检索结果-南通市图书馆

Assessment of the Design Displacement Values at Seismic Fault Crossings and of Their Excess Probability

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第2期8卷 228-233页

作者： STROM Alexander IVASCHENKO Alexey KOZHURIN Andrey institute of Geospheres Dynamics of Russian academy of sciences institute of Oceanology of Russian academy of sciences Geological institute of Russian academy of sciences

Line structures such as pipelines that cross active faults should be designed to retain leak-tightness if the design displacement (Ddesign) occurs. Principal approaches to the Ddesign and rupture kinematics assessment are described. They are based on relationships between earthquake magnitude, rupture length and displacement, and on the detailed field data on a specific fault that crosses the pipeline route. Since the future offset at the crossing may exceed the design value, the probability of a displacement occurrence where the safety of the structure can not be ensured should be estimated. Assessment method on such event probability is described and exemplified through active fault studies carried out at several pipeline projects in Russia.

关键词： Active Fault Surface Rupture Design Displacement Pipeline Sakhalin Island

Cobalamin-dependent radical S-adenosyl-L-methionine protein functions with a partner to successively methylate tricyclic indole alkaloid for chuangxinmycin maturation and derivatization

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期 308-316页

作者： Sili Wang Jiancheng Huang Yanan Du Wei Huang Yufeng Xue Xiaokun Xu Guannan Zhong Yuanyuan Shi Bin Hong Xiaoying Bian Wen Liu State Key Laboratory of Chemical Biology Shanghai Institute of Organic Chemistry University of Chinese Academy of SciencesChinese Academy of Sciences State Key Laboratory of Microbial Technology Shandong University National Health Commission (NHC) Key Laboratory of Biotechnology for Microbial Drugs Institute of Medicinal BiotechnologyChinese Academy of Medical Science & Peking Union Medical College

Cobalamin(Cbl)-dependent radical S-adenosyl-L-methionine(SAM) proteins constitute the largest collection of the radical SAM superfamily that has hundreds of thousands of individual members. Many of these proteins are involved in the biosynthesis of pharmaceutically important natural products to catalyze chemically demanding reactions. In the biosynthetic pathway of chuangxinmycin(CXM), a unique indole alkaloid antibiotic with potent anti-infective activity, functionalization of the characteristic thiopyrano[4,3,2-cd]indole scaffold by regio-and stereoselective C3-methylation is believed to rely on a Cbl-dependent radical process, which, however, remained to be reconstituted biochemically. We here report the dissection of this enzymatic process, which requires the incorporation of Cxm8, a Cbl-dependent radical SAM protein, with Cxm9, a DUF5825family protein that shares no homology to any proteins of known functions. Cxm8 and Cxm9 function together by forming an unexpected heterodimeric complex that selectively catalyzes C3-methylation of the tricyclic indole-S-hetero ring system in a successive manner, achieving CXM and a recently identified, C3-dimethylated congener. Detailed biochemical characterization,isotope labeling, structural simulation and bioinformatics analysis rationalized the catalysis of the Cxm8/Cxm9 complex and particularly the necessity of the DUF5825 protein for C3-methylase activity. This is the first example that a Cbl-dependent protein acts with a partner to exhibit radical SAM activity.

关键词：

同方期刊数据库

Effects of spectral composition,photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems(RAS)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2015年第1期33卷 45-56页

作者：仇登高徐世宏宋昌斌迟良李贤孙国祥刘宝良刘鹰 institute of Oceanology Chinese Academy of Sciences University of Chinese academy of sciences institute of Semiconductors Chinese Academy of Sciences

Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in ***,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not *** this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in *** demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light *** photoperiod had a significant effect on the secretion of sex steroids and melatonin(P0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm *** conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in *** results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

关键词： Salmo salar artificial light regimes gonadal development recirculating aquaculture systems (RAS)

A 270-MHz to 1.5-GHz CMOS PLL clock generator with reconfigurable multi-functions for FPGA

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2011年第4期32卷 149-154页

作者：张辉杨海钢王瑜刘飞高同强 institute of Electronics Chinese Academy of Sciences Graduate University of the Chinese academy of sciences institute of Electronics Chinese Academy of SciencesBeijing 100190China

A PLL clock generator with reconfigurable multi-functions for FPGA design applications is presented. This clock generator has two configurable operation modes to achieve clock multiplication and phase alignment functions,*** output clock signal has advanced clock shift ability such that the phase shift and duty cycle are *** order to further improve the accuracy of phase alignment and phase shift,a VCO design based on a novel quick start-up technique is proposed.A new delay partition method is also adopted to improve the speed of the post-scale counter,which is used to realize the programmable phase shift and duty cycle.A prototype chip implemented in a 0.13-μm CMOS process achieves a wide tuning range from 270 MHz to 1.5 *** power consumption and the measured RMS jitter at 1 GHz are less than 18 mW and 9 ps,*** settling time is approximately 2μs.

关键词： PLL clock generator reconfigurable VCO

High Fe‑Loading Single‑Atom Catalyst Boosts ROS Production by Density Effect for Efficient Antibacterial Therapy

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第2期17卷 187-203页

作者： Si Chen Fang Huang Lijie Mao Zhimin Zhang Han Lin Qixin Yan Xiangyu Lu Jianlin Shi Department of Cardiology Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200092People’s Republic of China Shanghai institute of Ceramics Chinese Academy of SciencesShanghai 200050People’s Republic of China Shanghai Frontiers Science Center of Nanocatalytic Medicine School of MedicineTongji UniversityShanghai 200092People’s Republic of China

The current single-atom catalysts(SACs)for medicine still suffer from the limited active site ***,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs by exchanging zinc with *** constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial ***,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading ***,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/*** addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GSH)*** in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound *** work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.

