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Mining Science and Technology 2010年第2期20卷 188-192页

作者： WANG, Haifeng CHENG, Yuanping YUAN, Liang WANG, Liang national engineering research center for coal & gas control china university of mining & technologyxuzhou 221008china huainan mining industry (group) limited liability company postdoctoral science research workstationhuainan 232046china

For a study of the movement and deformation of coal-rock mass and low protected seams below a stope,as well as for fracture developments and rules of evolution of permeability,we designed a plane strain model test stand to carry out model tests of similar materials in order to improve the effect of gas drainage from low protected seams and to measure the movement and deformation of coal-rock mass using a method of non-contact close-range *** results show that 1) using paraffin melting to take the place of coal seam mining can satisfy the mining conditions of a protective seam;2) coal-rock mass under goafs has an upward movement after the protective seam has been mined,causing floor heaving;3) low protected seams become swollen and deformed,providing a good pressure-relief effect and causing the coal-rock mass under both sides of coal pillars to become deformed by compression and 4) the evolution of permeability of low protected seams follows the way of initial values→a slight decrease→a great increase→stability→final ***,the coefficient of air permeability increased at a decreasing rate with an increase in interlayer spacing.

关键词： coal-rock mass below stope low protected seam plane strain similar model test

Calculation and characteristic analysis on synergistic effect of CF3I gas mixtures

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Plasma Science and Technology 2018年第6期20卷 39-43页

作者： Su ZHAO Yunkun DENG Yuhao GAO Dengming XlAO Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200030 People's Republic of China postdoctoral workstation on Yunnan Power Grid Corporation Kunming 650217 People's Republic of China School of Electrical and Electronic Engineering Hubei University of Technology Wuhan 430068 People's Republic of China

CF3I is a potential SF6 alternative *** order to study the insulation properties and synergistic effects of CF3I/N2 and CF3I/CO2 gas mixtures,two-term approximate Boltzmann equations were used to obtain the ionization coefficient α,attachment coefficient η and the critical equivalent electrical field strength（E/N）（cr）.The results show that the（E/N）（cr）of CF3I gas at 300 K is 1.2 times that of SF6 gas,and CF3I/N2 and CF3I/CO2 gas mixtures both have synergistic effect *** synergistic effect coefficient of CF3I/CO2 gas mixture was higher than that of CF3I/N2 gas *** the（E/N）（cr）of CF3I/N2 is higher than that of CF3I/CO2 under the same *** the content of CF3I exceeds 20%,the （E/N）（cr） of CF3I/N2 and CF3I/CO2 gas mixture increase linearly with the increasing of CF3I gas *** breakdown voltage of CF3I/N2 gas mixture is also higher than that of CF3I/CO2 gas mixture in slightly non-uniform electrical field under power frequency voltage,but the synergistic effect coefficients of the two gas mixtures are basically the same.

关键词： Boltzmann equation CF3I gas mixtures synergistic effect

Dantrolene enhances the protective effect of hypothermia on cerebral cortex neurons

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Neural Regeneration Research 2015年第8期10卷 1279-1285页

作者： Sui-yi Xu Feng-yun Hu Li-jie Ren Lei Chen Zhu-qing Zhou Xie-jun Zhang Wei-ping Li postdoctoral workstation Zhongshan School of Medicine Sun Yat-sen University Department of Brain Center Shenzhen Key Laboratory of Neurosurgery Shenzhen Second People’s Hospital Shenzhen University First Affiliated Hospital Department of Neurology Shanxi Provincial People’s Hospital Shanxi Medical University

Therapeutic hypothermia is the most promising non-pharmacological neuroprotective strategy against ischemic injury. However, shivering is the most common adverse reaction. Many studies have shown that dantrolene is neuroprotective in in vitro and in vivo ischemic injury models. In addition to its neuroprotective effect, dantrolene neutralizes the adverse reaction of hypothermia. Dantrolene may be an effective adjunctive therapy to enhance the neuroprotection of hypothermia in treating ischemic stroke. Cortical neurons isolated from rat fetuses were exposed to 90 minutes of oxygen-glucose deprivation followed by reoxygenation. Neurons were treated with 40 μM dantrolene, hypothermia（at 33°C）, or the combination of both for 12 hours. Results revealed that the combination of dantrolene and hypothermia increased neuronal survival and the mitochondrial membrane potential, and reduced intracellular active oxygen cytoplasmic histone-associated DNA fragmentation, and apoptosis. Furthermore, improvements in cell morphology were observed. The combined treatment enhanced these responses compared with either treatment alone. These findings indicate that dantrolene may be used as an effective adjunctive therapy to enhance the neuroprotective effects of hypothermia in ischemic stroke.

