provides a replicable model for the comprehensive implementation of ideological and political education in engineering courses and offers a reference for advancing ideological and political education and hybrid teaching reform in new engineering disciplines.展开更多
The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electri...The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electricity,lubricants,as well as chemicals and petrochemicals.In the petroleum industry,supply chain management presents several challenges,especially in the logistics sector,that are not found in other industries.In addition,logistical challenges contribute significantly to the cost of oil.Uncertainty regarding customer demand and supply significantly affects SC networks.Hence,SC flexibility can be maintained by addressing uncertainty.On the other hand,in the real world,decision-making challenges are often ambiguous or vague.In some cases,measurements are incorrect owing to measurement errors,instrument faults,etc.,which lead to a pentagonal fuzzy number(PFN)which is the extension of a fuzzy number.Therefore,it is necessary to develop quantitative models to optimize logistics operations and supply chain networks.This study proposed a linear programming model under an uncertain environment.The model minimizes the cost along the refineries,depots,multimode transport and demand nodes.Further developed pentagonal fuzzy optimization,an alternative approach is developed to solve the downstream supply chain using themixed-integer linear programming(MILP)model to obtain a feasible solution to the fuzzy transportation cost problem.In this model,the coefficient of the transportation costs and parameters is assumed to be a pentagonal fuzzy number.Furthermore,defuzzification is performed using an accuracy function.To validate the model and technique and feasibility solution,an illustrative example of the oil and gas SC is considered,providing improved results compared with existing techniques and demonstrating its ability to benefit petroleum companies is the objective of this study.展开更多
As Egyptian oil and gas downstream information technology has grown digitally over the past decade, security breaches against these digitally connected systems have also increased. These cyber security threats could h...As Egyptian oil and gas downstream information technology has grown digitally over the past decade, security breaches against these digitally connected systems have also increased. These cyber security threats could have devastating effects on the operations and reputation of these companies. Preventing such cyberattacks is crucial. Especially, with the significance of the Egyptian oil and gas downstream sector to the local economy and the fact that many of these connected systems are sometimes managed remotely. This paper examines the value of the ISO 27001 standard in mitigating the effect of cyber threat and seeks to inspire decision-makers to the importance of the proactive measures to strengthen their organization’s cybersecurity posture and protect information critical assets. The study stresses the importance of improving the local educational system to bridge the gap between supply and demand for cybersecurity specialists by implementing a structured approach that emphasizes behavior modification to get a high return on investment in cybersecurity awareness.展开更多
The research selected three typical areas for plant investigation, including upper reaches of Gangnan Reservoir, the area between Gangnan and downstream of Huangbizhuang Reservoir, and Huangbizhuang Reservoir. The res...The research selected three typical areas for plant investigation, including upper reaches of Gangnan Reservoir, the area between Gangnan and downstream of Huangbizhuang Reservoir, and Huangbizhuang Reservoir. The results showed that affected by water, plant species, species diversity and species richness were all decreasing in varying degrees as the distance with watercourse upper reaches was increasing, but the ratio of Anthropochory plants was growing. The research finally proposed countermeasures, including increasing wetland area, constructing forests and artificial water landscape of Hutuo River and reinforcing watercourse compre- hensive management.展开更多
In this study,the nonplanar post-buckling behavior of a simply supported fluid-conveying pipe with an axially sliding downstream end is investigated within the framework of a three-dimensional(3 D)theoretical model.Th...In this study,the nonplanar post-buckling behavior of a simply supported fluid-conveying pipe with an axially sliding downstream end is investigated within the framework of a three-dimensional(3 D)theoretical model.The complete nonlinear governing equations are discretized via Galerkin’s method and then numerically solved by the use of a fourth-order Runge-Kutta integration algorithm.Different initial conditions are chosen for calculations to show the nonplanar buckling characteristics of the pipe in two perpendicular lateral directions.A detailed parametric analysis is performed in order to study the influence of several key system parameters such as the mass ratio,the flow velocity,and the gravity parameter on the post-buckling behavior of the pipe.Typical results are presented in the form of bifurcation diagrams when the flow velocity is selected as the variable parameter.It is found that the pipe will stay at its original straight equilibrium position until the critical flow velocity is reached.Just beyond the critical flow velocity,the pipe would lose stability by static divergence via a pitchfork bifurcation,and two possible nonzero equilibrium positions are generated.It is shown that the buckling and post-buckling behaviors of the pipe cannot be influenced by the mass ratio parameter.Unlike a pipe with two immovable ends,however,the pinned-pinned pipe with an axially sliding downstream end shows some different features regarding post-buckling behaviors.The most important feature is that the buckling amplitude of the pipe with an axially sliding downstream end would increase first and then decrease with the increase in the flow velocity.In addition,the buckled shapes of the pipe varying with the flow velocity are displayed in order to further show the new post-buckling features of the pipe with an axially sliding downstream end.展开更多
