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Research on Ultrafine Tungsten Carbide-Cobalt(WC-Co) Cemented Carbide Rods of Miniature Drills for Highly Integrated Printed Circuit Board(PCB)

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Journal of materials Science & Technology 2005年第3期21卷 353-356页

作者： Xiaoliang SHI, Gangqin SHAO, Xinglong DUAN and runzhang yuan {2. key Laboratory of Advanced Technology for {4. synthesis & processing, wuhan university of Technology, wuhan 4.0070, china Lab. of Advanced Technology for materials synthesis and {2. Wuhan University of Technology Wuhan 430070 China

Nanocrystalline tungsten carbide-cobalt (WC-Co) composite powders produced through spray thermal decomposition-continuous reduction and carburization technology were used to prepare φ3.2. mm×38 mm ultrafine tungsten carbide-cobalt (WC-Co) cemented carbide rods through vacuum sintering plus sinterhip technology. The microstructure, Vickers hardness, density and Rockwell A hardness (HRA), transverse rupture strength (TRS), saturated magnetization and coercivity force were tested. The results show that the average grain size of the sintering body prepared through vacuum sintering plus sinterhip technology was 4.0 nm; transverse rupture strength (TRS) was 3850 MPa; Vickers hardness was 1890 and Rockwell A hardness of sintering body was 93. High strength and high hardness ultrafine WC-Co cemented carbide rods used to manufacture printed circuit board (PCB) drills were obtained.

关键词： Nanocrystalline Composite powder Cemented carbide Rods

Nafion/Silicon Oxide Composite Membrane for High Temperature Proton Exchange Membrane Fuel Cell

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Journal of wuhan university of Technology({2. Science) 2007年第3期22卷 478-481页

作者：余军 state key Laboratory of Advanced Technology for {2. synthesis and {4. Wuhan University of Technology

Nafion/Silicon oxide composite membranes were produced via in situ sol-gel reaction of tetraethylorthosilicate （TEOS） in Nafion membranes. The physicochemical properties of the membranes were studied by FT-IR,TG-DSC and tensile strength. The results show that the silicon oxide is compatible with the Nation membrane and the thermo stability of Nation/Silicon oxide composite membrane is higher than that of Nation membrane. Furthermore, the tensile strength of Nation/Silicon oxide composite membrane is similar to that of the Nation membrane. The proton conductivity of Nation/Silicon oxide composite membrane is higher than that of Nation membrane. When the Nation/Silicon oxide composite membrane was employed as an electrolyte in H2.O2.PEMFC, a higher current density value （1 000 mA/cm^2.at 0.38 V） than that of the Nafion1135 membrane （100 mA/cm^2.at 0.04.V） was obtained at 110 ℃.

关键词： PEMFC composite membrane silicon oxide high temperature

Fabrication of A1/Al_2._3 Composites and FGM

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Journal of materials Science & Technology 2001年第6期17卷 646-648页

作者： Hong TAO, chengji DENG, Lianmeng ZHANG and runzhang {2. state {4. Laboratory of Advanced Technology for materials synthesis and processing, wuhan university of Technology, wuhan 4.0070, china [Manuscript received November 2. wuhan Univ. of Technol. Wuhan 430070 China

Al/Al2.3 composites of different ratios were hot-press sintered at 575~64.℃ under a pressure of 30 MPa for 2.h in a vacuum furnace. It was found that the relative density of the Al/Al2.3 composites could be increased evidently with the rise of sinter temperature. No reaction occurred between At and Al2.3 at the sinter temperatures. Under 64.℃-30 MPa-2.h experimental condition, Al/Al2.3 system FGM was successfully fabricated, and its density range changed quasi-continuously from 2.887×103 kg/m3 to 3.1909×103 kg/m3 within the middle 1.0 mm thickness range.

关键词： Fabrication of Al/Al2.3 Composites and FGM Co Al

Fractal Analysis of Gas Diffusion Layer in PEM Fuel Cells

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Journal of wuhan university of Technology({2. Science) 2006年第1期21卷 22-25页

作者：石英肖金生 state key Laboratory of Advanced Technology for {2. synthesis and {4. Wuhan University of Technology Wuhan 430070ChinaSchool of Automation Wuhan University of Technology Wuhan 430070 China state key Laboratory of Advanced Technology for {2. synthesis and {4. Wuhan University of Technology Wuhan 430070ChinaSchool of Automotive EngineeringWuhan University of Technology Wuhan 430070China

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer （GDL） in Proton Exchange Membrane Fuel Cell （PEMFC）. The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene （PTFE） treated carbon paper shows a significantly high fractal dimension value than pare sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modificatious in the processing of materials.