关键词： Nanocatalytic medicine Single-atom catalysts Reactive oxygen species(ROS) High metal loading Oxidase catalysis

New Particle Swarm Optimisation Algorithm with Hénon Chaotic Map Structure

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2017年第4期26卷 747-753页

作者： YAN Tao LIU Fengxian CHEN Bin Chengdu institute of Computer Applications Chinese Academy of Sciences University of Chinese academy of sciences Guangzhou institute of Geochemistry Chinese Academy of Sciencess Guangzhou institute of Electronic Technology Chinese Academy of Sciences

A new Particle swarm optimisation(PSO)algorithm based on the H′enon chaotic map(hereafter HCPSO algorithm) is presented in this paper to deal with the premature convergence problem of the traditional PSO algorithm. The HCPSO algorithm changes the structure of the traditional PSO algorithm and deviates from the structures of conventional hybrid algorithms that merely introduce chaotic searching into PSO. Based on the convergence condition of PSO, the HCPSO algorithm can improve solution precision and increase the convergence rate by combing using the targeting technique of chaotic mapping. For validation, fourteen benchmark functions were used to compare the proposed algorithm with six other hybrid PSO algorithms. The experimental results indicated that the HCPSO algorithm is superior to the other algorithms in terms of convergence speed and solution accuracy.

关键词： Particle swarm optimization Chaotic op timization H′enon map Targeting of chaos

High performance AlGaN/GaN HEMTs with 2.4μm source-drain spacing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2010年第3期31卷 38-40页

作者：王东方魏珂袁婷婷刘新宇 institute of Microelectronics Chinese Academy of Sciences China Graduated University of the Chinese academy of sciences Graduated University of the Chinese academy of sciences institute of Microelectronics Chinese academy of sciences

This paper describes the performance of AIGaN/GaN HEMTs with 2.4μm source-drain spacing. So far these are the smallest source-drain spacing AIGaN/GaN HEMTs which have been implemented with a domestic wafer and domestic process. This paper also compares their performance with that of 4μm source-drain spacing devices. The former exhibit higher drain current, higher gain, and higher efficiency. It is especially significant that the maximum frequency of oscillation noticeably increased.

关键词： A1GaN/GaN HEMT high frequency source-drain spacing

Properties of Xanthoceras sorbifolia Husk Fibers With Chemical Treatment for Applications in Polymer Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2015年第2期31卷 164-170页

作者： Hongyu Wang Xudan Yao Guoxin Sui Liming Yin Lihua Wang institute of Metal Research Chinese Academy of Sciences Shenyang institute of Applied Ecology Chinese Academy of Sciences

Surface science of natural fibers plays an important role in polymer/natural fiber composites. The Xanthoceras sorbifolia husk fibers were selected and chemically treated by sodium hydroxide(Na OH) solution,coupling agents,their combination,and the mixtures of acetic acid with hydrogen peroxide,respectively. 3-aminopropyltriethoxysilane(KH550),γ-methacryloxypropyltrimethoxylsilane(KH570) and organic titanate(JN-9A) were used as coupling agents in this work. Cellulose content was found to be increased after alkalization due to the removal of the non-cellulose substances,which was evidenced by attenuated total reflectance-Fourier transform infrared(ATR e FTIR) spectroscopy spectrum analysis and thermogravimetric analysis(TGA) measurements. The highest cellulose content was obtained in the bleached fibers. TGA analysis revealed an improvement in thermal stability of the treated fibers,especially for alkali-KH570 treated fibers. The tensile strength of the alkali-KH570 treated fiber and the alkali-bleached fiber were higher than that of other fibers due to high cellulose content and high crystallinity.

关键词： Xanthoceras sorbifolia husk fibers Chemical treatm

Pneumatic Jet-control Valve for Dual Circulating Fluidized Beds

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2015年第6期24卷 574-582页

作者： JIANG Haibo DONG Pengfei ZHU Zhiping WANG Kun ZHANG Yukui LU Qinggang University of Chinese academy of sciences institute of Engineering Thermophysics Chinese Academy of Sciences

With the rapid development of circulating fluidized bed(CFB)technology in different fields,the disadvantages of conventional non-mechanical valves are becoming more apparent,and they are not suitable to be used in complex CFB *** this paper,a novel non-mechanical valve named the jet-control valve is presented which can avoid the fluidization of solid *** feasibility and performance characteristics of the new valve are investigated with a cold-model dual *** results show that compared with the conventional non-mechanical valve,the jet-control valve can transfer solid particles steadily over a larger range,prevent artesian flow,and improve the leakage *** effects of the operating parameters and structural parameters on the minimum aeration velocity,solid flow rate,and maximum solid flow rate are studied.A two-valve model is proposed to explain the transport capacity of the valve for one jet pipe.A semi-theoretical expression is obtained based on the experimental data with a maximum deviation of 30%providing useful guide for scaling-up the design.

关键词： jet-control valve circulating fluidized bed two-valve model