The Yalong River is an important river that runs across the abruptly changing terrain of the SE Tibetan Plateau. The terraces and Quaternary sediments in its valleys preserve the information of tectonic uplift, climat...The Yalong River is an important river that runs across the abruptly changing terrain of the SE Tibetan Plateau. The terraces and Quaternary sediments in its valleys preserve the information of tectonic uplift, climate changes, and landform evolution since the Middle Pleistocene. Based on geomorphological, sedimentological, and chronological investigations, 6-8 terraces are identified in the lower reaches of Yalong catchment and its tributary--the Anning River. The electron spin resonance （ESR） or optically stimulated luminescence （OSL） data on the alluvial sediments in the upper portion of terraces indicate that they formed in 1.10, 0.90, 0.72, 0.06-0.04, 0.03-0.02, and 0.01 Ma. Tectonic uplift and the climatic cycle controlled the formation of the Yalong River terraces. The former dominated the dissection depths and incision rates, whereas the latter controlled the transformation between accumulation, which developed during the glacial period, and incision, which developed during the glacial-interglacial transition. The Yalong downstream incised rapidly from 1.10 to 0.72 Ma and rapidly from 0.06 Ma until the present; the terraces developed during these two periods. The incision rates in space during the two periods indicate the uplifting extent of the Jinpingshan area, which decreases toward the east and the south. The results reveal two rapidly uplifting stages in the SE Tibetan Plateau, including an accelerated uplifting since 0.06 Ma. Since the Middle Pleistocene, the tectonic uplift of the SE and NE parts of the Tibetan Plateau is synchronous, according to the same development stages of the river terraces of the Yalong downstream and the Yellow River in the Lanzhou area of the NE Tibetan Plateau. The difference in the horizontal displacement between the Xianshuihe Fault and the Anninghe Fault bend resulted in the rapid uplift of the Jinpingshan area. The incision rate for the spatial distribution of the Yalong downstream is the geomorphologicai response of crustal shortening and uplift differences in the SE margin block of the Tibetan Plateau. The southeastward diffusion process of the Tibetan Plateau was recorded.展开更多
Gezhouba hydroproject was impounded and put into operation in 1981. In order to analyse the impact on the downstream river course, Jingjiang Hydrologic and Water Resources Survey Bureau of Changjiang Water Resources C...Gezhouba hydroproject was impounded and put into operation in 1981. In order to analyse the impact on the downstream river course, Jingjiang Hydrologic and Water Resources Survey Bureau of Changjiang Water Resources Commission has conducted prototype observation on the Yichang-Chenglingji river stretch. On basis of the observed data, the change in river regime and scour-sedimentation evolution and water surface profile below the dam are analysed systematically. The results show that the scouring of downstream river course mainly stretches from Yichang to Ouchikou, mainly occurring in 1980～1987; the scourring mainly takes place in the river channel and the water surface profile drops significantly in dry season,but not quite in high flood season.展开更多
This study uses eddy kinetic energy analysis and a targeting method to investigate how an extratropical transition（ET）event induced downstream development（the modification of the midlatitude flow downstream of the ...This study uses eddy kinetic energy analysis and a targeting method to investigate how an extratropical transition（ET）event induced downstream development（the modification of the midlatitude flow downstream of the ET system） in the midlatitude jet environment. The downstream development showed distinct characteristics of ＂coupling development＂ and being ＂boundary-trapped＂. Eddies（potential disturbances） first developed at the upper levels, and these triggered lower-level eddy development, with all eddies decaying away from the tropopause and the surface. Thereafter, a lower-level eddy caught up with the upper-level eddy ahead of it, and they coupled to form a cyclone extending through the whole troposphere. Vertical ageostrophic geopotential flux may be a crucial dynamic factor throughout the eddy＇s lower-level growth, boundary-trapping,and coupling development.Together with barotropic conversion, the ageostrophic geopotential fluxes that were transported from Hurricane Fabian（2003） to the midlatitudes by the outflow led to downstream ridge development in the upper-level jet. The strong downstream advection of eddy kinetic energy in the exit region of the jet streak triggered downstream trough development. The well-known ridge–trough couplet thus formed. The vertical ageostrophic fluxes that were transported downward from the developed upper-level systems converged near the surface and resulted in lower-level eddy growth. Baroclinic conversion was negligible near the boundaries, while it was the main source of eddy kinetic energy at mid-levels. In the upper-level jet, potential energy was converted to the mean kinetic energy of the jet, which in turn was converted to eddy kinetic energy through barotropic conversion.展开更多
