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191.
Yang Liu Yiyuan Gao Qian Yang Gao Xu Xingyu Zhou Dr. Guozheng Shi Xingyi Lyu Hao Wu Jun Liu Shiwen Fang Muhammad Irfan Ullah Leliang Song Kunyuan Lu Prof. Muhan Cao Prof. Qiao Zhang Tao Li Prof. Jianlong Xu Prof. Suidong Wang Prof. Zeke Liu Prof. Wanli Ma 《Angewandte Chemie (International ed. in English)》2023,62(17):e202300396
PbS quantum dots (QDs) are promising building blocks for solution-processed short-wavelength infrared (SWIR) devices. The recently developed direct synthesis of semi-conductive PbS QD inks has substantially simplified the preparation processing and reduced the material cost, while facing the challenge to synthesize large-size QDs with absorption covering the SWIR region. Herein, we for the first time realize a low-cost, scalable synthesis of SWIR PbS QD inks after an extensive investigation of the reaction kinetics. Finally, based on these PbS SWIR QD inks, the solar cell demonstrates a record-high power conversion efficiency (PCE) of 1.44 % through an 1100 nm cutoff silicon filter and the photodetector device shows a low dark current density of 2×10−6 A cm−2 at −0.8 V reverse bias with a high external quantum efficiency (EQE) of 70 % at ≈1300 nm. Our results realize the direct synthesis of low-cost and scalable SWIR QD inks and may accelerate the industrialization of consumer SWIR technologies. 相似文献
192.
The Mesomeric Effect of Thiazolium on non‐Kekulé Diradicals in Pichia stipitis Transketolase 下载免费PDF全文
Ning‐Shian Hsu Dr. Yung‐Lin Wang Kuan‐Hung Lin Dr. Chi‐Fon Chang Dr. Syue‐Yi Lyu Dr. Li‐Jen Hsu Dr. Yu‐Chen Liu Dr. Chin‐Yuan Chang Dr. Chang‐Jer Wu Dr. Tsung‐Lin Li 《Angewandte Chemie (International ed. in English)》2018,57(7):1802-1807
It is theoretically plausible that thiazolium mesomerizes to congeners other than carbene in a low effective dielectric binding site; especially given the energetics and uneven electronegativity of carbene groups. However, such a phenomenon has never been reported. Nine crystal structures of transketolase obtained from Pichia stipitis (TKps) are reported with subatomic resolution, where thiazolium displays an extraordinary ring‐bending effect. The bent thiazolium congeners correlate with non‐Kekulé diradicals because there is no gain or loss of electrons. In conjunction with biophysical and biochemical analyses, it is concluded that ring bending is a result of tautomerization of thiazolium with its non‐ Kekulé diradicals, exclusively in the binding site of TKps. The chemophysical properties of these thiazolium mesomers may account for the great variety of reactivities carried out by thiamine–diphosphate‐containing (ThDP) enzymes. The stability of ThDP in living systems can be regulated by the levels of substrates, and hydration and dehydration, as well as diradical‐mediated oxidative degradation. 相似文献
193.
Semiconducting Polymer Nanobiocatalysts for Photoactivation of Intracellular Redox Reactions 下载免费PDF全文
Yan Lyu Jingqi Tian Jingchao Li Prof. Peng Chen Prof. Kanyi Pu 《Angewandte Chemie (International ed. in English)》2018,57(41):13484-13488
An organic semiconducting polymer nanobiocatalyst (SPNB) composed of a semiconducting polymer core conjugated with microsomal cytochrome P450 (CYP) has been developed for photoactivation of intracellular redox. The core serves as the light‐harvesting unit to initiate photoinduced electron transfer (PET) and facilitate the regeneration of dihydronicotinamide adenine dinucleotide phosphate (NADPH), while CYP is the catalytic center for intracellular redox. Under light irradiation, the semiconducting core can efficiently catalyze the generation of NADPH with a turnover frequency (TOF) 75 times higher than the reported nanosystems, ensuring the supply of the cofactor for intracellular redox. SPNB‐mediated intracellular redox thus can be efficiently activated by light in living cells to convert the model substrate and also to trigger the bioactivation of anticancer drugs. This study provides an organic nanobiocatalytic system that allows light to remotely control intracellular redox in living systems. 相似文献
194.
