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Joint linear precoder and power allocation design for uplink MIMO systems with limited feedback

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 14-18页

作者： yan zhi wang wen-bo wang Jian-feng zheng kan Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In this article, the authors consider joint design of a linear precoder and power allocation for uplink multiuser multiple input multiple output （MIMO） communication systems with limited feedback to improve the bit error rate （BER） performance for all users. Precoder selection from the codebook set is directly based on the exact BER performance, instead of other suboptimal criteria, to achieve the optimal precoder matrix, but closed-form expressions may not exist in the view of power allocation based directly on the BER criterion. From this perspective, the authors propose the joint transmitter optimization algorithm for the consideration of precoder design, with total power constraint for asymptotic MBER （AMBER） criterion. In this AMBER criterion, a closed-form solution has been derived for power allocation with an optimal precoder. The simulation results show that the proposed joint design algorithm can achieve a much better performance than precoding with uniform power allocation and only consideration of power allocation.

关键词： MIMO linear precoder power allocation spatial multiplexing multiuser

Facile Synthesis of Polycarbonate Diol via Copolymerization of CO_(2) and Cyclohexene Oxide Catalysed by a Combination of One-Component Phosphonium borane Lewis Pair and Water

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Chinese Journal of Polymer Science 2023年第5期41卷 735-744,I0009页

作者： xiao-Wu wang Ji-wen Hui Yu-Tao Li yan-Ru Gu zhi-bo Li State Key Laboratory Base of Eco-Chemical Engineering/College of Chemical Engineering Qingdao University of Science and TechnologyQingdao 266042China Key Laboratory of Biobased Polymer Materials Shandong Provincial Education Department/School of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042China

Well-defined polycarbonate diol was successfully synthesized through a strategy using a combination of organocatalyst and *** strategy was less developed in organocatalyzed polymerization and frequently regarded as side ***,one-component phosphonium borane Lewis pairs PB1-PB8 were successfully applied in the copolymerization of CO_(2) and cyclohexene oxide(CHO)to generate poly(CHO-alt-CO_(2))carbonate(PCHC).Parameters of linker length and counter anion effects on the catalyst activity were *** was found that Lewis pair PB3 served as a dual initiator and catalyst in the copolymerization of CHO and CO_(2) with or without the presence of *** contrast,Lewis pair PB8 can serve as a true catalyst for the preparation of well-definedα,ω-hydroxyl PCHC *** was achieved by introducing a labile CF3COO group as counter anion through anion exchange reaction while water molecules acted as chain transfer *** function of trifluoroacetate group in the polymerization process was investigated in detail and possible mechanism was *** changing the amount of water and catalyst loading,PCHC diols with varied molecular weight(1.5 kg/mol to 7.5 kg/mol),low dispersities(Dbonate content(>99%)could be easily *** low molecular weight PCHC diol was used as a bifunctional macroinitiator for the ring-opening polymerization of L-lactide(LLA)to afford ABA triblock copolymer in one-pot synthesis.

关键词： Polycarbonate Phosphonium borane Lewis pair CO_(2)utilization Organocatalysis Ring-opening polymerization

Magneto-thermo-mechanical characterization of giant magnetostrictive materials

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Rare Metals 2013年第5期32卷 486-489页

作者： Li wang bo-wen wang zhi-Hua wang Ling weng wen-Mei Huang yan Zhou Province-Ministry Joint Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability Hebei University of Technology International Center for Materials Physics The Chinese Academy of Sciences School of Science Tianjin University of Commerce

The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed. The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materi- als in different temperatures and under different stresses. The coupling effects of axial stress, magnetic field, and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested. Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress. Therefore, the proposed model possesses an important significance for the design of magnetostrictive devices.

关键词： Nonlinear model Giant magnetostrictivematerials Temperature Stress

Creep prediction model for nickel-based single-crystal superalloys considering precipitation of TCP phase

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Rare Metals 2021年第10期40卷 2892-2904页

作者： xiao-yan wang Jia-Jia wang Cheng-Jiang Zhang wen-Wei Tong bo Jiang Guang-Xian Lu zhi-Xun wen Tao Feng Department of Engineering Mechanics Northwestern Polytechnical UniversityXi’an 710072China School of Science Xi’an Shiyou UniversityXi’an 710065China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China

The microstructure of nickel-based single-crystal(SC) superalloys has a pivotal influence on their creep properties. The addition of the Re element not only enhances the long-term creep properties of nickel-based SC superalloys, but also results in the formation of a topologically close-packed(TCP) phase which is a harmful and brittle hard phase. Here, high-temperature creep interruption tests of a nickel-based SC superalloy that contains4.8 wt% Re were performed under various temperatures and stress conditions, and the evolution of microstructure during creep was observed by scanning electron microscopy(SEM). The volume fraction of the TCP phase was also extracted to explore the mechanism that controls the impacts of the TCP phase on the creep *** to the microstructure evolution mechanism, the influence of the TCP phase was attributed to the initial damage and critical shear stress of the material. A creep performance prediction model for nickel-based SC superalloys considering the precipitation of the TCP phase that is based on the crystal plasticity theory and a modified creep damage model was established. The simulation curves fit well with the experimental results and the errors between prediction creep life with test results are within 5%.

