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Effects of high-pressure rheo-squeeze casting on the Fe-rich phases and mechanical properties of Al-17Si-(1,1.5)Fe alloys

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International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1018-1026页

作者： Chong Lin shu-sen wu shu-lin Lü Ping An He-bao wu State Key Laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology Hubei Provincial Key Laboratory of Chemical Equipment Intensification and Intrinsic Safety Wuhan Institute of Technology

The effects of high pressure rheo-squeeze casting(HPRC) on the Fe-rich phases(FRPs) and mechanical properties of Al-17 Si-(1,1.5)Fe alloys were investigated. The alloy melts were first treated by ultrasonic vibration(UV) and then formed by high-pressure squeeze casting(HPSC). The FRPs in the as-cast HPSC Al-17 Si-1 Fe alloys only contained a long, needle-shaped β-Al5 Fe Si phase at 0 MPa. In addition to the β-Al5 Fe Si phase, the HPSC Al-17 Si-1.5 Fe alloy also contained the plate-shaped δ-Al4 Fe Si2 phase. A fine, block-shaped δ-Al4 Fe Si2 phase was formed in the Al-17 Si-1 Fe alloy treated by UV. The size of FRPs decreased with increasing pressure. After UV treatment, solidification under pressure led to further refinement of the FRPs. Considering alloy samples of the same composition, the ultimate tensile strength(UTS) of the HPRC samples was higher than that of the HPSC samples, and the UTS increased with increasing pressure. The UTS of the Al-17 Si-1 Fe alloy formed by HPSC exceeded that of the Al-17 Si-1.5 Fe alloy formed in the same manner under the same pressure. Conversely, the UTS of the Al-17 Si-1 Fe alloy formed by HPRC decreased to a value lower than that of the Al-17 Si-1.5 Fe alloy formed in the same manner.

关键词： high pressure rheo-squeeze casting Al-17Si-(1,1.5)Fe alloys Fe-rich phases mechanical properties

Modeling the carbon dynamics of alpine grassland in the Qinghai-TibetanPlateau under scenarios of 1.5 and 2 ℃ global warming

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Advances in Climate Change Research 2019年第2期10卷 80-91页

作者： YI shu-hua XIANG Bo MENG Bao-Ping wu Xiao-Dong DING Yong-Jian Instiute o f Fragile Ecosystem and Environment Nantong University Nantong 226007 China of Geographic Sciences Nantong University Nantong 226007 China State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China Chongqing Climate Center Chongqing 401147 China Cryosphere Research Station on the Qinghai-Tibetan Plateau Lanzhou 730000 China Key Laboratory of Ecohydrology of Inland River Basin Chinese Academy of Sciences Lanzhou 730000 China University of Chinese Academy Sciences Beijing 100049 China

Alpine grassland occupies two-thirds of the Qinghai-Tibetan Plateau (QTP). It is vital to project changes of this vulnerable ecosystem under different climate change scenarios before taking any mitigation or adaptation measures. In this study, we used a process-based ecosystem model, driven with output from global circulation models under different Representative Concentration Pathways (RCPs), to project the carbon dynamics of alpine grassland. The results showed the following: 1) Vegetation carbon (C) on the QTP increased by 22—38 gC m^-2 during periods of 1.5 and 2 ℃ warming under different RCPs when compared to the baseline period (1981—2006), while soil C increased by 85—122 gC m^-2. 2) The increases of vegetation C and soil C at the period of 1.5 ℃ warming were about 15 gC m^-2 and 40 gC m^-2 smaller than those at the period of 2 ℃ warming, respectively;increase of C was greater for alpine meadow than for alpine steppe. 3) Precipitation, radiation, and permafrost changed significantly and showed heterogeneous spatial patterns, and caused heterogeneous response of C dynamics. For alpine meadow in regions transformed from permafrost to seasonally frozen soil with medium annual precipitation (200—400 mm), vegetation C and net primary production decreased by 18.7 gC m-2 and 3.1 gC m^-2 per year during 2 °C warming under RCP 4.5, respectively. This decrease can be attributed to the disappearing impermeable permafrost. Different from previous studies that indicated an unfavorable response of alpine grassland to climate warming, this study showed a relatively favorable response, which is mainly attributed to C 0 2 fertilization.

关键词： Permafrost Terrestrial ecosystem model Vegetation Soil Net primary production

HYDRAULIC CHARACTERISTICS OF PARTIAL OPENING OF THE WORKING GATE FOR A DISCHARGE TUNNEL

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Journal of Hydrodynamics 2007年第4期19卷 488-493页

作者： wu Jian-hua FENG shu-rong wu Wei-wei RUAN Shi-ping College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China China Hydro Mid-South Design and Research Institute Changsha 410014 China

The partial opening of the working gate for a discharge tunnel is used more and more widely in the various conditions, such as releasing discharge to meet the needs of the various stages under construction, or of the operations at low reservoir levels. In this article the hydraulic characteristics were investigated of the partial opening of the working gate based on the physical model experiments of the discharge tunnel for the Longtan Hydropower Project, including the discharge coefficient, the surface profile of the free flow section, the bottom pressure distribution of the tunnel with an aerator, the cavity length just from the ramp, and the wall pressure of the curve section of the outlet. Some new issues were discussed and the properties were presented of the partial opening of the gate.

