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1.
QIN Feng CHEN Jiang-ping ZHANG Wen-feng CHEN Zhi-jiu 《浙江大学学报(A卷英文版)》2007,8(2):197-204
INTRODUCTION Metal hydrides are special alloys which absorb and desorb hydrogen reversibly. At room temperature, metal hydrides could absorb as much hydrogen as liquid hydrogen of the same volume under much lower pressure and much higher temperature (Güther and Otto, 1999). Massive reaction heat is generated accompanying this reaction, which could be used for waste heat recovery, solar energy utilization and re-frigeration with no side effect to environment (Izhvanov et al., 1996). Con… 相似文献
2.
INTRODUCTION Shengmaiyin or Shengmaisan, one of the famous herbal recipes in traditional Chinese medicine, is made from Radix ginseng, Ophiopogon and Schi- sandra. It is used to treat hypotension (Chen et al., 2000; Gui, 2001), cardiovascular system diseases (Qian et al., 2004; Zeng and Zeng, 2004), to increase immunity (Wu et al., 1997; Guo et al., 2004) and cure other diseases (Li et al., 1996; Liu et al., 1998; Fang et al., 2000; Yi et al., 2003; Xu et al., 2003; Wang et al., 200… 相似文献
3.
ZHANG Xiu-yan RUAN Hui MU Lin HE Guo-qing TANG Xing-jun CHEN Qi-he 《浙江大学学报(A卷英文版)》2006,7(11):1948-1955
INTRODUCTION Enzymes are efficient and specific biocatalysts widely used in food industries, but their application in industrial process often involves special properties not found in natural source enzymes. In order to ob- tain desirable enzymes, in the past ten years, scientists have developed rational (Kurth et al., 1998; Mouratou et al., 1999; DeSantis et al., 1999) and irrational de- sign methods (Babbitt and Gerlt, 1997; O’Brien and Herschlag, 1999) to improve the enzyme propert… 相似文献
4.
INTRODUCTION Due to granulites representing products of thedeeper lower crust-upper mantle and having geneticassociation with early crustal evolution and forma-tion of large-scale metallogenic-forming and nonmetallogenic-forming belts, the study of granulitesin the world has resulted in much recent attention(Zhai and Liu, 2001; Liu and Zhou, 1994; Yu et al.,1998; 2003; Li et al., 2000; Zhang et al., 2001; Yuet al., 2002; Bingen and Stein, 2003; Blein et al.,2003; Garcia et al., … 相似文献
5.
YIN Ming-zhi 《浙江大学学报(A卷英文版)》2006,7(8)
INTRODUCTION Perovskite-type oxides have attracted consider-able interest regarding their various electronic, mag-netic and optical properties, such as superconductiv-ity, colossal magnetoresistance and ferroelectricity caused by strong interactions of their charge, spin and lattice characteristics (Millis, 1998; Wu et al., 2000; Gariglio et al., 2001). Currently, many investigations are underway to harmonize these properties and cre-ate new functional materials for applications to oxide… 相似文献
6.
INTRODUCTION Genomic DNA sequence analysis using wide range of statistical methods (Torney et al., 1999; Bulmer, 1987; Luo et al., 1998; Nieselt-Struwe, 1997; Fickett et al., 1992; Buldyrev et al., 1998; Azbel, 1995) and various symmetry investigations (Findley et al., 1982; Hornos and Hornos, 1993; Bashford et al., 1997; Bhry et al., 1998; Forger and Sachse, 1998; Frappat et al., 1998) is an extremely important tool for extracting hidden information on the dynamic process of evolu… 相似文献
7.
LIU Yun-kui XU Dan-qian XU Zhen-yuan ZHANG Yong-min 《Journal of Zhejiang University. Science. B》2006,(5)
INTRODUCTION Allyl selenides have drawn much attention as a class of important intermediates in organic synthesis. For example, they are useful synthetic precursors for the [1,3]- or [2,3]-sigmatropic rearrangements (Shar-pless and Lauer, 1972; Fujita et al., 1998; Carter and Bourland, 2000), allylic homocoupling reactions (Masugama et al., 1989), and various other chemical transformations (Shea et al., 1986; Back and Moussa, 2002; 2003). Generally, allyl selenides are synthe-sized fr… 相似文献
8.
LEE Sang Hun LEE Kunwoo 《浙江大学学报(A卷英文版)》2006,7(9):1535-1543
INTRODUCTION 3D CAD systems for the feature-based B-rep solid models (Choi et al., 2002; Kim et al., 2003; 2005; Koo and Lee, 2002; Lee et al., 2004; Lee, 2005a) are becoming more suitable for CAD when compared with the conventional polygon-based mul- tiresolution modelling in computer graphics (Cignoni et al., 1998; Schr?der et al., 1992). As illustrated in Fig.1b, the object of the feature-based multiresolution modelling is a solid model where the suppressed ob- jects are form feat… 相似文献
9.
