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Evaluation and assessment of semen for IVF/ICSI

Asian Journal of Andrology 2002年第4期4卷 281-285页

作者： d.y. liu H.W.G. Baker University of Melbourne department of Obstetrics and Gynaecology and Melbourne IVF and Reproductive Services Royal Women's Hospital Carlton Victoria 3053 AustraliaUniversity of Melbourne Department of Obstetrics and Gynaecology and Melbourne IVF and Reproductive Services Royal Women's Hospital Carlton Victoria 3053 Australia

Evaluation and assessment of semen is very important for both diagnosis of male infertility and selection of patients for treatment with IVF or ICSI. In standard IVF, sperm function is essential for normal fertilization: sperm must be able to bind to zona pellucida (ZP), undergo the acrosome reaction and penetrate the ZP and fuse with the oolemma before fertilization takes place. In contrast, most sperm functions are not required for fertilization in ICSI since sperm bypass the ZP and oolemma by injection of a single sperm directly into cytoplasm of oocyte. Therefore, the clinical decision on treatment of patients with either IVF or ICSI is mostly dependent on results of sperm tests. However, conventional semen analyses do not provide accurate information about sperm fertilizing ability since many patients with subtle sperm defects can not be detected. More advanced sperm function tests are required to detect sperm defects that may lead to failure of fertilization in standard IVF. In the last 15 years we performed extensive studies on relationship between sperm functions and fertilization rates by logistic regression analysis in large numbers of IVF patients including 370 patients with zero fertilization rate by IVF. We confirmed sperm morphology assessed strictly was strongly related to fertilisation rate with standard IVF. Thus sperm morphology assessment is very useful for selection of patients for ICSI. We also developed a number of new tests including sperm-ZP binding, sperm-ZP penetration and the ZP-induced AR and evaluated the clinical value of these tests. Sperm-ZP binding and sperm-ZP penetration tests are the most powerful indicators for sperm fertilizing ability in vitro. The ZP-induced AR is highly correlated with sperm-ZP penetration. We discovered a condition we call disordered ZP-induced AR which causes serve infertility in up to 25% men with otherwise idiopathic infertility In conclusion, the combination of semen analysis with advanced sperm function

关键词： male infertility sperm function tests sperm-oocyte interactions IVF/ICSI

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A STUdy OF ELECTROCHEMICAL BEHAVIOUR OF VARIOUS THERMAL HISTORy ZONES ANd dIFFERENT PHASE STRUCTURES ON THE WELdMENT FOR LOW ALLOy STEEL 16Mn IN NITRAfE SOLUTION

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Acta Metallurgica Sinica(English Letters) 1998年第4期11卷 270-274页

作者： y.S.Wu d.y. liu B. Cao F. L. Wang X.y. Wang Z.Fang and Z.G.du (department of Surface Science and Corrosion Engineering, University of Science and Technology Beijing,Beijing 100083, China) Univ of Science and Technology Beijing Beijing China

The electrochemical behaviour, including free corrosion potential, free corrosion current density and polarization curve, of various thermal history zones on the weldment was measured in this paper. The weldment consisted of matrix, tempering zone. incomplete normalized zone, normalized zone, overtemperature zone, fusion line zone and weld metal zone. The electrochemical behaviour of the ferrite, pearlite and mixed structure in various zones have successfully measured. The results showed that there was a difference of free corrosion potential which is smaller than ca. 200mV between various zones and about 20-150mV potential difference between ferrite and pearlite in every zone. The free cormsion potential of fusion line zone was the most negative between various zones. The free corrosion potential of pearlite was some dozens mV more negative than ferrite. The corrosion course of various zones and of different phase structures on the weldment and their effect on corrosion attack of weldment were discussed.

关键词： weldment phase electrochemistry galvanic effect thermal history zone

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Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen M M Chen y liu d W Cao G J Chen department of Microelectronics Jiangsu UniversityZhenjiang 212013China department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–Hong Kong–Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

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Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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Journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： y.B.Zhang S.J.Song F.liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3d CPFE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

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5α-reductase type 2 gene expression in human testis, epididymis and vas deferens

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Asian Journal of Andrology 2002年第4期4卷 306-306页

作者： d.y. liu, y.W. Wu, H.Z. Luo, Gui-yuan ZHANG National Institute for Family Planning Research, Beijing 100081, China

To study the expression pattern of 5α-reductase type 2 gene in human male reproductive organs. Methods: The expression level of 5ct-reductase type 2 gene in human testis, epididymis and vas deferens tissues was determined by in situ hybridization using a digoxin-labeled 5α-reductase type 2 cRNA probe. Results: The brown granules of hybridizing signals distributed in the cytoplasm of the Sertoli and Leydig cells of the testis, the principle cells of epididymis and the epithelial cells of vas deferens, but there was no positive signal in the nuclei of these cells. No positive signal was observed in the germ cells, basement of the testis, interstium of the epididymis and basement and the smooth muscle cells of vas deferens. Conclusion: This study confirmed that the 5a-reductase type 2 gene expressed in the Sertoli and Leydig cells of the testis and the principle cells of the epididymis. The expression pattem of the gene in these cells in the human was similar to that in the rat and monkey. The presence of 5α-reductase type 2 gene in the epithelial cells of the vas deferens suggests that it may play a physiological role in human reproduction. [Reprod Contracep (in English) 2002; 13: 67]

