Analysis and optimization of high-power pulse transformer for SXFEL

Longitudinal injection is a promising on-axis injection scheme for diffraction-limited storage rings. In the latest version of the Hefei advanced light source(HALS), both the dynamic aperture and momentum aperture have been optimized. A longitudinal injection scheme was investigated on the HALS using a doublefrequency radio frequency system. To evaluate the injection performance, various errors were considered. A series of tracking simulations were conducted, and the injection efficiency was obtained under different error levels.     

多功能行星变速箱的研制及应用

多功能行星变速箱是广泛应用于工程车辆及其它行业的一种专用传动装置.本文介绍了该类变速箱的结构、工作原理及研制中的几个关键技术问题.研制的多功能行星变速箱系列产品已在石油行业应用多年,替代了进口产品,取得了良好的使用效果.     

SiO2对金属锂盐聚合物电解质导电作用的影响

采用溶液浇注法制备了PEO基聚合物电解质,测定了该类电解质的电导率,并研究了温度、SiO2的颗粒度及表面性能对聚环氧乙烯/高氯酸锂(PEO/LiClO4)聚合物电解质体系电导率的影响.结果表明PEO-LiClO4-10%SiO2复合型聚合物电解质的室温电导率达到了1.033×10-4S/cm,同时对该电解质进行了差热分析,发现加入SiO2后,PEO/LiClO4体系熔融温度降低,非晶相含量增加,有利于提高离子电导率.     

Typoselectivity of Crude Geobacillus sp. T1 Lipase Fused with a Cellulose-Binding Domain and Its Use in the Synthesis of Structured Lipids

Typoselectivity of crude CBD-T1 lipase (Geobacillus sp. T1 lipase fused with a cellulose binding domain) was investigated. Multi-competitive reaction mixtures including a set of n-chain fatty acids (C8:0, C10:0, C12:0, C14:0, C18:1 n-9, C18:2 n-6 and C18:3 n-3) and tripalmitin-enriched triacylglycerols were studied in hexane. The crude CBD-T1 lipase discriminated strongly against C18:1 n-9 [competitive factor (α) = 0.23] and showed the highest preference for C8:0 (α = 1). Utilizing the catalytic properties of crude CBD-T1 lipase, acidolysis of soybean oil with C8:0 was selected as a model reaction to investigate the ability of the lipase to produce MLM-type (medium-long-medium) structured lipids. Several reaction parameters (added water amount, reaction temperature, substrate molar ratio and reaction time) examined for incorporating C8:0 into soybean oil, the optimum conditions were: 1:3 (soybean oil/C8:0) of molar ratio, 3 mL of hexane, 50 °C of temperature, 48 h of reaction time, 20 % of crude CBD-T1 lipase (w/w total substrates), and 7.5 % of water (w/w enzyme). Under these conditions, the incorporation of C8:0 was 29.6 mol%. The results suggest that crude CBD-T1 lipase, which showed different fatty acid specificity profiles, is a potential biocatalyst for the modification of fats and oils.     

不同切割损伤强度对红心萝卜抗氧化活性的影响

目的比较不同切割损伤强度对红心萝卜在5℃,48 h内抗氧化系统和抗氧化活性的影响。方法以切割后组织的表面积与质量的比值来定义切割损伤强度,单位为cm2/g。测定不同切割损伤强度(片状4.65cm2/g、丁状6.67 cm2/g、丝状11.87 cm2/g)下样品的多酚含量、抗氧化酶活性以及DPPH自由基清除率来评价抗氧化能力。结果不同切割损伤强度的鲜切处理均能在贮藏前24 h显著诱导酚类物质的合成和积累,提高抗氧化活性,其中损伤强度最大(11.87 cm2/g)的鲜切红心萝卜丝酚类物质含量和抗氧化活性最高。结论切割损伤在一定时间内可诱导红心萝卜中酚类物质的合成和积累,提高其抗氧化活性。     

基于SketchUp的农产品食品实训基地 三维虚拟构建

目的虚拟现实技术是一门新兴技术,在各个领域的应用越来越广。为进一步提高农产品食品实训基地的地理信息量,丰富实训基地的展示手段,拟采用先进的三维建模技术,构建实训基地的三维虚拟场景。方法结合数字化时代的三维虚拟技术,以浙江经贸职业技术学院农产品食品实训基地为研究对象,探讨基于Sketch Up软件的实训基地三维模型和场景的构建方法、技术路线和建模流程。结果开发了三维模型和可视化虚拟场景,对实训室总体建筑布局、检测室内部空间和检测仪器设备进行虚拟展示。结论 Sketch Up软件可以提供一种多视角的三维虚拟实训室解决方案,具有简单易学,可操作性强和流程化的特点,是一种非常实用的三维建模工具。项目研究可为高校虚拟实训室的建设提供有益的参考和借鉴。     

