检索结果-南通市图书馆

The criterion of the existence or inexistence of transverse shock wave at wedge supported oblique detonation wave

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2011年第5期27卷 611-619页

作者： Ai-Feng Wang wei Zhao zong-Lin Jiang Institute of Mechanics Chinese Academy of Sciences100190 Beijing China

A simplified theoretic method and numerical simulations were carried out to investigate the characterization of propagation of transverse shock wave at wedge supported oblique detonation *** solution validation,a criterion which is associated with the ratio Φ （u 2 /u CJ） of existence or inexistence of the transverse shock wave at the region of the primary triple was deduced systematically by 38 *** is observed that for abrupt oblique shock wave （OSW）/oblique detonation wave （ODW） transition,a transverse shock wave is generated at the region of the primary triple when Φ 〈 1,however,such a transverse shock wave does not take place for the smooth OSW/ODW transition when Φ 〉 *** parameter Φ can be expressed as the Mach number behind the ODW front for stable CJ *** 0.9 〈 Φ 〈 1.0,the reflected shock wave can pass across the contact discontinuity and interact with transverse waves which are originating from the ODW *** 0.8 〈 Φ 〈 0.9,the reflected shock wave can not pass across the contact discontinuity and only reflects at the contact *** condition （0.8 〈 Φ 〈 0.9） agrees well with the ratio （D ave /D CJ） in the critical detonation.

关键词： Oblique detonation wave Transverse shock wave Oblique shock wave Transition Numerical simulations

Nanofluidic memristor based on the elastic deformation of nanopores with nanoparticle adsorption

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 46-54页

作者： Xi Zhou Yuanyuan zong Yongchang Wang Miao Sun Deli Shi wei Wang Guanghua Du Yanbo Xie Department of Chemistry and Chemical Engineering Northwestern Polytechnical University School of Physical Science and Technology Northwestern Polytechnical University School of Aeronautics and Institute of Extreme Mechanics Northwestern Polytechnical University Institute of Modern Physics Chinese Academy of Sciences

The memristor is the building block of neuromorphic computing. We report a new type of nanofluidic memristor based on the principle of elastic strain on polymer nanopores. With nanoparticles absorbed at the wall of a single conical polymer nanopore, we find a pinched hysteresis of the current within a scanning frequency range of 0.01–0.1 Hz, switching to a diode below 0.01 Hz and a resistor above 0.1 Hz. We attribute the current hysteresis to the elastic strain at the tip side of the nanopore, caused by electrical force on the particles adsorbed at the inner wall surface. Our simulation and analytical equations match well with experimental results, with a phase diagram for predicting the system transitions. We demonstrate the plasticity of our nanofluidic memristor to be similar to a biological synapse. Our findings pave a new way for ionic neuromorphic computing using nanofluidic memristors.

关键词： nanofluidics memristor neurocomputing elastic deformation

Effects of lignin on nitrification in soil

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 Environmental Sciences 2003年第3期15卷 363-366页

作者： HUANG Yi-zong FENG zong-wei ZHANG Fu-zhu LIU Shu-qin Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China.

The effects of two lignins isolated from black liquor from pulping process on nitrification in soils after addition of urea, (NH_4)_2SO_4 and (NH_4)_2HPO_4 were investigated by incubation at 20 or 30℃ for 7 or 14 d. The effects of lignin on nitrous oxide emissions from soil were also determined. Results showed that both lignins were more effective for inhibiting nitrification of NH_4 +-N as (NH_4)_2SO_4 or (NH_4)_2HPO_4 as compared to urea-N. The effectiveness of lignin on nitrification was markedly affected by different soil type and temperature. Nitrous oxide emissions from soil declined when lignin was used. Urea plus 20 and 50 g/kg lignin reduced N_2O emissions by about 83% and 96%, respectively, while (NH_4)_2HPO_4 plus 20 and 50 g/kg lignin respectively reduced emissions by 83% and 93%. Because of its low cost and nonhazardous characteristics, lignin has potential value as a fertilizer amendment to improve N fertilizer efficiency.

关键词： lignin nitrification soil N_2O emission

考虑杆塔接地装置布置的埋地油气管道电位升抑制措施研究

在线全文

学校读者我要写书评

暂无评论

电瓷避雷器 2024年第2期 106-113页

作者：双明镜黄道春段绍辉刘媛宗伟阮江军周灵杰武汉大学电气与自动化学院武汉430072 深圳供电局有限公司广东深圳518020

雷击杆塔时会导致不满足国标要求的临近埋地油气管道产生过高电位升,如何在空间受限情况下进行改造成为了亟待解决的问题。提出基于杆塔接地装置布置的管道电位抑制方法,通过CDEGS建立临近接地装置的埋地油气管道模型,开展模拟试验验证... 详细信息

