Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization ...Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization of EFIs.Al/Ni RMF with different bilayer thicknesses and bridge dimensions were prepared by MEMS technology and electrical explosion tests were carried out.According to physical and chemical reactions in bridge,the electrical explosion process was divided into 5 stages:heating of condensed bridge,vaporization and diffusion of Al layers,intermetallic combination reaction,intrinsic explosion,ionization of metal gases,which are obviously shown in measured voltage curve.Effects of interface and grain boundary scattering on the resistivity of film metal were considered.Focusing on variations of substance and state,the resistivity was developed as a function of temperature at each stage.Electrical explosion curves were calculated by this model at different bilayer thicknesses,bridge dimensions and capacitor voltages,which showed an excellent agreement with experimental ones.展开更多
The capacitance-resistance model (CRM) is an alternative to conventional reservoir simulation. CRM, a simplification of complex numerical models, uses production and injection rates to infer a reservoir description....The capacitance-resistance model (CRM) is an alternative to conventional reservoir simulation. CRM, a simplification of complex numerical models, uses production and injection rates to infer a reservoir description. There is no prior geologic model. The principal output of CRM fitting is the fraction of injected fluid (usually water) that is produced at a producer at steady-state. These fractions are interwell connectivities. Interwell connectivities are fundamental information needed to manage waterfloods in oil reservoirs. The data-driven CRM is a fast tool to estimate these parameters in mature fields and allows one to make full use of the dynamic data available. This paper considers the problem of setting an upper bound on the uncertainty of interwell connectivities for linear-constrained models. Using analytical bounds and numerical simulations, we derive a consistent upper limit on the uncertainty of interwell connections that can be used to quantify the information content of a given dataset.展开更多
The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with th...The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with the increase of the plasma temperature. The significant discriminations among them appear at the plasma temperature lower than 2.5 eV, and the maximum gap of the pulsed inductive plasma accelerated efficiency is approximately 2.5%.Moreover, the pulsed inductive plasma accelerated efficiency is absolutely related to the dynamic impedance parameters, such as voltage, inductance, capacitance and flow rate. However, the distribution of the efficiency as a function of plasma temperature with three resistivity models has nothing to do with the dynamic impedance parameter.展开更多
Background: Animal models of diet-induced obesity(DIO) are commonly used in medical research for mimicking human diseases. There is no universal animal model, and careful evaluation of variety of factors needs to be c...Background: Animal models of diet-induced obesity(DIO) are commonly used in medical research for mimicking human diseases. There is no universal animal model, and careful evaluation of variety of factors needs to be considered when designing new experiments. Here, we investigated the effect of 9 weeks high-fat diet(HFD) intervention, providing 60% energy from fat, on parameters of inflammation and insulin resistance in male C57 BL/6 J mice.Methods: Six weeks old mice were initiated on regular diet(RD) or HFD providing 60 kcal energy from fat for 9 weeks. Fasting blood glucose levels were measured by glucometer, and fasting plasma levels of insulin and proinflammatory cytokines by Luminex assay. Insulin sensitivity was evaluated by using QUICKI and HOMA2 indexes.Results: HFD mice showed ~ 40% higher body weight and ~ 20% larger abdominal circumference, due to an increase in the white adipose tissue mass. Liver examination revealed increased size and higher hepatic lipid accumulation in livers from HFD mice compared to their RD counterparts. Animals from the HFD group were characterized with significantly higher presence of crown-like structures(CLS) in WAT and higher plasma levels of proinflammatory cytokines(TNF-α, IL-6, leptin, MCP-1, PAI-1, and resistin). HFD-fed mice also demonstrated impaired insulin sensitivity(lower QUICKI, higher HOMA-insulin resistance(HOMA-IR), and lower HOMA-percent sensitivity(HOMA-%S)) index values.Conclusion: Male C57 BL/6 J mice on 9 weeks HFD providing 60 kcal energy from fat display impaired insulin sensitivity and chronic inflammation, thus making this DIO mouse model appropriate for studies of early stages of obesity-related pathology.展开更多
Interwell connectivities are fundamental parameters required to manage waterfloods in oil reservoirs. Data-driven models, such as the capacitance-resistance model (CRM), are fast tools to estimate these parameters f...Interwell connectivities are fundamental parameters required to manage waterfloods in oil reservoirs. Data-driven models, such as the capacitance-resistance model (CRM), are fast tools to estimate these parameters from time-correlations of input (injection rates) and output (production rates) signals. Noise and structure of the input time-series impose limits on the information that can be extracted from a given data-set. This work uses the CRM to study general prescriptions for the design of input signals that enhance the information content of injection/production data in the estimation of well-to-well interactions. Numerical schemes and general features of the optimal input signal strategy are derived for this problem.展开更多