Downstream processing or product recovery plays a vital role in the development of bioprocesses.To improve the bioprocess efficiency,some unconventional methods are much required.The continuous manufacturing in downst...Downstream processing or product recovery plays a vital role in the development of bioprocesses.To improve the bioprocess efficiency,some unconventional methods are much required.The continuous manufacturing in downstream processing makes the Process Analytical Technologies(PATs)as an important tool.Monitoring and controlling bioprocess are an essential factor for the principles of PAT and quality by design.Spectroscopic methods can apply to monitor multiple analytes in real-time with less sample processing with significant advancements.Raman spectroscopy is an extensively used technique as an analytical and research tool owing to its modest process form,non-destructive,non-invasive optical molecular spectroscopic imaging with computer-based analysis.Generally,its application is essential for the analysis and characterization of biological samples,and it is easy to operate with minimal sample.The innovation on various types of enhanced Raman spectroscopy was designed to enhance the Raman analytical technique.Raman spectroscopy could couple with chemometrics to provide reliable alternative analysis method of downstream process analysis.Thus,this review aims to provide useful insight on the application of Raman spectroscopy for PAT in downstream processing of biotechnology and Raman data analysis in biological fields.展开更多
The transport characters of non-uniform sediment before and after the reservoir operation are compared and analyzed. Field data from the Three Gorges Reservoir (TGR), Danjiangkou, and Sanmenxia reservoir indicate that...The transport characters of non-uniform sediment before and after the reservoir operation are compared and analyzed. Field data from the Three Gorges Reservoir (TGR), Danjiangkou, and Sanmenxia reservoir indicate that the transport character of coarse particle is various in different reaches. Before the reservoir operation, the dramatic decrease of the hydraulic condition in some reaches is the main reason to cause the coarse particle deposited. After the reservoir operation, almost all grain sized sediment may be eroded, when the reach is eroded seriously. However, the transport character of the coarse particle will be consistent with what it was before, when the reach is not eroded seriously. The deposition amount will be less than its pre-dam value, and it will tend to decrease with the time going on. Erosion of fine particle results from its unsaturation. Longdistance erosion downstream from reservoir is caused by shortage of the supply from riverbed, especially the shortage of fine particle.展开更多
BACKGROUND Invasion and migration are the irreversible stages of colorectal cancer(CRC).The key is to find a sensitive,reliable molecular marker that can predict the migration of CRC at an early stage.N-myc downstream...BACKGROUND Invasion and migration are the irreversible stages of colorectal cancer(CRC).The key is to find a sensitive,reliable molecular marker that can predict the migration of CRC at an early stage.N-myc downstream regulated gene 1(NDRG1)is a multifunctional gene that has been tentatively reported to have a strong relationship with tumor invasion and migration,however the current molecular role of NDRG1 in CRC remains unknown.AIM To explore the role of NDRG1 in the development of CRC.METHODS NDRG1 stably over-expressed Caco2 cell line was established by lentiviral infection and NDRG1 knock-out Caco2 cell line was established by CRISPR/Cas9.Furthermore,the mRNA and protein levels of NDRG1 in Caco2 cells after NDRG1 over-expression and knockout were detected by real-time polymerase chain reaction and western blot.The cell proliferation rate was measured by the cell counting kit-8 method;cell cycle and apoptosis were detected by flow cytometry;invasion and migration ability were detected by the 24-transwell method.RESULTS NDRG1 over-expression inhibited Caco2 proliferation and the cell cycle could be arrested at the G1/S phase when NDRG1 was over-expressed,while the number of cells in the G2 phase was significantly increased when NDRG1 was knocked out.This suggests that NDRG1 inhibited the proliferation of Caco2 cells by arresting the cell cycle in the G1/S phase.Our data also demonstrated that NDRG1 promotes early cell apoptosis.Invasion and migration of cells were extensively inhibited when NDRG1 was over-expressed.CONCLUSION NDRG1 inhibits tumor progression in Caco2 cells which may represent a potential novel therapeutic strategy for the treatment of CRC.展开更多
In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff probe.The measured plasma density is in the range of 101...In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff probe.The measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPS powers of 2-4 kW and gas pressures of 0.87-4 Torr.The plasma density decreased with increasing gas pressures and RPS powers under various Ar/NF3 mixing ratios.This decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this system.The etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and powers.It was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).展开更多
Amh (anti-Müllerian hormone) is a single copy gene which is expressed strongly in Sertoli cells in the foetal testis and participates in the onset of sexual differentiation. Its promoter driving the expression of...Amh (anti-Müllerian hormone) is a single copy gene which is expressed strongly in Sertoli cells in the foetal testis and participates in the onset of sexual differentiation. Its promoter driving the expression of a reporter gene (d2EGFP) has been used to analyse the role of certain defined putative elements and a downstream enhancer element in gene expression. These experiments were carried out in vitro using a line of pre-pubertal mouse Sertoli cells, transienly transfected with circular DNA constructs with variously mutated promoter elements. A downstream enhancer element, situated immediately 3’ of the polyadenylation (PA) signal for Amh, has been inserted in an equivalent position in the d2EGFP construct. When the Amh promoter is unmodified, the downstream enhancer (DE) is positively associated with a large increase in EGFP expression. This is at least partly the consequence of an increased rate of expression by individual cells. Experiments using variously truncated Amh promoters indicate that an upstream region (-214 to -336) may play a minor role in facilitating enhancement. However mutation of the Wilms tumour factor-1 element, situated between the tata box and the start of translation, results in an almost complete suppression of enhancement.展开更多