关键词： 5-alpha reductase isoenzymes gene expression

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Construction of 2d/2d Ti_(3)C_(2)T_(x)MXene/CdS heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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Journal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.y.Huang Z.yang S.y.yang Z.H.dai y.J.liu J.H.Liao G.y.Zhong Z.J.Xie y.P.Fang S.S.Zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2d)CdS nanosheets on 2d MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2d/2d structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

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The variation of dOM during long distance water transport by the China South to North Water diversion Scheme and impact on drinking water treatment

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 85-100页

作者： Hankun yang yujuan Li Hongyu liu Nigel J.d.Graham Xue Wu Jiawei Hou Mengjie liu Wenyu Wang Wenzheng yu State Key Laboratory of Environmental Aquatic Chemistry Key Laboratory of Drinking Water Science and TechnologyResearch Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China School of Environment and Municipal Engineering Qingdao Technological UniversityQingdao266033China Colleges of Forestry Northeast Forestry UniversityHarbin150006China department of Civil and Environmental Engineering Imperial College LondonSouth Kensington CampusLondonSW7 2AZUK School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing100081China State Key Laboratory of Separation Membrane Processes School of Environment Science and EngineeringTiangong UniversityTianjin300387China

In this study,samples were taken from three locations,upstream to downstream,along the central route project of the China South to North Water diversion(SNWd)scheme in summer and *** were used to reveal the variations of dissolved organic matter(dOM)during the water transfer process,and the effects of these variations on drinking water treatment and disinfection by-products formation potential(dBPs-FP).The results showed that polysaccharides accumulate in summer and reduce in winter with flow distance,which has an important effect on the overall properties of dOM,as well as on the performance of coagulation,ultrafiltration,and the formation of *** substances,and their hydrophilic content,also increased in summer and decreased in winter with flow *** contrast,the concentration of small organic substances(MW≤1000 da)increased in both summer and winter with flow distance,which affected both nanofiltration(NF)membrane fouling and *** results provide a useful case study of spatial and temporal changes in raw water dOM during long distance water transfer and their impact on the treatment and quality of drinking water from the SNWd.

关键词： Long-distance water transfer The China South to North Water diversion Scheme Coagulation Membrane filtration disinfection by-products

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Prescribed-Time Nash Equilibrium Seeking for Pursuit-Evasion Game

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1518-1520页

作者： Lei Xue Jianfeng ye yongbao Wu Jian liu d.C.Wunsch Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of EducationNanjing 210096 School of Automation Southeast UniversityNanjing 210096China department of Electrical and Computer Engineering Missouri University of Science and TechnologyRollaMO 65409 USA IEEE

dear Editor,This letter is concerned with prescribed-time Nash equilibrium(PTNE)seeking problem in a pursuit-evasion game(PEG)involving agents with second-order *** order to achieve the prior-given and user-defined convergence time for the PEG,a PTNE seeking algorithm has been developed to facilitate collaboration among multiple pursuers for capturing the evader without the need for any global ***,it is theoretically proved that the prescribedtime convergence of the designed algorithm for achieving Nash equilibrium of ***,the effectiveness of the PTNE method was validated by numerical simulation results.A PEG consists of two groups of agents:evaders and *** pursuers aim to capture the evaders through cooperative efforts,while the evaders strive to evade *** is a classic noncooperative *** has attracted plenty of attention due to its wide application scenarios,such as smart grids[1],formation control[2],[3],and spacecraft rendezvous[4].It is noteworthy that most previous research on seeking the Nash equilibrium of the game,where no agent has an incentive to change its actions,has focused on asymptotic and exponential convergence[5]-[7].

关键词： seeking prescribed convergence

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Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)C+Al_(2)O_(3))/Al Neutron Absorbing Materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai B.M.Shi N.Li y.liu Z.G.Zhang y.N.Zan Q.Z.Wang B.L.Xiao Z.y.Ma Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)C/Al composites.

关键词： Al matrix composites Neutron absorbing materials (B_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

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Frequency Regulation of VSC-MTdC System with Offshore Wind Farms

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 275-286页

作者： Haoyu liu Chongru liu North China Electric Power University Beijing 102206China

Frequency regulation of voltage source converter-based multi-terminal high-voltage direct current(VSC-MTdC)system with offshore wind farms enhances the frequency stability by compensating the power for a disturbed AC ***,it is difficult to reasonably allocate frequency-regulation resources due to a lack of coordination mechanisms between wind farms and the MTdC ***,it is difficult for the frequency control of the wind farms to manage changes in wind speed;and the risk of wind-turbine stalls is ***,based on the kinetic energy of wind turbines and the power margin of the converters,the frequency-regulation capability of wind turbines is evaluated,and a dynamic frequency-support scheme considering the real-time frequency-support capability of the wind turbines and system frequency evolution is proposed to improve the frequency-support performance.A power adaptation technique at variable wind speeds is developed;the active power in the frequency-support stage and restoration stage is switched according to the wind speed.A hierarchical zoning frequency-regulation scheme is designed to use the frequency-regulation resources of different links in the MTdC system with wind *** simulation results show that the novel frequency-regulation strategy maintains frequency stability with wind-speed changes and avoids multiple frequency dips.

关键词： Wind generation voltage source converter-based multi-terminal high-voltage direct current(VSC-MTdC) frequency regulation cooperative control adaptive control variable wind speed

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