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排序方式: 共有117条查询结果,搜索用时 187 毫秒
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1-苯基-3-甲基-5-氯-4-吡唑甲醛与4-氨基-5-取代苯基-1,2,4-三唑-3-硫酮缩合生成4-(1-苯基-3-甲基-5-氯吡唑次甲亚胺基)-5-(取代苯基)-2H-1,2,4-三唑-3(4H)-硫酮,再烷基加成化为新型含吡唑基5,6-2H-1,2,4-三唑[3,4-b][1,3,4]噻二嗪衍生物。 化合物结构经1H NMR、IR以及元素分析确认。 初步生物活性测试结果表明,在100 mg/L浓度下,化合物8a(3-(2-甲基苯基)-6-(5-氯-2-甲基-4-苯基吡唑)-7-(4-硝基苯基)-5H-1,2,4-三唑[3,4-b][1,3,4]噻二嗪)对黄瓜炭疽病的抑制率达90%。 相似文献
43.
利用半离散的方法将两相同部件冷贮备可修系统中的μ(x)进行离散,得到两个偏微分方程,进一步利用算子半群的理论证明离散后的解是收敛于原方程的解. 相似文献
44.
Types 316 and 304 stainless steel are two candidates for the storage vessels and piping systems of LAB-based liquid scintillator (LS) in the JUNO experiment. LS aging experiments are carried out at temperatures of 40℃ and 25℃. After 192 days aging at 40℃, the attenuation length of LS was reduced by 6% in a glass container, 12% in a type 304 stainless steel tank, and 10% in a type 316 stainless steel tank. At 25℃ in 304 and 316 stainless steel tanks, the attenuation length was reduced by 6% after 307 days. The light yield and the absorption spectrum were practically the same as that of the unaged sample. The concentration of element Fe in the LAB-based LS did not show a clear change. Type 316 and 304 stainless steel can be used as vessels and transportation pipeline material for LAB-based LS. 相似文献
45.
石峰 吕军光 卢红 王焕玉 马宇蒨 胡涛 周莉 蔡啸 孙丽君 俞伯祥 方建 谢宇广 安正华 王志刚 高旻 李新乔 徐岩冰 王平 孙希磊 章爱武 薛镇 刘宏邦 王晓东 赵小芸 郑阳恒 孟祥承 王辉 《中国物理 C》2011,35(1):50-55
Silicon photomultipliers (SiPMs) are a new generation of semiconductor-based photon counting devices with the merits of low weight, low power consumption and low voltage operation, promising to meet the needs of space particle physics experiments. In this paper, comparative studies of SiPMs and traditional vacuum photomultiplier tubes (PMTs) have been performed regarding the basic properties of dark currents, dark counts and excess noise factors. The intrinsic optical crosstalk effect of SiPMs was evaluated. 相似文献
46.
THGEM with resistive Kapton electrodes (RETGEM) has been developed to make the THGEM more tolerant to discharges. At higher gains with resistive electrodes, serious discharges may travel to the streamer mode, in contrast to violent sparks in conventional GEMs. These streamers are mild and less dangerous to the detector and the front-end electronics. RETGEM looks very promising, and its basic properties are being studied. Recently we developed and tested the THGEM with electrodes using 20 um thick resistive kapton foils. The new RETGEM performs at a lower discharge current, has a lower discharge probability, and has a good energy resolution of 27% and a high effective gas gain and long-term stability. 相似文献
47.
ICP—OES同时测定三元复合肥中六种微量元素 总被引:2,自引:0,他引:2
用微波消解/电感耦合等离子体发射光谱法(ICP—OES)同时测定了三元复合肥中的铜、铁、锌、镍、锰、钼6种微量元素。结果表明,该法具有简便、快速、结果可靠、检出限低、良好的精密度、精确度、高回收率以及能够同时测量多种元素的优点;通过对比实验测量得到了有效态微量元素的浓度和微量元素的总量,结果显示大部分微量元素是以有效态形式存在于复合肥中。因此,该法可以作测量复合肥类产品中的微量元素的一种参考使用方法。 相似文献
48.
章爱武 谢宇广 俞伯祥 安正华 王志刚 蔡啸 孙希磊 石峰 方建 薛镇 吕绮雯 孙丽君 葛永帅 刘颖彪 刘宏邦 郑阳恒 谢一冈 胡涛 周莉 吕军光 《中国物理 C》2012,36(10):985-990
A micro-pattern gas detector named leak microstructure (LM) has been studied. A new chemical electrolytic technique is introduced to make perfect shaped LM needles with very sharp tips, and this method may be developed to make LM array detectors in batches. The experimental results are presented for both a single needle LM detector and a small LM array detector. The gas gain is up to 105 by calculation from the waveform. Good gain stability and uniformity are achieved. The light emission from the needle tip is also measured in Ar/CF4(95/5) gas mixture. The result shows a promising application for imaging. 相似文献
49.
本文主要研究由机器人与其安全装置组成的系统. 利用泛函分析方法将原系统的偏微分方程组转化成Banach空间中抽象的Cauchy问题.通过代数理论和$C_0$半群理论得到系统的瞬态可靠度和稳态可用度,利用转换变量证明了系统的可靠性和零状态可控性.最后利用Maple软件模拟出系统瞬态可靠度和稳态可用度图形. 相似文献
50.