En/Decoder for Spectral Phase-Coded OCDMA System Based on Amplitude Sampled FBG

A novel en/decoder for spectral phase-coded optical code-division multiple-access system based on amplitude sampled fiber Bragg grating (FBG) is proposed. Both equivalent chirp and equivalent phase shift are achieved by amplitude sampling. Compared with previous en/decoder based on step chirped FBG, it is easier to fabricate. The performance of the proposed en/decoder is verified by both numerical simulation and experimental demonstration.     

Geotechnical properties of the soft soil in Guangzhou College City

The paper describes some geotechnical properties of the soft soils in Guangzhou College City, China, which are difficult to both sample and test. Laboratory and in situ tests were carried out to assess the physical and mechanical indices of the soils. The data were statistically analyzed and linear regression undertaken such that equations could be developed by which the geotechnical properties of the soft soils can be predicted. The statistical validity of the degree of correlation confirmed that using these equations, the mechanical indices can be estimated from physical indices determined by routine testing.      

Novel blood-compatible waterborne polyurethane using chitosan as an extender

A series of novel block polymers of polyurethane (PU) and chitosan have been prepared in two steps. The first step is the preparation of PU prepolymer, obtained from polytetramethylene oxide glycol (PTMO, M_n = 1000), isophrone diisocyanate (IPDI), and 2,2′-dimethylol propionic acid (DMPA), followed by ionizing PU prepolymer with triethylamine (TEA). The second step involves PU chain-extended by water-soluble chitosan of low molecular weight (M_n = 5000) by self-emulsion polymerization method. The sizes of the latex particles, morphology, and copolymer architecture have been characterized by dynamic light scattering (DLS), general tensile test, infrared spectroscopy (IR), surface contact angle measurement, and transmission electron microscopy (TEM). Furthermore, it shows that the addition of chitosan remarkably increases anticoagulative property of PU elastomers confirmed by the recalcification time. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

无线数字通讯在耙料机控制系统中的应用

以无线通讯方式实现多台PLC之间以及PLC与微机之间的数据交换，在遥控监控站上完成对移动设备的控制与监视。     

漫谈钛合金在舰船上的应用

钛合金优良的耐海水腐蚀性能、高的比强度、无磁性等特点,使其在船用领域大有潜力可为,我国的船用钛合金经过近40年的研究开发,基本能满足舰艇不同强度级别的需求,在舰船上应用具有明显的社会效益和经济效益,值得进一步应用推广。本文介绍了国内外舰船用钛合金的开发及应用情况。对钛合金在鱼雷发射水缸、高压气瓶、一回路危急冷却器、声扫雷具、二回路泵、阀及管系、声纳导流罩、螺旋桨等方面的应用作了重点介绍。     

Metal micromolding: further experiments and preliminary finite element analysis

We report results of instrumented microscale compression molding experiments on Al with Ta mold inserts. The Ta inserts have high-aspect-ratio microscale structures fabricated by micro-electrical-discharge-machining. These microscale structures were further surface engineered by electrochemical polishing, followed by deposition of a conformal amorphous hydrogenated carbon based coating. The molding response of Al, in terms of molding force versus insert displacement, was measured in situ with a high-vacuum, instrumented, compression molding apparatus, and rationalized with a simple model on the mechanics of molding. Molding response was further studied numerically through finite element analysis.     

白酒中四大酸与酯平衡常数及其特定酒度下平衡比值的研究

白酒中酸与酯之间存在着动态平衡，低度白酒中由于在货架期内酸与酯之间重新平衡，对理化指标和口感质量都有较大影响。通过对酒中酸与酯的平衡常数及不同酒度下酸与酯的平衡比值的研究，为科学勾兑尤其是解决低度白酒在货架期内出现质量问题提供了理论依据，旨在把酸酯平衡问题引向理论研讨领域。     

高功率激光系统通过空间滤波和中继成像抑制自聚焦

讨论了由光束自聚焦引起的细丝形成和光束分裂，为了克服聚焦造成的破坏要求在光束传播中采用中继成像和空间滤波。     

LD泵浦Nd：YVO4内腔倍频激光器获得120mW绿光连续输出

利用半导体激光器（ＬＤ）端面泵浦Ｎｄ：ＹＶＯ＿４和用ＫＴＰ内腔倍频的绿激光器获得了１２０ｍＷ连续、稳定的５３２ｎｍ绿激光输出。泵浦阈值Ｐ＿（ｔｈ）＝１６０ｍＷ，光－光转换效率η＿ｓ＝８．１％。换用激光腔输出耦合镜，在不加ＫＴＰ晶体倍频时，可连续输出１．０６μｍ的红外激光，输出功率为４５０ｍＷ，光－光转换效率为３１％。     

组合式光纤流量传感器

提出了一种新型的组合式光纤流量传感器，介绍了它的工作原理，详细讨论了光脉冲转换器的设计要点，据此设计了传感头，并给出了它的实验结果。