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991.
LIU Jingbo LI Yuxin CHEN Youwei WU Changchun WAN Yingying WEI Wei XIONG Lixia ZHANG Xiao YU Shujing LI Zhengming 《高等学校化学研究》2016,32(1):41-48
Anthranilic diamides are one of the most important classes of modern agrochemical insecticides. To discover new structures with higher activity, lower toxicity and lower residue, a series of novel anthranilic diamides containing dihydroisoxazoline and isoxazole was designed and synthesized. Their structures were characterized by means of melting points, proton nuclear magnetic resonance(1H NMR), 13C NMR and high resolution mass spec-trometry(HRMS). According to the bioassay data, it was found that some of the title compounds exhibit moderate insecticidal activity and good antifungal activity. In particularly, compound 15b with a concentration of 50 mg/L shows a lethality rate of 60.0% against Mythimna separata Walker and a lethality rate of 50.0% against Culex pipiens pallens with a concentration of 1mg/L. Moreover, compound 15b showed good antifungal activities(58.8%, 77.1%, 70.7%, 55.3%, 60.7%, 65.4%) when against all the tested fungi(Cercospora arachidicola Hori, Physalospora piricola, Rhizoctonia cerealis, Bipolaris maydis, Watermelon anthracnose, Fusarium moniliforme). The effects of compounds 14h, 14j and 15b on the concentration of intracellular calcium ion([Ca2+]i) in the central neurons of Mythimna separate Walker were well investigated via calcium imaging technique. The results demonstrate that the novel compounds can elevate the calcium concentration in the neurons, denoting that some new structures are potential modulators of the insect ryanodine receptor(RyR). 相似文献
992.
PCrMo钢是导致火炮系统故障的磨损失效零部件主要材料.为了提高零部件的寿命,将固体润滑技术引入火炮抗磨减磨设计中.选取8 ~ 10 μm和3~5 μm两种粒度下二硫化钼作为固体润滑材料,采用激光熔覆工艺在PCrMo钢试样表面制备润滑涂层.通过对涂层宏观性能表征,发现粒度小的涂层熔覆厚度较好;采用扫描电镜和能谱仪分别对涂层表面、剖面微观形貌和化学成分进行分析,发现涂层表面有凹坑产生,且凹坑中氧的含量明显高于光滑表面;涂层剖面与基体结合处存在一定的缝隙,涂层元素与基体元素发生了熔渗.进一步开展的摩擦磨损试验表明:与PCrMo钢裸基材试样相比,两种粒度下润滑涂层试样摩擦系数和磨损量皆降低,磨损量分别为14.84%和42.01%,其中大粒度下涂层摩擦性能较优.二硫化钼润滑涂层起到了很好的润滑效果,可以作为火炮磨损零部件减磨的有效手段. 相似文献
993.
Sergej Malaschichin Changchun Fu Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2005,88(12):3253-3262
The reactions of 1,3‐dioxolane‐2‐thione ( 3 ) with (S)‐2‐methyloxirane ((S)‐ 1 ) and with (R)‐2‐phenyloxirane ((R)‐ 2 ) in the presence of SiO2 in anhydrous dichloroalkanes led to the optically active spirocyclic 1,3‐oxathiolanes 8 with Me at C(7) and 9 with Ph at C(8), respectively (Schemes 2 and 3). The analogous reaction of 1,3‐dimethylimidazolidine‐2‐thione ( 4a ) with (R)‐ 2 yielded stereoselectively (S)‐2‐phenylthiirane ((S)‐ 10 ) in 83% yield and 97% ee together with 1,3‐dimethylimidazolidin‐2‐one ( 11a ). In the cases of 3‐phenyloxazolidine‐2‐thione ( 4b ) and 3‐phenylthiazolidine‐2‐thione ( 4c ), the reaction with (RS)‐ 2 yielded the racemic thiirane (RS)‐ 10 , and the corresponding carbonyl compounds 11b and 11c (Scheme 4 and Table 1). The analogous reaction of 4a with 1,2‐epoxycyclohexane (= 7‐oxabicyclo[4.1.0]heptane; 7 ) afforded thiirane 12 and the corresponding carbonyl compound 11a (Scheme 5). On the other hand, the BF3‐catalyzed reaction of imidazolidine‐2‐thione ( 5 ) with (RS)‐ 2 yielded the imidazolidine‐2‐thione derivative 13 almost quantitatively (Scheme 6). In a refluxing xylene solution, 1,3‐diacetylimidazolidine‐2‐thione ( 6 ) and (RS)‐ 2 reacted to give two imidazolidine‐2‐thione derivatives, 13 and 14 (Scheme 7). The structures of 13 and 14 were established by X‐ray crystallography (Fig.). 相似文献
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In this paper, we propose an information-theoretic approach to the effective usage of auxiliary information from survey data,
which is suitable for both simple and complex survey data. Our estimator under simple random sampling without replacement
will be consistent and asymptotically normal. We show that the resulting estimates have smaller asymptotic variances than
the usual estimates which do not use auxiliary information. For more complex survey designs, the resulting estimator is in
essence asymptotically equivalent to a pseudo empirical likelihood estimator. Results of a limited simulation study show that
the proposed estimators perform well among a number of competitors. 相似文献
998.
X-射线光电子能谱(XPS)振起(Shake-Up)伴峰主要是伴随主光电子的电离所导致的最高占有轨道到最低未占有轨道电子跃迁的结果.Carlson及Clark的工作声明这种振起伴峰是某些共轭π电子体系的表征,振起伴峰的相对强度与π电子共轭情况有关。 含酚酞侧基聚芳醚酮(PEK-C)是一种新型耐高温工程塑料,其主侧链均带苯环: 相似文献
999.
本文讨论如下抛物型Monge-Ampere方程的第一初边值问题-ut+det1/n D2u=g(χ,t),(χ,t)∈Q=Ω×(0,T),u= (χ,t),(χ,t)∈ pQ,其中Ω为Rn中有界凸集.证明了在更一般的结构条件下[3,7]的结果仍然成立.证明中重要的一点是在Rn × R中非柱型域上“冻结问题”的可解性. 相似文献
1000.
On the beltram I flows 总被引:1,自引:0,他引:1
To illustrate the general properties of the Beltrami flows, a new sufficient and necessary condition of the general solution
of the Beltrami flows has been given, on whose basis some sufficient and necessary conditions and sufficient conditions in
literature are unified. The advantages of the new expressions are that one may get solutions of Beltrami flows with constant
proportional factors which satisfy some given asymptotic decaying conditions at infinity. Finally, we find a class of spherical
vortices of Beltrami flows, where the motion trajectories of the fluid particles are confined within a sphere or two adjacent
concentric spherical shells. We find that the superpositions of the spherical vortices of the same order with different polar
axes may produce chaotic trajectories.
The project is supported by the National Foundamental Research Programme of State Commission of Sciences and Technology. 相似文献