检索结果-南通市图书馆

Synthesis of GdF_3 from the Gd_2O_3-NH_4HF_2 system

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2007年第5期26卷 482-487页

作者： HAO Zhanzhong zhang Jianliang WANG Bin zhang xidong Metallurgical and Ecological Engineering School University of Science and Technology Beijing Beijing 100083 China Baotou Teachers College Baotou 014030 China

GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature,and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature,and the products were GdNH4F4,NH4F,NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment,accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps： synthesis,decomposition,and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained： synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.

关键词： inorganic chemistry Gd NH4HF2 synthesis

Three-dimensional flexible Au nanoparticles-decorated TiO_(2) nanotube arrays for photoelectrochemical biosensing

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第21期56卷 162-169页

作者： xidong zhang Dong Yue Ling zhang Shiwei Lin State Key Laboratory of Marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China

Controlling the charge transfer and thus enhancing the excitons’lifetime are the key to the realization of efficient photoelectrochemical(PEC)***,fabrication of flexible and collapsible sensors can greatly facilitate the implementation of smart PEC sensing devices into practical ***,we sagely designed and successfully fabricated three-dimensional flexible Au nanoparticles-decorated TiO_(2) nanotube arrays(Au@TiO2)for the efficient PEC biosensing of *** Schottky barrier derived from the Au@TiO2 heterostructure efficiently separates the charge carriers at the junction interfaces,thus greatly increasing the concentration and lifetime of holes left in the valence band of *** separated holes further evidently generate the active hydroxyl radicals,which can specifically recognize and oxidize *** a result,Au@TiO_(2) exhibits excellent photoelectric activity and selectivity,far superior to TiO_(2) without decorated Au *** addition,such asymmetric Au@TiO_(2) system has been proved to feature the intrinsic flexibility nature,since its PEC biosensing performance is almost unaffected under indirect light irradiation and serious tensile strain.

关键词： Photoelectrochemical biosensing Metal/semiconductor interface Flexibility TiO_(2)nanotube arrays

Novel titanium particles reinforced Zr-based bulk metallic glass composites prepared by infiltration casting

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第4期15卷 505-508页

作者： Cuimei zhang xidong Hui Meiling Wang Guoliang Chen State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

A novel Ti/Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 composite was successfully prepared by infiltrating the melt into sintered Ti preform. It shows that the introduction of Ti particles into the composite results in an increase in elastic strain to 3% and an enhancement of the strength up to 2.1 GPa. High specific strength has been obtained because of the decrease in density of the composite. It is suggested that an improvement in the mechanical properties of the composite may be attributed to the generation of multiple shear bands and some deformation in the Ti particles.

关键词： melt infiltration bulk metallic-glass Ti particles mechanical properties

敞开式TBM姿态控制及小直径转弯针对性设计

在线全文

学校读者我要写书评

暂无评论

建筑机械化 2024年第8期45卷 47-51页

作者：张雅博付晨光张喜冬中铁工程装备集团有限公司河南郑州450016

分析介绍了TBM姿态调整机构的工作原理,对比分析了主梁式TBM和凯式TBM姿态调整方式的不同,推导了主梁式TBM在小转弯过程中的设备上各位置距隧道中心的偏移量,并对在小转弯半径隧道施工的主梁式TBM设计提供了参考依据。

关键词：敞开式TBM 掘进机姿态控制小转弯半径

Thermodynamic evaluation and hydrothermal preparation of K_xNa_(1-x)NbO_3

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2008年第4期27卷 371-377页

作者： zhang Ci LV Haijun GUO Min zhang Mei WANG xidong Department of Physical Chemistry University of Science and Technology Beijing Beijing 100083 China College of Engineering. Peking University Beijing 100871 China

The Gibbs free energies of reaction △rGτ of KNbO3 and NaNbO3 were calculated and then that of KxNa1-xNbO3 was estimated. On the basis of the thermodynamic calculation results, the hydrothermal temperatures were designed at 100, 160, and 230℃ respectively. However, NaNbO3 was prepared when the heating temperature was higher than 160℃, and KNbO3 and KxNa1-xNbO3 were obtained at 230℃, suggesting that only at a higher temperature the kinetic requirement is satisfied. According to the X-ray diffraction results, both the solid solutions, NaNbO3-based solid solution, Na1-xKxNbO3, and KNbO3-based solid solution, K1-xNaxNbO3, were hydrothermally synthesized in 6 mol/L alkali （NaOH and KOH） solution at 230℃.

关键词： KNbO3 NaNbO3 thermodynamic calculation hydrothermal synthesis Gibbs free energy

考虑含HRD的光热电站和综合需求响应的综合能源系统低碳经济调度

在线全文

学校读者我要写书评

暂无评论

东北电力大学学报 2024年第1期44卷 72-82页

作者：王义军孙健淳高敏秦烨嵘张希栋东北电力大学电气工程学院吉林吉林132012 东北电力大学机械工程学院吉林吉林132012

在“双碳”的背景下,为进一步提升综合能源系统(Integrated Energy System, IES)的经济性和环境效益,文中提出一种在奖惩阶梯型碳交易机制下考虑含热回收装置(Heat Recycling Device, HRD)的光热电站和综合需求响应的IES系统低碳经济调... 详细信息

