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Periodic Solution to BAM-type Cohen-Grossberg Neural Network with Time-varying Delays

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 427-442页

作者： An-ping Chen qun-hua gu Department of Mathematics Xiangnan University Chenzhou Hunan 423000 China School of Mathematics and Computational Science Xiangtan University Xiangtan Hunan 411005 China

By using the continuation theorem of Mawhin＇s coincidence degree theory and the Liapunov func tional method, some sufficient conditions are obtained to ensure the existence, uniqueness and the global exponential stab... 详细信息

关键词： periodic solution time-varying delays global exponential stability BAM-type Cohen-Grossberg neural network coincidence degree theory

Predictors for partial suppression of spermatogenesis of hormonal male contraception

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Asian Journal of Andrology 2008年第5期10卷 723-730页

作者： Jing-Wen Li Yi-qun gu peking Union Medical College Postgraduate School Beijing 100730 China National Research Institute for Family Planning Beijing 100081 China

Aim： To analyze factors influencing the efficacy of hormonal suppression of spermatogenesis for male contraception. Methods： A nested case-control study was conducted, involving 43 subjects, who did not achieve azoospermia or severe oligozoospermia when given monthly injections of 500 mg testosterone undecanoate （TU）, defined as partial suppressors compared with 855 subjects who had suppressed spermatogenesis （complete suppressors）. Sperm density, serum testosterone, luteinizing hormone （LH） and follicle stimulating hormone （FSH） concentrations at the baseline and the suppression phase were compared between partial and complete suppressors. Polymorphisms of androgen receptor （AR） and three single nucleotide variants and their haplotypes of FSH receptor （FSHR） genes determined by polymerase chain reaction （PCR） and DNA sequencing technique were compared between 29 partial and 34 complete suppressors. Results： Baseline serum LH level was higher and serum LH as well as FSH level during the suppression phase was less suppressed in partial suppressors. Additionally, in a logistic regression analysis larger testis volume, higher serum FSH concentrations alone, or interaction of serum LH, FSH, testosterone and sperm concentrations were associated with degree of suppression. The distribution of polymorphisms of AR or FSH receptor genes did not differ between partial and complete suppressors. In cases with incomplete FSH suppression （FSH 〉 0.2 IU/L）, the chances of reaching azoospermia were 1.5 times higher in the subjects with more than 22 CAG triplet repeats. Conclusion： Partial suppression of spermatogenesis induced by 500 mg TU monthly injections is weakly influenced by hormonal and clinical features but not polymorphism in AR and FSHR genes.

关键词： male contraception genetic polymorphism androgen receptor CAG repeats follicle stimulating hormone receptor single nucleotide polymorphism sperm concentration

Testosterone replacement therapy： dilemmas and challenges in China and Asia

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Asian Journal of Andrology 2018年第2期20卷 149-151页

作者： Qi An Yi-qun gu Graduate School Peking Union Medical College Beijing 100730 China Nationa Health and Family Planning Key Laboratory of Male Reproductive Health National Research Institute for Family Planning Beijing 100081 China

Late-onset hypogonadism （LOH） has been described as a clinical syndrome comprising symptoms consistent with androgen deficiency and a circulating concentration of testosterone in the low-to-normal range in some middle-aged and elderly men. The presence of symptoms may affect the health and quality of life in aging men and it has become a hot spot in global medical research, diagnosis, and treatment in the recent years.

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Insights into semen analysis： a Chinese perspective on the fifth edition of the WHO laboratory manual for the examination and processing of human semen

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Asian Journal of Andrology 2010年第4期12卷 605-606页

作者： Wen-Hong Lu Yi-qun gu National Research Institute for Family Planning Beijing 100081 China

We are very glad to see that the Asian Journal of Andrology published a Special Issue on Semen Analysis in 21st Century Medicine, which well revealed some behind-the-scene controversies of the 5th edition of the WHO laboratory manual for the examination and processing of human semen [1]. Three articles from the special issue, two on the reference values of semen parameters [2, 3] and another presenting the investigation results of 118 laboratories performing semen analysis in China's Mainland [4], are very thoughtprovoking and we would like to share some of our views on these topics.

关键词： WHO laboratory examination semen

The Synthesis and Characterization of High Molecular Weight Poly(phenylene sulfide/ether)

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Chinese Chemical Letters 2006年第10期17卷 1373-1376页

作者： Ai qun gu Mei Ju XIE Zi Li YU Institute of Materials Science ＆ Technology Analytical ＆ Testing Center Sichuan University Chengdu 610064

Poly（phenylene sulfide/ether）（PPSE） was synthesized from 4,4＇-dihydroxydiphenyl sulfide and 4,4＇-dichlorodiphenyl sulfide in solution by nucleophilic substitution reaction. The resulting polymer was characterized by viscosity measurement, elemental analysis, FT-IR, ^1H NMR, X-ray diffraction and thermal analysis. The results showed that the viscosities of the resulting polymer were above 0.68 dL/g, and the linear chain structure of product was confirmed. PPSE had the same reflex indices as poly（p-phenylene sulfide）, an orthorhombic crystalline with unit cell a=0.853, b=0.562, c=1.026nm. The melting temperature, glass transition temperature and initial decomposition temperature were found to be 228℃, 85℃ and 325℃, respectively. The product was soluble in common organic solvents such as NMP, N, N＇-dimethylformamide, N, N＇-dimethylacetamide and 1,2-dichloroethane.