关键词： partial opening hydraulic characteristics working gate discharge tunnel

Assessing Soil Water Retention Characteristics and Their Spatial Variability Using Pedotransfer Functions

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Pedosphere 2011年第4期21卷 413-422页

作者： LIAO Kai-hua1, XU Shao-Hui2,.2, wu Ji-Chun1, JI shu-hua2 and LIN Qing2 XU Shao-Hui wu Ji-Chun JI shu-hua LIN Qing Department of Hydrosciences Nanjing University Nanjing 210093 (China) Department of Environmental Science Qingdao University Qingdao 266071 (China)

A total of 107 soil samples were taken from the city of Qingdao,Shandong Province,*** water retention data at 2.5,6,10,33,100,300,and 1 500 kPa matric potentials were measured using a pressure membrane *** linear regression (MLR) was used to develop pedotransfer functions (PTFs) for single point estimation and van Genuchten parameter estimation based on readily measurable soil properties,i.e.,MLR-based point (MLRP) PTF and MLR-based parametric (MLRV) *** double cross-validation method was used to evaluate the accuracy of PTF estimates and the stability of the PTFs developed in this *** performance of MLRP and MLRV PTFs in estimating water contents at matric potentials of 10,33,and 1 500 kPa was compared with that of two existing PTFs,the Rawls PTF and the Vereecken *** addition,geostatistical analyses were conducted to assess the capabilities of these PTFs in describing the spatial variability of soil water retention *** showed that among all PTFs only the Vereecken PTF failed to accurately estimate water retention *** the MLRP PTF can be used to predict retention characteristics through traditional statistical analyses,it failed to describe the spatial variability of soil water retention *** the MLRV and Rawls PTFs failed to describe the spatial variability of water contents at a matric potential of 10 kPa,they can be used to quantify the spatial variability of water contents at matric potentials of 33 and 1 500 kPa.

关键词： double cross-validation method multiple linear regression soil water content van Genuchten parameter

Study on the flow field uniformity of hydro-floating ship lift combined type hydraulic-driven system based on the residual energy theory

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Journal of Hydrodynamics 2022年第6期34卷 1156-1161页

作者： Bo wu Ya-an Hu shu Xue State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing210029China Key Laboratory of Transport Technology in Navigation Building Construction Nanjing Hydraulic Research InstituteNanjing210029China

The hydro-floating ship lift originally invented in China is a major innovation in the field of navigation *** shaft water levels synchronization of its unique hydraulic-driven system plays a crucial role in reducing the torque of the synchronous shafts and ensuring the safety and stability operation of the ship *** study aims to investigate the muti-shaft water level synchronization and the flow velocity uniformity of the combined type hydraulic-driven *** on the theory of residual energy,a new index m2 proposed in this study is more suitable for evaluating the flow velocity uniformity of the combined hydraulic-driven ***,the critical value of m2=75 is calculated via the results of the scaled physical mode test as the threshold of water flow uniformity,and it provides a basis for determining the reasonable height of the pressure stabilizing chamber.

关键词： Hydro-floating ship lift water levels synchronism residual energy velocity distribution uniformity coefficient

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6σ稳健设计在单目标优化问题中的仿真应用

太原科技大学学报 2011年第4期32卷 300-304页

作者：周峰张学良贾庭芳温淑花吴量太原科技大学机械电子工程学院太原030024

引入6σ设计理念将可靠性理论和容差技术相结合,提出了一种稳健设计优化模型,采用粒子群算法,实现对目标函数的优化。以圆柱螺旋压缩弹簧为应用实例,基于ISIGHT集成MATLAB平台,对圆柱螺旋压缩弹簧的约束函数进行可靠性、稳健性评估,证... 详细信息

引入6σ设计理念将可靠性理论和容差技术相结合,提出了一种稳健设计优化模型,采用粒子群算法,实现对目标函数的优化。以圆柱螺旋压缩弹簧为应用实例,基于ISIGHT集成MATLAB平台,对圆柱螺旋压缩弹簧的约束函数进行可靠性、稳健性评估,证明了该方法的有效性。

关键词：可靠性 6σ稳健设计粒子群优化算法 ISIGHT

Gelation of polymeric nanoparticles

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Particuology 2014年第3期12卷 1-11页

作者： hua wu Massimo Morbidelli Institute for Chemical and Bioengineering.Department of Chemistry and Applied Biosciences ETH Zurich8093 ZurichSwitzerland

We review how, starting from polymeric nanoparticles, to generate clusters of fractal morphology and to expand the entire space and interconnect to form gels, through either Brownian motion or intense shear-induced aggregation. In the case of Brownian motion-induced gelation, specific techniques developed to obtain uniform structure of gels under both reaction-limited and diffusion-limited cluster aggregation conditions have been described. In the case of intense shear-induced gelation as a newly developed technique, our focus is on its principle, theoretical development and advantages with respect to Brownian motion-induced gelation in practical applications. We consider gelation of both rigid and soft particles. As a physical process, the bonding between the particles within gels is owed to van der Waals attractions, thus being easily broken. However, in the case of soft particles that can coalesce upon contact, the coalescence can allow the particles to stick together forming permanent gels. In this case, the gel structure can be controlled by controlling the degree of coalescence. Techniques used to control the degree of coalescence have also been described.

