In this work,the discharge properties and electrochemical behaviors of as-cast AZ80-La-Gd anode for Mg-air battery have been investigated and compared with the AZ80 anode.The microstructure evolution,electrochemical b...In this work,the discharge properties and electrochemical behaviors of as-cast AZ80-La-Gd anode for Mg-air battery have been investigated and compared with the AZ80 anode.The microstructure evolution,electrochemical behaviors and surface morphologies after discharge have been discussed to connect the discharge properties.The results indicate that the modified AZ80-La-Gd is an outstanding candidate for anode for Mg-air batter,which has high cell voltage,stable discharge curves,good specific capacity and energy,and good anodic efficiency.It exhibits the best anodic efficiency,specific capacity and energy of 76.45%,1703.6 mAh·g^(-1)and 2186.3 mWh·g^(-1),respectively,which are20.24%,18.92%and 25.71%higher than values for AZ80 anode.Such excellent discharge performance is attributed to the Al-RE particles.They refine the Mg_(17)Al_(12)phase and therefore improve the self-corrosion resistance and desorption ability of AZ80 anode.展开更多
Based on plasticity theory and physical experiments, the quantitative relationships between elongation δ obtained byuniaxial tensile test and forming limits of tensile stamping operations are given, which mainly reso...Based on plasticity theory and physical experiments, the quantitative relationships between elongation δ obtained byuniaxial tensile test and forming limits of tensile stamping operations are given, which mainly resolves the problem thatforming limits can be derived from simple tensile test. The forming limit nomogram of tensile stamping operationsis also established to apply to engineering.展开更多
As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory...As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory and practice meaning of the technology alliance, cooperative game method is used to analyze the forming process of the cooperative mechanism, and it points out that cooperation will make both sides get the largest benefits.展开更多
This text combines authors＇ visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates ＂three culture e...This text combines authors＇ visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates ＂three culture effects＂ of Park development in terms of cultural system emphatically, then proposes some suggestions of cultural innovation in the Park of China.展开更多
For maritime radiation source target tracking in particular electronic counter measures（ECM）environment,there exists two main problems which can deteriorate the tracking performance of traditional approaches.The frs...For maritime radiation source target tracking in particular electronic counter measures（ECM）environment,there exists two main problems which can deteriorate the tracking performance of traditional approaches.The frst problem is the poor observability of the radiation source.The second one is the measurement uncertainty which includes the uncertainty of the target appearing/disappearing and the detection uncertainty（false and missed detections）.A novel approach is proposed in this paper for tracking maritime radiation source in the presence of measurement uncertainty.To solve the poor observability of maritime radiation source target,using the radiation source motion restriction,the observer altitude information is incorporated into the bearings-only tracking（BOT）method to obtain the unique target localization.Then the two uncertainties in the ECM environment are modeled by the random fnite set（RFS）theory and the Bernoulli fltering method with the observer altitude is adopted to solve the tracking problem of maritime radiation source in such context.Simulation experiments verify the validity of the proposed approach for tracking maritime radiation source,and also demonstrate the superiority of the method compared with the traditional integrated probabilistic data association（IPDA）method.The tracking performance under different conditions,particularly those involving different duration of radiation source opening and switching-off,indicates that the method to solve our problem is robust and effective.展开更多
With the reform of the state-owned enterprises, the level of the human resources management of a lot of state-owned enterprises has been gradually improved. However, because of the macroscopic system, history, culture...With the reform of the state-owned enterprises, the level of the human resources management of a lot of state-owned enterprises has been gradually improved. However, because of the macroscopic system, history, culture and their own reasons, there are still a series of problems in the human resources management of state-owned enterprises. In order to promote the reform of state-owned enterprises and to improve the competitiveness of enterprises, we should critically research these urgent problems. The paper will take an example of one company which was investigated by state-owned enterprises will be listed and analysed. the author, and the common problems which exist in most state-owned enterprises will be listed and analysed.展开更多
Just as the regional economy and city economy, the industrial economy is the economic aggregation lying in between the macroeconomy and microeconomy. Mesoeconomic management is the extension of the macroeconomic manag...Just as the regional economy and city economy, the industrial economy is the economic aggregation lying in between the macroeconomy and microeconomy. Mesoeconomic management is the extension of the macroeconomic management and has its own operation rules. The relationship between the macroeconomic and the mesoeconomic management is just like between the general department and the specialized department of the government while reflecting on the subject of the management. Establishment of the mesoeconomic management system is a model of the reform in the specialized economic departments of Chinese government.展开更多
In order to realize the impersonality, justness, impartiality and rationality in the awarding work of science ＆ technology, it is necessary to establish an evaluating model to make the evaluating course numeric as we...In order to realize the impersonality, justness, impartiality and rationality in the awarding work of science ＆ technology, it is necessary to establish an evaluating model to make the evaluating course numeric as well as a complete system of evaluating indexes. The theory of fuzzy mathematics is adopted in this paper to establish a multilevel fuzzy synthetical model to quantitate the evaluating index system for science ＆ technology awarding and to provide the scientific decision-making basis for science ＆ technology awarding.展开更多
The paper summarizes, contrasts and expands the definitions of Internet economics, puts forward the theory of Internet economics development stage and analyzes the reason of the development of Internet economics.