As an important and typical arid inland region in China,Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment,whose ecological land suitability restricts the develop...As an important and typical arid inland region in China,Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment,whose ecological land suitability restricts the development of the local human activities.Therefore,Shiyang River Basin was selected as the case study,the minimum cumulative resistance(MCR)model and GIS technique were integrated to create land suitability evaluation map.We calculated the MCR value of ecological source and living source,and divided the whole basin into five partitions according to the difference between ecological source and living source,and analyzed the patterns and characteristics of the ecological land suitability evaluation(ELSE)regions,respectively.The results showed that:1)The suitable ecological land includes prohibited development region and restricted development region,which accounts for 15.45%and 23.35%of the total land area of the Shiyang River Basin,respectively.These two regions mainly distributed high altitude region in the southern Qilian Mountain and low altitude region where had high density of rivers.2)The protection of ecological land requires not only conserving existing ecological land but also focusing on ecological buffer belts around ecological sources and improving ecological land service ability.3)Ecological networks should be constructed through artificial planting trees around the boundary of oasis and ecological restoration region.Buffer greenbelts should also be established between optimized development region and ecological restoration region.展开更多
The aphid quantity ratio(AQR) is defined as the number of aphids on each cultivar divided by the number of aphids on all cultivars. AQR is based on the correlation between aphid populations and their host plants and...The aphid quantity ratio(AQR) is defined as the number of aphids on each cultivar divided by the number of aphids on all cultivars. AQR is based on the correlation between aphid populations and their host plants and is an important tool that has been utilized in evaluating Medicago sativa(alfalfa) cultivar resistance to aphids. However, assessment of alfalfa resistance to aphids can be confused by the presence of aphid predators, causing the assessment of plant resistance to aphids to be based on incorrect aphid population data. To refine the AQR and account for the effect of predators on aphid population assessments, we introduced a parameter ‘α', corresponding to the predator quantity ratio, and used αAQR as the ratio to quantify aphid populations. Populations of both aphids(4 species) and their predators(12 species) occurring in 28 M. sativa cultivars were sampled over two years at a research station near Cangzhou, Hebei Province, China. Results showed that the most suitable evaluation period was from May to June, as the aphid population was stable during this period. Compared with the AQR method, the predator population numbers based on the αAQR had a significant inverse relationship with aphid population numbers and the 28 cultivars were clustered into three classes: the resistant class, tolerant class, and susceptible class. In addition, 17 cultivars were reassigned when evaluated using αAQR. All numerical values calculated by αAQR were displayed as a Gaussian distribution, which showed that the 28 cultivars could be clustered into nine groups using a median value(±SE) of 1±0.1. Hence, ongoing alfalfa breeding trials will be assessed using the αAQR to establish a robust system that includes agronomic performance parameters in order to generalize the new method for further studies.展开更多
The ductility map of 304HC stainless was determined by using the Gleeble-1500 dynamic thermal-mechanical simulator. The effect of Cu on the hot ductility of 304HC stainless steel was analyzed and the mathematical mode...The ductility map of 304HC stainless was determined by using the Gleeble-1500 dynamic thermal-mechanical simulator. The effect of Cu on the hot ductility of 304HC stainless steel was analyzed and the mathematical model of resistance to deformation was established. The microstructure, inclusion and fracture surface were studied by using the method of micro structure analysis, scanning, energy spectrum and electron microscope. The results show that Cu has effect on the hot ductility, and the hot ductility of 304HC stainless steel decrease with the increase of content of Cu. The deformation temperature also has much effect on the hot ductility, the suitable deformation temperature are 1100-1200℃. The reason of it is that the Cu rich chemical compounds were precipitated from austenite phase during cooling. The Cu rich chemical compounds are brittle substance such as Cu2S, Cu2O and ε-Cu etc.展开更多
