检索结果-南通市图书馆

Journal of Thermal Science 2019年第3期28卷 463-471页

作者： GAO Wei YAO Mingyu CHEN Yong li hongzhi ZHANG Yifan ZHANG Lei Xi'an Thermal Power Research Institute Co. Ltd.

This paper researches the performance of a novel supercritical carbon dioxide(S-CO_2) Brayton cycle and organic Rankine cycle(ORC) combined system with a theoretical solar radiation diurnal distribution. The new system supplies all solar energy to a S-CO_2 Brayton cycle heater, where heat releasing from the S-CO_2 cooler is stored in the thermal storage system which is supplied to the ORC. Therefore, solar energy is kept at a high temperature, while at the same time the thermal storage system temperature is low. This paper builds a simple solar radiation diurnal distribution model. The maximum continuous working time, mass of thermal storage material, and parameter variations of the two cycles are simulated with the solar radiation diurnal distribution model. 10 organic fluids and 5 representative thermal storage materials are compared in this paper, with the mass and volume of these materials being shown. The longer the continuous working time is, the lower the system thermal efficiency is. The maximum continuous working time can reach 19.1 hours if the system provides a constant power output. At the same time, the system efficiency can be kept above 38% for most fluids.

关键词： solar power generation S-CO2 brayton cycle ORC thermal storage temperature combined cycle

Synthesis and Electrochemical Performance of Co3O4/Graphene

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2014年第4期30卷 650-655页

作者： WANG hongzhi SHI Yulei li Zixuan ZHANG Weiguo YAO Suwei Department of Applied Chemistry School oJ Chemical Engineering and Technology Tianjin University Tianjin 300072 P. R. China

Co3O4/reduced graphene oxide composites were synthesized via a simple electrochemical method from graphene oxide and Co（NO3）2·6H2O as raw ***3O4 nanoparticles with sizes of around 30-50 nm were distributed on the surface of graphene nanosheets confirmed by scanning electron microscopy and transmission electron *** properties of Co3O4/graphene composite were tested by cyclic voltammetry,galvanostatic charge-discharge,and electrochemical impedance *** Co3O4/reduced graphene oxide composite was used as the pseudocapacitor electrode in the 2 mol/L NaOH aqueous electrolyte *** Co3O4/reduced graphene oxide composite electrode exhibited a specific capacitance of 357 F/g at a current density of 0.5 A/g in a three-electrode system.72％ of capacitance was retained when the current density increased to 3 A/*** Co3O4/reduced graphene oxide composite prepared electrodes show a high rate capability and excellent long-term *** 1000 cycles of charge and discharge,the capacitance is still maintained 87％ at a current density of 1 A/g,indicating that the composite is a oromising alternative electrode material used for supercapacitors.

关键词： Cobalt oxide Graphene Composite Electrochemical preparation Supercapacitor

Enhanced Data Transmission Rate of XCTD Profiler Based on OFDM

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

Journal of Ocean University of China 2019年第5期18卷 1079-1085页

作者： li hongzhi ZHANG Sai QIN Xiaocong ZHANG Xiaoyang ZHENG Yu National Ocean Technology Center Tianjin 300112China School of Electronics and Information Engineering Tianjin Polytechnic UniversityTianjin 300387China

An expendable conductivity-temperature-depth profiler(XCTD)is one of the most important instruments used to obtain hydrological data,such as temperature and conductivity,and detect ocean depth in a large ***,the XCTD channel provides poor time-varying performance,narrowband,and low signal-to-noise ratio(SNR),which severely restricts the data transmission *** contrast to conventional single-carrier modulation techniques,such as amplitude-shift keying and differential phase-shift keying,this article provides a new method,based on orthogonal frequency division multiplexing(OFDM)to enhance the data transmission rate of deep-sea abandoned *** apply the OFDM to enhance the SNR of the XCTD,which is achieved by reducing the data transmission rate of each ***,the bandwidth utilization may be improved by increasing the number of subcarriers in a given bandwidth,which enhances the data transmission *** on analysis of the XCTD channel model,OFDM with different parameters such as constellation mapping,number of subcarriers,subcarrier spacing,signal period and cyclic prefix are *** verify the effectiveness of the OFDM,this study investigates the influence of different parameters on the data transmission rate at different noise levels,i.e.,-20 dB and-40 d B.

