大豆脂肪氧化酶酶活性变化研究

采用分光光度法对大豆中三种脂肪氧化酶（同工酶）进行检测并测定脂肪氧化酶活性,研究表明：大豆粉碎后随着贮存时间的延长,脂肪氧化酶活性逐渐降低,大豆发芽后脂肪氧化酶活性降低了43%.     

Timing-jitter-free demultiplexing of an all-optical signal processor based on the intensity-dependent self-wavelength conversion of Raman solitons

An all-optical signal processor based on the self-wavelength conversion of Raman solitons is described. The processor consists of an erbium-doped fiber amplifier (EDFA), a highly nonlinear fiber, and an optical bandpass filter. The timing-jitter-free demultiplexing of the processor was demonstrated by an 80-km transmission experiment. Error-free bit error rate (BER) performance was achieved. Transmitted fourfold optical time-division multiplexing (OTDM) signals with a large timing jitter of about 16 ps for an OTDM signal interval of 25 ps were demultiplexed to 9.95-Gb/s signals without signal degradation.     

Hard X-Ray Microscope With Submicrometer Spatial Resolution

A high-resolution hard x-ray microscope is described. This system is capable of detecting line features as small as 0.6 µm in width, and resolving line pairs 1.2-µm wide and 1.2-µm apart. Three types of two-dimensional image detectors are discussed and compared for use with hard x rays in high resolution. Principles of x-ray image magnification are discussed based on x-ray optics and diffraction physics. Examples of applications are shown in microradiography with fiber reinforced composite materials (SiC in Ti₃Al Nb) and in diffraction imaging (topography) with device patterns on a silicon single crystal. High-resolution tomography has now become a reality.     

Proton conduction in Nafion composite membranes filled with mesoporous silica

Studies of proton-conductive polymer membranes are vital for the future development of high-performance polymer electrolyte membrane fuel cells (PEM-FC). In particular, a method for inhibiting the volatility of water in the polymer matrix at high temperatures is a crucial issue, directly related to the operation of PEM-FC system. In this study, we focus on polymer composite membranes, which consist of commercial Nafion and mesoporous silica (MPSi) as novel inorganic additives, and investigate an improvement in the total proton conductivities and the good electrochemical stability at high temperatures. MPSi, which can be synthesized with pore sizes from 1 to 10 nm, has a wide range of potential applications because of its extraordinary properties, such as extremely large surface area, flawless surface condition and well-regulated porous structure. We found that the Nafion composites filled with MPSi have approximately 1.5 times higher proton conductivities (more than 0.1 S cm⁻¹ at 80 °C and 95%RH) than pure Nafion and can display good temperature performance relative to pure Nafion and the particle SiO₂ composite. Moreover, the conductivity of Nafion/sulfonated MPSi was the highest (0.094 S cm⁻¹) at 40 °C and 95%RH. These are probably due to the large surface area of MPSi, which can increase the water adsorption in Nafion matrix.     

Electricity markets volatility: estimates,regularities and risk management applications

The recent deregulation of the market for electric power in many parts of the US and Canada has expanded the set of potential tools for managing the types of risks faced by both generators and consumers of electric power. In particular manufacturing and other firms whose operations are powered by electricity now face, on a continuing basis, the engineering management decisions concerning whether they should buy or produce electricity, and if they are to buy or sell electricity, what types of contracts are optimum. These types of risk management decisions typically involve futures, forwards, options and other financial derivatives. The price and volatility of electric power are known to play an essential role in determining which of these instruments should be used. However, electricity as a commodity possesses certain special features not shared by other commodities and hence its risk properties are not yet well understood. In this paper we consider and test certain hypotheses about the properties of electricity price using recent market data. We find that electricity prices possess certain volatility and other systematic properties that can be characterized by the type and method of delivery of electricity. These properties can be used by firms in formulating their optimal demand and supply schedules of electric power.     

木材结构分级多孔ZnO的同步辐射XAFS研究

利用同步辐射XAFS (X-ray AbsorptionFine Structure)实验及FEFF计算进行数据拟合,研究遗态转化工艺制备的ZnO产物的微观晶体结构参数.研究结果表明,遗态转化工艺得到了ZnO产物,木材结构分级多孔ZnO产物的第一壳层Zn-O距离为0.1986nm,第二壳层Zn-Zn距离为0.3240n...     

Preparation and properties of CuInS2 thin film prepared from electroplated precursor

Thin CuInS₂ films were prepared by sulfurization of Cu/In bi-layers. First, the precursor layer was electroplated onto the treated surface of Mo-coated glass. Observation of the cross-section prepared by focused ion beam (FIB) etching revealed that the void-free film was initially formed on the top surface of the precursor layer and continued to grow until the advancing front of the film reached the Mo layer. The nucleation of voids near the bottom of the CuInS₂ film followed. To determine whether the condition of the Cu/In alloy influences the CuInS₂ quality we investigated the Cu/In alloy state using FIB. We found that the annealed precursor of low Cu/In ratio (1.2) has several voids in the mid position in the layer compared with Cu-rich precursor (1.6). The cross-sectional view of the Cu-rich absorber layer is uniform compared with the low copper absorber layer. Thin film solar cells were fabricated using the CuInS₂ film (Cu/In ratio: 1.2) as an optical absorber layer. It was found that the optimization of a sulfurization period is important in order to improve the cell efficiency. We have not yet obtained good results with high Cu-rich absorber because of a blister problem. This blister was found before sulfurization. So, we are going to solve this blister problem before sulfurization.     

Notch effect on creep–fatigue life for Sn–3.5Ag solder

This paper studies the creep–fatigue crack initiation and failure lives of Sn–3.5Ag solder notched specimens focused on the multiaxial strain at the notch root. Push–pull creep–fatigue tests were performed using three circumferential notched specimens using four kinds of creep–fatigue strain waveforms. Multiaxial strains at the notched section were calculated by finite element (FE) analysis under four kinds of creep–fatigue loading. Creep–fatigue damage laws were applied for evaluating the crack initiation and failure lives using the multiaxial strains obtained by the FE analysis. von Mises equivalent strain at the notch root estimated the crack initiation lives with a large scatter as well as the failure lives. Instead, the mean value of von Mises equivalent strain over the cross section of the notch root estimated the crack initiation and failure lives with a small scatter.     

河道疏浚淤泥固化处理设备、流程及应用

河道疏浚中产生的淤泥如采取抛弃处理会造成资源浪费。介绍一种淤泥固化系统,可对城市污泥、淤泥、隧洞和建筑工程等产生的污泥在工地现场进行瞬间造粒后固化。以图示方式简单描述了淤泥投入、固化出料及养护的处理流程。根据强度试验结果,经系统固化后改良土的强度达到第3类工程用土。总结了淤泥固化系统具有体积小、高机动性、无副产物和处理数据自动记录等特点。介绍了该系统在日本应用的工程实例。最后指出,污泥固化处理成本取决于污泥特性、产物用途及环境指标等因素。