The numerical solution of Green’s function for the potential in 2-D arbitrary in-homogeneous media with axial symmetry has been given by use of efficient half-analytical, half-numerical hybrid method. Then the loggin...The numerical solution of Green’s function for the potential in 2-D arbitrary in-homogeneous media with axial symmetry has been given by use of efficient half-analytical, half-numerical hybrid method. Then the logging responses of various kinds of the DC resistivity log with axisymmetric excitation have been obtained by using surface integral equation method to match the boundary conditions on the electrodes of the logging sonde. Comparing the results with that obtained by other methods, one can see good precision and efficiency of the given method. Some applications of the numerical modeling have been also discussed.展开更多
The linear evolution of a resistive wall mode(RWM)with magnetic shears was analytically studied in a cylindrical geometry.The incompressible magnetohydrodynamic(MHD)equations were solved by the Fourier analysis method...The linear evolution of a resistive wall mode(RWM)with magnetic shears was analytically studied in a cylindrical geometry.The incompressible magnetohydrodynamic(MHD)equations were solved by the Fourier analysis method,and various equilibrium magnetic fields were considered.The shear in the magnetic field had an unstable effect on the linear evolution of the RWM.The linear growth rate increased obviously with increase of the magnetic shear rate for higher magnetic shears.Slow plasma rotation could stabilize the RWM with low magnetic shears,but the plasma rotation could not stabilize the RWM with high magnetic shears.The stabilizing effects of the wall conductivity on the RWM are more efficient for lager magnetic shear.展开更多
Homology models of the ligand binding domain of the wild-type and Y151S mutant brown planthopper {Nilaparvata lugens)α1 and rat(Rattus norvegicus)β2 nicotinic acetylcholine receptor(nAChR) subunits were generated ba...Homology models of the ligand binding domain of the wild-type and Y151S mutant brown planthopper {Nilaparvata lugens)α1 and rat(Rattus norvegicus)β2 nicotinic acetylcholine receptor(nAChR) subunits were generated based on the crystal structure of acetylcholine binding protein of Lymnaea stagnalis.Neonicotinoid insecticide imidacloprid was docked into the putative binding site of wild-type and mutantα1β2 dimeric receptors by Surflex-docking,and the calculated docking energies were in agreement with experimen...展开更多
With the progress of the semiconductor industry, resistive memories, especially the memristor, have drawn increasing attention. The resistive memory based on memrsitor has not been commercialized mainly because of dat...With the progress of the semiconductor industry, resistive memories, especially the memristor, have drawn increasing attention. The resistive memory based on memrsitor has not been commercialized mainly because of data error. Currently, there are more studies focused on fault tolerance of resistive memory. This paper studies the resistive switching mechanism which may have time-varying characteristics. Resistive switching mechanism is analyzed and its respective circuit model is established based on the memristor Spice model.展开更多
With the progress of the semiconductor industry,the resistive random-access memory(RAM) has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on ...With the progress of the semiconductor industry,the resistive random-access memory(RAM) has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.展开更多
Based on 30MnSiV steel, the deformation resistance was studied by using Gleeble 1500 thermomechanical simulator. The mathematical model of the deformation resistance is established by analyzing the relationship of the...Based on 30MnSiV steel, the deformation resistance was studied by using Gleeble 1500 thermomechanical simulator. The mathematical model of the deformation resistance is established by analyzing the relationship of the deformation temperature, deformation rate and deformation resistance. The regression equation is highly noticeable by means of regression analysis. The mathematical model corresponds to test data by means of the contrast.展开更多
The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in se...The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in seven crosses of C224 with maintainer lines.The results showed that the stripe resistance of C224 was controlled by two major genes with additive-dominance-epistasis effects plus polygenes with additive-dominance effects (E-1 model).These two genes had additive effects of-12.47% and-24.75%,respectively,showing negative dominance effects.There were significant epistasis and interaction effects between the two major genes.The heritability of the two major genes was 92.12%,while that of polygenes was 2.74%,indicating that the stripe resistance had dominant major gene effect.Of the seven crosses,five displayed high or medium resistance to the stripe disease.展开更多
