检索结果-南通市图书馆

Research on the quasi-isentropic driving model of aluminized explosives in the detonation wave propagation direction

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 596-618页

作者： Hongfu Wang Yan Liu Fan bai Chao He Yingliang xu Qiang Zhou Chuan Xiao Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China China Research and Development Academy of Machinery Equipment Beijing100089China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive formulations when driving metal flyer plates in the denotation wave propagation *** research results showed that the formulations with 43 μm aluminum(Al) powder particles(The particle sizes of Al powder were in the range of 2~43 μm) exhibited the optimal performance in driving flyer plates along the denotation wave propagation direction. Compared to the formulations with Al powder 13 μm, the formulations with Al powder 2 μm delivered better performance in accelerating metal flyer plates in the early stage, which, however, turned to be poor in the later stage. The CL-20-based explosives containing 25% Al far under-performed those containing 15% Al. Based on the proposed quasi-isentropic hypothesis, relevant isentropy theories, and the functional relationship between detonation parameters and entropy as well as Al reaction degree, the characteristic lines of aluminized explosives in accelerating flyer plates were theoretically studied, a quasi-isentropic theoretical model for the aluminized explosive driving the flyer plate was built and the calculation methods for the variations of flyer plate velocity, Al reaction degree, and detonation product parameters with time and axial positions were developed. The theoretical model built is verified by the experimental results of the CL-20-based aluminized explosive driving flyer plate. It was found that the model built could accurately calculate the variations of flyer plate velocity and Al reaction degree over time. In addition, how physical parameters including detonation product pressure and temperature varied with time and axial positions was identified. The action time of the positive pressure after the detonation of aluminized explosives was found prolonged and the downtrend of the temperature was

关键词： Aluminized explosive Flyer plate experiment Quasi-isentropic theoretical model Al reaction Driving characteristics

Hydrophobic effects on photophysical and photochemical processes——Ⅵ.Character of aggregates formed by hydrocarbon with long chain in poor solvents

在线全文

学校读者我要写书评

暂无评论

Acta Chimica Sinica English Edition 1989年第1期7卷 72-78页

作者： xu Cheng-bai TONG Zhen-He Institute of Photographic Chemistry,Academia Sinica,Beijing

Dodecyl β-naphthoate and 3-octadecyl pyrene were used as fluorescence probes for estimation of microscopic polarity in aggregates formed by long chain hydrocarbon C_n(n=10,12, 14,16,18)in dimethyl sulfoxide-water mixed *** polarity in the aggregates is similar to that in *** average aggregation number(N)was determined by using time resolved fluorescence technique.N is dependent on substrate chain length and varies from 15 to *** microviscosity was also measured by fluorescence depolarization *** phase transition temperature,the microviscosity in aggregates is slightly larger than that in micelle,but below this temperature,the microviscosity in aggregates is as large as that in solid phase.

关键词： Character of aggregates formed by hydrocarbon with long chain in poor solvents

Abnormal mechanochemical effect in ultraprecision machining of an additively manufactured precipitation-strengthened high-entropy alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第3期170卷 221-237页

作者： Long xu Yuchao bai Yunfa Guo Chang Ren Xiaohua Tan Yandong Jia Gang Wang Hao Wang Institute of Materials Shanghai UniversityShanghai 200444China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100China Department of Mechanical Engineering National University of SingaporeSingapore 117575Singapore

Recently,researchers have explored the use of precipitation strengthening and finer microstructures with high-density dislocations in additive manufacturing to produce high-entropy alloys(HEAs)with adjustable ***,the inherent surface roughness and lack of machinability research in AMed HEAs limit their engineering *** this study,we systematically investigated the microstructural characteristics,mechanical properties,and machinability of Fe_(29.3)Co_(28.7)Ni_(28.6)Al_(6.8)Ti_(6.6)(at.%)HEAs with three different structures:single FCC phase cellular(SPC),dual precipitation-strengthened(DPS),and single precipitation-strengthened(SPS).These structures were fabricated by selective laser melting and isothermally annealing at 780 and 940℃.Compared to SPC HEA,DPS HEA exhibits a significant increase in yield strength and ultimate tensile strength but with a dramatic sacrifice in *** HEA exhibits similar mechanical properties to SPC HEA due to the pronounced coarsening of L21 *** ultraprecision machining micro-cutting test showed that SPC HEA had a significant mechanochem-ical effect,as evidenced by a sharp drop in cutting force for inked workpieces,but not DPS *** abnormal finding was that the negligible reflection of cutting force for SPS HEAs suggested a negative mechanochemical effect,even though SPS HEA had equally excellent plasticity like SPC *** was found that nanocrystallization-induced strength enhancement and ductility reduction of SPS HEA lead to chips’deformation dominated by shear avalanche rather than chip folding of SPC HEA,which involves the reduction of surface energy and friction of chips’***,these results and our research findings may guide the machining of AMed precipitation-strengthened HEAs and accelerate their engineering ap-plication.