The difference of regional economy comes from capital dissymmetry, technology dissymmetry, manpower dissymmetry and the information dissymmetry. In the knowledge-based economic ages, globalization and information exce...The difference of regional economy comes from capital dissymmetry, technology dissymmetry, manpower dissymmetry and the information dissymmetry. In the knowledge-based economic ages, globalization and information exceed any age of the history. It provides the new terrace for the balanced development of global economy. The flows of capital and technology improve the regional dissymmetry of production factor. By establishing circulating channels, the flows of the production factor will be enlarged. This will raise the distribution efficiency of global resources and lead to the global economic growth.展开更多
The problem considered is the correlation between stock exchange and economy growth. Stepwise regression is being used on the following figures： increasing rate of GDP, the volume of stock market, and liquidity. As a...The problem considered is the correlation between stock exchange and economy growth. Stepwise regression is being used on the following figures： increasing rate of GDP, the volume of stock market, and liquidity. As a result, we give .an.equation of national economy and stock market. Then, we use Granger＇s Causality test to prove that the stock market has positive effects on the national economy.展开更多
Four Mg–Gd–Y–Nd–Zr alloys were prepared by mold casting to investigate the effects of Nd/Gd ratios on microstructures and mechanical properties.The as-cast alloys mainly consist ofα-Mg andβ-Mg5(GdYNd).Volume fra...Four Mg–Gd–Y–Nd–Zr alloys were prepared by mold casting to investigate the effects of Nd/Gd ratios on microstructures and mechanical properties.The as-cast alloys mainly consist ofα-Mg andβ-Mg5(GdYNd).Volume fractions of the second phase increase and grains were slightly refined with the rising Nd/Gd ratio,when the alloying addition is equal.Meanwhile,fibers of second phase also increase in the extruded alloys when the Nd/Gd value increases.However,the Nd/Gd ratio could hardly influence the mechanical properties of the extruded alloys.The aging hardening response of the extruded alloy differs due to different Nd/Gd ratios.The potential mechanisms have also been discussed in detail.展开更多
Fragility analysis for highway bridges has become increasingly important in the risk assessment of highway transportation networks exposed to seismic hazards. This study introduces a methodology to calculate fragility...Fragility analysis for highway bridges has become increasingly important in the risk assessment of highway transportation networks exposed to seismic hazards. This study introduces a methodology to calculate fragility that considers multi-dimensional performance limit state parameters and makes a first attempt to develop fragility curves for a multi-span continuous (MSC) concrete girder bridge considering two performance limit state parameters: column ductility and transverse deformation in the abutments. The main purpose of this paper is to show that the performance limit states, which are compared with the seismic response parameters in the calculation of fragility, should be properly modeled as randomly interdependent variables instead of deterministic quantities. The sensitivity of fragility curves is also investigated when the dependency between the limit states is different. The results indicate that the proposed method can be used to describe the vulnerable behavior of bridges which are sensitive to multiple response parameters and that the fragility information generated by this method will be more reliable and likely to be implemented into transportation network loss estimation.展开更多
A comprehensive two-dimensional axisymmetric mathematical model that couples transient electromagnetic force with fluid flow,heat transfer,and solidification was established to describe the interaction of multiphysics...A comprehensive two-dimensional axisymmetric mathematical model that couples transient electromagnetic force with fluid flow,heat transfer,and solidification was established to describe the interaction of multiphysics field during DC casting.The melt flow,heat transfer,and solidification characteristics under differential phase pulse magnetic field and differential phase low-frequency electromagnetic field(DP-PMF and DP-LFEF)were numerically investigated by means of numerical simulation during electromagnetic direct-chill(DC)casting of AZ31 alloy at the same casting conditions.The effects of differential phase electromagnetic fields on Lorentz forces distributions,melt flow,heat transfer,and liquid sump shape were discussed systematically.Based on measured current waveform,the results were compared with those obtained without magnetic field(MF)and under conventional pulse magnetic field(PMF)and low-frequency electromagnetic field(LFEF)under the same conditions.The results show that the application of magnetic fields can significantly change the solidification process of DC casting.Differential phase magnetic fields(DP-LFEF and DP-PMF)can effectively reduce the temperature of the melt in the liquid sump,and the shallower liquid sump depth can be obtained under the differential phase magnetic fields.A large velocity vibration amplitude and a lower temperature are available simultaneously under DP-PMF,resulting in more uniform temperature distribution.展开更多