<span style="font-family:Verdana;">Several studies on PV solar cells are found in</span> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><...<span style="font-family:Verdana;">Several studies on PV solar cells are found in</span> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">literature which use static models. Those models are mainly one-diode, two-diode or three-diode models. In the dynamic modelling</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> a variable parallel capacitance is incorporated. Unlike the previous studies which do not clearly establish a relationship between the capacitance and the voltage, in the present paper, the link between the capacitance and the voltage is investigated and established. In dynamic modelling investigated in this paper, the dynamic resistance is introduced in the modelling of the solar cell. It is introduced in the current-voltage characteristic. The value of the dynamic resistance is evaluated at the maximum po</span><span style="font-family:Verdana;">wer point and its effect on the maximum power is investigated. The study</span> <span style="font-family:Verdana;">shows for the first time, that the dynamic resistance must be introduced in</span> <span style="font-family:Verdana;">the current-voltage characteristic, because it has an influence on the PV cell </span><span style="font-family:Verdana;">output</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span>展开更多
Multidrug resistance protein 5 (MRP5/ABCC5) is a 161 kDa member of the super family of ATP-binding cassette (ABC) superfamily of transmembrane transporters that is clinically relevant for its ability to confer multidr...Multidrug resistance protein 5 (MRP5/ABCC5) is a 161 kDa member of the super family of ATP-binding cassette (ABC) superfamily of transmembrane transporters that is clinically relevant for its ability to confer multidrug resistance by actively e?uxing anticancer drugs. ABCC5 has also been identified as an efflux transporter of cGMP (cyclic guanosine monophosphate). Elevated intracellular levels of cGMP in cancer cells have been implicated in several clinical studies, that may induce apoptosis, and as a result many different cancer cells seem to overcome this deleterious effect by increased efflux of cGMP through ABCC5. Thus inhibition of ABCC5 may have cytotoxic effects mediated through cGMP and it will also increase the intracellular concentration of other drugs that are aimed for the treatment of cancer which are otherwise exported out of the cells. Considering the functional importance and lack of X-ray crystal structure of ABCC5, present work was undertaken to construct 3D structure of protein using homology modeling protocol of YASARA structure (V. 16.3.28). In this study, five different ABC templates (PDB ID’s: 4F4C, 4Q9H, 4M1M, 4M2T and 4KSD) were used for homology modeling. Five models were constructed on each template and a hybrid model was built using all five templates. All models were refined and ranked as per their overall Z-score. The top ranked ABBC5 model was based on template 4Q9H that had 91.2% of residues in allowed regions as revealed by PROCHECK-NMR and the QMEAN score was 0.54 which indicated a reliable model. The results of the study and the proposed model can be further used for elucidating the structural and functional aspects of ABCC5 and to gain more insights to the molecular basis of ABCC5 inhibition through docking studies.展开更多
A numerical study on the multi-parameter control method based on nonlinear auto-regressive with exogenous input neural network (NARX) is presented here. Welding current was set as the input parameter; electrode disp...A numerical study on the multi-parameter control method based on nonlinear auto-regressive with exogenous input neural network (NARX) is presented here. Welding current was set as the input parameter; electrode displacement and dynamic resistance were set us the output parameters. The NARX model using these parameters was set up to simulate the multi-parameter resistance spot welding process. By comparing actual experimental data and NARX model output data, it was validated that the results from the model reflect the relationship between input parameter and output parameters correctly under the influence of many affecting factors.展开更多
In order to study the high temperature flow behaviour of the V modified 2.25Cr-1Mo steel plate to guide the industrial rolling practice, the hot compression tests were carried out at the temperatures from 900 ℃ to 11...In order to study the high temperature flow behaviour of the V modified 2.25Cr-1Mo steel plate to guide the industrial rolling practice, the hot compression tests were carried out at the temperatures from 900 ℃ to 1150 ℃ and the strain rates from 0.01s^-1 to 1 s^-1 on Thermecmastor-Z equipment. Based on the experimental data of the hot compression tests, a kind of Arrhenius-type constitutive equation was developed.The equation can accurately show the relationship between the flow stress and the deformation temperature, the strain and the strain rate. The measured true stress-true strain curves exhibit two kinds of flow stress curves. Moreover, the forming mechanisms of these two types curves were explained by softening, wok hardening theory as well as metallographic and hardness experimental results. The accuracy of the developed Arrheniustype constitutive equation was identified by three kinds of statistic parameters and also by comparison of the measured and predicted data. The reasonable value of the three types of statistic parameters and the good agreement between the experimental and predicted data can confirm the validity of the developed Arrheniustype constitutive equation for V modified 2.25 Cr-1 Mo heat resistant steel plate.展开更多
基金National Natural Science Foundation of China(Grant No.11872013)for supporting this project.