关键词： TCP phase Nickel-based single-crystal superalloys Microstructure evolution Creep performance prediction Crystal plasticity theory

Clustering of Cardiovascular Risk Factors and Diabetes： A Prospective Cohort Study on the Inner Mongolian Population in China

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Biomedical and Environmental Sciences 2018年第10期31卷 749-756页

作者： wang ting ting LIN bo CUI wen Xiu ZHANG Ming zhi ZHANG Yong Hong ZHANG Shao yan Department of Epidemiology School of Public Health andJiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases Medical College of Soochow University Suzhou 215123 Jiangsu China Harbin Center for Disease Control and Prevention Harbin 150000 Heilongjiang China

Objective To evaluate the effect of clustering of cardiovascular risk factors（CVRFs） on type 2 diabetes mellitus（T2 DM） incidence and identify some high predictive clusters in the Inner Mongolian population in China. Methods A total of 1,884 Mongolian individuals aged 20 years or above were followed up from 2002 to 2013 and included in the final analysis. We categorized the participants into two subgroups according to the study outcome event. A Cox proportional hazards model was used to evaluate the effect of clustering of CVRFs on the incidence of T2 DM. Areas under the curve were used to compare the effect of every cluster on T2 DM and identify those having higher predictive value. Results We found 203 persons with T2 DM. Subjects with incident T2 DM tended to be older, had a higher prevalence of drinking, had higher systolic and diastolic pressures; total cholesterol, triglyceride, low-density lipoprotein cholesterol, and C-reactive protein levels; waist circumference; body mass index; and heart rate and lower HDL-C level than did those without T2 DM. The multivariable adjusted hazard ratio（95% confidence interval） of T2 DM was calculated based on comparisons with subjects with 0 CVRFs; in participants with 2 and ≥ 3 factors, the adjusted hazard ratios were 2.257（1.448, 3.518） and 3.316（2.119, 5.188）, respectively. Conclusion The clustering of CVRFs increased the risk of T2 DM. On the basis of fast heart rate, the cluster of abdominal obesity and other CVRFs had higher predictive value for T2 DM than the other three CVRF clusters.

关键词： Type 2 diabetes Cardiovascular risk factors Abdominal obesity Heart rate

A New Manganese(Ⅱ) Coordination Compound Constructed by 1,10-Phenanthroline Derivative and Chlorine Anions: Synthesis, Crystal Structure and Theoretical Calculation

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Chinese Journal of Structural Chemistry 2019年第5期38卷 819-824,671页

作者： wang Xiu-yan GAO wen-Yu ZHOU xiao-Hang LIU Dong-Xue HU bo KONG zhi-Guo Key Laboratory of Preparation and Applications of Environmental Friendly Materials Jilin Normal University Siping 136000 China Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education Jilin Normal University Siping 136000 China Department of Chemistry Jilin Normal University Siping 136000 China

The new manganese（Ⅱ） coordination compound, [Mn（Cl）2（L）2]（1, L = 11-fluorodipyrido[3,2-a:2?,3?-c]phenazine）, has been achieved under hydrothermal conditions. The structure of compound 1 was determined by single-crystal X-ray diffraction. 1 crystallizes in monoclinic system, space group C2/c with a = 8.419（2）, b = 12.286（2）, c = 28.451（6） ?, β = 95.889（3）°, V =2927.5（10） ?3, Z = 4, C36 H16 MnF2 Cl2 N8, Mr = 724.41, Dc = 1.644 g/cm3, F（000） = 1460, μ（Mo Ka）= 0.691 mm-1, R = 0.0445 and wR = 0.0982. Adjacent compounds are stacked by one type of π-πinteraction among L ligands to generate a 1D supramolecular chain. Further, the 1D supramolecular chains are stacked by another type of π-π interaction among L ligands to give a 2D supramolecular layer. Moreover, the C-F···π interactions between the carbon atom of the L ligand and the pyrazine ring of the adjacent L ligand further stabilize the supramolecular layer of 1. In addition, natural bond orbital（Nbo） analysis has been calculated by the B3LYP/LANL2DZ method, which shows obvious covalent interaction between the coordinated atoms and Mn（Ⅱ） ion.

关键词： crystal structure coordination compound 11-fluoro-dipyrido[3,2-a:2',3'-c]phenazine manganese(Ⅱ) theoretical calculation

Transformation from AA to AB-Stacked Bilayer Graphene on α−SiO_(2 )under an Electric Field

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Chinese Physics Letters 2011年第8期28卷 266-269页

作者： LIU yan AO zhi-Min wang Tao wang wen-bo SHENG Kuang YU Bin Second Affiliated Hospital College of MedicineZhejiang UniversityHangzhou 230031 College of Electrical Engineering Zhejiang UniversityHangzhou 230031 School of Materials Science and Engineering The University of New South WalesSydneyNSW 2052Australia College of Nanoscale Science and Engineering State University of New YorkAlbanyNew York 12203USA

The energetic and electronic structure of bilayered graphene(BLG)with AA stacking arrangement on a SiO_(2) substrate is investigated in the presence of an electric field F of different intensities by ab initio density functional *** AA−stacked bilayer graphene is stable on the SiO_(2) substrate in the absence of an electric ***,as F increases,the AA-stacked bilayer graphenes are gradually shifted with each other and finally transfers into AB-stacked bilayer *** bandgap is accordingly changed.