Probabilistic evaluation for the implicit limit-state function of stability of a highway tunnel in China

This paper presents a practical algorithm for the first-order reliability method (FORM) to deal with the implicit nature of a limit-state function (LSF) in reliability assessment of stability of a working highway tunnel, which is constructed in a mountainous area in China. First, a mechanical model to determine the LSF that is not explicitly known with complex non-linear behaviour is formulated for the primary support provided by the combination of shotcrete and rockbolts. After reviewing concisely the basic concepts relevant to the FORM, the central difference approximation is subsequently introduced to estimate the partial derivatives of the LSF. By consideration of Taylor’s formula, this LSF can be transformed into an equation involving a single unknown described as the reliability index, and then the resulting solution procedure for determination of the reliability index can be rendered based on the derivation rule of compound function. A flow for tunnel reliability problem posed by the implicit LSF in applying the FORM is further developed. Eventually, the proposed methodology for the LSF in the non-explicit circumstance is used to perform the probabilistic evaluation for such a working tunnel where the choices of values of step length coefficient affecting the calculation results are suggested. Comparisons are made with the Monte-Carlo simulation method (MCSM) to assess the computational accuracy and efficiency of the algorithm proposed in this paper. It is shown that the MCSM used to obtain the “exact” solutions entails the formidable computational effort, whereas the current algorithm that alleviates the computational labour dramatically can provide an efficient way of implementing reliability calculations for the implicit LSF and offer results which are found to be in satisfactory agreement with the “exact” ones when the step length coefficient is properly taken.     

Polynuclear Lanthanoid Complexes Containing Aluminium—The Structure of[HoAl(CF_3COO)_2(CF_3CHOO)(C_2H_5)_2(C_4H_8O)_2]_2 at 233K

[HoAl(CF_3COO)_2(CF_3CHOO)(C_2H_5)_2(C_4H_8O)_2]_2,Mr=1468.7,monoclinic,P 2_1/n,a=1.0084(4),b=1.8453(6),c=1.4501(6)nm,β=102.40(3)°,V=2.6355(1)nm~3,Z=2,D_c=1.81gcm~(-3),F(000)=1511,T=233K,Mo Kα radiation(λ=0.071069nm).R=0.052 for 6176 unique reflections[Ⅰ≥36(Ⅰ)].The structuralunits consist of dimeric molecules with the mixed ligand and central bimetallic atoms,which are polynuclearlanthanoid complexes containing aluminium.Ho-Ho'distance is 0.3619(1)nm.The coordination polyhedron ofHo can be described in terms of a distored bicap-prism.     

Synthesis，Characterization and Crystal Structure of Cyclotetramer of Europium（Ⅱ）－arene Complex：［Eu（C_6Me_6）（AlCl_4）_2l_4·Me_4C_6H_2

Ｓｙｎｔｈｅｓｉｓ，ＣｈａｒａｃｔｅｒｉｚａｔｉｏｎａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＣｙｃｌｏｔｅｔｒａｍｅｒｏｆＥｕｒｏｐｉｕｍ（Ⅱ）－ａｒｅｎｅＣｏｍｐｌｅｘ：［Ｅｕ（Ｃ_６Ｍｅ_６）（ＡｌＣｌ_４）_２ｌ_４·Ｍｅ_４Ｃ_６Ｈ_２ＬｉａｎｇＨ...     

Studies on adsorption, desorption and biodegradation of pentachlorophenol by the anaerobic granular sludge in an upflow anaerobic sludge blanket (UASB) reactor

PCP-degrading anaerobic granular sludge could be formed in an upflow anaerobic sludge blanket (UASB) reactor that was seeded with anaerobic sludge acclimated to chlorophenol. When hydraulic retention time (HRT) was 20-22 h and PCP loading rate was 200-220 mgL(-1)d(-1), the wastewater containing 170-180 mgL(-1) PCP could be treated effectively in UASB reactor, and PCP removal rate reached up to 99.5%. PCP adsorption and desorption by anaerobic granular sludge follow Freundlich isothermal equation and part of adsorption capacity was not reversible. And the isothermal equation could well describe the variation law of PCP adsorption and desorption by anaerobic granular sludge. The results indicated that the principal removal mechanism of PCP was biodegradation by anaerobic granular sludge, but not adsorption or volatilization.