文摘Al/Ni reactive multilayer foil(RMF)possesses excellent comprehensive properties as a promising substitute for traditional Cu bridge.A theoretical resistivity model of Al/Ni RMF was developed to guide the optimization of EFIs.Al/Ni RMF with different bilayer thicknesses and bridge dimensions were prepared by MEMS technology and electrical explosion tests were carried out.According to physical and chemical reactions in bridge,the electrical explosion process was divided into 5 stages:heating of condensed bridge,vaporization and diffusion of Al layers,intermetallic combination reaction,intrinsic explosion,ionization of metal gases,which are obviously shown in measured voltage curve.Effects of interface and grain boundary scattering on the resistivity of film metal were considered.Focusing on variations of substance and state,the resistivity was developed as a function of temperature at each stage.Electrical explosion curves were calculated by this model at different bilayer thicknesses,bridge dimensions and capacitor voltages,which showed an excellent agreement with experimental ones.
基金YPF for financial support and to the Center for Petroleum Asset Risk Management of the University of Texas at Austin for hospitality and an exciting research environment
文摘The capacitance-resistance model (CRM) is an alternative to conventional reservoir simulation. CRM, a simplification of complex numerical models, uses production and injection rates to infer a reservoir description. There is no prior geologic model. The principal output of CRM fitting is the fraction of injected fluid (usually water) that is produced at a producer at steady-state. These fractions are interwell connectivities. Interwell connectivities are fundamental information needed to manage waterfloods in oil reservoirs. The data-driven CRM is a fast tool to estimate these parameters in mature fields and allows one to make full use of the dynamic data available. This paper considers the problem of setting an upper bound on the uncertainty of interwell connectivities for linear-constrained models. Using analytical bounds and numerical simulations, we derive a consistent upper limit on the uncertainty of interwell connections that can be used to quantify the information content of a given dataset.
基金Supported by the Fund of Science and Technology on Vacuum Technology and Physics Laboratory of Lanzhou Institute of Physics under Grant No YSC0715the National Natural Science Foundation of China under Grant No 62601210the Civil Aerospace Technology Research Project under Grant No D010509
文摘The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with the increase of the plasma temperature. The significant discriminations among them appear at the plasma temperature lower than 2.5 eV, and the maximum gap of the pulsed inductive plasma accelerated efficiency is approximately 2.5%.Moreover, the pulsed inductive plasma accelerated efficiency is absolutely related to the dynamic impedance parameters, such as voltage, inductance, capacitance and flow rate. However, the distribution of the efficiency as a function of plasma temperature with three resistivity models has nothing to do with the dynamic impedance parameter.
基金Gerald J.and Dorothy R.Friedman New York Foundation for Medical Research
文摘Background: Animal models of diet-induced obesity(DIO) are commonly used in medical research for mimicking human diseases. There is no universal animal model, and careful evaluation of variety of factors needs to be considered when designing new experiments. Here, we investigated the effect of 9 weeks high-fat diet(HFD) intervention, providing 60% energy from fat, on parameters of inflammation and insulin resistance in male C57 BL/6 J mice.Methods: Six weeks old mice were initiated on regular diet(RD) or HFD providing 60 kcal energy from fat for 9 weeks. Fasting blood glucose levels were measured by glucometer, and fasting plasma levels of insulin and proinflammatory cytokines by Luminex assay. Insulin sensitivity was evaluated by using QUICKI and HOMA2 indexes.Results: HFD mice showed ~ 40% higher body weight and ~ 20% larger abdominal circumference, due to an increase in the white adipose tissue mass. Liver examination revealed increased size and higher hepatic lipid accumulation in livers from HFD mice compared to their RD counterparts. Animals from the HFD group were characterized with significantly higher presence of crown-like structures(CLS) in WAT and higher plasma levels of proinflammatory cytokines(TNF-α, IL-6, leptin, MCP-1, PAI-1, and resistin). HFD-fed mice also demonstrated impaired insulin sensitivity(lower QUICKI, higher HOMA-insulin resistance(HOMA-IR), and lower HOMA-percent sensitivity(HOMA-%S)) index values.Conclusion: Male C57 BL/6 J mice on 9 weeks HFD providing 60 kcal energy from fat display impaired insulin sensitivity and chronic inflammation, thus making this DIO mouse model appropriate for studies of early stages of obesity-related pathology.