INTRODUCTION Lipase (EC 3.1.1.3) is an important hydrolysis enzyme (Jaeger et al., 1994) excreted to the envi-ronment by plant roots and microorganisms. Many pollutants such as organophosphorus pesticides and synthetic polyesters and polyamides can be degraded by lipase (Monroy-Noyola et al., 1999; Marten et al., 2003). In soil, enzymatic reactions occur in a het-erogeneous rather than homogeneous environment (Huang et al., 1998). Catalytic function of lipase, an extracelluar enzyme, … 相似文献
10.
An efficient method for tracing planar implicit curves 总被引：1，自引：0，他引：1
YU Zheng-sheng CAI Yao-zhi OH Min-jae KIM Tae-wan PENG Qun-sheng 《浙江大学学报(A卷英文版)》2006,7(7):1115-1123
INTRODUCTION Tracing a planar implicit curve f(x, y)=0 on a rectangular region [xl, xr]×[yb, yt] is of great interest in Computer-Aided Design and Computer Graphics. While parametric curves are easy to plot, plotting implicit curves is a challenging problem. Planar im- plicit curve plotting method can be classified into two categories (Shou et al., 2005; Martin et al., 2002; Lopes et al., 2002). In the first category are subdivi- sion methods (Shou et al., 2005; Martin et al., 2002) … 相似文献
11.
WANG Xiu-li TU Jiang-ping CHEN Chang-pin ZHANG Xiao-bin ZHAO Xin-bing 《Journal of Zhejiang University. Science. B》2005,(3)
Mg2Ni0.8Cr0.2-x wt.% CoO/Al2O3 (x=0.5, 1, 2 and 3) composites were prepared by mechanically milling sintered Mg2Ni0.8Cr0.2 alloy and CoO/Al2O3 compound for 45 h. The addition of CoO/Al2O3 compound resulted in the good kinetics properties of hydriding/dehydriding reaction of the composites. The composite with 1.0 wt.% CoO/Al2O3 catalyst could reach the maximum hydrogen absorption capacity (2.9 wt.%) within 5 min at 393 K under H2 pressure of 4 MPa, and can desorb rapidly at 493 K. The decomposition and synthesis of hydrogen molecule on Mg2Ni0.8Cr0.2 alloy surface was promoted by addition of CoO/Al2O3 catalyst. In addition, the formation of metallic Ni particles, strain and defects during the ball milling process also resulted in the improved hydrogenation performance of Mg2Ni-based alloys. 相似文献
12.
利用Al-TiO2-C体系熔铸法制备含稀土LaO2原位自生Al2O3-TiCp／Al基复合材料,借助差示扫描量热仪（DSC）、扫描电子显微镜（SEM）、能谱分析仪（EDS）、X射线衍射仪（XRD）等测试技术,对Al-TiO2-C体系的组织结构进行了详尽的分析,讨论了稀土LaO2铝对Al2O3-TiCp/Al基复合材料的影响规律。实验结果表明,稀土LaO2的加入可改善陶瓷颗粒Al2O3和TiC与熔体的润湿性,而且有效细化和净化了组织,降低了反应温度。稀土LaO2添加剂含量为0,5％时利用熔铸法制备的复合材料中原位形的Al2O3,TiC颗粒尺寸较小,分布均匀。 相似文献
13.
利用Al-TiO2-C体系熔铸法制备含稀土LaO2原位自生Al2O3-TiCp／Al基复合材料,借助差示扫描量热仪（DSC）、扫描电子显微镜（SEM）、能谱分析仪（EDS）、X射线衍射仪（XRD）等测试技术,对Al-TiO2-C体系的组织结构进行了详尽的分析,讨论了稀土LaO2铝对Al2O3-TiCp/Al基复合材料的影响规律。实验结果表明,稀土LaO2的加入可改善陶瓷颗粒Al2O3和TiC与熔体的润湿性,而且有效细化和净化了组织,降低了反应温度。稀土LaO2添加剂含量为0,5％时利用熔铸法制备的复合材料中原位形的Al2O3,TiC颗粒尺寸较小,分布均匀。 相似文献
14.
The Mg-based hydrogen storage alloys Mg2Ni, Mg2Ni0.7Fe0.3 and Mgl.7Alo.3Ni were successfully synthesized by a two-step process （sintering and ball milling）. The crystal structure and microstructure were examined by X-ray diffraction, Scanning Electron Microscope and Malvern particle size analyzer. New phase appears in the tripe alloys doped with A1 and Fe, and the particle size ranges from 3μm to 5 μm. The electrochemical performance studies indicate that the partial substitution of AI for Mg, and Fe for Ni significantly improve the cycle life, reversibility of hydrogen absorption and desorption. The diffusion process is the control step in the electrode reaction of hydrogen storage alloys. 相似文献
15.