关键词： Poly(phenylene sulfide/ether) (PPSE) synthesis characterization.

Characterization of Structural Knot Distributions in UHMWPE Fibers

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Chinese Journal of Polymer Science 2016年第5期34卷 606-615页

作者： Hao-jun Xu Min-fang An You Lv 王宗宝 qun gu Ningbo Key Laboratory of Specialty Polymers Faculty of Materials Sctence and Chemical Engineering Ningbo University Ningbo 315211 China College of Material Engineering Ningbo University of Technology Ningbo 315211 China

Microbeam wide-angle X-ray diffraction（WAXD） experiments were carried out at different structural knot positions of SIOC and M4 fibers of ultra-high molecular weight polyethylene（UHMWPE）. The optical microscope images revealed that SIOC fiber had bamboo-like structural knots, and M4 fiber had chaotic distribution of structural knots. WAXD patterns showed the monoclinic unit cell in the whole M4 fiber, but different lamellar orientations in the bamboo joint of SIOC fiber. In addition, small-angle X-ray scattering（SAXS） patterns confirmed that the SIOC fiber contained uniform distribution of shish structures, and differential scanning calorimetry（DSC） measurements showed that its less branched and short chains benefited the orthorhombic-hexagonal phase transformation.

关键词： UHMWPE shish hexagonal calorimetry SAXS lamellar bamboo crystalline chains WAXD

Structure and Properties of Gel-spun Ultra-high Molecular Weight Polyethylene Fibers with High Gel Solution Concentration

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Chinese Journal of Polymer Science 2017年第4期35卷 524-533页

作者： Min-fang An You Lv Hao-jun Xu qun-gu 王宗宝 Ningbo Key Laboratory of Specialty Polymers Faculty of Materials Science and Chemical Engineering Ningbo University Ningbo 315211 China College of Material Engineering Ningbo University of Technology Ningbo 315211 China

The gel-spun ultra-high molecular weight polyethylene （UHMWPE） fibers were prepared at the industrial production line with different gel solution concentrations of 15 wt%, 18 wt% and 24 wt%. The difference in ultimate structure and mechanical properties of UHMWPE fibers for different gel solution concentrations were analyzed by tensile testing, differential scanning calorimetry （DSC）, wide angle X-ray diffraction （WAXD） and small angle X-ray scattering （SAXS）. With the increase of gel solution concentration, the ultimate mechanical properties of UHMWPE fibers were decreased and the crystallization and orientation of UHMWPE fibers became inferior. Besides, both the average shish length （（Lshsh）） and shish misorientation （B0） of UHMWPE fibers were decreased with the increase of gel solution concentration. In addition, the appropriate increase of spinning temperature led to the further optimization of the ultimate structure and mechanical properties of UHMWPE fibers.

关键词： UHMWPE fibers Gel solution concentration Orientation Crystallization Shish structure

Three new aspochalasin derivatives from the marine-derived fungus Spicaria elegans

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Chinese Chemical Letters 2010年第7期21卷 824-826页

作者： Zhen Jian Lin Tian Jiao Zhu Li Chen Qian qun gu Key Laboratory of Marine Drugs Chinese Ministry of EducationInstitute of Marine Drugs and FoodOcean University of ChinaQingdao 266003China

Three new aspochalsins（R-T）（1-3） were isolated from the marine-derived fungus Spicaria *** structures were elucidated on the basis of comprehensive spectral analysis including 1D and 2D NMR techniques,and HR-ESI-MS.

关键词： Aspochalasin Spicaria elegans Marine fungus

Joint Design of Clustering and In-cluster Data Route for Heterogeneous Wireless Sensor Networks

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International Journal of Automation and computing 2017年第6期14卷 637-649页

作者： Liang Xue Ying Liu Zhi-qun gu Zhi-Hua Li Xin-Ping guan School of Information and Electrical Engineering Hebei University of Engineering State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications System Control and Information Processing Key Laboratory of Ministry of Education Shanghai Jiao Tong University

A heterogeneous wireless sensor network comprises a number of inexpensive energy constrained wireless sensor nodes which collect data from the sensing environment and transmit them toward the improved cluster head in a coordinated way. Employing clustering techniques in such networks can achieve balanced energy consumption of member nodes and prolong the network *** classical clustering techniques, clustering and in-cluster data routes are usually separated into independent operations. Although separate considerations of these two issues simplify the system design, it is often the non-optimal lifetime expectancy for wireless sensor networks. This paper proposes an integral framework that integrates these two correlated items in an interactive entirety. For that,we develop the clustering problems using nonlinear programming. Evolution process of clustering is provided in simulations. Results show that our joint-design proposal reaches the near optimal match between member nodes and cluster heads.

关键词： Heterogeneous wireless sensor networks clustering technique in-cluster data routes integral framework network lifetimes