基金financial support and to the Center for Petroleum Asset Risk Management of the University of Texas at Austin for hospitality and an exciting research environment
文摘Interwell connectivities are fundamental parameters required to manage waterfloods in oil reservoirs. Data-driven models, such as the capacitance-resistance model (CRM), are fast tools to estimate these parameters from time-correlations of input (injection rates) and output (production rates) signals. Noise and structure of the input time-series impose limits on the information that can be extracted from a given data-set. This work uses the CRM to study general prescriptions for the design of input signals that enhance the information content of injection/production data in the estimation of well-to-well interactions. Numerical schemes and general features of the optimal input signal strategy are derived for this problem.
基金Under the auspices of National Natural Science Foundation of China(No.41861040,41761047)。
文摘As an important and typical arid inland region in China,Shiyang River Basin plays an important role in maintaining the sustainable development of eco-environment,whose ecological land suitability restricts the development of the local human activities.Therefore,Shiyang River Basin was selected as the case study,the minimum cumulative resistance(MCR)model and GIS technique were integrated to create land suitability evaluation map.We calculated the MCR value of ecological source and living source,and divided the whole basin into five partitions according to the difference between ecological source and living source,and analyzed the patterns and characteristics of the ecological land suitability evaluation(ELSE)regions,respectively.The results showed that:1)The suitable ecological land includes prohibited development region and restricted development region,which accounts for 15.45%and 23.35%of the total land area of the Shiyang River Basin,respectively.These two regions mainly distributed high altitude region in the southern Qilian Mountain and low altitude region where had high density of rivers.2)The protection of ecological land requires not only conserving existing ecological land but also focusing on ecological buffer belts around ecological sources and improving ecological land service ability.3)Ecological networks should be constructed through artificial planting trees around the boundary of oasis and ecological restoration region.Buffer greenbelts should also be established between optimized development region and ecological restoration region.
基金funded by the earmarked fund for China Agriculture Research System (CARS-34-07)the National Department of Public Benefit Research Foundation, China (201303057)
文摘The aphid quantity ratio(AQR) is defined as the number of aphids on each cultivar divided by the number of aphids on all cultivars. AQR is based on the correlation between aphid populations and their host plants and is an important tool that has been utilized in evaluating Medicago sativa(alfalfa) cultivar resistance to aphids. However, assessment of alfalfa resistance to aphids can be confused by the presence of aphid predators, causing the assessment of plant resistance to aphids to be based on incorrect aphid population data. To refine the AQR and account for the effect of predators on aphid population assessments, we introduced a parameter ‘α', corresponding to the predator quantity ratio, and used αAQR as the ratio to quantify aphid populations. Populations of both aphids(4 species) and their predators(12 species) occurring in 28 M. sativa cultivars were sampled over two years at a research station near Cangzhou, Hebei Province, China. Results showed that the most suitable evaluation period was from May to June, as the aphid population was stable during this period. Compared with the AQR method, the predator population numbers based on the αAQR had a significant inverse relationship with aphid population numbers and the 28 cultivars were clustered into three classes: the resistant class, tolerant class, and susceptible class. In addition, 17 cultivars were reassigned when evaluated using αAQR. All numerical values calculated by αAQR were displayed as a Gaussian distribution, which showed that the 28 cultivars could be clustered into nine groups using a median value(±SE) of 1±0.1. Hence, ongoing alfalfa breeding trials will be assessed using the αAQR to establish a robust system that includes agronomic performance parameters in order to generalize the new method for further studies.
基金This study was financially supported by both the National Natural Science Founda- tion of China (Grant No.59995440)the Natural Science Foundation of Liaoning Province (Grant No.2001101021).