BACKGROUND AND PURPOSE Knowledge about risk factors contributes to understanding the pathophysiological mechanisms that cause intracranial aneurysm rupture and helps to develop possible treatment strategies.We aimed t...BACKGROUND AND PURPOSE Knowledge about risk factors contributes to understanding the pathophysiological mechanisms that cause intracranial aneurysm rupture and helps to develop possible treatment strategies.We aimed to study lifestyle and personal characteristics as risk factors for the rupture of intracranial aneurysms.METHODS We performed a case-control study with 250 patients with an aneurysmal subarachnoid hemorrhage and 206 patients with an unruptured intracranial aneurysm.All patients with an aneurysmal subarachnoid hemorrhage and patients with a unruptured intracranial aneurysm were asked to fill in a structured questionnaire about their lifestyle and medical history.For patients with an unruptured intracranial aneurysm,we also collected data on the indication for imaging.With logistic regression analysis,we identified independent risk factors for aneurysmal rupture.RESULTS Reasons for imaging in patients with an unruptured intracranial aneurysm were atherosclerotic disease(23%),positive family history(18%),headache(8%),preventive screening(3%),and other(46%).Factors that increased risk for aneurysmal rupture were smoking(odds ratio,1.9;95% confidence interval,1.2-3.0) and migraine(2.4;1.1-5.1);hypercholesterolemia decreased this risk(0.4;0.2-1.0),whereas a history of hypertension did not independently influence the risk.CONCLUSIONS Smoking,migraine and,inversely,hypercholesterolemia are independent risk factors for aneurysmal rupture.Data from the questionnaire are insufficient to conclude whether hypercholesterolemia or its treatment with statins exerts a risk-reducing effect.The pathophysiological mechanisms through which smoking and migraine increase the risk of aneurysmal rupture should be investigated in further studies.Although a history of hypertension does not increase risk of rupture,a sudden rise in blood pressure might still trigger aneurysmal rupture.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.51974082)the Programme of Introducing Talents of Discipline Innovation to Universities 2.0(the 111 Project of China 2.0,No.BP0719037)
文摘In this work,the discharge properties and electrochemical behaviors of as-cast AZ80-La-Gd anode for Mg-air battery have been investigated and compared with the AZ80 anode.The microstructure evolution,electrochemical behaviors and surface morphologies after discharge have been discussed to connect the discharge properties.The results indicate that the modified AZ80-La-Gd is an outstanding candidate for anode for Mg-air batter,which has high cell voltage,stable discharge curves,good specific capacity and energy,and good anodic efficiency.It exhibits the best anodic efficiency,specific capacity and energy of 76.45%,1703.6 mAh·g^(-1)and 2186.3 mWh·g^(-1),respectively,which are20.24%,18.92%and 25.71%higher than values for AZ80 anode.Such excellent discharge performance is attributed to the Al-RE particles.They refine the Mg_(17)Al_(12)phase and therefore improve the self-corrosion resistance and desorption ability of AZ80 anode.
文摘Based on plasticity theory and physical experiments, the quantitative relationships between elongation δ obtained byuniaxial tensile test and forming limits of tensile stamping operations are given, which mainly resolves the problem thatforming limits can be derived from simple tensile test. The forming limit nomogram of tensile stamping operationsis also established to apply to engineering.
文摘As an innovation mode of organization, technology alliance has being increasingly paid more attention to by more and more small and medium-sized enterprises （SME）. In this paper, on the basis of analyzing the theory and practice meaning of the technology alliance, cooperative game method is used to analyze the forming process of the cooperative mechanism, and it points out that cooperation will make both sides get the largest benefits.