关键词： PEMFC gas diffusion layer fractal dimension mewury porosimetry

Dynamic Sulfur-Rich Polymers from Elemental Sulfur and Epoxides

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Chinese Journal of Polymer Science 2024年第10期42卷 1479-1487,I0010页

作者： Ke-Xiang chen chen-Hui Cui Zhen Li Ting {2. Hao-qing Teng Zhi-{4. He Yin-Zhou Guo Xiao-qing Ming Zhi-Shen Ge Yan-Feng Zhang Tie-Jun Wang School of Chemistry Engineering Research Center of Energy Storage Materials and DevicesMinistry of EducationXi’an Jiaotong UniversityXi’an710049China state key Lab for Strength and Vibration of Mechanical Structures Department of Engineering MechanicsXi’an Jiaotong UniversityXi’an710049China

Sulfur-containing dynamic polymers had attracted significant attention due to their unique chemical structures with high *** sulfur, an inexpensive industrial waste product, to synthesize dynamic polysulfide polymers through reverse vulcanization has been a notable approach. However, this method required high temperatures and resulted in the release of unpleasant oders. In this study, we presented a robust method for the preparation of sulfur-rich polymers with dynamic polysulfide bonds from elemental sulfur and inexpensive epoxide monomers via a one-pot strategy at the mild room temperature. Different types of polysulfide molecules and polymers were synthesized by reacting various epoxide compounds with sulfur, along with the investigation of their structures and dynamic behaviors. It was noteworthy that the obatined polymers prepared from m-(2.3-epoxypropoxy)-N,N-bis(2.3-epoxypropyl)aniline and elemental sulfur exhibit multiple dynamic behaviors, including polysulfide metathesis and polysulfide-thiol exchange, enabling their rapid stress relaxation, self-healing, reprocessing and degradable properties of the cross-linked polymer. More importantly, the hydroxyl groups at the side chains from epoxide ring opening exhibited potential transesterification. This work provided a facile strategy for designing dynamic sulfur-rich polymers via a mild synthesis route.

关键词： Elemental sulfur Sulfur-containing polymer Dynamic covalent bond Dynamic polymer

INTERPHASE　STRESS　CORROSION　CRACKING　OF　ALLOY　Ti－2.Al－11Nb　IN　METHANOL　SOLUTION

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Acta Metallurgica Sinica(English Letters) 1996年第2期9卷 121-128页

作者： ZHANG Yue CHU Wuyang XIAO Jimei(Department of materials Physics,university of Science and Technology Beijing,Beijing 100083,{2.) OUYANG Shixi yuan {4.(state key Laboratory for synthesis and processing of Advanced materials.wuhan university of Techn Univ of Science and Technology Beijing Beijing China

For alloy Ti-2.Al-11Nb,stress corrosion cracking(SCC) in methanol solution and hydrogen induced cracking(HIC) during dynamic charging at room temperature have been *** has shown that the normalised threshold stress intensities of SCC failure for various microstructures are KISCC/KC =0.53 0.69 and the threshold value for SCC arresting KISCC/ KIC=*** threshold values of HIC during dynamic charging are close to that of SCC,but da/dt or fracture time of HIC is one to three orders of magnitude smaller or longer than that of SCC,*** surface for HIC is also different from that for *** the Ti-2.Al-Nb alloy-methanol systein,a kind of inierphase SCC has been found For the microstructures resulting from furnace cooling,SCC initiated and propagated preferentially along theα2.βinterphase boundaries,displaying the microstructure on the fracture surface of ***,there is no interphase SCC for the microstructure resulting from air cooling.

关键词： Ti-2.Al-11Nb,hydrogen induced cracking,interphase stress corrosion cracking methanol

Novel Magnetorheological Suspensions Based on Co-Phthalocyanine/Fe Nanocomposite Particles

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Journal of materials Science & Technology 2001年第5期17卷 511-516页

作者： Rongzhou GONG and Zekun FENG Dept. of Electronic Science and Technology, Huazhong university of Science and Technology, wuhan 4.0074.{2. Jianguo GUAN and runzhang {4. state key Laboratory of Advanced Technology for materials synthesis and processing, wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430070 Peoples R China Huazhong Univ Sci & Technol Dept Elect Sci & Technol Wuhan 430074 Peoples R China