雷击杆塔时会导致不满足国标要求的临近埋地油气管道产生过高电位升,如何在空间受限情况下进行改造成为了亟待解决的问题。提出基于杆塔接地装置布置的管道电位抑制方法,通过CDEGS建立临近接地装置的埋地油气管道模型,开展模拟试验验证其准确性,定义风险系数评估管道风险并分析隔离、垂直引流和水平引流3类措施对管道电位升的抑制效果。结果表明:加装隔离墙降压效果最优,最高可降38.2%;引流类措施在高土壤电阻率情况下降压效果更好,选用30 m左右的接地体效益最高,最后提出了一种组合措施,可以使风险系数降低到安全区附近。研究结果可为架空输电线路杆塔临近埋地油气管道燃爆风险防控提供支撑。

关键词：空间受限接地装置管道电位升模拟试验抑制措施风险系数

同方期刊数据库

Detecting and Monitoring Tidal Dissipation of Hot Jupiters in the Era of SiTian

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第5期22卷 36-46页

作者： Fan Yang wei Wang Xing wei Hui Zhang Ji-Lin Zhou Su-Su Shan Jie Zheng wei-Kai zong Ming Yang Yu Bai Song Wang Jia-Chen Zheng Yu-Ru Xu Yu-Feng Li You-Jun Lu Ji-Feng Liu Department of Astronomy Beijing Normal UniversityBeijing 100875China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China

Transit Timing Variation(TTV)of hot Jupiters provides direct observational evidence of planet tidal *** tidal dissipation through TTV needs high precision transit timings and long timing *** this work,we predict and discuss the potential scientific contribution of the SiTian Survey in detecting and analyzing exoplanet *** develop a tidal dissipation detection pipeline for the SiTian Survey that aims at time-domain astronomy with 721 m optical *** pipeline includes the modules of light curve deblending,transit timing acquisition and TTV *** is capable of detecting more than 25,000 exoplanets among which we expect~50 sources to show evidence of tidal *** present detection and analysis of tidal dissipating targets,based on simulated SiTian light curves of XO-3b and WASP-161 *** transit light curve modeling gives consistent results within 1σto input values of simulated light ***,the parameter uncertainties predicted by Markov Chain Monte Carlo are consistent with the distribution obtained from simulating and modeling the light curve 1000 *** timing precision of SiTian observations is~0.5 minutes with one transit *** show that differences between TTV origins,e.g.,tidal dissipation,apsidal precession and multiple planets,would be significant,considering the timing precision and *** detection rate of tidal dissipating hot Jupiters would answer a crucial question of whether the planet migrates at an early formation stage or random stages due to perturbations,e.g.,planet scattering or secular *** identified targets would be constructive given that the sample would extend tenfold.

关键词： planets and satellites gaseous planets-planets and satellites physical evolution-planets and satellites dynamical evolutionand stability-planetsandsatellites detection

江汉平原北部典型农业区表层土壤重金属生态风险评价与来源解析

在线全文

学校读者我要写书评

暂无评论

资源环境与工程 2024年第4期38卷 437-445页

作者：宗维王德宝江宜匡华罗华李煜祝安安杨青雄湖北省地质调查院湖北武汉430034 资源与生态环境地质湖北省重点实验室湖北武汉430034 湖北省自然资源资产运营有限公司湖北武汉430062 湖北地矿投资集团有限公司湖北武汉430014

为了解湖北省江汉平原农业区表层土壤重金属污染情况,选择沙洋县汉江沿岸典型农业区为研究对象,依据规范采集表层土壤样品800件,测定8项重金属含量,运用地累积指数法、潜在生态风险指数法分析土壤重金属的潜在生态风险,运用正定矩阵因... 详细信息

为了解湖北省江汉平原农业区表层土壤重金属污染情况,选择沙洋县汉江沿岸典型农业区为研究对象,依据规范采集表层土壤样品800件,测定8项重金属含量,运用地累积指数法、潜在生态风险指数法分析土壤重金属的潜在生态风险,运用正定矩阵因子分析模型(PMF)识别重金属的来源。研究表明,研究区表层土壤重金属As、Cd、Ni、Zn、Cu存在一定程度的富集;研究区潜在生态风险程度整体较低,地累积指数平均值依次为Cd>Zn>Ni>As>Cu>Cr>Pb>Hg,潜在生态风险程度依次为Cd>Hg>As>Ni>Cu>Pb>Cr>Zn,对研究区表层土壤影响最大的是Cd;通过PMF模型源解析识别出研究区重金属主要有工业源、交通运输源、农业源和自然源等4种来源,其相对贡献率分别为3.71%、30.07%、34.79%、31.43%,Hg主要来自于工业活动,Pb、Zn主要来自于交通运输,农业活动造成了土壤中Cd、Zn、Cu的高载荷,As、Cr则多来自于地质背景引起的自然源。

关键词：表层土壤重金属生态风险评价来源解析典型农业区

Efficacy and safety of sacubitril/valsartan after six months in patients with heart failure with reduced ejection fraction and asymptomatic hypotension