文摘This text combines authors＇ visits and examinations on the spot of Silicon Valley of U.S.A. and Park of Singapore, after analyzing the Park development experience of U.S.A. and Singapore, elucidates ＂three culture effects＂ of Park development in terms of cultural system emphatically, then proposes some suggestions of cultural innovation in the Park of China.
基金supported by the National Natural Science Foundation of China(No.61101186)
文摘For maritime radiation source target tracking in particular electronic counter measures（ECM）environment,there exists two main problems which can deteriorate the tracking performance of traditional approaches.The frst problem is the poor observability of the radiation source.The second one is the measurement uncertainty which includes the uncertainty of the target appearing/disappearing and the detection uncertainty（false and missed detections）.A novel approach is proposed in this paper for tracking maritime radiation source in the presence of measurement uncertainty.To solve the poor observability of maritime radiation source target,using the radiation source motion restriction,the observer altitude information is incorporated into the bearings-only tracking（BOT）method to obtain the unique target localization.Then the two uncertainties in the ECM environment are modeled by the random fnite set（RFS）theory and the Bernoulli fltering method with the observer altitude is adopted to solve the tracking problem of maritime radiation source in such context.Simulation experiments verify the validity of the proposed approach for tracking maritime radiation source,and also demonstrate the superiority of the method compared with the traditional integrated probabilistic data association（IPDA）method.The tracking performance under different conditions,particularly those involving different duration of radiation source opening and switching-off,indicates that the method to solve our problem is robust and effective.
文摘With the reform of the state-owned enterprises, the level of the human resources management of a lot of state-owned enterprises has been gradually improved. However, because of the macroscopic system, history, culture and their own reasons, there are still a series of problems in the human resources management of state-owned enterprises. In order to promote the reform of state-owned enterprises and to improve the competitiveness of enterprises, we should critically research these urgent problems. The paper will take an example of one company which was investigated by state-owned enterprises will be listed and analysed. the author, and the common problems which exist in most state-owned enterprises will be listed and analysed.
文摘Just as the regional economy and city economy, the industrial economy is the economic aggregation lying in between the macroeconomy and microeconomy. Mesoeconomic management is the extension of the macroeconomic management and has its own operation rules. The relationship between the macroeconomic and the mesoeconomic management is just like between the general department and the specialized department of the government while reflecting on the subject of the management. Establishment of the mesoeconomic management system is a model of the reform in the specialized economic departments of Chinese government.
文摘In order to realize the impersonality, justness, impartiality and rationality in the awarding work of science ＆ technology, it is necessary to establish an evaluating model to make the evaluating course numeric as well as a complete system of evaluating indexes. The theory of fuzzy mathematics is adopted in this paper to establish a multilevel fuzzy synthetical model to quantitate the evaluating index system for science ＆ technology awarding and to provide the scientific decision-making basis for science ＆ technology awarding.
文摘The paper summarizes, contrasts and expands the definitions of Internet economics, puts forward the theory of Internet economics development stage and analyzes the reason of the development of Internet economics.
文摘The difference of regional economy comes from capital dissymmetry, technology dissymmetry, manpower dissymmetry and the information dissymmetry. In the knowledge-based economic ages, globalization and information exceed any age of the history. It provides the new terrace for the balanced development of global economy. The flows of capital and technology improve the regional dissymmetry of production factor. By establishing circulating channels, the flows of the production factor will be enlarged. This will raise the distribution efficiency of global resources and lead to the global economic growth.
文摘The problem considered is the correlation between stock exchange and economy growth. Stepwise regression is being used on the following figures： increasing rate of GDP, the volume of stock market, and liquidity. As a result, we give .an.equation of national economy and stock market. Then, we use Granger＇s Causality test to prove that the stock market has positive effects on the national economy.
基金the National Basic Research Program of China(2013CB632203)Liaoning Provincial Natural Science Foundation(Grant No.2014028027)。
文摘Four Mg–Gd–Y–Nd–Zr alloys were prepared by mold casting to investigate the effects of Nd/Gd ratios on microstructures and mechanical properties.The as-cast alloys mainly consist ofα-Mg andβ-Mg5(GdYNd).Volume fractions of the second phase increase and grains were slightly refined with the rising Nd/Gd ratio,when the alloying addition is equal.Meanwhile,fibers of second phase also increase in the extruded alloys when the Nd/Gd value increases.However,the Nd/Gd ratio could hardly influence the mechanical properties of the extruded alloys.The aging hardening response of the extruded alloy differs due to different Nd/Gd ratios.The potential mechanisms have also been discussed in detail.
