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91.
A novel dual-slab laser with an off-axis one-sided stable-unstable resonator which can compensate for thermal distortion to some extent by flipping the optical beam is described in this paper. The output power,efficiency, and near-field and far-field intensity distributions of the dual-slab laser have been studied. The results indicate that the novel dual-slab laser has better performance than the normal dual-slab laser with the same off-axis one-sided stable-unstable resonator. 相似文献
92.
93.
Shui Feng ZHANG Li Shi WANG Zhi DANG 《中国化学快报》2006,17(9):1229-1232
This paper reported a compact system of capacitively coupled contactless conductivity detection (C4D) based on the square wave excitation voltage for capillary electrophoresis, and it exhibited excellent sensitivity at the optimal frequency of 198 kHz. The feasibility and sensitivity of this detector was demonstrated by simultaneous detection of thirteen ions including alkali, alkaline earth and heavy metal ions. And the detection limits (S/N 3) were in the range of 0.2-1μmol/L for Mn^2+, K^+, Na^+, Mg^2+, Ca^2+, Li^+, Ba^2+, and 7-25 μmol/L for Ni^2+, Cu^2+, Cd^2+, Pb^2+, Co^2+, Zn^2+. 相似文献
94.
A De Giorgi Type Result to Divergence Degenerate Elliptic Equation with Bounded Coefficients Related To Hörmander's Vector Fields 下载免费PDF全文
Lingling Hou 《偏微分方程(英文版)》2023,36(1):22-47
In this paper, we consider the divergence degenerate elliptic equation with bounded coefficients constructed by Hörmander's vector fields. We prove a De Giorgi type result, i.e., the local Hölder continuity for the weak solutions to the equation by providing a De Giorgi type lemma and extending the Moser iteration to the setting here. As a consequence, the Harnack inequality of weak solutions is also given. 相似文献
95.
Lingling Wang Yilan Jiang Yi Zhou Ruikai Shi Fumio Hosokawa Osamu Terasaki Qing Zhang 《Particle & Particle Systems Characterization》2023,40(1):2200122
It has become very important to study and find optimal conditions for imaging electron-beam (e-beam) sensitive materials in scanning transmission electron microscopy under low electron-dose with high signal-to-noise ratio (SNR). Convergence and collection angles and electron-probe current are essential parameters. However, these parameters have rarely been discussed in a systematic way. In this paper, the illumination and collection conditions are optimized according to the resolution requirement of different materials by adjusting the condenser and intermediate lenses in a commercial transmission electron microscope. To demonstrate the significance of optimizing these parameters, two examples, zeolite MFI and metal–organic framework (MOF) MIL-101, are taken among the sensitive materials, with the most important electron incidences along the [010] and <110> directions, respectively. High SNR atomic resolution images of MFI are obtained with e-beam current as low as 0.50 pA, reaching information transfer for reflection up to 18 0 2 corresponding to d-spacing of 0.11 nm, close to the resolution limit of 0.098 nm from resolvable diffraction limit. MOF MIL-101 is characterized under an even lower e-beam 0.2 pA to avoid severe beam damage. High-quality annular dark and bright field images are obtained, which proves the wide applicability of this method on more e-beam sensitive materials. 相似文献
96.
Hechong Chen Zehong Liang Xinyue Wang Yong Zhang Lingling Shui Dongmei Deng 《Annalen der Physik》2023,535(1):2200375
By applying a virtual source method, the exact and the paraxial solutions of the Swallowtail beams (SBs) that are governed by the inhomogeneous Helmholtz equation are introduced. The paraxial SBs generated experimentally possess both self-accelerating and self-focusing features. The parameters controlling the field distributions are discussed in theory. From the spectral representation of the Swallowtail wave, in the appropriate limit, the first four terms of the nonparaxial correction series for the (1+2)-dimensional Swallowtail waves that simplify to the SBs are obtained. 相似文献
97.
98.
Merging Photoredox and Nickel Catalysis: The Direct Synthesis of Ketones by the Decarboxylative Arylation of α‐Oxo Acids 下载免费PDF全文
Dr. Lingling Chu Jeffrey M. Lipshultz Prof. Dr. David W. C. MacMillan 《Angewandte Chemie (International ed. in English)》2015,54(27):7929-7933
The direct decarboxylative arylation of α‐oxo acids has been achieved by synergistic visible‐light‐mediated photoredox and nickel catalysis. This method offers rapid entry to aryl and alkyl ketone architectures from simple α‐oxo acid precursors via an acyl radical intermediate. Significant substrate scope is observed with respect to both the oxo acid and arene coupling partners. This mild decarboxylative arylation can also be utilized to efficiently access medicinal agents, as demonstrated by the rapid synthesis of fenofibrate. 相似文献
99.
Effect of polyethylene glycol on the crystallization and impact properties of polylactide‐based blends 下载免费PDF全文
Polylactide (PLA) was plasticized by polyethylene glycols (PEGs) with five different molecular weights (Mw = 200–20,000 g/mol). The effects of content and molecular weight of PEG on the crystallization and impact properties of PLA were studied by wide‐angle X‐ray diffraction, differential scanning calorimetry, scanning electron microscopy, transmission electron microscopy, and V‐notched impact tests, respectively. The results revealed that PEG‐10,000 could significantly improve the crystallization capacity and impact toughness of PLA. When the PEG‐10,000 content ranged from 0 to 20 wt%, the increases in both V‐notched Izod and Charpy impact strengths of PLA/PEG‐10,000 blends were 206.10% and 137.25%, respectively. Meanwhile, the crystallinity of PLA/PEG‐10,000 blends increased from 3.95% to 43.42%. For 10 wt% PEG content, the crystallization and impact properties of PLA/PEG blends mainly depended upon PEG molecular weight. With increasing the Mw of PEG, the crystallinity and impact strength of PLA/PEG blends first decreased and then increased. The introduction of PEG reduced the intermolecular force and enhanced the mobility of PLA chains, thus improving the crystallization capacity and flexibility of PLA. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
100.
Two Uranyl Complexes with Pyromellitic Acid. A Heterometallic Complex with U=O–CuII Interaction 下载免费PDF全文
Lingling Liang Yige Cai Xiang Li Ronglan Zhang Jianshe Zhao Chiyang Liu Ng Seik Weng 《无机化学与普通化学杂志》2015,641(10):1744-1748
Two uranyl complexes based on pyromellitic acid were hydrothermally synthesized, and their X‐ray single‐crystal diffraction structures were determined. Complex [UO2(Hbtec)]–(Himd)+ · H2O ( 1 ) (H4btec = pyromellitic acid, imd = imidazole), is an ionic complex, which shows a typical (4, 4) topological structure in the space. A heterometallic complex, UO2Cu(btec)(phen) ( 2 ) (phen = 1,10‐phenanthroline) results from the reaction of uranyl nitrate and copper(II) bromide with pyromellitic acid. The structure of complex 2 revealed that the chains of UO7 and CuO3N2 units were connected to each other through the carboxyl groups and U=O–Cu interactions to create a two‐dimensional framework. 相似文献