文摘The ductility map of 304HC stainless was determined by using the Gleeble-1500 dynamic thermal-mechanical simulator. The effect of Cu on the hot ductility of 304HC stainless steel was analyzed and the mathematical model of resistance to deformation was established. The microstructure, inclusion and fracture surface were studied by using the method of micro structure analysis, scanning, energy spectrum and electron microscope. The results show that Cu has effect on the hot ductility, and the hot ductility of 304HC stainless steel decrease with the increase of content of Cu. The deformation temperature also has much effect on the hot ductility, the suitable deformation temperature are 1100-1200℃. The reason of it is that the Cu rich chemical compounds were precipitated from austenite phase during cooling. The Cu rich chemical compounds are brittle substance such as Cu2S, Cu2O and ε-Cu etc.
基金Supported by the National Natural Science FoundatiOn of China
文摘The numerical solution of Green’s function for the potential in 2-D arbitrary in-homogeneous media with axial symmetry has been given by use of efficient half-analytical, half-numerical hybrid method. Then the logging responses of various kinds of the DC resistivity log with axisymmetric excitation have been obtained by using surface integral equation method to match the boundary conditions on the electrodes of the logging sonde. Comparing the results with that obtained by other methods, one can see good precision and efficiency of the given method. Some applications of the numerical modeling have been also discussed.
基金National Science Foundation of Shangong Province of China(No.ZR2016AM30)National Natural Science Foundation of China(No.11875290)Foundation of Shandong Province Higher Educational Science and Technology Program,China(No.J15LN15)
文摘The linear evolution of a resistive wall mode(RWM)with magnetic shears was analytically studied in a cylindrical geometry.The incompressible magnetohydrodynamic(MHD)equations were solved by the Fourier analysis method,and various equilibrium magnetic fields were considered.The shear in the magnetic field had an unstable effect on the linear evolution of the RWM.The linear growth rate increased obviously with increase of the magnetic shear rate for higher magnetic shears.Slow plasma rotation could stabilize the RWM with low magnetic shears,but the plasma rotation could not stabilize the RWM with high magnetic shears.The stabilizing effects of the wall conductivity on the RWM are more efficient for lager magnetic shear.
文摘Homology models of the ligand binding domain of the wild-type and Y151S mutant brown planthopper {Nilaparvata lugens)α1 and rat(Rattus norvegicus)β2 nicotinic acetylcholine receptor(nAChR) subunits were generated based on the crystal structure of acetylcholine binding protein of Lymnaea stagnalis.Neonicotinoid insecticide imidacloprid was docked into the putative binding site of wild-type and mutantα1β2 dimeric receptors by Surflex-docking,and the calculated docking energies were in agreement with experimen...
基金Project supported by the National Natural Science Foundation of China(Grant No.60921062)
文摘With the progress of the semiconductor industry, resistive memories, especially the memristor, have drawn increasing attention. The resistive memory based on memrsitor has not been commercialized mainly because of data error. Currently, there are more studies focused on fault tolerance of resistive memory. This paper studies the resistive switching mechanism which may have time-varying characteristics. Resistive switching mechanism is analyzed and its respective circuit model is established based on the memristor Spice model.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60921062)
文摘With the progress of the semiconductor industry,the resistive random-access memory(RAM) has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.
文摘Based on 30MnSiV steel, the deformation resistance was studied by using Gleeble 1500 thermomechanical simulator. The mathematical model of the deformation resistance is established by analyzing the relationship of the deformation temperature, deformation rate and deformation resistance. The regression equation is highly noticeable by means of regression analysis. The mathematical model corresponds to test data by means of the contrast.
基金supported by the Guiding Plans for Natural Sciences Foundation of Liaoning Province,China(Grant No.20092207)the Special Foundation for Young Scientists of Liaoning Rice Research Institute,Shenyang,China(Grant No.DZS-2008-1)
文摘The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in seven crosses of C224 with maintainer lines.The results showed that the stripe resistance of C224 was controlled by two major genes with additive-dominance-epistasis effects plus polygenes with additive-dominance effects (E-1 model).These two genes had additive effects of-12.47% and-24.75%,respectively,showing negative dominance effects.There were significant epistasis and interaction effects between the two major genes.The heritability of the two major genes was 92.12%,while that of polygenes was 2.74%,indicating that the stripe resistance had dominant major gene effect.Of the seven crosses,five displayed high or medium resistance to the stripe disease.