The population located along Mono River in the Yoto district faces great challenges in terms of repeated flood disasters in recent years. This paper aims at assessing the conditions which influence flood damage in the...The population located along Mono River in the Yoto district faces great challenges in terms of repeated flood disasters in recent years. This paper aims at assessing the conditions which influence flood damage in the study area by using indicators to compute a Flood Vulnerability Index (FVI). The study relies on Turner?et al.’s vulnerability framework and distinguishes three main components (exposure, susceptibility and resilience) that allow a more in-depth analysis and interpretation of local indicators. As a result flood disaster in the study area is not only due to the extreme variability in terms of flood magnitude and frequency in the Mono River, but also to the interaction between human and the environment. The lack of vegetation along the river bank, the closeness of households’ farmlands to the river body, the type of construction and the position of settlements, the household size, the low level education of household head, the lack of diversification of livelihood strategies, the lack of adequate flood warning system, the lack of willingness and ability to take responsive actions coupled with inadequate emergency services, are identified as main determinants increasing communities’ vulnerability to flood disaster. Furthermore, the computation of Flood Vulnerability Index (FVI) offers easy comparison of communities’ vulnerability to flood disaster and pinpoints the most vulnerable communities. At the end of the study, flood exposure, susceptibility, resilience and vulnerability maps were generated.展开更多
This paper discusses pressure variation on a wall during the process of liquid flow and droplet formation in a T-junction microchannel. Relevant pressure in the channel, deformation of the elastic wall, and responses ...This paper discusses pressure variation on a wall during the process of liquid flow and droplet formation in a T-junction microchannel. Relevant pressure in the channel, deformation of the elastic wall, and responses of the droplet generation are analyzed using a numerical method.The pressure difference between the continuous and dispersed phases can indicate the droplet-generation period. The pressure along the channel of the droplet flow is affected by the position of droplets, droplet-generation period, and droplet escape from the outlet. The varying pressures along the channel cause a nonuniform deformation of the wall when they are elastic. The deformation is a vibration and has the same period as the droplet generation arising from the process of droplet formation.展开更多
According to the measured data after impoundment and operation of the Three Gorges Reservoir,the reservoir sediment deposition and downstream river channel scouring are described briefly and compared with the research...According to the measured data after impoundment and operation of the Three Gorges Reservoir,the reservoir sediment deposition and downstream river channel scouring are described briefly and compared with the research results achieved in the demonstration stage.It is indicated through analysis that the reservoir sediment deposition and downstream river channel scouring during 8-year impoundment and operation are still within the original forecast,so the original forecasting results are feasible.The further observation and comparison should be conducted because the comparison between the observed data and the original forecast is not so sufficient in time and the prototype observation and related research work should be strengthened in the future.展开更多
1 Production and Running Status of China＇s Refractories Industry in 2013 1.1 Refractories Output In 2013, China＇ s refractories output was 29. 283 million tons increasing by 3.88% YOY; in which the outputs of den...1 Production and Running Status of China＇s Refractories Industry in 2013 1.1 Refractories Output In 2013, China＇ s refractories output was 29. 283 million tons increasing by 3.88% YOY; in which the outputs of dense shaped refractory products, insulating refractory products, monolithic refractories were 17.307 million tons increasing by 5.93% YOY, 557.3 thousand tons decreasing by 2.67% YOY and 11. 418 million tons increasing by 1.24% YOY, respectively.展开更多
On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed wit...On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations （St. Venant equations here） and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy.展开更多
Plasma behaviour and the scaling relations in a coaxial plasma opening switch （POS） using hydrogen plasma are studied self-consistently based on the two-dimensional magnetohydrodynamic （MHD） equations in conjuncti...Plasma behaviour and the scaling relations in a coaxial plasma opening switch （POS） using hydrogen plasma are studied self-consistently based on the two-dimensional magnetohydrodynamic （MHD） equations in conjunction with the generalized Ohm＇s law. The vacuum region on the right of POS is included in the model and the influence of downstream flow on the conduction characteristics is discussed. It is found that with the penetration of magnetic field, the pure hydrogen plasma is pushed downstream significantly; and POS still conducts current after the magnetic field arrives at the load edge of POS, which is different from the previous experimental results in a multispecies POS. It is because that the noticeable downstream plasma in the pure hydrogen POS may continue to conduct the current, while in the multispecies POS, the downstream plasma is unimportant so that the conduction phase ends soon after the magnetic field reaches the load edge. The scaling relation obtained from the simulations including the downstream region is consistent with the experimental results.展开更多
基金the National Natural Science Foundation of China(Grant Nos.42205059 and 42005075)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA23090303 and XDB40010302)+1 种基金the State Key Laboratory of Cryospheric Science(Grant No.SKLCS-ZZ-2024 and SKLCS-ZZ-2023)the Key Laboratory of Mountain Hazards and Earth Surface Processes.
