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LH Plays a Role to Enhance the Nuclear and Cytoplasm Synchronization During In vitro Maturation of Ovine Oocytes

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Agricultural Sciences in China 2011年第1期10卷 136-141页

作者： LI Kai NI He-min LIU yun-hai ZHAO yan-wei QU yang-yan LI Xiao-yan GUO Yong Department of Animal Science ＆ Technology Beijing University o[ Agriculture Beijing 102206 P.R.China

This study is aimed to investigate the effect of luteinizing hormone （LH） on maturation and fertilization in vitro of ovine oocytes. The ovine oocytes were cultured in vitro in medium with or without LH, and then checked by confocal laser scanning microscope to observe the distribution of cortical granules stained with FITC-LCA during different maturation periods. Similarly, some in vitro matured oocytes were also fertilized in vitro for analysis of their developmental potentiality further. After being cultured in vitro for 4 h, there were significant differences about the rate of germinal vesicle break down （GVBD） between the treatment （with LH） and the control groups （without any hormones）（36.76% vs 18%, P〈0.05）. Further, there were also significant differences of the cleavage and blastocyst rates between these two groups （67.15% vs 42.37%, 21.9% vs 12.71%, P〈0.05, respectively）. The distribution of cortical granules appeared to spread from the edges to the central site of sheep oocytes following their delaying durations of maturation in vitro. It can be concluded that LH may play a role to delay the occurence of GVBD, prolong the maturation duration of cytoplasm, and enhance the nuclear and cytoplasm synchronization of ovine oocytes matured in vitro and finally improve their in vitro developmental potentiality.

关键词： ovine oocyte luteinizing hormone in vitro maturation in vitro fertilization distribution of cortical granules

Novel chiral multidentate P3N4-type ligand for asymmetric transfer hydrogenation of aromatic ketones

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Chinese Chemical Letters 2017年第1期28卷 97-100页

作者： Meng Tao Fang Wu Teng Li yan-yun Li Jing-Xing Gao College of Chemistry and Chemical Engineering and National Engineering Laboratory for Green Chemical Production of Alcohols-Ethers-EstersXiamen University Xiamen 361005 China

Novel chiral multidentate P3N4-type ligand has been synthesized and characterized by NMR and *** i-PrOH as solvent and hydrogen source, asymmetric transfer hydrogenation of various ketones was investigated. The catalyst generated in situ from chiral multidentate aminophosphine ligand（R,R,R,R）-3 and IrCl（CO）（PPh3）2exhibited highly catalytic activity and excellent enantioselectivity under mild conditions, achieving the corresponding chiral alcohols with up to 99% yield and 99% ee.

关键词： Chiral aminophosphine ligand Asymmetric catalysis Asymmetric transfer hydrogenation Chiral alcohols Aromatic ketones

Review of the fatigue behavior of hard coating–ductile substrate systems

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International Journal of Minerals,Metallurgy and Materials 2021年第1期28卷 46-55页

作者： yan-yun Bai Jin Gao Tao Guo Ke-wei Gao Alex A.Volinsky Xiao-lu Pang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Department of Mechanical Engineering University of South FloridaTampaFL 33620USA Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China

With the wide application of coating materials in aerospace and other fields, their safety under fatigue conditions in service is ***, research on the fatigue properties of ceramic hard coatings started late, and a unified standard is yet to be established to evaluate the fatigue life of hard coating–ductile substrate *** also present different opinions on whether coatings can improve or reduce the fatigue life of *** this paper, the influence of the properties of ceramic coatings on fatigue performance is reviewed, and the effects of coating on the mechanism of fatigue crack initiation in substrates are discussed, aiming to help readers understand the fatigue behavior of hard coating–ductile substrate systems.

关键词： fatigue hard coating residual stress fracture toughness film thickness

Observer-based Output-feedback Stabilization Control Design for a Class of Nonlinear Uncertain Systems

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自动化学报 2006年第1期32卷 101-106页

作者： ZHANG yun LIU yun-Gang LI yan-Fang School of Control Science and Engineering Shandong University Jinan 250061

The output-feedback stabilization control problem is investigated for a class of nonlinear uncertain systems. Based on the multivariable analog of circle criterion, an observer is designed to estimate the system states and hence the dynamical equations that the estimation error satisfies are derived first. Then, by using integral backstepping approach together with completing square technique, the output-feedback stabilization control is constructively designed such that the closed-loop system is asymptotically stable. Finally, an example is given to illustrate the main results of this paper.