Amorphous alloy Mg1.8Cu0.2Ni was successfully prepared by mechanical alloying (MA) and a series of (n?x)Nix(Ti?B) composites were synthesized by MA. The electrochemical properties of Mg1.8Cu0.2Ni coated by Ni, Ti and B were studied by cyclic charge-discharge, linear polarization curve, and hydrogen diffusion coefficient experiments. Experimental results indicate that Mg1.8Cu0.2Ni-[0.9Ni0.6(Ti?B)] composite which was MA 30 h exhibited the best performance and its initial discharge capacity arrived to 714.1 mAh/g. After 30 cycles the discharge capacity was above 530 mAh/g, which was much higher than that of Mg1.8Cu0.2Ni. And after 100 cycles it holded still 442.1 mAh/g. On all accounts, after modification by Ni, Ti and B, the initial discharge capacity and high-rate discharge ability of the electrode were evidently increased. At the same time, the cycle performance was also improved significantly. 相似文献
16.
在固定床反应器中研究了二甲基二硫醚对Ni/Al2O3上模拟裂解汽油原料油中主要化合物芳烃、单烯烃和共轭烯烃的加氢活性的影响。结果显示,二甲基二硫醚对以上化合物加氢抑制的顺序为:芳香环单烯烃共轭烯烃。通过XRD和XPS表征分析,推测了Ni/Al2O3催化剂失活的可能原因。 相似文献
17.
成守权 《顺德职业技术学院学报》2008,6(3):23-26
通过热重分析实验,研究了在高温空气气氛中覆盖在Al-Zn—Si合金表面的MgO引发剂对铝合金直接氧化生长过程的作用。结果表明：MgO能显著缩短Al-Zn—Si合金熔体直接氧化所需的孕育期及Al2O3／Al复合材料的生长时间。同时发现MgO有助于Al2O3／Al复合材料以光滑的方式进行氧化生长,形成细化胞状晶团,提高组织结构的均匀度和材料的致密度。促进Al2O3／Al复合材料生长的MgO覆盖最佳量为12mg／cm^2。 相似文献
18.
WANG Xiu-li TU Jiang-ping ZHANG Pei-long ZHAO Xin-bing 《浙江大学学报(A卷英文版)》2007,8(9):1510-1513
Mg-25 wt% Mg2Ni composite was prepared by sintered method,hydrided at 613 K and then ball-milled with 1.5 wt% PdCl2 additive for 51 h. The effects of PdCl2 on the hydriding and dehydriding behavior of Mg-25 wt% Mg2Ni composite were investigated. The absorption and desorption rate of the composite with PdCl2 is fast and the hydrogen storage capacity is more than that of the composite without PdCl2. The maximum hydrogen storage capacity reached 3.48 wt% at 373 K,and 5.05 wt% H at 453 K,respectively. The improvement of sorption and desorption kinetics is attributed to the catalytic effect of PdCl2,and the grain refining and lattice strain introduced by ball milling. 相似文献
19.
MH-Ni电池充放电性能和贮存性能的研究 总被引：1，自引：0，他引：1
研究了负极材料为Mm0.8La0.2Ni4.0(MnCoAl)1.0贮氢合金的MH-Ni电池的充放电性能,在0.2A电流下的充电电压和放电电压分别为1.4V和1.2V,充电效率为89.1%。电池贮存30天自放电率为22.6%,其原因为电极中氢的解吸和贮氢合金的氧化。 相似文献
20.
采用HNO3/H2O2湿法微波消解制样,利用全谱直读电感耦合等离子原子发射光谱法(ICP-OES),全面详细地分析测定了青海红果枸杞子中的矿质元素,共检出K、Na、S、P、Mg、Ca、Si、Al、Fe、Zn、B、Cu、Mn、Se、Pb、Sr、Ti、Ba、Cr等19种矿质元素。分析结果相对标准偏差RSD值在2.41%~10.1%之间,其中10种元素在5%以内。枸杞子中所含人体常量元素K、Na、S、P、Mg、Ca等的质量分数分别为0.96%、0.25%、0.22%、0.19%、0.080%和0.077%;微量元素Fe、Zn、B、Cu、Mn、Se、Sr、Cr等的含量分别为5.97、1.34、1.09、0.88、0.57、0.52、0.33、0.055 mg/100g。此外,还含有9.35 mg/100g的Al和0.45 mg/100g的Pb。 相似文献