文摘Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in the world.This study,using multisource datasets(including satellite data and meteorological observations and reanalysis data)revealed the mutual feedback mechanisms between changes in climate(temperature and precipitation)and vegetation coverage in recent decades in the Hengduan Mountains Area(HMA)of the southeastern TP and their influences on climate in the downstream region,the Sichuan Basin(SCB).There is mutual facilitation between rising air temperature and increasing vegetation coverage in the HMA,which is most significant during winter,and then during spring,but insignificant during summer and autumn.Rising temperature significantly enhances local vegetation coverage,and vegetation greening in turn heats the atmosphere via enhancing net heat flux from the surface to the atmosphere.The atmospheric heating anomaly over the HMA thickens the atmospheric column and increases upper air pressure.The high pressure anomaly disperses downstream via the westerly flow,expands across the SCB,and eventually increases the SCB temperature.This effect lasts from winter to the following spring,which may cause the maximum increasing trend of the SCB temperature and vegetation coverage in spring.These results are helpful for estimating future trends in climate and eco-environmental variations in the HMA and SCB under warming scenarios,as well as seasonal forecasting based on the connection between the HMA eco-environment and SCB climate.
基金Guangdong Province Undergraduate Online Open Course Guidance Committee Research Project(2022ZXKC462)Foshan Philosophy and Social Science Planning Project(2024-GJ 037)+4 种基金Provincial First-Class Undergraduate Courses of Guangdong Provincial Education Department(Guangdong Education Gaohan[2022]No.10)Innovation Project of Guangdong Graduate Education(2022JGXM129,2022JGXM128,2023ANLK-080)Foshan University Curriculum Ideological and Political Teaching Reform and Practice Demonstration Project in 2023Quality Engineering Project of Foshan University in 2023Collaborative Education Project of the Ministry of Education in 2023(230703232312141)。
文摘In the context of emerging engineering disciplines,a hybrid teaching reform for the Bioengineering Downstream Technology course,based on ideological and political education and online open courses,is being carried out.This reform focuses on aspects such as“building a professional teacher team for ideological and political education,scientifically designing the ideological and political teaching system,innovating classroom teaching methods,and improving both formative and summative evaluation systems.”The“Craftsmanship in Education and Cultivating Soul and Roots”small private online course hybrid teaching reform for the Bioengineering Downstream Technology online open course provides a replicable model for the comprehensive implementation of ideological and political education in engineering courses and offers a reference for advancing ideological and political education and hybrid teaching reform in new engineering disciplines.
文摘The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electricity,lubricants,as well as chemicals and petrochemicals.In the petroleum industry,supply chain management presents several challenges,especially in the logistics sector,that are not found in other industries.In addition,logistical challenges contribute significantly to the cost of oil.Uncertainty regarding customer demand and supply significantly affects SC networks.Hence,SC flexibility can be maintained by addressing uncertainty.On the other hand,in the real world,decision-making challenges are often ambiguous or vague.In some cases,measurements are incorrect owing to measurement errors,instrument faults,etc.,which lead to a pentagonal fuzzy number(PFN)which is the extension of a fuzzy number.Therefore,it is necessary to develop quantitative models to optimize logistics operations and supply chain networks.This study proposed a linear programming model under an uncertain environment.The model minimizes the cost along the refineries,depots,multimode transport and demand nodes.Further developed pentagonal fuzzy optimization,an alternative approach is developed to solve the downstream supply chain using themixed-integer linear programming(MILP)model to obtain a feasible solution to the fuzzy transportation cost problem.In this model,the coefficient of the transportation costs and parameters is assumed to be a pentagonal fuzzy number.Furthermore,defuzzification is performed using an accuracy function.To validate the model and technique and feasibility solution,an illustrative example of the oil and gas SC is considered,providing improved results compared with existing techniques and demonstrating its ability to benefit petroleum companies is the objective of this study.
文摘As Egyptian oil and gas downstream information technology has grown digitally over the past decade, security breaches against these digitally connected systems have also increased. These cyber security threats could have devastating effects on the operations and reputation of these companies. Preventing such cyberattacks is crucial. Especially, with the significance of the Egyptian oil and gas downstream sector to the local economy and the fact that many of these connected systems are sometimes managed remotely. This paper examines the value of the ISO 27001 standard in mitigating the effect of cyber threat and seeks to inspire decision-makers to the importance of the proactive measures to strengthen their organization’s cybersecurity posture and protect information critical assets. The study stresses the importance of improving the local educational system to bridge the gap between supply and demand for cybersecurity specialists by implementing a structured approach that emphasizes behavior modification to get a high return on investment in cybersecurity awareness.
基金Supported by Hebei Provincial Natural Science Foundation(D2012302007)Science and Technology Project of Hebei Academy of Sciences(14111)~~
文摘The research selected three typical areas for plant investigation, including upper reaches of Gangnan Reservoir, the area between Gangnan and downstream of Huangbizhuang Reservoir, and Huangbizhuang Reservoir. The results showed that affected by water, plant species, species diversity and species richness were all decreasing in varying degrees as the distance with watercourse upper reaches was increasing, but the ratio of Anthropochory plants was growing. The research finally proposed countermeasures, including increasing wetland area, constructing forests and artificial water landscape of Hutuo River and reinforcing watercourse compre- hensive management.
