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排序方式: 共有314条查询结果,搜索用时 15 毫秒
191.
Dr. Anusha Sebastian Dr. Vunnam Srinivasulu Prof. Dr. Imad A. Abu-Yousef Prof. Dr. Orive Gorka Prof. Dr. Taleb H. Al-Tel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(69):15710-15735
Diversity-oriented synthesis (DOS) has become a powerful synthetic tool that facilitates the construction of nature-inspired and privileged chemical space, particularly for sp3-rich non-flat scaffolds, which are needed for phenotypic screening campaigns. These diverse compound collections led to the discovery of novel chemotypes that can modulate the protein function in underrepresented biological space. In this context, starting material-driven DOS is one of the most important tools used to build diverse compound libraries with rich stereochemical and scaffold diversity. To this end, ene/yne tethered salicylaldehyde derivatives have emerged as a pluripotent chemical platform, the products of which led to the construction of a privileged chemical space with significant biological activities. In this review, various domino transformations employing o-alkene/alkyne tethered aryl aldehyde/ketone platforms are described and discussed, with emphasis on the period from 2011 to date. 相似文献
192.
Qinghua HUANG Hengxin REN Dan ZHANG Y. John CHEN 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2015,91(1):17-24
Recently developed numerical simulation technique can simulate the coupled seismic and electromagnetic signals for a double couple point source or a finite fault planar source. Besides the source effect, the simulation results showed that both medium structure and medium property could affect the coupled seismic and electromagnetic signals. The waveform of coupled signals for a layered structure is more complicated than that for a simple uniform structure. Different from the seismic signals, the electromagnetic signals are sensitive to the medium properties such as fluid salinity and fluid viscosity. Therefore, the co-seismic electromagnetic signals may be more informative than seismic signals. 相似文献
193.
Dr. Wei Guo Yihua Shen Dr. Mingxing Wu Dr. Liang Wang Linlin Wang Prof. Tingli Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(25):7862-7868
Low‐cost quantum‐dot sensitized solar cells (QDSSCs) were fabricated by using the earth‐abundant element SnS quantum dot, novel TiC counter electrodes, and the organic disulfide/thiolate (T2/T?) redox couple, and reached an efficiency of 1.03 %. QDSSCs based on I?/I3?, T2/T?, and S2?/Sx2? redox couples were assembled to study the role of the redox couples in the regeneration of sensitizers. Charge‐extraction results reveal the reasons for the difference in JSC in three QDSSCs based on I?/I3?, T2/T?, and S2?/Sx2? redox couples. The catalytic selectivity of TiC and Pt towards T2/T? and I?/I3? redox couples was investigated using Tafel polarization and electrochemical impedance analysis. These results indicated that Pt and TiC show a similar catalytic selectivity for I?/I3?. However, TiC possesses better catalytic activity for T2/T? than for I?/I3?. These results indicate the great potential of transition metal carbide materials and organic redox couples used in QDSSCs. 相似文献
194.
Linear higher-grade higher-order elastic constitutive laws for compatible (defect-free) and incompatible (containing crystal line defects) media are presented. In the proposed model, the free energy density of a body subjected to elastic deformation under the action of surface tractions, moments or hyper-traction tensors (second-order tensors whose anti-symmetric part corresponds to moments) has contributions coming from the first two gradients of displacements. Thermodynamic considerations reveal that only the symmetric component of the gradient of elastic displacement, i.e., compatible elastic strain tensor, and the anti-symmetric component of the second gradient of elastic displacement, i.e., compatible third-order elastic curvature tensor, contribute to the free energy density during compatible deformation of the body. The line crystal defect contributions are accounted for by incorporating the incompatible components of elastic strains, curvatures and symmetric 2-distortions as state variables of the free energy density. In particular, the presence of generalized disclinations (G-disclinations) is acknowledged when the medium is subjected to surface hyper-traction tensors having a non-zero symmetric component along with surface-tractions on its boundary. Mechanical dissipation analysis provides for the coupling between the Cauchy stresses and third-order symmetric hyper-stresses. The free energy density and elastic laws for a defect-free and line crystal defected medium are proposed in a linear setting. In the special case of isotropy, the cross terms between elastic strains and curvatures contribute to the free energy density through a single elastic constant. More interestingly, the Cauchy and couple stresses are found to have contributions coming from both, elastic strains and curvatures. 相似文献
195.
B. Bora H. Bhuyan M. Favre E. Wyndham H. Chuaqui C.S. Wong 《Current Applied Physics》2013,13(7):1448-1453
Plasma parameters from the discharge characteristics of a 13.56 MHz capacitively coupled radio frequency Ar plasma are evaluated on the basis of homogeneous discharge model for wide range of operating pressure. The homogeneous discharge model of capacitively coupled radio frequency discharge is modified to take into account the nonlinear plasma series resonance effect. The effect of drift velocity of the electron due to change in radio frequency electric field and operating pressure is also considered. Considerable dependent of plasma parameters on the drift velocity of the electron as well as on the plasma series resonance effect are observed in low pressure. An irregular variation of calculated plasma density with operating pressure is observed, which is reconfirmed with optical emission spectroscopy. 相似文献
196.
分别针对剪切和扭转两种工况给出了微纳米薄壁蜂窝等效剪切模量的解析计算方法.该方法综合考虑了由面板对芯层的约束导致的高度效应和当蜂窝胞壁厚度进入微纳米量级时引起的尺度效应.首先对蜂窝各胞壁选取了可反映面板约束以及受力状态的三角级数位移场,然后在本构关系中引入修正偶应力理论以描述尺度效应,最后应用能量均匀化方法求得蜂窝的等效剪切模量.以典型六边形蜂窝为例,给出了完整的计算过程和结果.与文献中的等效剪切模量结果进行对比,讨论了不同工况下等效剪切模量随芯层高度和胞壁厚度的变化趋势,以及高度效应和尺度效应之间的相互影响. 相似文献
197.
198.
199.
重建极性连续统理论的基本定律和原理(Ⅲ)--Noether定理 总被引:6,自引:6,他引:0
对现有的各种偶应力理论进行了认真的再研究,目的是要提出一个耦合型的Noether定理并由此重新建立偶应力弹性动力学的较为完整的守恒定律和相应的均衡方程.这里给出了新的各种守恒定律和均衡方程的具体形式,并建立起从给定的不变性要求所得到的这类守恒定律的确切属性.最后,由这里的结果自然地推导出各种特殊情形;并可自然地过渡到微极连续统的结果. 相似文献
200.
Cai-Wan Chang-Jian Her-Terng Yau 《Acta Mechanica Solida Sinica》2007,20(4):309-316
This study performs a dynamic analysis of a rotor supported by two squeeze couple stress fluid film journal bearings with nonlinear suspension.The numerical results show that the stability of the system varies with the non-dimensional speed ratios and the dimensionless parameter l*.It is found that the system is more stable with higher dimensionless parameter l*. Thus it can conclude that the rotor-bearing system lubricated with the couple stress fluid is more stable than that with the conventional Newtonian fluid.The modeling results thus obtained by using the method proposed in this paper can be used to predict the stability of the rotor-bearing system and the undesirable behavior of the rotor and bearing center can be avoided. 相似文献