关键词： XCTD OFDM subcarrier bandwidth utilization data transmission rate

基于轮轨切向力的防空转/滑行效率计算方法研究

在线全文

学校读者我要写书评

暂无评论

铁道车辆 2024年第1期62卷 92-98页

作者：陈玉田敬雷李洪智丛明中铁检验认证(青岛)车辆检验站有限公司山东青岛266031

地铁车辆在完成防空转/滑行试验后,通常通过计算防空转/滑行效率来评价车辆防空转/滑行的性能,目前地铁车辆关于防空转/滑行效率缺少统一的计算方法。为解决该问题,文章系统介绍了轮轨黏着机理及特性,对比分析了既有车辆黏着控制策略和... 详细信息

地铁车辆在完成防空转/滑行试验后,通常通过计算防空转/滑行效率来评价车辆防空转/滑行的性能,目前地铁车辆关于防空转/滑行效率缺少统一的计算方法。为解决该问题,文章系统介绍了轮轨黏着机理及特性,对比分析了既有车辆黏着控制策略和防空转/滑行效率计算方法,建立了车辆牵引和制动工况力学模型并提出了一种基于轮轨切向力的防空转/滑行效率计算方法。与现有防空转/滑行效率计算方法相比,该方法同时适用于防空转试验和防滑行试验效率计算,排除了车辆运行阻力对计算结果的影响,在不同试验工况下的计算结果一致性较好。

关键词：防空转/滑行效率黏着特性轮轨切向力黏着控制策略

经跟腱旁入路切开复位内固定治疗后踝夹心形骨折

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2024年第6期28卷 934-938页

作者：郑加法宋秀锋李宏志周锦明关盛溢于鹤大连市第二人民医院骨科辽宁省大连市116011

背景:踝关节骨折直视下精准复位已经成为足踝外科医生的共识,如何充分显露后踝的游离或压缩骨折块,仍然是具有挑战性的难题之一。目的:探讨经跟腱旁入路切开复位内固定治疗后踝夹心形骨折的临床疗效。方法:回顾性分析2020年1-12月大连... 详细信息

背景:踝关节骨折直视下精准复位已经成为足踝外科医生的共识,如何充分显露后踝的游离或压缩骨折块,仍然是具有挑战性的难题之一。目的:探讨经跟腱旁入路切开复位内固定治疗后踝夹心形骨折的临床疗效。方法:回顾性分析2020年1-12月大连市第二人民医院收治的26例后踝夹心形骨折患者的临床资料,均采用经跟腱旁入路切开复位内固定治疗,其中经跟腱外侧入路21例,经跟腱内侧入路5例;男19例,女7例;年龄24-69岁,平均38.6岁。记录手术时间,观察术后并发症情况;通过Burwell-Charnley影像学标准评价骨折复位情况;记录术前、术后3个月及末次随访时目测类比评分、踝关节跖屈及背伸活动度和美国足踝外科协会踝-后足功能评分,评估临床效果。结果与结论:(1)26例患者均获随访,随访时间13-18个月,平均14.6个月;手术时间52-85 min,平均64.2 min;(2)1例患者术后外踝切口部分皮缘坏死,通过换药后完全愈合;其余患者手术切口均Ⅰ期愈合;(3)Burwell-Charnley影像学标准评价:24例解剖复位,2例复位良好,优良率为100%;(4)末次随访时目测类比评分为(1.19±0.40)分,较术前(6.81±0.80)分明显下降(P<0.01);末次随访时踝关节跖屈为(33.5±5.02)°,踝关节背伸为(17.23±0.99)°,较术前(14.58±2.50)°、(5.81±1.02)°均明显增加(P<0.01);美国足踝外科协会踝-后足功能评分为(89.31±3.62)分,较术前(46.00±5.45)分明显升高(P<0.01);其中优23例,良3例,优良率为100%;(5)提示经跟腱旁入路切开复位内固定治疗后踝夹心形骨折手术时间短,骨折复位良好,并发症少,关节活动度及功能恢复满意。