基金Project supported by the National Natural Science Foundation of China(Nos.11622216,11602090,and 11672115)the Natural Science Foundation of Hubei Province(No.2017CFB429)the fundamental Research Funds for the Central Universities of China(No.2017KFYXJJ135)
文摘In this study,the nonplanar post-buckling behavior of a simply supported fluid-conveying pipe with an axially sliding downstream end is investigated within the framework of a three-dimensional(3 D)theoretical model.The complete nonlinear governing equations are discretized via Galerkin’s method and then numerically solved by the use of a fourth-order Runge-Kutta integration algorithm.Different initial conditions are chosen for calculations to show the nonplanar buckling characteristics of the pipe in two perpendicular lateral directions.A detailed parametric analysis is performed in order to study the influence of several key system parameters such as the mass ratio,the flow velocity,and the gravity parameter on the post-buckling behavior of the pipe.Typical results are presented in the form of bifurcation diagrams when the flow velocity is selected as the variable parameter.It is found that the pipe will stay at its original straight equilibrium position until the critical flow velocity is reached.Just beyond the critical flow velocity,the pipe would lose stability by static divergence via a pitchfork bifurcation,and two possible nonzero equilibrium positions are generated.It is shown that the buckling and post-buckling behaviors of the pipe cannot be influenced by the mass ratio parameter.Unlike a pipe with two immovable ends,however,the pinned-pinned pipe with an axially sliding downstream end shows some different features regarding post-buckling behaviors.The most important feature is that the buckling amplitude of the pipe with an axially sliding downstream end would increase first and then decrease with the increase in the flow velocity.In addition,the buckled shapes of the pipe varying with the flow velocity are displayed in order to further show the new post-buckling features of the pipe with an axially sliding downstream end.
基金supported by the Project of China Geological Survey (grant nos.1212011120071,201211077-3 and 1212011120182)
文摘The Yalong River is an important river that runs across the abruptly changing terrain of the SE Tibetan Plateau. The terraces and Quaternary sediments in its valleys preserve the information of tectonic uplift, climate changes, and landform evolution since the Middle Pleistocene. Based on geomorphological, sedimentological, and chronological investigations, 6-8 terraces are identified in the lower reaches of Yalong catchment and its tributary--the Anning River. The electron spin resonance （ESR） or optically stimulated luminescence （OSL） data on the alluvial sediments in the upper portion of terraces indicate that they formed in 1.10, 0.90, 0.72, 0.06-0.04, 0.03-0.02, and 0.01 Ma. Tectonic uplift and the climatic cycle controlled the formation of the Yalong River terraces. The former dominated the dissection depths and incision rates, whereas the latter controlled the transformation between accumulation, which developed during the glacial period, and incision, which developed during the glacial-interglacial transition. The Yalong downstream incised rapidly from 1.10 to 0.72 Ma and rapidly from 0.06 Ma until the present; the terraces developed during these two periods. The incision rates in space during the two periods indicate the uplifting extent of the Jinpingshan area, which decreases toward the east and the south. The results reveal two rapidly uplifting stages in the SE Tibetan Plateau, including an accelerated uplifting since 0.06 Ma. Since the Middle Pleistocene, the tectonic uplift of the SE and NE parts of the Tibetan Plateau is synchronous, according to the same development stages of the river terraces of the Yalong downstream and the Yellow River in the Lanzhou area of the NE Tibetan Plateau. The difference in the horizontal displacement between the Xianshuihe Fault and the Anninghe Fault bend resulted in the rapid uplift of the Jinpingshan area. The incision rate for the spatial distribution of the Yalong downstream is the geomorphologicai response of crustal shortening and uplift differences in the SE margin block of the Tibetan Plateau. The southeastward diffusion process of the Tibetan Plateau was recorded.
文摘Gezhouba hydroproject was impounded and put into operation in 1981. In order to analyse the impact on the downstream river course, Jingjiang Hydrologic and Water Resources Survey Bureau of Changjiang Water Resources Commission has conducted prototype observation on the Yichang-Chenglingji river stretch. On basis of the observed data, the change in river regime and scour-sedimentation evolution and water surface profile below the dam are analysed systematically. The results show that the scouring of downstream river course mainly stretches from Yichang to Ouchikou, mainly occurring in 1980～1987; the scourring mainly takes place in the river channel and the water surface profile drops significantly in dry season,but not quite in high flood season.
