机械定尺飞锯机中的555时基电路

介绍了５５５时基电路在机械定尺飞锯机中的应用及工作原理。     

Binding of cadmium,copper, and zinc to humic substances originating from municipal solid waste compost

The application of municipal solid waste (MSW) compost increases both the trace metal loading and the organic matter in the soil. To characterize the quality and metal-binding capacity of the compost OM, we extracted humic acid (HA) and fulvic acid (FA) from mature MSW compost and analyzed them for elemental composition, acid-titratable functional groups, total metal content, and structural components (by ¹³C NMR). HA constituted 67% of all extracted humic substances and differed significantly from HAs of cultivated lands: The compost HA exhibited smaller molecular size, a higher N content, and lower aromaticity due to large amounts of saturated aliphatic components. Metal complexation studies of the extracted HA and FA were performed by equilibrium dialysis titration. The complexing capacity (CC) was highest for Cu: CC_HA = 3357 and CC_FA = 5221 μmol Cu g⁻¹ of dissolved organic carbon (DOC) at pH 5. Zn and Cd were bound (at pH 7) in smaller concentrations: CC_HA(Zn) = 2167, CC_FA(Zn) = 2809, CC_HA(Cd) = 2386, and CC_FA(Cd) = 2468 μmol metal g⁻¹ of DOC. Stability constants for binding on the strongest sites (pK_int) were determined as pK_intHA = 6.6 and pK_intFA = 7.3 for Cu at pH 5; and pK_intHA = 8.0 and pK_intFA = 6.4 for Cd at pH 7. Since these measured parameters fall within the ranges of values obtained for soil humic substances, we conclude that in soils with little organic matter, compost addition will significantly increase the amount of highly reactive organic complexing agents for trace metals in the soil.     

Synchronized chaotic optical communications at high bit rates

Basic issues regarding synchronized chaotic optical communications at high bit rates using semiconductor lasers are considered. Recent experimental results on broadband, high-frequency, phase-locked chaos synchronization, and message encoding-decoding at 2.5 Gb/s are presented. System performance at a bit rate of 10 Gb/s is numerically studied for the application of three encryption schemes, namely chaos shift keying, chaos masking, and additive chaos modulation, to three chaotic semiconductor laser systems, namely the optical injection system, the optical feedback system, and the optoelectronic feedback system. By causing synchronization error in the forms of synchronization deviation and desynchronization bursts, the channel noise and the laser noise both have significant effects on the system performance at high bit rates. Among the three laser systems, the optoelectronic feedback system has the best performance while the optical feedback system has the worst. Among the three encryption schemes, only the performance of additive chaos modulation with low-noise lasers is acceptable at high bit rates.     

多离子束反应共溅射制备PbTiO_3铁电薄膜的微结构研究

本文利用多离子束反应共溅射装置，分别在Ｓｉ和ＭｇＯ衬底上原位制备了ＰｂＴｉ氧化物薄膜。研究表明，利用多离子束反应共溅射技术，可以显著降低薄膜后续热处理的温度；薄膜中焦绿石结构的消失温度与薄膜中Ｐｂ的含量有关；较之Ｓｉ衬底，在ＭｇＯ衬底上的薄膜较易获得好的晶体结构和优良的薄膜表面形貌。对所观察到的现象，从衬底与薄膜相互作用的角度进行了讨论     

浅谈ispLSI及其应用

本文以ｉｓｐＬＩＳＩ１０００系列为例，对ｉｓｐ技术及ｉｓｐＬＳＩ器件进行了较为详细的介绍，并结合具体设计实例，介绍ｉｓｐＬＳ开发工具的使用。     

电分标准工作曲线的推导与实践研究

本文根据人眼视觉特性、孟塞尔方程及彩色复制理论,并结合实际工艺路线和工艺条件,推导出标准阶调复制曲线和标准电分工作曲线。它与德国Hell公司所绘的电分标准工作曲线基本一致。并做到了各工序有数据,有质量标准,使平印制版做到有规可循。     

Implementation and experimental studies of an adaptive self-optimizing power system stabilizer

This paper describes the implementation and experimental studies of an adaptive self-optimizing pole shifting power system stabilizer. Using an Intel iSBC386/21 single-board computer, the adaptive power system stabilizer has been tested on a physical model of a single-machine infinite-bus power system. Under different operating conditions and disturbances, the behavior of the proposed adaptive stabilizer was investigated. Comparison has also been made to a digital-type conventional fixed-parameter power system stabilizer. Results of the experimental studies show that the proposed adaptive stabilizer outperforms the conventional stabilizer.     

露天矿山裂隙岩体爆破孔距变化的研究

文中指出裂隙岩体大孔距爆破在一点条件下与结构面的特性变化关系密切，并按两组三结构面建立了孔距计算公式。     

Observation of atomic steps on CaCO3 crystal surface

By using scanning polarization force microscopy,the deliquescence process and the atomic steps on the cleavage surface of CaCO3 in air were studied in situ.Under an exposure to medium umidity(-57%),the sloiw step movement has been observed.     

Occlusion of large atrial septal defects with a centering buttoned device: early clinical experience

A feasibility clinical study was conducted for the transcatheter occlusion of large ostium secundum atrial septal defects with the centering buttoned device. The centering buttoned device is a modification of the regular buttoned device in which a centering counter-occluder is sutured at the central 40% portion of the occluder. During centering it is stretched, forming a parachute-shaped structure and pulling the occluder over the center of the defect. During buttoning, the counter-occluder forms a double figure eight, opposing the right atrial side of the atrial septum. Occlusion was performed in 12 patients aged 6 to 56 years. All had been rejected for transcatheter occlusion by the regular buttoned device, because of either their defect size or the lack of adequate septal rim. The defect size varied between 23 and 31 mm, and the device size varied between 45 and 60 mm. Nine had immediate effective occlusions of their defects and three residual shunts. One patient with unbuttoning had hemolysis at 2 weeks and underwent surgery. Early results of the transcatheter occlusion of large atrial septal defects are promising, and larger clinical trials are justified.