检索结果-南通市图书馆

Tailoring sulfur-doped and nitrogen-defective carbon nitride nanosheets for efficient photo-controlled radical polymerizations

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第7期67卷 2325-2334页

作者： Xue Li Meng Kai Xu Yuan Huang tao cai Key Laboratory of Biomedical Polymers of Ministry of Education College of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072China Wuhan University Shenzhen Research Institute Shenzhen 518057China

Despite the challenges that remain,the synergistic adjustment of various microstructures and photochemical parameters of graphitic carbon nitride(g-C_(3)N_(4))in photocatalytic reactions holds promises for improving catalytic efficiency and reducing energy consumption.Herein,sulfur-doped and nitrogen-defective g-C_(3)N_(4)(n-SC_(3)N_(x))nanosheets were designed and elaborately synthesized.The resultant n-SC_(3)N_(x)possessed a precisely defined 2D layer structure with extensive porosity and incremental specific surface area.Enhanced photoinduced electron transfer-reversible addition-fragmentation chain transfer(PET-RAFT)polymerization of vinyl monomers with low dispersity,excellent temporal control and high chain-end fidelity was achieved under mild blue light irradiation in a nondegassed system.Owing to their ultrathin nanostructures with nitrogen defects and sulfur dopants,n-SC_(3)N_(x)was capable of catalyzing RAFT polymerization in aqueous solutions at significantly accelerated rates,which were nearly 8 times faster compared to bulk g-C_(3)N_(4).The ease of separation and efficient reusability in subsequent polymerizations was enabled by the heterogeneous nature of n-SC_(3)N_(x).The appeal of this approach was illustrated by the fact that utilizing a reusable and metal-free photocatalyst in aqueous environments allowed for the synthesis of polymers with molecular weight up to 300 kg mol-1and a dispersity of 1.32.

关键词： graphitic carbon nitride nitrogen defects sulfur dopants PET-RAFT polymerization recyclability

Temperature Dependence of Laminar Burning Velocity in Ammonia/Dimethyl Ether-air Premixed Flames

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第1期31卷 189-197页

作者： cai tao ZHAO Dan Department of Mechanical Engineering College of EngineeringUniversity of CanterburyChristchurch 8041New Zealand

The combustion of ammonia(NH3)has attracted wide interest in fuel vehicle engines,marine engines,and power generators to mitigate carbon dioxide emissions.Unfortunately,the relatively low laminar flame speed presents a technical barrier for this renewable fuel to be used in practice.This work is concerned with numerical examining the effects of elevating inlet temperature on the laminar burning velocity of NH3/air flames with various contents of dimethyl ether(DME)using ID freely propagating flame calculations,and to shed light on the flame enhancement mechanism.For this,the mechanism is first validated by comparing the numerical predictions with experimental data.Results show that increasing the inlet temperature has a positive effect on the laminar burning velocity of pure NH3/DME/air flames.It is revealed that elevating inlet temperature contributes to a higher adiabatic flame temperature,which is beneficial to the overall chemical reaction rate.Furthermore,the thermal diffusivity of the binary mixture is observed to increase substantially as well.Further kinetic and sensitivities analyses reveal that the inlet temperature has a minimal effect on the reaction pathway,leading to the relative importance of the dominant chain branching over terminating reaction steps to be varied negligibly.The present work confirms that the flame speed enhancement with increasing inlet temperature is primarily the synergetic result of the thermal and diffusion effects,rather than the chemical effect.

关键词： ammonia dimethyl ether laminar burning velocity temperature dependence kinetic analyses

You've got questions?She's got answers(But you probably won't like them)

在线全文

学校读者我要写书评

暂无评论

The World of Chinese 2024年第2期 126-126页

作者： cai tao Gao Fei

Dear Ayi,I tried to avoid crowds this Labor Day holiday by visiting a small village in the middle of nowhere.Iended up bored out of my mind.Where can I go that's quiet and fun?

