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1.
Mathematical Programming - We seek tight bounds on the viable parallelism in asynchronous implementations of coordinate descent that achieves linear speedup. We focus on asynchronous coordinate... 相似文献
2.
This study extends the investigation of quantum dissipative effects of a cosmological scalar field by taking into account cosmic expansion and contraction.Cheung,Drewes,Kang,and Kim calculated the effective action and quantum dissipative effects of a cosmological scalar field in a recent work,where analytical expressions for the effective potential and damping coefficient were presented using a simple scalar model with quartic interactions,and the work was conducted using Minkowski-space propagators in loop diagrams.In this work,we incorporate the Hubble expansion and contraction of the cosmic background and focus on the thermal dynamics of a scalar field in a regime where the effective potential changes slowly.Given that the Hubble parameter,H,attains a small but non-zero value,we carry out calculations to the first order in H.If we set H=0,all results match those in flat spacetime.Interestingly,we must integrate over the resonances,which in turn leads to an amplification of the effects of a non-zero H.This is an intriguing phenomenon,which cannot be uncovered in flat spacetime.The implications on particle creations in the early universe will be studied in a forthcoming study. 相似文献
3.
Dr. Kwan Yin Cheung Prof. Yasutomo Segawa Prof. Kenichiro Itami 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(65):14791-14801
The development of carbon nanobelts and related belt-shaped polycyclic aromatic hydrocarbons has gained momentum in recent years. This Minireview focuses on the synthetic strategies used in constructing these aesthetically appealing molecular nanocarbons. Examples of carbon nanobelts and related belt-shaped polycyclic aromatic hydrocarbons reported in recent years as well as some representative synthetic attempts in earlier times are discussed. 相似文献
4.
Jianshuang Wang Michael Van Parys Lin Pan Yuan Chen Dorothy Cheung Janine McKnight Dennis Milanowski Xiao Ding Brian Dean 《Biomedical chromatography : BMC》2019,33(4)
A specific and robust LC–MS/MS method was developed and validated for the quantitative determination of GDC‐3280 in human plasma and urine. The nonspecific binding associated with urine samples was overcome by the addition of CHAPS. The sample volume was 25 μL for either matrix, and supported liquid extraction was employed for analyte extraction. d6‐GDC‐3280 was used as the internal standard. Linear standard curves (R2 > 0.9956) were established from 5.00 to 5000 ng/mL in both matrices with quantitation extended to 50,000 ng/mL through dilution. In plasma matrix, the precision (RSD) ranged from 1.5 to 9.9% (intra‐run) and from 2.4 to 7.2% (inter‐run); the accuracy (RE) ranged from 96.1 to 107% (intra‐run) and from 96.7 to 104% (inter‐run). Similarly, in urine the precision was 1.5–6.2% (intra‐run) and 1.9–6.1% (inter‐run); the accuracy was 83.1–99.3% (intra‐run) and 87.1–98.3% (inter‐run). Good recovery (>94%) and negligible matrix effect were achieved in both matrices. Long‐term matrix stability was established for at least 703 days in plasma and 477 days in urine. Bench‐top stability of 25 h and five freeze–thaw cycles were also confirmed in both matrices. The method was successfully implemented in GDC‐3280's first‐in‐human trial for assessing its pharmacokinetic profiles. 相似文献
5.
Jia Min Lee Sean Kang Qiang Suen Wei Long Ng Wai Cheung Ma Wai Yee Yeong 《Macromolecular bioscience》2021,21(1)
Collagen is the most abundant extracellular matrix protein that is widely used in tissue engineering (TE). There is little research done on printing pure collagen. To understand the bottlenecks in printing pure collagen, it is imperative to understand collagen from a bottom‐up approach. Here it is aimed to provide a comprehensive overview of collagen printing, where collagen assembly in vivo and the various sources of collagen available for TE application are first understood. Next, the current printing technologies and strategy for printing collagen‐based materials are highlighted. Considerations and key challenges faced in collagen printing are identified. Finally, the key research areas that would enhance the functionality of printed collagen are presented. 相似文献
6.
Periodica Mathematica Hungarica - In this paper we introduce a new conformable derivative call it mixed conformable partial derivative, which obeys classical properties, including linearity,... 相似文献
7.
Dr. Wei Wei Ka Key Cheung Dr. Ran Lin Lam Cheung Kong Ka Lok Chan Dr. Herman H. Y. Sung Prof. Dr. Ian D. Williams Prof. Dr. Rongbiao Tong Prof. Dr. Zhenyang Lin Prof. Dr. Guochen Jia 《Angewandte Chemie (International ed. in English)》2023,62(36):e202307251
A unique benzannulation strategy for regioselective de novo synthesis of densely functionalized phenols is described. Through metal-mediated formal [2+2+1+1] cycloaddition of two different alkynes and two molecules of CO, a series of densely functionalized phenols were obtained. The benzannulation strategy allows efficient regioselective installation up to five different substituents on a phenol ring. The resulting phenols have a substitution pattern different from those obtained from Dötz and Danheiser benzannulations. 相似文献
8.
Nonlinear static and dynamic analysis for laminated,annular, spherical caps of moderate thickness 总被引:1,自引:0,他引:1
Based on Timoshenko-Mindlin kinematic hypothesis, the shallow shell theory is extended to include the transverse shear deformation for the nonlinear axisymmetric dynamic analysis of the symmetric cross-ply shallow spherical shell. Using the orthogonal point collocation method and the Newmark scheme, an iterative solution is formulated. The numerical results for the nonlinear static and dynamic responses and dynamic buckling of these shallow spherical shells with circular holes under uniformly distributed static or dynamic normal impact loads are presented and compared with available data. 相似文献
9.
用Trefftz型边界解法分析了中厚板弯曲问题,发现了一类新的、因Trefftz函数溢机引起的“自锁现象”,并提出了一种消除这类自锁问题的“变量减缩法”。 相似文献
10.
A range of activated indole-2-carboxylate derivatives was prepared via the Hemetsberger indole synthesis. Vilsmeier formylation was explored to establish regioselectivity and to prepare a range of new indole carbaldehydes. The indole aldehydes were reduced to the corresponding hydroxymethylindoles in good yields by the use of sodium borohydride in THF. Symmetrical 4,4′-, 6,6′- and 7,7′-diindolylmethanes were prepared via the acid-catalysed reaction of the corresponding hydroxymethylindoles. Furthermore, the treatment of methyl 4-hydroxymethyl-5,6-dimethoxyindole-2-carboxylate and a range of methyl indole esters with acetic acid led to the formation of unsymmetrical 4,6′- and 4,7′-dindolylmethanes. 相似文献