关键词： field Transformation arrangement

Icariin Ameliorates D-galactose-induced Cell Injury in Neuron-like PC12 Cells by Inhibiting MPTP Opening

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Current Medical Science 2024年第4期44卷 748-758页

作者： Shan-shan HU Tong-yao wang Lu NI Fan-xin HU bo-wen YUE Ying zheng Tian-lun wang Abhishek KUMAR yan-yan wang Jin-e wang zhi-yong ZHOU Third-grade Pharmacological Laboratory of Traditional Chinese Medicine State Administration of Traditional Chinese MedicineChina Three Gorges UniversityYichang 443002China College of Medicine and Health Sciences China Three Gorges UniversityYichang 443002China College of Basic Medical Science China Three Gorges UniversityYichang 443002China

Objective Icariin(ICA)has a good neuroprotective effect and can upregulate neuronal basal autophagy in naturally aging *** dysfunction is associated with brain aging-related neurodegenerative *** opening of the mitochondrial permeability transition pore(mPTP)is a crucial factor in mitochondrial dysfunction and is associated with excessive *** study aimed to explore that ICA protects against neuronal injury by blocking the mPTP opening and down-regulating autophagy levels in a D-galactose(D-gal)-induced cell injury *** A cell model of neuronal injury was established in rat pheochromocytoma cells(PC12 cells)treated with 200 mmol/L D-gal for 48 *** this cell model,PC12 cells were pre-treated with different concentrations of ICA for 24 *** was used to detect cell *** associatedβ-galactosidase(SA-β-Gal)staining was used to observe cell *** blot analysis was performed to detect the expression levels of a senescence-related protein(p21),autophagy markers(LC3B,p62,Atg7,Atg5 and Beclin 1),mitochondrial fission and fusion-related proteins(Drp1,Mfn2 and Opa1),and mitophagy markers(Pink1 and Parkin).The changes of autophagic flow were detected by using mRFP-GFP-LC3 *** intracellular ultrastructure was observed by transmission electron *** was used to detect mPTP,mitochondrial membrane potential(MMP),mitochondrial reactive oxygen species(mtROS)and ROS *** and apoptosis levels were detected by flow *** D-gal treatment significantly decreased the viability of PC12 cells,and markedly increased the SA-β-Gal positive cells as compared to the control *** the D-gal stimulation,the expression of p21 was significantly ***,D-gal stimulation resulted in an elevated LC3B II/I ratio and decreased p62 ***,autophagosomes and autolysosomes were significantly increased,indicating abnormal activation of autophag

关键词： icariin neuronal injury mitochondrial dysfunction mitochondrial permeability transition pore autophagy

Microstructure and microtexture evolution characteristics of a powder metallurgy Ni-based superalloy during static recrystallization

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Journal of Iron and Steel Research International 2024年第9期31卷 2308-2325页

作者： zhi-qiang Li De-cheng wang Yue-wen Zhai Chao Jiang Le-yu Zhou zhi-guang Zhou Hui-zhen wang Zi-bo Zhang Lin yan Li-ping wang Guang Yu Department of Mechanical Engineering Tsinghua UniversityBeijing100084China Beijing Research Institute of Mechanical and Electrical Technology Co. Ltd.CAMBeijing100083China China Academy of Machinery Science and Technology Group Beijing100044China Institute of Advanced Manufacturing and Intelligent Technology Beijing University of TechnologyBeijing100124China

Static recrystallization(SRX)characteristics of a powder metallurgy superalloy were investigated by isothermal compression at 1080–1170℃ under strain rates of 0.01–0.1 s^(−1),strains of 0.1,0.22,or 0.5,and holding time of 0–300 *** impacts of temperature,strain rate,holding time,and strain on the SRXed grain size,volume fraction,and microtexture were explored by electron backscatter diffraction *** was found that temperature played a key role in these *** SRX progressed,thefiber parallel to the axis compression direction gradually weakened and was replaced by thefiber becausewas the preferred recrystallization orientation and grain growth direction for the Ni-based ***,high temperatures and low strain rates promoted the formation of the*** nucleation mechanisms during SRX process were found:grain boundary bulging,primary twin assistance,and subgrain *** boundary bulging occurred under all process conditions;however,at low temperatures and high strain rates,the latter two mechanisms could provide additional nucleation *** addition,SRX size and volume fraction models were established.

关键词： Powder metallurgy Ni-based superalloy Static recrystallization Microtexture evolution Recrystallization mechanism Prediction model