关键词： High-entropy alloy Selective laser melting Precipitation strengthening Machinability Mechanochemical effect

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

离子色谱-质谱法检测五种水溶性毒物

实验与分析 2024年第2期2卷 37-40页

作者：梁如柯白旭张高勤辛国斌卫娟娜朱军山西医科大学山西030600 山西省公安厅山西030001 法庭毒物分析公安部重点实验室北京100192 公安部鉴定中心北京100038

为建立一种离子色谱-质谱法检测血液中γ-羟基丁酸(GHB)、氟乙酸钠、亚硝酸钠、草甘膦和草铵膦五种水溶性毒物的方法,选用AS19阴离子色谱柱进行分离,以在线产生的50 mmol/L氢氧化钠为淋洗液等度淋洗,飞行时间质谱仪作检测器,采用电喷雾... 详细信息

为建立一种离子色谱-质谱法检测血液中γ-羟基丁酸(GHB)、氟乙酸钠、亚硝酸钠、草甘膦和草铵膦五种水溶性毒物的方法,选用AS19阴离子色谱柱进行分离,以在线产生的50 mmol/L氢氧化钠为淋洗液等度淋洗,飞行时间质谱仪作检测器,采用电喷雾电离源负离子模式、选择离子监测模式(Selected Ion Monitor,SIM)进行分析,外标法定量。利用离子色谱-质谱法检测五种水溶性毒物简单快速、专属性强、灵敏度高,可为司法鉴定实践提供重要的科学支撑。

关键词：离子色谱-质谱联用 γ-羟基丁酸氟乙酸钠亚硝酸钠草甘膦草铵膦检验

Progress in Research of Roses in Diabetes Treatment

在线全文

学校读者我要写书评

暂无评论

Agricultural Biotechnology 2021年第6期10卷 57-61页

作者： xu bai Yanrui CHEN Guangxi Key Laboratory of Diabetes System Medicine Guilin Medical UniversityGuilin 541004China Institute of Basic Medical Sciences Faculty of Basic Medical SciencesGuilin Medical UniversityGuilin 541004China

Diabetes is a common endocrine and metabolic disease,which is mainly caused by insufficient insulin secretion and improper secretion of glucagon by the *** mortality of diabetes and its complications is only second to tumors and cardiovascular *** present,the research on natural drugs related to diabetes attracts much attention,and roses,as a traditional Chinese medicine that can be used as both medicine and food,are considered to be a new therapeutic agent for diabetes research in the *** this paper,progress in research on the treatment of diabetes by rose was reviewed from the aspects of chemical constituents,pharmacological effects and their relationship with *** review includes Rosa rugosa Thunb.,Branchlets *** Thunb.,*** Miller and ***‘Hetian’.It can be seen that roses are rich in polyphenols,flavonoids,pectic bee pollen polysaccharide,quercetin,tannins,organic acids and other hypoglycemic chemical *** pharmacological studies show that roses have hypoglycemic *** has been reported in animal experiments that rose extract can reduce blood sugar and improve diabetes ***,the clinical hypoglycemic effect and hypoglycemic mechanism of rose have yet to be clarified,and the comparative study of hypoglycemic effects of different rose varieties has not been published.

关键词： Roses Hypoglycemic effect Diabetes Research progress

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

Cloud Computing(4)

ZTE Communications 2010年第1期8卷 57-60页

作者： Wang bai xu Liutong School of Computer Science and Technology Beijing University of Posts and TelecommunicationsBeijing 100876 P. R. China

Editor＇s Desk： The first three parts of this series discussed cloud computing in terms of basic concept, applications, architecture, and computing model, and a comparison was made with other distributed computing technologies. In the final of this series, three cases are examined to determine key factors for success in cloud computing. Several economic and technical issues associated with cloud computing--including business model, reliability, security, privacy and developing trends--are discussed.

