Evolution of heat transport pathways in the Indonesian Archipelago during last deglaciation

The Indonesian Archipelago provides important heat transport pathways of the Western Pacific Warm Pool between the northern Indian Ocean and western equatorial Pacific Ocean, that exert important impacts on global climate change. This study investigated AMS ¹⁴C, δ¹⁸O, planktonic foraminifer assemblages and sedimentation rates in three piston cores collected in the Indonesian Archipelago. The results indicate that changes in the Indonesian Archipelago heat transport pathways were phase characteristic and in steps during the last deglaciation. In the deglaciation Termination IA, at about 12.5 kaBP, sea level rose rapidly in a short time period, and Makassar and Lombok straits widened suddenly for warm and fresh water from the Pacific to pour into the Java Sea and eastern Indian Ocean. During the Termination IB, about 9.5 kaBP, sea level rose rapidly again, and the South China Sea (SCS) started to connect with the Java Sea. With monsoon actions, a large amount of fresh water from the SCS shelf area flew through the Indonesian Archipelago.     

DS18B20在花棚温度监测中的应用

DS18B20是达拉斯半导体公司的1-wire器件。介绍了DS18B20在温度监测系统中的应用,讨论了DS18B20的特点及系统的硬件、软件设计,给出了硬件接口电路和部分软件编程。系统具有设计简单、成本低廉、可靠性高的特点。     

基于DS18B20的智能温度测量装置

文章介绍了新型单总线结构温度传感器D618820的结构特征及控制方法、并以此为传感器，以89C2051单片机为构成的温度测量装置的电路组成、原理、程序设计．该装置适应于人民日常生活、工业生产和科学研究领域对温度测量的需要．文章中介绍的温度测量装置具有推广应用价值。     

DSP与数字温度传感器DS18820的接口设计

简要介绍了单总线数字温度传感器DS18B20的特性及工作原理,并给出了DS18B20与TMS320LF2407A接口设计电路以及相应的软件。     

1Cr18Ni9Ti热喷涂层在含硫油品中的耐蚀性研究

针对含硫油对石油炼制设备腐蚀严重的实际 ,研究了热喷涂 1 Cr1 8Ni9Ti层对设备进行腐蚀防护 .测定了涂层的孔隙率以及不同温度、不同硫浓度下 1 Cr1 8Ni9Ti涂层的腐蚀速率 .用化学反应动力学理论模型模拟了此腐蚀过程 ,求出了反应过程的反应活化能、反应速率常数和反应速率方程 ;并用三电极电化学研究系统测试了 1 Cr1 8Ni9Ti涂层在含硫油中的极化曲线 ,认为 1 Cr1 8Ni9Ti涂层在含硫油中的腐蚀为电化学腐蚀控制过程 .     

顺(反)-4,4''''-双(4-羟基苯基偶氮)二苯并冠醚的合成与表征

以顺(反)-二氨基二苯并-14-冠-4、顺(反)-二氨基二苯并-18-冠-6和苯酚为原料,通过重氮化和偶联反应合成了4个新的顺(反)-4,4′-双(4-羟基苯基偶氮)二苯并-14-冠-4(化合物1和2)和顺(反)-4,4'-双(4-羟基苯基偶氮)二苯并-18-冠-6(化合物3和4).化合物的结构通过元素分析、紫外光谱、红外光谱和核磁共振波谱等手段确证.发现反式-构型的化合物2和4的熔点高于顺式-构型的化合物1和3的熔点.     

Phylogenetic position of Ephedra rhytidosperma, a species endemic to China： Evidence from chloroplast and ribosomal DNA sequences

The chloroplast genes matK and rbcL, ribosomal gene 18S and ITS regions of nuclear ribosomal DNA from Ephedra rhytidosperma, a species endemic to China, were sequenced and its phylogenetic position was investigated. Independent and combined phylogenetic analyses for the DNA sequences from 16 taxa representing 15 species of the genus Ephedra were performed using the maximum parsimony （MP）, neighbor-joining （N J）, minimum evolution （ME） and maximum likelihood （ML） methods. The results indicate that E. rhytidosperma is closely related to E. equisetina. The divergence time between them is estimated to be 10.85±2.44 Ma based on the results of the relative-rate tests and the evolutionary rate of rbcL gene.     

Effects of isoxazolyl-naphthoquinoneimines on growth and oxygen radical production inTrypanosoma cruzi andCrithidia fasciculata

Several 4-(aminomethylisoxazolyl)-1,2-naphthoquinones inhibited growth and DNA synthesis inTrypanosoma cruzi and stimulated O₂ uptake and generation by the parasite epimastigotes and their mitochondrial and microsomal membranes; these results support the idea that oxygen radicals play a role in quinone toxicity. Maximal effects on respiration and generation were observed with antimycin-inhibited cells. Similar results as well as stimulation of H₂O₂ production were obtained withCrithidia fasciculata despite the presence of catalase in this organism.Acknowledgments. This work was aided by grants from the University of Buenos Aires, the Scientific Office of the American States Organization and CEDIQUIFA (Buenos Aires). S.G.G. and M.P.M.P. are Research Fellows and A.O.M.S. is Career Investigator of CONICET (Argentina). L. T. Viñas and M. G. Gutierrez lent able technical assistance.     

基于KYN18-12高压开关柜事故原因及相应措施

随着配电网自动化的迅速发展和供电可靠性的日益提高，对开关柜的要求也愈来愈高了，特别是变电所在逐步实现综合自动化进而为无人值守时，对开关及开关柜运行状态的无事故提出了更多的要求。文章阐述了高压开关柜的概念、并结合KYN18-12开关柜具体论述了常见的事故及原因，并针对事故做出了具体的技术改善对策。     

Dawson结构磷钨酸钕制备、表征及催化合成四氢呋喃

通过复分解法制备Dawson结构Nd₂P₂W₁₈O₆₂催化剂,并通过XRD、EDS、SEM和FT-IR等方法表征催化剂.以催化1,4-丁二醇液相脱水环化合成四氢呋喃为探针反应,通过正交实验确定了反应的最佳条件:w(催化剂)=2.6%(相对于1,4-丁二醇质量),反应温度为190 ℃,反应时间为40 min,四氢呋喃的平均产率为97.6%,催化剂重复使用到第3次时,四氢呋喃收率为87.9%.本工艺具有绿色、安全、操作简单、收率高等优点.