在“双碳”的背景下,为进一步提升综合能源系统(Integrated Energy System, IES)的经济性和环境效益,文中提出一种在奖惩阶梯型碳交易机制下考虑含热回收装置(Heat Recycling Device, HRD)的光热电站和综合需求响应的IES系统低碳经济调度方法。首先,在源侧构建含热回收装置的光热电站与加装碳捕集的热电联产机组联合运行的IES架构,并分析电转气两阶段的运行原理,建立计及余热回收的电转气设备模型。其次,考虑到负荷侧电、热、气三种负荷的柔性特性,在负荷侧建立电热气综合需求响应模型。最后,引入奖惩阶梯型碳交易机制,进一步减小系统碳排放量,构建调度周期内以含购能成本、运维成本、碳交易成本等系统总运行成本最小为目标的综合能源系统低碳优化调度模型。通过算例分析结果表明,所提方法不仅能提高机组的运行潜力,而且有效降低了系统总运行成本与碳排放量。

关键词：光热电站热回收装置碳捕集技术奖惩阶梯碳交易综合需求响应

考虑变掺氧富氧燃烧与利用LNG冷能的LAES的综合能源系统低碳经济调度

在线全文

学校读者我要写书评

暂无评论

东北电力大学学报 2024年第2期44卷 99-109页

作者：王义军秦烨嵘高敏孙健淳张希栋东北电力大学电气工程学院吉林吉林132012 东北电力大学机械工程学院吉林吉林132012

为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid ... 详细信息

为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid Air Energy Storage,LAES),提出了一种电热气冷IES低碳经济优化策略。首先,构建含变掺氧富氧燃烧燃气机组、利用LNG冷能的LAES、电转气(Power To Gas,P2G)设备、中央空调和溴化锂制冷机的IES架构,并建立各设备的数学模型;其次,引入阶梯式碳交易机制,建立了以系统运行成本最小为目标的电热气冷IES低碳经济调度模型;最后,采用MATLAB调用GUROBI求解器对多个场景进行求解,验证了文中提出的低碳经济优化调度策略可以提高系统的风电消纳、有效降低系统运行成本,实现碳减排。

关键词：液化空气储能 LNG冷能富氧燃烧变掺氧电热气冷综合能源系统

Clinical Efficacy of Recombinant Brain Natriuretic Peptide in Patients with Acute Myocardial Infarction After On-Pump Coronary Artery Bypass Grafting (CABG)

在线全文

学校读者我要写书评

暂无评论

Proceedings of Anticancer Research 2019年第6期3卷 15-18页

作者： xidong zhang Department of cardiac surgery Anhui Provincial HospitalHefeiChina

Objective:To evaluate the clinical efficacy of intravenous recombinant human brain natriuretic peptide(rhBNP)in patients with acute myocardial infarction after on-pump coronary artery bypass grafting(CABG).Methods:40 cases of coronary heart disease,left ventricular ejection fraction300 pg/ml underwent on-pump coronary artery bypass surgery with cardiopulmonary bypass were enrolled and randomly divided into two groups,experimental group of 20 patients after operation on the basis of conventional therapy plus recombinant human brain natriuretic peptide treatment(first loading dose of 1.5μg/kg intravenously,to maintain dose of 0.01μg/kg/min continuous infusion of 72h),20 cases of the control group was given routine treatment,observe two groups of patients before and after treatment of blood pressure,heart rate,urine volume,blood creatinine and NT-proBNP,and to observe the left ventricular ejection fraction(LVEF),echocardiography and the length of time the ***:the experimental group after treatment,urine volume,left ventricular ejection fraction(LVEF),cardiac index(CI)was significantly higher than that before treatment,the serum creatinine,plasma N-terminal pro brain natriuretic peptide(NTproBNP),the content of serum troponin T peptide(cT nT),creatine kinase isoenzyme(CK MB)was significantly lower than before ***:Recombinant human brain natriuretic peptide can improve cardiac and renal function in patients with acute period of acute myocardial infarction underwent coronary artery bypass surgery,shorten the hospitalization time,and it is safe and feasible.

关键词： Natriuretic peptide Brain Coronary artery bypass grafting Myocardial infarction Renal function Hemodynamics

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

圆柱绕流中扰动体强化传热和减阻

化工学报 2014年第2期65卷 488-494页

作者：张喜东黄护林南京航空航天大学高新技术研究院江苏南京210016

以圆柱上游布置扰动体的双钝体绕流模式为研究对象，通过有限体积法数值研究了 Reynolds 数 Re=1000时钝体直径比（d/D）、间隙率（S/D）对双钝体系统传热性能和系统阻力的影响规律。结果表明，小直径扰钝体对系统的对流换热更为有利，... 详细信息

以圆柱上游布置扰动体的双钝体绕流模式为研究对象，通过有限体积法数值研究了 Reynolds 数 Re=1000时钝体直径比（d/D）、间隙率（S/D）对双钝体系统传热性能和系统阻力的影响规律。结果表明，小直径扰钝体对系统的对流换热更为有利，且系统的对流换热随间隙率的增大而递增。以等直径双钝体（d/D=1）系统为基准，总换热增长量（HI）随间隙率和扰动体直径的增大而减小，且间隙率小于临界值（S/D=4）时换热增长量波动比较明显。当d/D=0.1，S/D≥5时，系统的换热增长量为22.3%～25%，且此时系统的流动阻力可减小约40%，这表明上游小直径扰动体的利用在增强系统换热性能的同时也减小了系统的阻力。

关键词：扰动体换热换热增长量流动阻力对流