牛津型斯特林制冷机的失效分析方法

分析了牛津型斯特林制冷机的主要失效机理、参数表征及探测方法,提出了制冷机的失效分析方法和程序。该方法将用于80K/2W制冷机加速寿命试验后的失效分析,为确认其失效模式和机理提供依据。     

带铁芯托卡马克装置的等离子体平衡数值解法

本文提出一种计算铁芯变压器托卡马克装置中等离子体平衡的数值方法。将铁芯对等离子体平衡的影响等效地看作外部线圈电流的作用,这样问题就转化为求解空芯变压器装置的等离子体平衡问题。这一方法的另一特点是计算区域减至最小。     

An improved palladium-based DMFCs cathode catalyst

A novel carbon-supported palladium-rich Pd3Pt1/C catalyst prepared by a modified polyol process showed a better cell performance than Pt/C in direct methanol fuel cells, which may be attributed to palladium's inactivity to methanol electro-oxidation while exhibiting good performance to oxygen reduction reaction.     

百叶窗浓缩器气固两相流动的试验研究

本文在以往试验基础上对百叶窗浓缩器进行了更加深入的试验研究，分析了百叶窗结构、气流等因素对浓缩器性能，即浓淡风比、阻力系数、浓缩率三个参数的影响，从而得到了优化的百叶窗结构。     

Online scheduling with reassignment

This paper studies online scheduling problems with reassignment on two identical machines. We can reassign some jobs under certain rules after all the jobs have been assigned. Three different versions are studied and optimal algorithms are proposed.     

HYPERBOLIC-PARABOLIC CHEMOTAXIS SYSTEM WITH NONLINEAR PRODUCT TERMS

We prove the local existence and uniqueness of week solution of the hyperbolic-parabolic Chemotaxis system with some nonlinear product terms. For one dimensional case, we prove also the global existence and uniqueness of the solution for the problem.     

常曲率空间关于直交全脐超曲面系的特征性质

Let V_n be Riemannian space of genernal constant curvature.In this paper, we have proved following;Theorem I If a V_n(n≥5 ) admits three mutually orthogonal families oftotally numbilical hypersurfaces such that they are of constant curvature and Einsteinian and of general constant curvature respectively, then V_n is space with constant curvature.Theorem 2 If a V_n ( n ≥ 5 ) admits three mutually orthogonal famities of totally umbilical hypersurfaces, of which one is conformally flat and other two are Einsteinian and of constant curvature respectively, and latter either is of constant meam curvature, then V_n is of constant curvature.     

第一性原理研究KDP晶体中Ba取代K点缺陷

 用基于第一性原理的CASTEP模拟了Ba替代K缺陷前后形成的电子结构和能态密度。发现晶体能带宽度降至6.4 eV左右,对应着380 nm的双光子吸收,这一结果可以解释掺Ba晶体在紫外波段的吸收现象。Ba替代K点缺陷仅使其周围的晶格及电子结构发生轻微畸变,对晶体整体结构影响不大。     

Copper‐catalyzed asymmetric 1,4‐conjugate addition of dialkylzinc to enones

Asymmetric 1,4‐conjugation addition of dialkylzinc (diethylzinc and dimethylzinc) to cyclic enones, chalcone and nitroalkenes was achieved by a 25 mol% (R)‐6,6′‐Br₂‐BINOL( 1f ), 25 mol% CuSPh and 100 mol% dicyclohexylmethylamin(Cy₂NMe) catalyst system. The Cu(I) catalyst system enables the cyclic enone, chalcone and nitroalkene generality with high enantioselectivity (up to 84% ee) and isolated yield (up to 94%) under mild reaction conditions. Copyright © 2010 John Wiley & Sons, Ltd.     

Modular amino acid amide chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes

Enantioselective addition of diethylzinc to a series of aromatic aldehydes was developed using a modular amino acid amide chiral ligand (2S)‐3‐phenyl‐N‐((R)‐1‐phenyl‐ethyl)‐2‐(tosylamino)propanamide without using titanium complex. The catalytic system employing 10 mol% of 1g was found to promote the addition of diethylzinc (ZnEt₂) to a wide range of aromatic aldehydes with electron‐donating and electron‐withdrawing substituents, giving up to 82% ee of the corresponding secondary alcohol under mild conditions. Copyright © 2011 John Wiley & Sons, Ltd.