关键词： nerve regeneration ischemic stroke oxygen-glucose deprivation fluorescent probe neurons flow cytometry apoptosis calcium overload reactive oxygen neural regeneration

Comparisons of Protein Composition of Grains at Different Positions in Panicles between Erect and Curved Panicle Type Japonica Rice

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Agricultural Biotechnology 2015年第6期4卷 1-6,9页

作者： Shuqiang CHEN Jingfang XUE Xiaodong DU Limin YANG Haixin ZHAO Tong ZHOU Lili SHAN Cui WANG Min LI Guojun PAN postdoctoral workstation Heilongjiang Academy of Agricultural Sciences postdoctoral Research Station Northeast Forestry University Jiamusi Rice Research Institute Heilongjiang Academy of Agricultural Sciences

Under field conditions, three erect panicle type japonica dee cultivars and three curved panicle type japonica rice cultivars were applied as experimental materials to investigate the differences of protein composition of grains at different positions in panicles between two different panicle types of japonica rice. Accord- ing to the results, the panicle type of japonica rice had no direct correlation with albumin content, globulin content, prolamin content and glutelin content in rice, variations of protein composition of grains at different positions in panicles. There were certain correlations between soluble protein contents at different grain posi- tions in the same panicle and the flowering order of glumous flowers in the panicle. Albumin content, prolamin content and glutelin content in grains on secondary rachis branches of two panicle types （erect and curved） of japonica rice cuhivars were higher than that on primary rachis branches, while globulin content exhibited an opposite trend. Globulin content, prolamin content and glutelin content in grains at different positions demonstrated a descending order of bottom 〉 middle 〉 top, while albumin content exhibited an opposite trend. The interactions between primary and secondary rachis branches and among top, middle and bottom rachis branches significantly affected soluble protein contents.

关键词： Japonica rice Panicle type Grain position Protein composition

Economic Policy Uncertainty and Stock Risk Features

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2019年第3期14卷 461-495页

作者： Guojin Chen Runze Zhang Xiangqin Zhao Department of Finance School of EconomicsXiamen UniversityXiamen 361005China Wang Yanan Institute for Studies in Economics Xiamen UniversityXiamen 361005China postdoctoral workstation Guosen SecuritiesShenzhen 518001China

In this paper,we introduce economic policy uncertainty by using a stochastic discount *** parameter calibration and static analysis,we investigate the dynamic characteristics of stock risk on different policy *** this basis,we test the channel through policy uncertainty affects stock risk by empirical simulation,and the effect of policy uncertainty on stock risk formation by portfolio analysis,in order to verify the applicability of the theoretical model in ***,the panel model is used to quantitatively analyze the relationship between policy uncertainty and stock *** results show that policy uncertainty can inereuse stock risk through enterprise cash flow,discounting factors and correlation *** effect is still significant after controlling traditional risk factors,corporate heterogeneity,and external environmental *** that are non-state-owned,have lower returns on invested capital and lower asset growth rate manifest greater stock risk when policy uncertainty is *** magnitude of the effect of policy uncertainty on stock risk is larger when the economy is weaker and the policy environment is more unstable.

关键词： economic policy uncertainty (EPU) stock risk transmission mechanism panel regression

Introducing voids around the interlayer of AlN by high temperature annealing

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Chinese Physics B 2022年第7期31卷 448-453页

作者： Jianwei Ben Jiangliu Luo Zhichen Lin Xiaojuan Sun Xinke Liu Xiaohua Li College of Materials Science and Engineering Shenzhen University-Hanshan Normal University Postdoctoral WorkstationShenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

Introducing voids into AlN layer at a certain height using a simple method is meaningful but *** this work,the AlN/sapphire template with AlN interlayer structure was designed and grown by metal-organic chemical vapor ***,the AlN template was annealed at 1700℃for an hour to introduce the *** was found that voids were formed in the AlN layer after high-temperature annealing and they were mainly distributed around the AlN ***,the dislocation density of the AlN template decreased from 5.26×10^(9)cm^(-2)to 5.10×10^(8)cm^(-2).This work provides a possible method to introduce voids into AlN layer at a designated height,which will benefit the design of AlN-based devices.