关键词： Structured material Fractal Gelation Gel Polymer

Synthesis and characterization of a novel amphiphilic biodegradable β-cyclodextrin/poly(γ-benzyl L-glutamate) copolymer

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Chinese Chemical Letters 2009年第3期20卷 362-365页

作者： Qiu hua wu Fang Liang Tian Zhu Wei Xi Ming Song shu-Yao wu Guo Lin Zhang Key Laboratory of Green Synthesis and Preparative Chemistry of Advanced Materials (Liaoning University) The Education Department of Liaoning Province Shenyang 110036 China College of Chemistry Liaoning University Shenyang 110036 China

β-Cyclodextrin/poly（γ-benzyl L-glutamate）（β-CD-PBLG） copolymers were synthesized by ring-opening polymerization of N- carboxy-γ-benzyl L-glutamate anhydride （BLG-NCA） in N,N-dimethylformamide （DMF） initiated by mono-amino-β-cyclodextrin（H2N-β-CD）. The structures of the copolymers were confirmed by IR, ^1H NMR and GPC. The fluorescence technique was used to determine the critical micelle concentrations （CMC） of copolymer micell solution, the diameter and the distribution of micelles were characterized by DLS. The results showed that BLG-NCA could be initiated by H2N-β-CD to produce copolymer. The nanomicells were formed by these copolymers in water.

关键词： β-Cyclodextrin Poly(γ-benzyl-L-glutamate) Amphiphilic biodegradable copolymers Critical micelle concentration

Evodiamine Inhibits Angiotensin Ⅱ-Induced Rat Cardiomyocyte Hypertrophy

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Chinese Journal of Integrative Medicine 2018年第5期24卷 359-365页

作者： HE Na GONG Qi-hai ZHANG Feng ZHANG Jing-yi LIN shu-xian HOU hua-hua wu Qin SUN An-sheng Key Laboratory of Basic Pharmacology of Guizhou Departmentof Pharmacology Zunyi Medical College Zunyi GuizhouProvince (563099) China

Objective: To investigate the effects of evodiamine(Evo), a component of Evodiaminedia rutaecarpa(Juss.) Benth, on cardiomyocyte hypertrophy induced by angiotensin Ⅱ(Ang Ⅱ) and further explore the potential mechanisms. Methods: Cardiomyocytes from neonatal Sprague Dawley rats were isolated and characterized, and then the cadiomyocyte cultures were randomly divided into control, model(Ang Ⅱ 0.1 μmol/L), and Evo(0.03, 0.3, 3 μmol/L) groups. The cardiomyocyte surface area, protein level, intracellular free calcium([Ca]i) concentration, activity of nitric oxide synthase(NOS) and content of nitric oxide(NO) were measured, respectively. The m RNA expressions of atrial natriuretic factor(ANF), calcineurin(CaN), extracellular signal-regulated kinase-2(ERK-2), and endothelial nitric oxide synthase(e NOS) of cardiomyocytes were analyzed by real-time reverse transcriptionpolymerase chain reaction. The protein expressions of calcineurin catalytic subunit(CnA) and mitogen-activated protein kinase phosphatase-1(MKP-1) were detected by Western blot analysis. Results: Compared with the control group, Ang Ⅱ induced cardiomyocytes hypertrophy, as evidenced by increased cardiomyocyte surface area, protein content, and ANF m RNA expression; increased intracellular free calcium([Ca]i) concentration and expressions of CaN m RNA, CnA protein, and ERK-2 m RNA, but decreased MKP-1 protein expression(P<0.05 or P<0.01). Compared with Ang Ⅱ, Evo(0.3, 3 μmol/L) significantly attenuated Ang Ⅱ-induced cardiomyocyte hypertrophy, decreased the [Ca]i concentration and expressions of CaN m RNA, CnA protein, and ERK-2 m RNA, but increased MKP-1 protein expression(P<0.05 or P<0.01). Most interestingly, Evo increased the NOS activity and NO production, and upregulated the e NOS m RNA expression(P<0.05). Conclusion: Evo significantly attenuated Ang Ⅱ-induced cardiomyocyte hypertrophy, and this effect was partly due to promotion of NO production, reduction of [Ca]i concentration, and inhibition of CaN and

关键词： evodiamine cardiomyocyte hypertrophy angiotensin Ⅱ calcineurin extracellular signal regulated kinase-2 nitric oxide