On the stability of Riemannian manifold with parallel spinors

Inspired by the recent work [HHM03], we prove two stability results for compact Riemannian manifolds with nonzero parallel spinors. Our first result says that Ricci flat metrics which also admit nonzero parallel spinors are stable (in the direction of changes in conformal structures) as the critical points of the total scalar curvature functional. Our second result, which is a local version of the first one, shows that any metric of positive scalar curvature cannot lie too close to a metric with nonzero parallel spinor. We also prove a rigidity result for special holonomy metrics. In the case of SU(m) holonomy, the rigidity result implies that scalar flat deformations of Calabi-Yau metric must be Calabi-Yau. Finally we explore the connection with a positive mass theorem of [D03], which presents another approach to proving these stability and rigidity results. Dedicated to Jeff Cheeger for his sixtieth birthday     

Enantiomeric separation of basic drugs with partially filled serum albumin as chiral selector in capillary electrophoresis.

A reliable method is presented for the chiral separation of three basic drugs (mexiletine, chlorpheniramine and propranolol) with serum albumins (human and porcine, HSA and PSA) as chiral selectors by capillary electrophoresis in combination with the partial filling technique. Based on the systematic optimization of operation variables, the chiral separation of mexiletine, chlorpheniramine and propranolol was achieved in the pH 7.4 phosphate buffer by using HSA, PSA and PSA as selectors, respectively. The chiral recognition ability of HSA and PSA was compared. HSA and PSA show a different chiral recognition ability for each of the three drugs. In addition, the association constants between enantiomeric drugs and proteins were determined to be 2.00 and 3.80 x 10(2) M(-1) for mexiletine and HSA, 0.59 and 1.12 x 10(3) M(-1) for chlorpheniramine and PSA, and 0.87 and 1.42 x 10(3) M(-1) for propranolol and PSA. The method for the chiral separation and determination of association constants possesses the advantages of simple performance, effective avoiding of the interference of the UV detection from protein, and lowering of the reagent consumption.     

An overall study of convergence conditions for algorithms in nonlinear programming

Since the point-to-set maps were introduced by Zangwill^[1] in the study of conceptual algorithms, various sufficient conditions for the algorithms to be of global convergence have been established. In this paper, the relations among all these conditions are illustrated by a unified approach; still more, unlike the sufficient conditions previously given in the literature, a new necessary condition is put forward at the end of the paper, so that it implies more applications.     

自相似结构壳模型

为了扩展以简谐振子为基矢的常规壳模型（ＳＭ）计算到晕核，提出了自相似结构壳模型（ＳＳＭ）．通过对简谐振子动能项和势能项的重度规以及单粒子平均场模拟，可以得到ＳＳＭ中的单粒子轨道有态相关的圆频率，在ＳＳＭ中，晕核大的均方根半径、厚的中子皮以及Ｂｏｒｒｏｍｅａｎ晕核和的束缚态性质能够再现出来。     

腔靶等离子体辐射温度空间分布测量

本文描述了用膜吸收法测量激光等离子体辐射温度空间分布的原理和方法给出了柱形缝靶轴向辐射温度随空间位置变化的特征,对测量结果进行了分析讨论。     

稳态锁模产生4ps激光脉冲

首次利用ＧａＡｓ光电导开关，控制Ｎｄ：ＹＬＦ激光器腔内Ｑ值，实现稳态锁模，获得脉宽和能量稳定性极高的４ｐｓ激光脉冲。     

Growth and optical properties of a new self-Q-switched laser crystal: Cr:Yb3Al5O12

Cr⁴⁺:YbAG (Cr⁴⁺:Yb₃Al₅O₁₂) crystal with a size up to Φ24 mm×30 mm was grown by the Czochralski method. In the absorption spectrum, there are two absorption bands at 939 and 969 nm, respectively, which are suitable for InGaAs diode laser pumping, and there is an absorption band at 1030 nm, which is suitable for passive Q-switched laser output at 1.03 μm. A broad emission spectrum from 970 to 1100 nm was exhibited from 940 nm wavelength pumping. This crystal is promising as a self-Q-switched laser crystal used for compact, efficient, highly stable, passive self-Q-switched thin chip solid-state lasers.     

A floating-point genetic algorithm for solving the unit commitment problem

This paper proposes a floating-point genetic algorithm (FPGA) to solve the unit commitment problem (UCP). Based on the characteristics of typical load demand, a floating-point chromosome representation and an encoding–decoding scheme are designed to reduce the complexities in handling the minimum up/down time limits. Strategic parameters of the FPGA are characterized in detail, i.e., the evaluation function and its constraints, population size, operation styles of selection, crossover operation and probability, mutation operation and probability. A dynamic combination scheme of genetic operators is formulated to explore and exploit the FPGA in the non-convex solution space and multimodal objective function. Experiment results show that the FPGA is a more effective technique among the various styles of genetic algorithms, which can be applied to the practical scheduling tasks in utility power systems.     

Solvothermal Synthesis of Molybdenum Disulfide Hollow Spheres Modified by Cyanex 301 in Water–Ethanol Medium

Hollow spherical molybdenum disulfide has been successfully synthesized via a solvothermal method using Cyanex 301 as sulfur source and modification agent. The hollow spheres are characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Energy-Dispersive X-ray analysis. The influences of reaction conditions are also discussed while a mechanism is proposed to explain the formation of the peculiar morphology.     

Polynomial decay rate for the dissipative wave equation

Using Fourier integral operators with special amplitude functions, we analyze the stabilization of the wave equation in a three-dimensional bounded domain on which exists a trapped ray bouncing up and down infinitely between two parallel parts of the boundary.