基金jointly supported by the International Cooperating Program of Science and Technology (Grant No. 2010DFA24650)the National Natural Science Foundation of China (Grant No. 41175061)
文摘This study uses eddy kinetic energy analysis and a targeting method to investigate how an extratropical transition（ET）event induced downstream development（the modification of the midlatitude flow downstream of the ET system） in the midlatitude jet environment. The downstream development showed distinct characteristics of ＂coupling development＂ and being ＂boundary-trapped＂. Eddies（potential disturbances） first developed at the upper levels, and these triggered lower-level eddy development, with all eddies decaying away from the tropopause and the surface. Thereafter, a lower-level eddy caught up with the upper-level eddy ahead of it, and they coupled to form a cyclone extending through the whole troposphere. Vertical ageostrophic geopotential flux may be a crucial dynamic factor throughout the eddy＇s lower-level growth, boundary-trapping,and coupling development.Together with barotropic conversion, the ageostrophic geopotential fluxes that were transported from Hurricane Fabian（2003） to the midlatitudes by the outflow led to downstream ridge development in the upper-level jet. The strong downstream advection of eddy kinetic energy in the exit region of the jet streak triggered downstream trough development. The well-known ridge–trough couplet thus formed. The vertical ageostrophic fluxes that were transported downward from the developed upper-level systems converged near the surface and resulted in lower-level eddy growth. Baroclinic conversion was negligible near the boundaries, while it was the main source of eddy kinetic energy at mid-levels. In the upper-level jet, potential energy was converted to the mean kinetic energy of the jet, which in turn was converted to eddy kinetic energy through barotropic conversion.
基金This work was supported by the National Natural Science Foundation of China(No.21878263,22078286)。
文摘Downstream processing or product recovery plays a vital role in the development of bioprocesses.To improve the bioprocess efficiency,some unconventional methods are much required.The continuous manufacturing in downstream processing makes the Process Analytical Technologies(PATs)as an important tool.Monitoring and controlling bioprocess are an essential factor for the principles of PAT and quality by design.Spectroscopic methods can apply to monitor multiple analytes in real-time with less sample processing with significant advancements.Raman spectroscopy is an extensively used technique as an analytical and research tool owing to its modest process form,non-destructive,non-invasive optical molecular spectroscopic imaging with computer-based analysis.Generally,its application is essential for the analysis and characterization of biological samples,and it is easy to operate with minimal sample.The innovation on various types of enhanced Raman spectroscopy was designed to enhance the Raman analytical technique.Raman spectroscopy could couple with chemometrics to provide reliable alternative analysis method of downstream process analysis.Thus,this review aims to provide useful insight on the application of Raman spectroscopy for PAT in downstream processing of biotechnology and Raman data analysis in biological fields.
基金the National Basic Research Program of China("973" Program, No.2003CB415200)
文摘The transport characters of non-uniform sediment before and after the reservoir operation are compared and analyzed. Field data from the Three Gorges Reservoir (TGR), Danjiangkou, and Sanmenxia reservoir indicate that the transport character of coarse particle is various in different reaches. Before the reservoir operation, the dramatic decrease of the hydraulic condition in some reaches is the main reason to cause the coarse particle deposited. After the reservoir operation, almost all grain sized sediment may be eroded, when the reach is eroded seriously. However, the transport character of the coarse particle will be consistent with what it was before, when the reach is not eroded seriously. The deposition amount will be less than its pre-dam value, and it will tend to decrease with the time going on. Erosion of fine particle results from its unsaturation. Longdistance erosion downstream from reservoir is caused by shortage of the supply from riverbed, especially the shortage of fine particle.
基金the National Natural Science Foundation of China,No.81260361Incubation Project of Mianyang Central Hospital,No.2020FH05.
文摘BACKGROUND Invasion and migration are the irreversible stages of colorectal cancer(CRC).The key is to find a sensitive,reliable molecular marker that can predict the migration of CRC at an early stage.N-myc downstream regulated gene 1(NDRG1)is a multifunctional gene that has been tentatively reported to have a strong relationship with tumor invasion and migration,however the current molecular role of NDRG1 in CRC remains unknown.AIM To explore the role of NDRG1 in the development of CRC.METHODS NDRG1 stably over-expressed Caco2 cell line was established by lentiviral infection and NDRG1 knock-out Caco2 cell line was established by CRISPR/Cas9.Furthermore,the mRNA and protein levels of NDRG1 in Caco2 cells after NDRG1 over-expression and knockout were detected by real-time polymerase chain reaction and western blot.The cell proliferation rate was measured by the cell counting kit-8 method;cell cycle and apoptosis were detected by flow cytometry;invasion and migration ability were detected by the 24-transwell method.RESULTS NDRG1 over-expression inhibited Caco2 proliferation and the cell cycle could be arrested at the G1/S phase when NDRG1 was over-expressed,while the number of cells in the G2 phase was significantly increased when NDRG1 was knocked out.This suggests that NDRG1 inhibited the proliferation of Caco2 cells by arresting the cell cycle in the G1/S phase.Our data also demonstrated that NDRG1 promotes early cell apoptosis.Invasion and migration of cells were extensively inhibited when NDRG1 was over-expressed.CONCLUSION NDRG1 inhibits tumor progression in Caco2 cells which may represent a potential novel therapeutic strategy for the treatment of CRC.
文摘In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff probe.The measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPS powers of 2-4 kW and gas pressures of 0.87-4 Torr.The plasma density decreased with increasing gas pressures and RPS powers under various Ar/NF3 mixing ratios.This decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this system.The etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and powers.It was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).