The ionic conductivity and the mechanical strength are two key factors for the performance ofpoly(ethylene oxide) (PEO) based polyelectrolytes.However,crystallized PEO suppresses ion conductivity at low temperature and melted PEO has low mechanical strength at high temperature.Here,random binary brush copolymer composed of PEO-and polystyrene (PS)-based side chains is synthesized.PEO crystallinity is suppressed by the introduction of PS brushes.Doping with lithium trifluoromethanesulfonate (LiTf) induces microphase separation.Due to a random arrangement of the brushes,the microphase segregation is incomplete even at high salt loading,which provides both high ionic conductivity and high mechanical strength at room temperature.These results provide opportunities for the design of polymeric electrolytes to be used at room temperature. 相似文献
195.
A novel method for measuring the linewidth of each laser and channel spacing in a multichannel transmission system is presented. Using the dependence of the Stokes frequency shift on the pump wavelength in stimulated Brillouin scattering, we are able to construct a delayed self-heterodyne interferometer that can measure the linewidths and channel spacing simultaneously. 相似文献
196.
介绍水质浊度国家二级标准物质的研制。参照国际标准ISO 7027中规定的方法,以硫酸肼和六次甲基四胺为原料,采用重量-容量法,根据样品的纯度值、称取的质量及溶液定容体积计算配制值作为标准值,采用高精度浊度仪进行量值核对。样品分装成90瓶后,使用高精度浊度仪进行均匀性和稳定性检验。从样品中随机抽取16瓶进行测定,对测定结果进行F检验,证明标准溶液的均匀性良好。对标准物质溶液进行稳定性检验,证明在1年有效期内稳定性良好。研制的水质浊度标准物质的浊度值为400 NTU,相对扩展不确定度为3%(k=2)。该标准物质符合国家二级标准物质的要求,能够用于水质监测质量控制。 相似文献
197.
Shuang Men Xinyang Jiang Xiaotong Xiang Guoxin Sun Yahong Yan Zhenghong Lyu Yujuan Jin 《Polymer Science Series B》2018,60(3):349-353
In this study, we prepared cellulose long-chain esters homogeneously in 1-butyl-3-methylimidazolium acetate, using cotton linter as the raw material, long-chain fatty acid as the esterification agent and paratoluensulfonyl chloride as the co-reactant. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction were used to characterize the product. The maximum degree of substitution was found to be 1.53 when the molar ratio of cellulose, lauric acid and paratoluensulfonyl chloride was 1 : 6 : 6, provided that the reaction temperature was 60°C and the reaction time was 24 h. The mechanical property of the free-film made of cellulose laurate was also tested. It was found that the toughness of cellulose laurate was much better than that of cellulose acetate. 相似文献
198.
Gao Zhihua Wu Chengwei Lv Sha Wang Cong Zhang Nan Xiao Shuai Han Ying Xu Huo Zhang Yan Li Feng Lyu Jianxin Shen Zhifa 《Analytical and bioanalytical chemistry》2018,410(26):6819-6826
Analytical and Bioanalytical Chemistry - In this study, a biosensing system based on nicking-enhanced rolling circle amplification (N-RCA) was proposed for the highly sensitive detection of... 相似文献
199.
Microencapsulation of styrene with melamine-formaldehyde resin 总被引:1,自引:0,他引:1
Haiping Wang Yanchao Yuan Minzhi Rong Mingqiu Zhang 《Colloid and polymer science》2009,287(9):1089-1097
Melamine-formaldehyde (MF) resin-walled microcapsules containing styrene were prepared by in situ polymerization in an oil-in-water
emulsion. In response to the characteristics of styrene (i.e., high volatility, non-polarity, low molecular weight, and low
viscosity), the synthesis method was improved by optimizing the reaction conditions accordingly. It was found that utilization
of macromolecular emulsifier of lower molecular weight, moderate dispersion rate, and higher feeding weight ratio of core/shell
monomers is critical for the fast formation of capsules’ wall. The highest loading of styrene in the resultant microcapsules
can be about 60%, and mean diameter of the capsules fell in the range of 20∼71 μm, which can be adjusted by changing processing
parameters. It is believed that the present work provides a feasible approach to encapsulate monomers for manufacturing polyester
based self-healing composites. 相似文献
200.
Hui-zhen Li Xiang-wen Chen Si-we Lyu 《International Journal of Infrared and Millimeter Waves》2001,22(6):895-904
This paper describes a global optimization design for power combiner of solid-state millimeter wave source in rectangular wave- guide cavity. The algorithm can determine a neighborhood of the global optimum of an objective function. In this paper, the performance parameter are presents by combining efficiency, tuning range, frequency drift, and FM noise were done the objective functions respectively. And it is to calculate the global optima respectively. 相似文献