内应力对Mn2NiGa铁磁形状记忆合金的结构、相变和磁性能的影响

通过施加压应力的方法,在铁磁形状记忆合金Mn₂NiGa中引入残留内应力,研究了内应力对 Mn₂NiGa材料的结构、相变和磁性能的影响.研究发现,加压过程使材料发生了塑性形变,在材料内部引入了大量的位错缺陷.卸载后保留的位错缺陷在材料中造成了残留的内应力,导致了马氏体相变温度大幅度提高, 使原本室温下的母相转变成了马氏体相.测量到导致样品转变成马氏体的阈值压应力为1.0 GPa.加压形成的马氏体中的残留内应力将矫顽力从低于50 Oe提高到350 Oe.残留内应力在730 K的热处理中由于位错缺陷的消失而得以消除,样品实现了马氏体逆相变.如此高的逆相变温度使得 Mn₂NiGa马氏体的居里温度测量成为可能,获得了530K的数值.     

Data Acquisition and Transfer System for In-situ Atomic Emission Spectroscopic Analysis

A new method of data acquisition,proceeding and data share is introduced and a data acquisition and transfer system targeting in-situ spectroscopic analysis in metallurgy is established. This system is designed for the critical control of steelmaking, which greatly requires rapid and suitable information feedback. The information includes analysis data, measurement data and controls. The analysis data are acquired from the serial port of the computer-aided spectrometers or other devices and are identified, converted and then stored to the standard database in a network server. The network is based on the Intranet structure and works on the Windows NT operation system. It supports remote access and Internet connection so that the analysis data can be shared,proceeded and developed by certified personnel throughout the network. A set of specially designed data transfer devices with display panel are used in the severe places to display real-time analysis data and other information, which are offered from the nearest workstation on the network. These devices are dust-proofed and anti-magnetic. Each device offers up to 30 terminals with the limited distance of 3000 meters at 2400 baud-rates under the industrial condition. The application program for the data proceeding is integrated to the system. It includes system security, data acquisition, data transfer, data process and display. It also includes auxiliary functions such as operation help, system's resources monitoring and other customer-defined parameters. The software's functions directly related to the system are detailed discussed. Associated with another management and control software programmed for this system,the critical control of steelmaking can be approached.     

Noether's theory of mechanical systems with unilateral constraints

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Simultaneous Determination of Hydrocodone, and Its Two Metabolites in Human Plasma by HPLC�CMS�CMS

A rapid, sensitive and specific assay method has been developed to simultaneously determine human plasma concentrations of hydrocodone and its metabolites, norhydrocodone, hydromorphone, using high-performance liquid chromatography with an electrospray ionization (ESI) tandem mass spectrometry (HPLC?CMS?CMS). Hydrocodone, its metabolites, and internal standard, hydrocodone-d ₃, norhydrocodone-d ₃, hydromorphone-d ₃, were separated from human plasma using solid-phase extraction (Empore MPC-SD Solid Phase Extraction Disk). The eluate was dried, reconstituted and injected into the LC?CMS?CMS system. Chromatographic separation was performed on a Kromasil 100-5SIL-Dimensions C₁₈ column (100 × 2.1 mm, 5.0 ??m, Thermo Hypersil-Keystone, USA) using a gradient mobile phase with 20 mmol L^?1 ammonium formate in water with 0.2% formic acid and 0.1% formic acid in acetonitrile. Detection and quantitation were performed by MS/MS using electrospray ionization and multiple reactions monitoring in the positive ion mode. The calibration curves were linear over the concentration ranges 0.05?C50 ng mL^?1 for hydrocodone (r ² = 0.9991) and norhydrocodone (r ² = 0.9990), and 0.01?C10 ng mL^?1 for hydromorphone (r ² = 0.9990). The limit of quantification was 0.05 ng mL^?1 for hydrocodone and norhydrocodone, and 0.01 ng mL^?1 for hydromorphone. The extraction recovery was above 64.36, 68.51 and 71.78% for hydrocodone, norhydrocodone and hydromorphone. The accuracy was higher than 99.06, 97.70 and 100.07% for hydrocodone, norhydrocodone and hydromorphone. The intra- and inter-day precisions were <5.80, 5.90 and 3.02% for hydrocodone, norhydrocodone and hydromorphone. The method was accurate, sensitive and simple and was successfully applied to a pharmacokinetic study after a single oral administration of hydrocodone bitartrate at a dose of 5 mg in 12 healthy Chinese volunteers.     

An Analogue-difference Method and Application to Induction Motor Models

The paper established a so-called analogue-difference method (ADM) to compute the numerical solutions for boundary value problems of higher-order differential equations, which can be a fundamental method and performs much better than the finite difference method (FDM), even for second-order boundary value problems. Numerical examples and results illustrate the simplicity, efficiency and applicability of the method, which also show that the proposed method has obvious advantages over the methods presented by recent state-of-the-art work for induction motor models.     

年龄结构的致命性传染病控制模型

本文在Ｂｒａｕｅｒ［１３］的基础上建立了一个致命性大范围传染病的年龄结构分布控制模型（这是一个具有非局部边界条件的偏微分方程组），证明了解的存在唯一性并分析了定常系统的非负平衡态的存在性，建立了相应的稳定性及其收敛性定理．     

“半波损失”的实验研究

利用光的干涉现象,通过在半平玻板上涂敷光密介质获得了有错移的明暗相间的干涉条纹,直观地展示了"半波损失"现象.然后推导出干涉图样分布方程,并结合实验数据计算出不同介质表面反射时产生的额外光程差,从而定量地分析了"半波损失"现象.同时基于导出的干涉图样分布方程对实验结果进行了计算机模拟,从另一个角度说明了"半波损失"现象.     

室温下纳米氧化锌新相的合成及表征

常温常压下,用高分子聚乙烯吡咯烷酮(PVP)作为表面修饰剂,成功地合成了粒度分布窄、平均粒度为4.0nm的氧化锌纳米微粒,其晶体结构与文献报道在高温高压(450℃,6×10⁸Pa)下合成的体相ZnO具有相同结构.EXAFS实验结果表明,纳米Zn-O的键长比体相发生收缩,Zn原子周围的氧配位数减少.     

Fresnel hologram reconstruction of complex three-dimensional object based on compressive sensing

Reconstruction the computer generated Fresnel hologram of complex 3D object based on compressive sensing （CS） is presented. The hologram is synthesized from a color image and the depth map of the 3D object. With the depth map, the intensity of the color image can be divided into multiple slices, which satisfy the condition of the sparsity of CS. Thus, the hologram can be reconstructed at different distances with corresponding scene focused using the CS method. The quality of the recovered images can be greatly improved compared with that from the back-propagation method. What＇s more, with the sub-sampled hologram, the image can be ideally reconstructed by the CS method, which can reduce the data-rate for transmission or storage.