基金National Natural Science Foundation of China Under Award Number 50878184National High Technology Research and Development Program (863 Program) of China Under Grant No. 2006AA04Z437Graduate Starting Seed Fund of Northwestern Polytechnical University Under the Grant No. Z2012059
文摘Fragility analysis for highway bridges has become increasingly important in the risk assessment of highway transportation networks exposed to seismic hazards. This study introduces a methodology to calculate fragility that considers multi-dimensional performance limit state parameters and makes a first attempt to develop fragility curves for a multi-span continuous (MSC) concrete girder bridge considering two performance limit state parameters: column ductility and transverse deformation in the abutments. The main purpose of this paper is to show that the performance limit states, which are compared with the seismic response parameters in the calculation of fragility, should be properly modeled as randomly interdependent variables instead of deterministic quantities. The sensitivity of fragility curves is also investigated when the dependency between the limit states is different. The results indicate that the proposed method can be used to describe the vulnerable behavior of bridges which are sensitive to multiple response parameters and that the fragility information generated by this method will be more reliable and likely to be implemented into transportation network loss estimation.
基金the National Natural Science Foundation of China(51974082)the National Natural Science Foundation of China(51771043)the Programme of Introducing Talents of Discipline Innovation to Universities 2.0(the 111 Project 2.0 of China,No.BP0719037).
文摘A comprehensive two-dimensional axisymmetric mathematical model that couples transient electromagnetic force with fluid flow,heat transfer,and solidification was established to describe the interaction of multiphysics field during DC casting.The melt flow,heat transfer,and solidification characteristics under differential phase pulse magnetic field and differential phase low-frequency electromagnetic field(DP-PMF and DP-LFEF)were numerically investigated by means of numerical simulation during electromagnetic direct-chill(DC)casting of AZ31 alloy at the same casting conditions.The effects of differential phase electromagnetic fields on Lorentz forces distributions,melt flow,heat transfer,and liquid sump shape were discussed systematically.Based on measured current waveform,the results were compared with those obtained without magnetic field(MF)and under conventional pulse magnetic field(PMF)and low-frequency electromagnetic field(LFEF)under the same conditions.The results show that the application of magnetic fields can significantly change the solidification process of DC casting.Differential phase magnetic fields(DP-LFEF and DP-PMF)can effectively reduce the temperature of the melt in the liquid sump,and the shallower liquid sump depth can be obtained under the differential phase magnetic fields.A large velocity vibration amplitude and a lower temperature are available simultaneously under DP-PMF,resulting in more uniform temperature distribution.
文摘BACKGROUND AND PURPOSE Knowledge about risk factors contributes to understanding the pathophysiological mechanisms that cause intracranial aneurysm rupture and helps to develop possible treatment strategies.We aimed to study lifestyle and personal characteristics as risk factors for the rupture of intracranial aneurysms.METHODS We performed a case-control study with 250 patients with an aneurysmal subarachnoid hemorrhage and 206 patients with an unruptured intracranial aneurysm.All patients with an aneurysmal subarachnoid hemorrhage and patients with a unruptured intracranial aneurysm were asked to fill in a structured questionnaire about their lifestyle and medical history.For patients with an unruptured intracranial aneurysm,we also collected data on the indication for imaging.With logistic regression analysis,we identified independent risk factors for aneurysmal rupture.RESULTS Reasons for imaging in patients with an unruptured intracranial aneurysm were atherosclerotic disease(23%),positive family history(18%),headache(8%),preventive screening(3%),and other(46%).Factors that increased risk for aneurysmal rupture were smoking(odds ratio,1.9;95% confidence interval,1.2-3.0) and migraine(2.4;1.1-5.1);hypercholesterolemia decreased this risk(0.4;0.2-1.0),whereas a history of hypertension did not independently influence the risk.CONCLUSIONS Smoking,migraine and,inversely,hypercholesterolemia are independent risk factors for aneurysmal rupture.Data from the questionnaire are insufficient to conclude whether hypercholesterolemia or its treatment with statins exerts a risk-reducing effect.The pathophysiological mechanisms through which smoking and migraine increase the risk of aneurysmal rupture should be investigated in further studies.Although a history of hypertension does not increase risk of rupture,a sudden rise in blood pressure might still trigger aneurysmal rupture.