关键词： cloud distributed computing development technology successful introduce paradigm Internet interest typical related aspects origin issues users topic parts Major view own

Complementary and alternative medicine on cognitive defects and neuroinflammation after sepsis

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2024年第2期44卷 408-416页

作者： LI Zhenxuan WANG xuerui Luis Ulloa Ayman Youssef bai Yunjing xu Xiaolong LIU Qingquan Department of Infectious Diseases Beijing Hospital of Traditional Chinese MedicineCapital Medical UniversityBeijing 100010China Beijing Key Laboratory of Basic Research with Traditional Chinese Medicine on Infectious Diseases Beijing 100010China Infection immunity laboratory Beijing Institute of Traditional Chinese MedicineBeijing 100010China Clinical College of Traditional Chinese Medicine Capital Medical UniversityBeijing 100069China Center for Perioperative Organ Protection Department of AnesthesiologyDuke University Medical CenterDurhamNorth Carolina 27710USA

Sepsis-associated encephalopathy(SAE)is a common manifestation of sepsis,ranging from mild confusion and delirium to severe cognitive impairment and deep *** is associated with higher mortality and long-term outcomes,particularly substantial declines in cognitive *** mechanisms of SAE probably include neuroinflammation that is mediated by systemic inflammation and ischemic lesions in the brain,a disrupted blood–brain barrier,oxidative stress,neurotransmitter dysfunction,and severe microglial *** evidence suggests that complementary and alternative medicine,especially Traditional Chinese Medicine(TCM),is favorable in alleviating cognitive decline after ***,we summarized the studies of traditional herbal remedies,TCM formulas and acupuncture therapy in animal models of neurological dysfunctions after sepsis in recent decades and reviewed their potential mechanisms.

关键词： sepsis-associated encephalopathy cognitive dysfunction complementary therapies neuroinflammatory diseases medicine Chinese traditional review

Dual-additives enable stable electrode-electrolyte interfaces for long life Li-SPAN batteries

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 459-465页

作者： Zhenqiang Guo Huicong Yang Qian Wei Shengjun xu Guangjian Hu Shuo bai Feng Li School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Department of Biochemistry and Molecular Biology College of Life ScienceChina Medical UniversityShenyang 110122China Dalian National Laboratory for Clean Energy Dalian 116023China Shenyang King Power Technology Co. Ltd.Shenyang 110016China

Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur ***,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical *** this study,an electrolyte with dual-additives comprising 2-fluoropyridine(2-FP)and lithium difluorobis(oxalato)phosphate(LiDFBOP)was used to improve the performance of Li||SPAN cells.2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte,leading to its prior reduction.A LiF-rich film can be formed on the electrode,effectively improving the stability of the electrolyte-electrode interfaces and prolonging the ***,LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li_(x)PO_(y)F_(z) species,compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode ***,an electrode-interface film with good chemical stability and high Li^(+) transport was established by LiF and Li_(x)PO_(y)F_(z)-rich *** Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5%after 200 cycles at 1.0 C,25℃,comparing to 56.2%capacity retention without ***,the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C,comparing to only 813.5 mAh/g using electrolyte without *** results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.

关键词： Sulfurized polyacrylonitrile Lithium metal Interface film 2-Fluoropyridine Difluorobis(oxalato)phosphate

Random Exponential Attractor for Stochastic Non-autonomous Suspension Bridge Equation with Linear Multiplicative White Noise

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research with Applications 2024年第1期44卷 81-112页

作者： Ling xu Runjie LIU xue bai College of Mathematics and Statistics Northwest Normal University

In this paper, we mainly consider the long-time behavior of stochastic non-autonomous suspension bridge equation by linear multiplicative white noise with small coefficient. First step,the well-posedness for the cocycle associated with the considered system is established. Second step, the existence of random attractor for the system is investigated. Third step, the upper semicontinuity of random attractor is also provided when the coefficient of random term approaches zero. Fourth step, we prove the regularity of random attractor in a higher regular space by the“iteration” method. Finally, we give the existence of a random exponential attractor for the considered system, which implies the finiteness of fractal dimension of random attractor.

关键词： stochastic non-autonomous suspension bridge equation multiplicative white noise random attractor fractal dimension random exponential attractor