关键词： tried probably answer

Engineering of cofactor preference and catalytic activity of methanol dehydrogenase by growth-coupled directed evolution

在线全文

学校读者我要写书评

暂无评论

Green Carbon 2024年第2期2卷 242-251页

作者： Jinxing Yang Liwen Fan Guimin Cheng tao cai Jibin Sun Ping Zheng Shuang Li Yu Wang School of Biology and Biological Engineering South China University of TechnologyGuangzhou 510006China Haihe Laboratory of Synthetic Biology Tianjin 300308China Key Laboratory of Engineering Biology for Low-Carbon Manufacturing Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Technology Innovation Center of Synthetic Biology Tianjin 300308China College of Biotechnology Tianjin University of Science and TechnologyTianjin 300222China

Methanol,produced from carbon dioxide,natural gas,and biomass,has drawn increasing attention as a promising green carbon feedstock for biomanufacturing due to its sustainable and energy-rich properties.Nicotinamide adenine dinucleotide(NAD+)-dependent methanol dehydrogenase(MDH)catalyzes the oxidation of methanol to formaldehyde via NADH generation,providing a highly active C1 intermediate and reducing power for subsequent biosynthesis.However,the unsatisfactory catalytic efficiency and cofactor bias of MDH significantly impede methanol valorization,especially in nicotinamide adenine dinucleotide phosphate(NADP+)-dependent biosynthesis.Herein,we employed synthetic NADH and NADPH auxotrophic Escherichia coli strains as growth-coupled selection platforms for the directed evolution of MDH from Bacillus stearothermophilus DSM 2334.NADH or NADPH generated by MDH-catalyzed methanol oxidation enabled the growth of synthetic cofactor auxotrophs,establishing a positive correlation between the cell growth rate and MDH activity.Using this principle,MDH mutants exhibiting a 20-fold improvement in catalytic efficiency(kcat/Km)and a 90-fold cofactor specificity switch from NAD+to NADP+without a decrease in specific enzyme activity,were efficiently screened from random and semi-rationally designed libraries.We envision that these mutants will advance methanol valorization and that the synthetic cofactor auxotrophs will serve as versatile selection platforms for the evolution of NAD(P)+-dependent enzymes.

关键词： Growth-coupled screening Methanol dehydrogenase Cofactor engineering Directed evolution C1 bioconversion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

大世界小剧场:丁衍庸的晚年“戏画”

美术学报 2024年第1期 35-45页

作者：蔡涛广州美术学院艺术与人文学院

本文关注了丁衍庸晚年在香港地区创作的神鬼题材的水墨画。这些题材新颖多变的画作,一方面反映了他所追求的以“神趣”为要旨的文化自觉和境界升华,同时也让人联想到艺术家披沥的世变沧桑,反映为一种“晚期风格”,尤其在艺术家心理创伤... 详细信息

本文关注了丁衍庸晚年在香港地区创作的神鬼题材的水墨画。这些题材新颖多变的画作,一方面反映了他所追求的以“神趣”为要旨的文化自觉和境界升华,同时也让人联想到艺术家披沥的世变沧桑,反映为一种“晚期风格”,尤其在艺术家心理创伤的层面上,可被视为一种深有意味的癫狂。擅长野兽派画风的丁衍庸,此时对八大山人的大写意画风进行了创造性融合,以一种人鬼神之际、东西洋之交的新颖“戏画”,演绎出一幕幕“大世界小剧场”。而丁氏的晚年“戏画”,在中国现代美术史上占据的重要位置,尚未获得应有的评价。

关键词：丁衍庸野兽派八大山人晚年“戏画” 神鬼题材

Another End of the Line

在线全文

学校读者我要写书评

暂无评论

The World of Chinese 2022年第2期 92-94页

作者：杨婷婷 cai tao WANG SIQI 不详

How to identify and deal with common phone scams诈骗新套路,你中招了吗?随附反诈指南,拿走不谢"Hi,it’s Little Zhang,your long-lost friend from middle school!Listen,can you do me a favor?"comes the voice over your phone.It may at first sound like the rekindling of a beautiful old friendship,but wait...you don’t remember this Zhang guy,he’s calling on a"withheld"number,and now he’s asking for cash for emergency surgery.

