Discharge properties and electrochemical behaviors of AZ80-La-Gd magnesium anode for Mg-air battery

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.

Study on the Forming Limit Nomogram of Tensile Stamping Operations

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.

The Dragon-shape Strategy of China＇s Regional Economic Development and Policy Analysis

According to this paper, the dragon-shape strategy is the optimized option of China＇s future strategy with respect to the geographic distribution of regional economy.

A Game Analysis on Technology Alliance of Tech-typed Small and Medium-sized Enterprises

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.

Enlightenment of Cultural Innovation in the Park of China from the Park Development of U.S.A. and Singapore

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.

Diagnosis on the Problem of the Human Resources Management of State-owned Enterprises

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.

Selection of Operation and Management Model for Industrial Mesoeconomy

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.

Study on Multilevel Fuzzy Synthetical Evaluating Model of Science ＆ Technology Awarding

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.

Study on Internet Economics

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 Economic Growth with the Flows of Capital ＆ Technology

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.

Analysis on the Correlation between Stock Exchange and Economic Growth

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.

Will the Historic Southeasterly Wind over the Equatorial Pacific in March 2022 Trigger a Third-year La Niña Event?

Based on the updates of the Climate Prediction Center and International Research Institute for Climate and Society(CPC/IRI)and the China Multi-Model Ensemble(CMME)El Niño-Southern Oscillation(ENSO)Outlook issued in April 2022,La Niña is favored to continue through the boreal summer and fall,indicating a high possibility of a three-year La Niña(2020-23).It would be the first three-year La Niña since the 1998-2001 event,which is the only observed three-year La Niña event since 1980.By examining the status of air-sea fields over the tropical Pacific in March 2022,it can be seen that while the thermocline depths were near average,the southeasterly wind stress was at its strongest since 1980.Here,based on a quaternary linear regression model that includes various relevant air-sea variables over the equatorial Pacific in March,we argue that the historic southeasterly winds over the equatorial Pacific are favorable for the emergence of the third-year La Niña,and both the anomalous easterly and southerly wind stress components are important and contribute~50%of the third-year La Niña growth,respectively.Additionally,the possible global climate impacts of this event are discussed.

Effects of Nd/Gd value on the microstructures and mechanical properties of Mg-Gd-Y-Nd-Zr alloys

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.

Seismic fragility analysis of highway bridges considering multi-dimensional performance limit state

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.

Macro-physical field of large diameter magnesium alloy billet electromagnetic direct-chill casting:A comparative study

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.

影响颅内动脉瘤破裂风险的患者个体特征(英文)

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.

pH-sensitive polymeric micelles triggered drug release for extracellular and intracellular drug targeting delivery

Most of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy.Based on physiological differences between the normal tissue and the tumor tissue,one effective approach to improve the efficacy of cancer chemotherapy is to develop pH-sensitive polymeric micellar delivery systems.The copolymers with reversible protonationedeprotonation core units or acid-liable bonds between the therapeutic agents and the micelle-forming copolymers can be used to form pH-sensitive polymeric micelles for extracellular and intracellular drug smart release.These systems can be triggered to release drug in response to the slightly acidic extracellular fluids of tumor tissue after accumulation in tumor tissues via the enhanced permeability and retention effect,or they can be triggered to release drug in endosomes or lysosomes by pH-controlled micelle hydrolysis or dissociation after uptake by cells via the endocytic pathway.The pH-sensitive micelles have been proved the specific tumor cell targeting,enhanced cellular internalization,rapid drug release,and multidrug resistance reversal.The multifunctional polymeric micelles combining extracellular pH-sensitivity with receptor-mediated active targeting strategies are of great interest for enhanced tumor targeting.The micelles with receptor-mediated and intracellular pH targeting functions are internalized via receptor-mediated endocytosis followed by endosomal-pH triggered drug release inside the cells,which reverses multidrug resistance.The pH sensitivity strategy of the polymeric micelles facilitates the specific drug delivery with reduced systemic side effects and improved chemotherapeutical efficacy,and is a novel promising platform for tumor-targeting drug delivery.

Numerical simulation of DC casting of AZ31 magnesium slab at different casting speeds

A mathematical model of the direct chill(DC)casting process for AZ31magnesium slab has been developed to predict the temperature evolution in the slab.The temperature fields at different casting speeds were compared and the optimum casting speed of 300 mm×800 mm magnesium slab in the certain pouring temperature and cooling-water flow rate was obtained.The casting speed during the plant trial was consistent with the calculation.

A forecasting model for wave heights based on a long short-term memory neural network

To explore new operational forecasting methods of waves,a forecasting model for wave heights at three stations in the Bohai Sea has been developed.This model is based on long short-term memory(LSTM)neural network with sea surface wind and wave heights as training samples.The prediction performance of the model is evaluated,and the error analysis shows that when using the same set of numerically predicted sea surface wind as input,the prediction error produced by the proposed LSTM model at Sta.N01 is 20%,18%and 23%lower than the conventional numerical wave models in terms of the total root mean square error(RMSE),scatter index(SI)and mean absolute error(MAE),respectively.Particularly,for significant wave height in the range of 3–5 m,the prediction accuracy of the LSTM model is improved the most remarkably,with RMSE,SI and MAE all decreasing by 24%.It is also evident that the numbers of hidden neurons,the numbers of buoys used and the time length of training samples all have impact on the prediction accuracy.However,the prediction does not necessary improve with the increase of number of hidden neurons or number of buoys used.The experiment trained by data with the longest time length is found to perform the best overall compared to other experiments with a shorter time length for training.Overall,long short-term memory neural network was proved to be a very promising method for future development and applications in wave forecasting.

Effects of casting process on microstructures and flow stress behavior of Mg-9Gd-3Y-1.5Zn-0.8Zr semi-continuous casting billets

Mg-9Gd-3Y-1.5Zn-0.8Zr alloys own high strength,good heat and corrosion resistance.However,it is difficult for the fabrication of large-scale billets,due to the poor deformation ability and strong hot-crack tendency.This work investigated the casting process on the microstructures and flow stress behaviors of the semi-continuous casting billets for the fabrication of large-scale Mg-9Gd-3Y-1.5Zn-0.8Zr billets.The casting process(electromagnetic intensity and casting speed)shows outstanding effects on the microstructures and flow stress behavior of the billets.The billets with the specific casting process(I=68 A,V=65 mm/min)exhibit uniform microstructures and good deformation uniformity.