文摘<span style="font-family:Verdana;">Several studies on PV solar cells are found in</span> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">literature which use static models. Those models are mainly one-diode, two-diode or three-diode models. In the dynamic modelling</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> a variable parallel capacitance is incorporated. Unlike the previous studies which do not clearly establish a relationship between the capacitance and the voltage, in the present paper, the link between the capacitance and the voltage is investigated and established. In dynamic modelling investigated in this paper, the dynamic resistance is introduced in the modelling of the solar cell. It is introduced in the current-voltage characteristic. The value of the dynamic resistance is evaluated at the maximum po</span><span style="font-family:Verdana;">wer point and its effect on the maximum power is investigated. The study</span> <span style="font-family:Verdana;">shows for the first time, that the dynamic resistance must be introduced in</span> <span style="font-family:Verdana;">the current-voltage characteristic, because it has an influence on the PV cell </span><span style="font-family:Verdana;">output</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">.</span></span></span>
文摘Multidrug resistance protein 5 (MRP5/ABCC5) is a 161 kDa member of the super family of ATP-binding cassette (ABC) superfamily of transmembrane transporters that is clinically relevant for its ability to confer multidrug resistance by actively e?uxing anticancer drugs. ABCC5 has also been identified as an efflux transporter of cGMP (cyclic guanosine monophosphate). Elevated intracellular levels of cGMP in cancer cells have been implicated in several clinical studies, that may induce apoptosis, and as a result many different cancer cells seem to overcome this deleterious effect by increased efflux of cGMP through ABCC5. Thus inhibition of ABCC5 may have cytotoxic effects mediated through cGMP and it will also increase the intracellular concentration of other drugs that are aimed for the treatment of cancer which are otherwise exported out of the cells. Considering the functional importance and lack of X-ray crystal structure of ABCC5, present work was undertaken to construct 3D structure of protein using homology modeling protocol of YASARA structure (V. 16.3.28). In this study, five different ABC templates (PDB ID’s: 4F4C, 4Q9H, 4M1M, 4M2T and 4KSD) were used for homology modeling. Five models were constructed on each template and a hybrid model was built using all five templates. All models were refined and ranked as per their overall Z-score. The top ranked ABBC5 model was based on template 4Q9H that had 91.2% of residues in allowed regions as revealed by PROCHECK-NMR and the QMEAN score was 0.54 which indicated a reliable model. The results of the study and the proposed model can be further used for elucidating the structural and functional aspects of ABCC5 and to gain more insights to the molecular basis of ABCC5 inhibition through docking studies.
文摘A numerical study on the multi-parameter control method based on nonlinear auto-regressive with exogenous input neural network (NARX) is presented here. Welding current was set as the input parameter; electrode displacement and dynamic resistance were set us the output parameters. The NARX model using these parameters was set up to simulate the multi-parameter resistance spot welding process. By comparing actual experimental data and NARX model output data, it was validated that the results from the model reflect the relationship between input parameter and output parameters correctly under the influence of many affecting factors.
基金Funded by the New Product Research Program(No.X18ECQ0A00)of Baoshan Iron&Steel Co.Ltd.
文摘In order to study the high temperature flow behaviour of the V modified 2.25Cr-1Mo steel plate to guide the industrial rolling practice, the hot compression tests were carried out at the temperatures from 900 ℃ to 1150 ℃ and the strain rates from 0.01s^-1 to 1 s^-1 on Thermecmastor-Z equipment. Based on the experimental data of the hot compression tests, a kind of Arrhenius-type constitutive equation was developed.The equation can accurately show the relationship between the flow stress and the deformation temperature, the strain and the strain rate. The measured true stress-true strain curves exhibit two kinds of flow stress curves. Moreover, the forming mechanisms of these two types curves were explained by softening, wok hardening theory as well as metallographic and hardness experimental results. The accuracy of the developed Arrheniustype constitutive equation was identified by three kinds of statistic parameters and also by comparison of the measured and predicted data. The reasonable value of the three types of statistic parameters and the good agreement between the experimental and predicted data can confirm the validity of the developed Arrheniustype constitutive equation for V modified 2.25 Cr-1 Mo heat resistant steel plate.