关键词： remember beautiful sound

综合行政执法改革过程中的多维结构变迁与能动者策略

在线全文

学校读者我要写书评

暂无评论

理论与改革 2024年第1期 152-165,168页

作者：叶贵仁蔡龚涛华南理工大学公共管理学院

推动执法权属地化与综合化是夯实基层政权建设的重要一环,但在政策实践中,并不必然带来治理效能的提升。事权下放后,基层治理结构的实质性变革如何形塑执法主体的行为策略,以提升事权承接的有效性,是亟待回答的重要议题。文章从“结构... 详细信息

推动执法权属地化与综合化是夯实基层政权建设的重要一环,但在政策实践中,并不必然带来治理效能的提升。事权下放后,基层治理结构的实质性变革如何形塑执法主体的行为策略,以提升事权承接的有效性,是亟待回答的重要议题。文章从“结构—过程—功能”的视角出发,对一个街道综合行政执法体制改革进行系统考察,构建理解多维结构变迁中能动者策略生成的分析框架。研究发现,在改革过程中,综合执法部门所嵌入的横向结构在权力、责任和资源维度发生系统性变迁。执法主体在基层治理结构所设定的规则约束与行动空间中,基于复杂性和概率性两个维度,划分四种类型的执法任务,并能动地创设动员式、裁剪式、扩容式等执法策略,衔接再配置的结构性要素与复杂外部事务治理环节,从而有效回应“块块”运作规则和事权下放的内在要求。

关键词：综合行政执法结构功能主义能动者策略基层治理执法任务

A novel apolipoprotein E mutation (p.Arg150Cys)in a Chinese patient with lipoprotein glomerulopathy

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2019年第2期132卷 237-239页

作者： Ming KO cai tao An-An Zhou Yuan Cheng Qi-Jun Wan Depatment of Nephrology the First Affiliated Hospital of Shenzhen UniversityShenzhenGuangdong 518035China Department of Nephrology Shenzhen Second People's HospitalClinical Medicine College of Anhui Medical UniversityShenzhenGuangdong 518035China Shenzhen Chi Biology Technology Co. UdShenzhenGuangdong 518000China

To the Editor:Lipoprotein glomerulopathy (LPG) is an uncommon inherited renal disease characterized by lipoprotein thrombi in the markedly dilated capillary lumina of affected glomeruli, high plasma concentrations of apolipoprotein E (apoE), and proteinuria.[1] It mainly affects people of Japanese and Chinese origin, and approximately 117 cases have been reported to date.[2,3] Several genetic studies have demonstrated that APOE gene mutations may lead to the development of LPG;[4,5,6] however, conflicting published evidence has found that some patients with APOE variants were unaffected.[7] Thus, further studies are needed to examine the role of APOE mutations in the pathogenesis of LPG.This study investigated a novel point mutation in the APOE gene in a family with one LPG patient and an asymptomatic carrier of the same APOE variant.

关键词： Lipoprotein glomerulopathy lipoprotein however

在线全文

学校读者我要写书评

暂无评论

赣深高速铁路桥上半封闭式声屏障设计

工程建设与设计 2024年第7期 112-115页

作者：蔡涛中铁第四勘察设计院集团有限公司武汉430063

赣深高铁涉及深圳市城市建成区,结合城区路段噪声敏感建筑物以及环评降噪要求,对半封闭式声屏障从梁型、结构型式、安装方式等方面进行研究,以期选择最佳的半封闭声屏障,为高速铁路采用半封闭声屏障降噪设计提供了实际工程案例,为后续... 详细信息

赣深高铁涉及深圳市城市建成区,结合城区路段噪声敏感建筑物以及环评降噪要求,对半封闭式声屏障从梁型、结构型式、安装方式等方面进行研究,以期选择最佳的半封闭声屏障,为高速铁路采用半封闭声屏障降噪设计提供了实际工程案例,为后续解决高速铁路城区段噪声问题提供了借鉴。

关键词：高速铁路半封闭式声屏障降噪设计

维普期刊数据库博看期刊