A novel magnetorheological (MR) suspension was based on methyl silicone oil and cobalt-phthalocyanine (Co-Pc)/Fe nanocomposite particles, which were synthesized by thermally decomposing liquid carbonyl Fe in the solution of Co-Pc in N, N-dimethyl formamide. The nanocomposite particles were fully characterized by XRD, SEM and HREM, and the thermal, magnetic and MR properties of nanocomposite particles were measured. Such factors as weight percent of particles (w), magnetic field strength (H), temperature (T) and shear rate (gamma) etc influencing on MR properties were investigated. The results indicated that Co-Pc/Fe nanocomposite with density of 3.66 g/cm(3) was almost micro-sized regular spheroids consisting of tens of Co-Pc coated alpha -Fe nanoparticles in inner and Co-Pc layers on surface of the spheroids. They showed good characteristics of anti-oxidation and soft magnetic. Increment of w increased field-induced shear stress (Delta tau) and zero-field viscosity (eta (0)) of MR suspensions monotonously, and improved anti-settlement stability, but eta (0) increased more markedly than Delta tau with increasing w. Delta tau was basically independent on T and gamma while increased obviously with increasing H. With increasing T, response time of the MR suspension to external magnetic field seemed to decrease. As a result, MR suspensions with satisfactory stability and rapid, completely reversible and significant MR effect can be obtained from Co-Pc/Fe nanocomposite particles.

关键词： Fe Co Novel Magnetorheological Suspensions Based on Co-Phthalocyanine/Fe Nanocomposite Particles

Effect of Grinding and Polishing on the Residual Stress and Bending Strength of a Silicon Nitride Ceramic

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Journal of wuhan university of Technology({2. Science) 2005年第1期20卷 46-48页

作者：高玲 state key Lab of Advanced Technology for {2. synthesis and {4. Wuhan University of TechnologyWuhan 430070China

The residual stresses on the surface of the d ifferently ground and polished silicon nitride ceramics were measured using X-r ay diffraction and identified by *** effect of the residual stress on the be nding strength was *** investigations show that the grinding proces s can introduce subatantial tensile residual stresses up to 2.0MPa on the surfac e of silicon nitride ceramics,which has a significant effect on reducing the ben ding strength of the ceramics after ***,in comparison with the ceramic s with a rough surface,the ceramics with a mirror image surface may have a lower *** can smooth the residual *** we evaluate the qualit y of the ceramic components after grinding,we must take residual stress into con sideration. The grinding methods and grinding conditions must be carefully selec ted in order to get the favorite residual stress as well as the surface smoothne ss.

关键词： residual stress grinding bending strengt h ceramics

Follicle stimulating hormone controls granulosa cell glutamine synthesis to regulate ovulation

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Protein & Cell 2024年第7期15卷 512-529页

作者： Kai-Hui Zhang Fei-Fei Zhang Zhi-Ling Zhang Ke-Fei Fang wen-Xing Sun Na Kong Min Wu Hai-Ou Liu Yan Liu Zhi Li qing-qing Cai Yang Wang Quan-Wei Wei Peng-cheng Lin Yan Lin Wei {4. Cong-Jian {4. Yi-yuan yuan Shi-Min Zhao The Obstetrics&Gynecology Hospital of Fudan university State Key Laboratory of Genetic EngineeringFudan UniversityShanghai 200090China Shanghai key Laboratory of Metabolic Remodeling and Children’s Hospital of Fudan UniversityShanghai 200032China School of Life Sciences and Institutes of Biomedical Sciences Fudan UniversityShanghai 200438China Department of Nutrition and Food Hygiene School of Public HealthNantong UniversityNantong 226019China Reproductive Medicine Center The Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing 210008China Shanghai Fifth People’s Hospital of Fudan university Fudan UniversityShanghai 200240China Department of Animal Science and Technology Nanjing Agricultural UniversityNanjing 210014China key Laboratory for Tibet Plateau Phytochemistry of qinghai Province College of PharmacyQinghai University for NationalitiesXining 810007China Pediatric Research Institute Children’s Hospital Affiliated to Shandong University(Jinan Children’s Hospital)Jinan 250022China

Polycystic ovary syndrome(PCOS)is the leading cause of anovulatory *** understanding of the ovulation drivers hinders PCOS ***,we report that follicle stimulating hormone(FSH)controls follicular fluid(FF)glutamine levels to determine *** ovulation starts from FF-exposing granulosa cell(GC)*** glutamine,which decreases in pre-ovulation porcine FF,elevates in PCOS patients ***-glutamine chow to elevate FF glutamine inhibits mouse GC apoptosis and induces hormonal,metabolic,and morphologic PCOS ***,follicle-development-driving FSH promotes GC glutamine synthesis to elevate FF glutamine,which maintain follicle wall integrity by inhibiting GC apoptosis through inactivating ASK1-JNK apoptotic *** and glutamine inhibit the rapture of cultured murine *** removal or ASK1-JNK pathway activation with metformin or AT-101 reversed PCOS traits in PCOS models that are induced with either glutamine or *** suggest that glutamine,FSH,and ASK1-JNK pathway are targetable to alleviate PCOS.

关键词： ovulation glutamine granulosa cells PCOS FSH