关键词：非线性系统不确定性输出反馈稳定性误差估计

INTERMOLECULAR AND INTRAMOLECULAR INTERACTIONS OF POLYMER GUAR GUM IN SOLUTIONS

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Chinese Journal of Polymer Science 2005年第5期23卷 557-559页

作者： yun-fei yan Hai-yang yang Wen-yong Liu Ping-ping Zhu Ping-sheng He Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China Structure Research Laboratory University of Science and Technology of China Hefei 230026 China

The tetrahedral borate ion can crosslink with polymer guar gum in aqueous solutions. If the concentration of guar gum is less than 0.045 g/dL, the intramolecular interaction between guar gum and borate ion increases due to the formation of crosslinks. As a result, the polymer chains of guar gum in solution shrink in size and the reduced viscosity of polymer solution decreases accordingly. On the other hand, if the concentration of guar gum is greater than 0.045 g/dL, the intermolecular interaction becomes apparent due to the same reason. The polymer chains, therefore, associate together and the reduced viscosity of polymer solution increases considerably. According to this technique, the critical concentration c^＊, presented by de-Gennes, is determined successfully.

关键词： Guar gum Crosslink reaction Critical concentration c^*.

Non-Adiabatic Molecular Dynamics Simulations of Non-Charge-Transfer and Charge-Transfer Scattering in H^++CO2 at ELab=30 eV

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Chinese Journal of Chemical Physics 2018年第3期31卷 300-312,367,368页

作者： yun-An yan Jorge A.Morales Guizhou Provincial Key Laboratory of Computational Nano-material Science Guizhou Education University Guiyang 550018China Department of Chemistry and Biochemistry Texas Tech UniversityPO Box 41061LubbockTX 79409-1061USA

The H^++CO2 reaction at high energies is relevant in atmospheric chemistry,astrophysics,and proton cancer therapy ***,we present herein a complete investigation of H^++CO2 at ELab=30 eV with the simplest-level electron nuclear dynamics(SLEND)*** describes nuclei via classical mechanics and electrons with a singledeterminantal Thouless *** 3402 SLEND conducted simulations from 42 independent CO2 target orientations provide a full description of all the reactive processes and their mechanisms in this system:non-charge-transfer scattering(NCTS),charge-transfer scattering(CTS),and single C=O bond dissociation;all this valuable information about reactivity is not accessible *** details of the projectile scattering patterns are provided,including the appearance and coalescence of primary and secondary rainbow angles as a function of the target *** NCTS and CTS differential cross sections(DCSs)are evaluated in conjunction with advanced semi-classical *** NCTS DCS agrees well with its experimental counterpart at all the measured scattering angles,whereas SLEND CTS DCS agrees well at high scattering angles but less satisfactorily at lower ***,both NCTS and CTS SLEND DCSs predict the primary rainbow angle signatures in agreement with the experiment.

关键词： Quantum non-adiabatic dynamics Proton-molecule reactions Chargetransfer reactions Primary and secondary rainbow angle effects Collision-induced bond breaking Proton cancer therapy

Effectiveness of Tenofovir Alafenamide in Chronic Hepatitis B Patients with Normal Alanine Aminotransferase and Positive Hepatitis B Virus DNA

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Journal of Clinical and Translational Hepatology 2022年第1期10卷 112-119页

作者： Wen-Kang Gao yan-yun Shu Yue Chen yan Ai Xiao-Qian yang Fan Du Jin Ye Division of Gastroenterology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina

Background and Aims:With an increasing understanding of hepatitis B,the antiviral indications have been broadening *** evaluate the effectiveness of tenofovir alafena-mide(TAF)in chronic hepatitis B(CHB)patients with normal alanine aminotransferase(ALT)and detectable hepatitis B virus(HBV)DNA,those who are ineligible for broader anti-viral criteria from the Chinese CHB prevention guide(2019).Methods:A total of 117 patients were recruited and their data were collected from paper or electronic medical *** DNA and liver function were measured at baseline and throughout the 24-week *** effectiveness end-point was complete virological *** safety endpoint was the first occurrence of any clinical adverse event during the ***:Among the 117 patients,45 had normal ALT as well as detectable HBV DNA and they were not recommended for antiviral therapy according to Chinese Guidelines(2019).After TAF antiviral therapy,the rates of patients who achieved HBV DNA<20 IU/mL at 4,12 and 24 weeks were 77.1%,96.7%and 96.8%*** them,the undetectable rates of HBV DNA in patients with low baseline viral load at 4,12 and 24 weeks were 92.3%,100%and 100%,while the rates of those with high baseline viral load were 68.2%,94.1%and 94.4%.Compared with 71.4%,94.4%and 94.7%in the high baseline group,the undetectable rates of HBV DNA at 4,12 and 24 weeks in the low baseline liver stiffness group were 85.7%,100%and 100%.There was no statistical significance among the above ***:CHB patients who had normal ALT and detectable HBV DNA and did not meet“CHB prevention guide(2019)”,could achieve complete virological response in 24 weeks after antiviral treatment by TAF.

关键词： Chronic hepatitis B virus Tenofovir alafenamide Effectiveness Observational study

Luminescence enhancement of CaMoO_(4):Eu^(3+) phosphor by charge compensation using microwave sintering method

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Journal of Advanced Ceramics 2015年第4期4卷 318-325页

作者： Zhiping ZHOU Yingsen YU Xiaotang LIU Weihao YE Guangqi HU Bingfu LEI yun yan College of Materials and Energy South China Agricultural UniversityGuangzhou 510642China

CaMoO_(4):Eu^(3+)and CaMoO_(4):Eu^(3+),A+(A=Li,Na,K)phosphors for light-emitting diode(LED)applications have been prepared by microwave sintering method(MSM),and their structure and luminescence properties are *** influences of microwave reaction time and concentration of different kinds of charge compensation A+and Eu^(3+)on luminescence have also been *** samples emit a red luminescence at 615 nm attributed to the^(5)D0→^(7)F2 transition of Eu^(3+)under 464 nm *** is observed that adding charge compensation A+in the sample synthesis increases luminescence *** optimized sample made with 32 mol%Li+and 32 mol%Eu^(3+)has an enhancement factor of 4 in photoluminescence compared to the sample made without charge *** CIE(Commission Internationale de l'Eclairage)coordinates of Ca0.36MoO_(4):0.32Eu^(3+),0.32Li+are x=0.661 and y=0.339,which indicate that the obtained phosphor can be a promising red color candidate for white LED fabrications.

关键词： CaMoO4:Eu^(3+)phosphor luminescence enhancement charge compensation microwave sintering white light-emitting diode(LED)

Orthogonal Experiments on Direct Reduction of Carbon-bearing Pellets of Bayer Red Mud

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Journal of Iron and Steel Research International 2015年第8期22卷 686-693页

作者： Dun-cheng FAN Wen NI Ai-yun yan Jian-yue WANG Wei-hua CUI Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines University of Science and Technology Beijing Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants University of Science and Technology Beijing School of Civil and Environmental Engineering University of Science and Technology Beijing School of Water Resources Environment China University of Geosciences

To recycle residual iron efficiently in Bayer red mud, three-factor three-level orthogonal experiments on carbon-bearing pellets of Bayer red mud were conducted on the basis of their characteristics. The influences of CaO dosage, temperature and roast- ing time on total iron content and iron recovery of reduced iron powder were studied. Results showed that these factors slightly influenced iron recovery, but significantly influenced total iron content. The principal factor influencing total iron content was CaO dosage, followed by temperature and roasting time. An increase in CaO dosage could decrease total iron content, whereas an increase in temperature and an extension of roasting time could improve total iron content. The reduced iron powder with total iron content of 88.4 l% and iron recovery rate of 97.97% can be obtained under the optimal conditions of temperature of 1 275 ℃, roasting time of 60 min and CaO dosage of 7.5%. The X-ray diffraction （XRD） and scanning electron microscopy （SEM） analyses of the reduced pellets showed that iron minerals in red mud were almost completely reduced to metallic iron. The principal factor influencing the total iron content of reduced iron powder was the grain size of metallic iron particles. An increase in CaO dosage hindered the growth of metallic iron particles, whereas an increase in temperature and an extension of roasting time could neutralise the effect of CaO dosage. Therefore, CaO dosage should be decreased when iron minerals in red mud can be adequately reduced into metallic iron.

关键词： Bayer red mud direct reduction orthogonal experiment iron particle growth