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771.
Guo Z Yao C Pan Y Tong H Wei X 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):344-347
[Ni(CH(3)COO)(2)·(NH(2)CH(2)Ph)(4)] complex was synthesized using benzylamine and nickel acetate. The molecular structure of this complex was obtained by single crystal X-ray diffraction and characterized by elemental analysis, IR spectrometry and thermal analysis. The complex crystallized in the monoclinic space group P2(1)/n with cell parameters a=11.234(4)?, b=6.459(2)?, c=22.647(8)?, α=90.00, β=91.149(4)°, γ=90.00, V=1642.8(10)?(3), Z=2. The structure has been solved by direct methods and refined to R(1)=0.0876 for 6377 observed reflections I>2σ(I). Magnetic studies for complex show the data over the whole temperature range 5-300 K are well fitted to the Curie-Weiss law with C=1.03 cm(3) K mol(-1) and θ=-1.38 K. This fitting indicates antiferromagnetic interaction between the Ni ions and the metal center exhibits distorted octahedral coordination geometries. The thermal analysis was carried out to understand the thermal stability of the title complex. 相似文献
772.
Chen X Wang H Jin X Feng J Wang Y Lu P 《Chemical communications (Cambridge, England)》2011,47(9):2628-2630
Phenalenone derivatives were efficiently constructed from 1,8-diiodonaphthalene and tertiary propynols via a one-pot domino reaction which eventually included Pd-catalyzed Sonogoshira coupling, Pd-catalyzed allylic oxidation and Pd-catalyzed C(sp(2))-H activation. Moreover, the synthesized phenalenone derivative presented a practical application as a fluorescent chemosensor for fluoride anion with high sensitivity and selectivity. 相似文献
773.
This article deals with averaging principle for stochastic FitzHugh–Nagumo system with different time-scales. Under suitable conditions, the existence of an averaging equation eliminating the fast variable for this coupled system is proved, and as a consequence, the system can be reduced to a single stochastic ordinary equation with a modified coefficient. Moreover, the rate of convergence for the slow component towards the solution of the averaging equation is of order 1/2. 相似文献
774.
周维民 单连强 吴俊峰 蔡洪波 刘东晓 刘红杰 毕碧 张锋 王为武 吴凤娟 朱斌 吴玉迟 温贤伦 何颖玲 周沧涛 曹莉华 吴思忠 魏来 曹柱荣 袁铮 杨志文 谷渝秋 张保汉 《强激光与粒子束》2015,27(3):032017-164
与中心点火相比,快点火将压缩和点火过程分开,大大放宽了对压缩对称性和驱动能量的要求。通过在神光Ⅱ激光装置上开展了快点火锥壳靶预压缩实验研究,利用X射线背光分幅照相方法观察到了清晰完整的快点火锥壳靶内爆压缩过程,并利用阿贝反演结合剩余烧蚀质量的方法得到了不同时刻燃料密度、面密度分布数据,当前实验条件下获得的最大压缩密度和面密度分别为30g/cm3和50mg/cm2;为解决金柱腔M带对导引锥的预热以及由此导致的燃料-锥体材料混合问题,提出了一种在锥体表面镀低Z材料的方法,实验和辐射流体数值模拟结果验证了该方法的有效性,该方法的成功解决了间接驱动快点火激光聚变的重要关键技术问题。 相似文献
775.
提出一种用于分析硅纳米梁动态特性的改良型半连续体模型,对比传统的连续体理论,这种新模型使用了Keating势,并考虑了纳米梁在宽厚两个维度的分立特性。依据Sun-Zhang模型思想和能量守恒定律,建立了改良型Keating模型,并进行了双端固支梁的基频计算。在这个过程中,对一些表面效应也进行系统分析。结果表明,该改良模型一方面在纳米尺度下与Material StudioTM软件仿真结果较为符合,另一方面也能在微观尺度下较好的接近连续体模型的计算数据。同时,该模型还反映了基频随纳米梁宽度变化的特性,这也符合一些实际实验。 相似文献
776.
综述了未知物组分剖析的技术特点及难点。介绍了剖析的一般实施步骤及常用仪器方法,对定性定量困难等问题进行讨论。归纳了未知物组分剖析技术在成分分析、反向工程、健康环保及失效分析领域的最新应用进展。 相似文献
777.
Hongbo Li Cui WangZaisheng Wu Limin Lu Liping QiuHui Zhou Guoli ShenRuqin Yu 《Analytica chimica acta》2013
Due to the ubiquity and essential of the proteins in all living organisms, the identification and quantification of disease-specific proteins are particularly important. Because the conformational change of aptamer upon its target or probe/target/probe sandwich often is the primary prerequisite for the design of an electrochemical aptameric assay system, it is extremely difficult to construct the electrochemical aptasensor for protein assay because the corresponding aptamers cannot often meet the requirement. To circumvent the obstacles mentioned, an electronic channel switching-based (ECS) aptasensor for ultrasensitive protein detection is developed. The essential achievement made is that an innovative sensing concept is proposed: the hairpin structure of aptamer is designed to pull electroactive species toward electrode surface and makes the surface-immobilized IgE serve as a barrier that separates enzyme from its substrate. It seemingly ensures that the ECS aptasensor exhibits most excellent assay features, such as, a detection limit of 4.44 × 10−6 μg mL−1 (22.7 fM, 220 zmol in 10-μL sample) (demonstrating a 5 orders of magnitude improvement in detection sensitivity compared with classical electronic aptasensors) and dynamic response range from 4.44 × 10−6 to 4.44 × 10−1 μg mL−1. We believe that the described sensing concept here might open a new avenue for the detection of proteins and other biomacromolecules. 相似文献
778.
779.
780.
Single-pulse and multi-pulse damage behaviors of "standard"(with λ/4 stack structure) and "modified"(with reduced standing-wave field) HfO2/SiO2 mirror coatings are investigated using a commercial 50-fs,800-nm Ti:sapphire laser system.Precise morphologies of damaged sites display strikingly different features when the samples are subjected to various number of incident pulses,which are explained reasonably by the standing-wave field distribution within the coatings.Meanwhile,the single-pulse laser-induced damage threshold of the "standard" mirror is improved by about 14% while suppressing the normalized electric field intensity at the outmost interface of the HfO2 and SiO2 layers by 37%.To discuss the damage mechanism,a theoretical model based on photoionization,avalanche ionization,and decays of electrons is adopted to simulate the evolution curves of the conduction-band electron density during pulse duration. 相似文献