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2023年第12期20卷 855-866页

作者： An-Hu WU zong-wei LIN Zhuo-Hao YANG Hui ZHANG Jia-Yi HU Yi WANG Rui TANG Xin-Yu ZHANG Xiao-Ping JI Hui-Xia LU National Key Laboratory for Innovation and Transformation of Luobing Theory The Key Laboratory of Cardiovascular Remodeling and Function ResearchChinese Ministry of EducationChinese National Health Commission and Chinese Academy of Medical SciencesDepartment of CardiologyQilu Hospital of Shandong UniversityJinanChina

BACKGROUND It is not clear whether sacubitril/valsartan is beneficial for patients with heart failure(HF)with reduced ejec-tion fraction(HFrEF)and low systolic blood pressure(SBP).This study aimed to investigate the efficacy and tolerability of sacu-bitril/valsartan in HFrEF patients with SBP<100 ***&RESULTS An observational study was conducted on 117 patients,40.2%of whom had SBP<100 mmHg wit-hout symptomatic hypotension,and 59.8%of whom had SBP≥100 mmHg in an optimized HF follow-up management *** the 6-month follow-up,52.4%of patients with SBP<100 mmHg and 70.0%of those with SBP≥100 mmHg successfully rea-ched the target dosages of sacubitril/valsartan.A reduction in the concentration of N-terminal pro-B-type natriuretic peptide was similar between patients with SBP<100 mmHg and SBP≥100 mmHg(1627.5 pg/mL and 1340.1 pg/mL,respectively;P=0.75).The effect of sacubitril/valsartan on left ventricular ejection fraction was observed in both SBP categories,with a 10.8%increase in patients with SBP<100 mmHg(P<0.001)and a 14.0%increase in patients with SBP≥100 mmHg(P<0.001).The effects of sac-ubitril/valsartan on SBP were statistically significant and inverse across both SBP categories(P=0.001),with an increase of 7.5 mmHg in patients with SBP<100 mmHg and a decrease of 11.5 mmHg in patients with SBP≥100 *** statistically signi-ficant differences were observed between the two groups in terms of the occurrence of symptomatic hypotension,deteriorating re-nal function,hyperkalemia,angioedema,or *** Within an optimized HF follow-up management system,sacubitril/valsartan exhibited excellent tolerability and prompted left ventricular reverse remodeling in patients with HFrEF who presented asymptomatic hypotension.

关键词： patients hypotension dosage

Synergistic regulation of drought-responsive genes by transcription factor OsbZIP23 and histone modification in rice

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2020年第6期62卷 723-729页

作者： wei zong Jun Yang Jie Fu Lizhong Xiong National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhan 430070China

Thousands of differentially expressed genes(DEGs)have been identified in rice under drought stress ***,the regulatory mechanism of these DEGs remains largely ***,we report an interplay between histone H3K4me3 modification and transcription factor Osb ZIP23 in the regulation of a dehydrin gene cluster under drought stress conditions in *** the H3K4me3 modification level was increased,the dehydrin gene expression levels were increased,and the binding levels of Osb ZIP23 to the promoter of the dehydrin genes were also ***,the H3K4me3 modification and dehydrin gene expression levels were downregulated in the osbzip23 mutant under drought stress *** study uncovers a collaboration between transcription factor and H3K4me3 modification in the regulation of droughtresponsive genes,which will help us to further understand the gene regulation mechanism under stress conditions in plants.

关键词： responsive conditions. drought

CO_(2) corrosion of X80 steel welded joints under micro-turbulence induced by welding reinforcement height

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第4期31卷 1015-1032页

作者： Xiao-hui Dou Bin Li zong-hao He Xin-wei Zhang Da-lei Zhang Yan Li School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

Corrosion failure accidents owing to flow erosion and pipeline corrosion frequently occur during *** welding reinforcement height(WRH)can induce locally micro-turbulent flow field,which aggravates local corrosion of welded joints.A high wall shear stress(WsS)experimental setup was established to conduct the online electrochemical corrosion *** influence of WRH sizes on local corrosion of welded joints was studied at different flow *** electrochemical signals of the local corrosion of X80 welded joints at different flow rates were monitored in real time using electrochemical impedance spectroscopy and wire beam *** addition,the corrosion products composition and properties were *** results show that the micro-turbulent flow fields induced by the WRHs can enhance ion mass transfer near the welded *** corrosion products on the WRH surface also present different microscopic morphologies at different flow *** strong flow fields,the locally enhanced wsS can peel off the dense corrosion product partially,leading to the electrochemical distribution of large cathode and small anode,which accelerates the occurrence and development processes of the local corrosion of welded *** scientific guidelines for the corrosion protection of long-distance oil and gas pipelines can be potentially provided.

关键词： X80 steel welded joint Welding reinforcement height Micro-turbulence CO_(2)corrosion-Ion mass transfer