文摘Amh (anti-Müllerian hormone) is a single copy gene which is expressed strongly in Sertoli cells in the foetal testis and participates in the onset of sexual differentiation. Its promoter driving the expression of a reporter gene (d2EGFP) has been used to analyse the role of certain defined putative elements and a downstream enhancer element in gene expression. These experiments were carried out in vitro using a line of pre-pubertal mouse Sertoli cells, transienly transfected with circular DNA constructs with variously mutated promoter elements. A downstream enhancer element, situated immediately 3’ of the polyadenylation (PA) signal for Amh, has been inserted in an equivalent position in the d2EGFP construct. When the Amh promoter is unmodified, the downstream enhancer (DE) is positively associated with a large increase in EGFP expression. This is at least partly the consequence of an increased rate of expression by individual cells. Experiments using variously truncated Amh promoters indicate that an upstream region (-214 to -336) may play a minor role in facilitating enhancement. However mutation of the Wilms tumour factor-1 element, situated between the tata box and the start of translation, results in an almost complete suppression of enhancement.
文摘The population located along Mono River in the Yoto district faces great challenges in terms of repeated flood disasters in recent years. This paper aims at assessing the conditions which influence flood damage in the study area by using indicators to compute a Flood Vulnerability Index (FVI). The study relies on Turner?et al.’s vulnerability framework and distinguishes three main components (exposure, susceptibility and resilience) that allow a more in-depth analysis and interpretation of local indicators. As a result flood disaster in the study area is not only due to the extreme variability in terms of flood magnitude and frequency in the Mono River, but also to the interaction between human and the environment. The lack of vegetation along the river bank, the closeness of households’ farmlands to the river body, the type of construction and the position of settlements, the household size, the low level education of household head, the lack of diversification of livelihood strategies, the lack of adequate flood warning system, the lack of willingness and ability to take responsive actions coupled with inadequate emergency services, are identified as main determinants increasing communities’ vulnerability to flood disaster. Furthermore, the computation of Flood Vulnerability Index (FVI) offers easy comparison of communities’ vulnerability to flood disaster and pinpoints the most vulnerable communities. At the end of the study, flood exposure, susceptibility, resilience and vulnerability maps were generated.
基金supported by the National Natural Science Foundation of China(Grants 11072011 and 11572013)the Doctoral Fund of Innovation of the Beijing University of Technology
文摘This paper discusses pressure variation on a wall during the process of liquid flow and droplet formation in a T-junction microchannel. Relevant pressure in the channel, deformation of the elastic wall, and responses of the droplet generation are analyzed using a numerical method.The pressure difference between the continuous and dispersed phases can indicate the droplet-generation period. The pressure along the channel of the droplet flow is affected by the position of droplets, droplet-generation period, and droplet escape from the outlet. The varying pressures along the channel cause a nonuniform deformation of the wall when they are elastic. The deformation is a vibration and has the same period as the droplet generation arising from the process of droplet formation.
基金support from the Technology Pillar Program during the"Eleventh Five-year Plan"Period (No.2006BAB05B02No.2006BAB05B03) are acknowledged
文摘According to the measured data after impoundment and operation of the Three Gorges Reservoir,the reservoir sediment deposition and downstream river channel scouring are described briefly and compared with the research results achieved in the demonstration stage.It is indicated through analysis that the reservoir sediment deposition and downstream river channel scouring during 8-year impoundment and operation are still within the original forecast,so the original forecasting results are feasible.The further observation and comparison should be conducted because the comparison between the observed data and the original forecast is not so sufficient in time and the prototype observation and related research work should be strengthened in the future.
文摘1 Production and Running Status of China＇s Refractories Industry in 2013 1.1 Refractories Output In 2013, China＇ s refractories output was 29. 283 million tons increasing by 3.88% YOY; in which the outputs of dense shaped refractory products, insulating refractory products, monolithic refractories were 17.307 million tons increasing by 5.93% YOY, 557.3 thousand tons decreasing by 2.67% YOY and 11. 418 million tons increasing by 1.24% YOY, respectively.
基金Supported by the 863 Programof China (2001AA242111)
文摘On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations （St. Venant equations here） and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy.
基金National Natural Science Foundation of China(No.10376003)
文摘Plasma behaviour and the scaling relations in a coaxial plasma opening switch （POS） using hydrogen plasma are studied self-consistently based on the two-dimensional magnetohydrodynamic （MHD） equations in conjunction with the generalized Ohm＇s law. The vacuum region on the right of POS is included in the model and the influence of downstream flow on the conduction characteristics is discussed. It is found that with the penetration of magnetic field, the pure hydrogen plasma is pushed downstream significantly; and POS still conducts current after the magnetic field arrives at the load edge of POS, which is different from the previous experimental results in a multispecies POS. It is because that the noticeable downstream plasma in the pure hydrogen POS may continue to conduct the current, while in the multispecies POS, the downstream plasma is unimportant so that the conduction phase ends soon after the magnetic field reaches the load edge. The scaling relation obtained from the simulations including the downstream region is consistent with the experimental results.