关键词： AlN template AlN interlayer voids high-temperature annealing

How to Construct a Lower Risk FOF Based on Correlation Network? The Method of Principal Component Risk Parity Asset Allocation

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Journal of Systems Science & Complexity 2024年第3期37卷 1052-1079页

作者： BAI Wei ZHANG Junting LIU Haifei LIU Kai School of Management and Engineering Nanjing UniversityNanjing 210093China postdoctoral workstation of Bank of Jiangsu Co. LtdNanjing 210006China College of Finance Nanjing Agricultural UniversityNanjing 210095China University of Prince Edward Island 550 University AveCharlottetownPE C1A4P3Canada

In order to build a low-risk Fund of Funds(FOF), from the perspective of correlation, the principal component factor is used to improve the traditional risk parity model. Principal component analysis is used to decompose the underlying assets and generate unrelated principal component factors,and then the authors can construct a principal component risk parity portfolio. The proposed empirical results based on China’s mutual fund market show that the performance of principal component risk parity portfolio(PCRPP) is better than that of equal weight portfolio(EWP) and traditional risk parity portfolio(RPP). That is to say, not only the PCRPP in this paper has much lower risk than EWP and RPP, but also slightly better than EWP and RPP in terms of average return. Moreover, the study of dividing the underlying assets shows that the PCRPP in this paper is not sensitive to the underlying assets. The PCRPP in this paper is better than EWP and RPP for both the better performing funds and the worse performing funds. In addition, the empirical results on dynamic portfolio adjustments show that it is not appropriate to adjust asset allocation too frequently when the expected rate of return is calculated using the arithmetic mean.

关键词： Fund of funds(FOF) mutual funds portfolio risk principal component analysis risk parity portfolio

An operation optimization method of a fully mechanized coal mining face based on semi-physical virtual simulation

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International Journal of Coal Science & Technology 2020年第1期7卷 147-163页

作者： Hengbo Shi Jiacheng Xie Xuewen Wang Juanli Li Xing Ge College of Mechanical and Vehicle Engineering Key Laboratory of Fully Mechanized Coal Mining EquipmentTaiyuan University of TechnologyTaiyuan 030024ShanxiChina Taiyuan Mining Machinery Group Co. Ltd.Postdoctoral Science Research WorkstationTaiyuan 030032ShanxiChina

A mathematical hydraulic support self-tracking model for three-machine cooperative mining is proposed to address low efficiency and difficulties in strategy evaluation of a fully mechanized coal *** proposed model uses the coordinates and traction speed of the shearer to calculate the frequency of the circular hydraulic support and realize the coordinated operation of the three-machine mining technology.A unity3d hardware-in-the-loop simulation experimental hearer and hydraulic support platform was used to validate the model of autonomous *** results indicate that collaborative control of coal mining allowed for an efficiency 3.76%higher than under automatic operation mode and 46.03%higher than under manual control;thus,The mathematical model provided an improved production efficiency of the fully mechanized mining *** mathematical model also provides a more intelligent and reliable security support,and improves the intelligent level of hydraulic support follow-up control.

关键词： Semi-physical simulation Virtual reality Unity3d Human-computer interaction Shearer traction speed

Performance Analysis and Parameter Optimizing Rules of LT Codes

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China Communications 2010年第4期7卷 103-107页

作者： GUO Chunmei BI Xueya Zhongguancun Haidian Science Park postdoctoral workstation Lenovo Security Substation Beijing 100086 China Institute of Software Chinese Academy of Sciences Beijing 100190 China

As a new class of forward error correcting encoding algorithm,Luby Transform codes are suitable for the erasure channel environment based on the packet *** encoding,decoding algorithms and the implementation of LT codes are summarized in the *** simulations of the ideal soliton distribution and robust soliton distribution are conducted to evaluate the performance of LT codes in terms of successful decoding probability,mean degree and decoding time over the erasure *** parameter optimization rules of LT codes are deeply discussed and proposed in the *** research results are of great practical importance for improving the real time performance in the erasure correction applications.

关键词： Digital Fountain Codes LT Codes Degree Distribution Algorithm Erasure channel