关键词：踝损伤后踝夹心形骨折骨折固定术内固定手术入路

Expression of inducible nitric oxide synthase in the brain tissue of rats at preoxygenation, hypoxia/reoxygenation

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2006年第8期1卷 689-692页

作者： hongzhi Chen Lu li Hong Zhao Department of Anesthesiology Shengjing Hospital China Medical University Shenyang 110004 Liaoning ProvinceChina Department of AnesthesiologyShengjing Hospital China Medical University Shenyang 110004 Liaoning ProvinceChina Department of AnesthesiologyShengjing Hospital China Medical University Shenyang 110004 Liaoning ProvinceChina

BACKGROUND: The disorder of the respiratory and circulation system during the anesthesia and operation often can lead to severe hypoxia. Preoxygenation is a conventional therapy for treatment of hypoxia. OBJECTIVE: To observe the change in the expression of inducible nitric oxide synthase(iNOS), i.e. brain tissue injury degree, in cerebral cortex of rats after hypoxia/reoxygenation under the condition of different levels of preoxygenation. DESIGN: Randomized controlled animal experiment. SETTING: Department of Anesthesiology and Central Laboratory, Shengjing Hospital Affiliated to China Medical University. MATERIALS: This experiment was carried out in the laboratory of Shengjing Hospital Affiliated to China Medical University from March 2003 to March 2004. Seventy-two male Wistar rats, weighing from 250 to 300 g, were provided by the Animal Experimental Room of Shengjing Hospital of China Medical University [license No. SYXK (liao) 2003-0019]. Seventy-two rats were randomized into 3 groups: preoxygenation group, hypoxia group and reoxygentation group. Each group was divided into 4 subgroups, 6 rats in each subgroup. METHODS: 0.21, 0.50, 0.75 and 0.98 volume fraction of oxygen was given to 4 subgroups of preoxygenation group respectively. The rats in each subgroup of hypoxia group inhaled oxygen for 30 minutes according to the method of preoxygenation. Then, nitrogen gas replaced oxygen and was pumped into the cabin, and the volume fraction of oxygen was decreased to be 0.05 within 20 minutes. The rats in each subgroup of reoxygenation group were treated with the experimental methods of preoxygenation and hypoxia separately, then they were moved into the wide mouthed bottle with two-air-duct rubber stopper. Finally, oxygen was pumped and the volume fraction of oxygen reached over 0.98 within 20 minutes. After 24 hours, all the surviving rats were killed by decapitation. Cerebral tissue was sliced and stained by haematoxylin-eosin and then enveloped. Brain tissue inju

关键词： volume fraction tissue injury nitric oxide synthase animal experiment result analysis neuronal injury cerebral cortex brain injury Wistar rats methods of method of

Jumonji domain-containing protein family： the functions beyond lysine demethylation

在线全文

学校读者我要写书评

暂无评论

Journal of Molecular Cell Biology 2018年第4期10卷 371-373页

作者： Yuan Meng hongzhi li Changwei liu li Zheng Binghui Shen Department of Cancer Genetics and Epigenetics Beckman Research Institute of City of Hope Duarte CA 91010 USA Department of Molecular Medicine Beckman Research Institute of City of Hope Duarte CA 91010 USA

Two of the unsolved but important questions in epigenetics are whether arginine demethylases （RDMs） exist and whether proteolytic cleavage of the histone tails and subsequent histone remodeling are a major epigenetic modification process. Jumonji domain （JmjC）-containing proteins have been characterized as lysine demethylases （KDMs） in a certain degree （Klose et al., 2006）. Emerging evidences indicate that they also catalyze demethylation reaction on the arginine residues and proteolytic removal of histone tails. These processes are likely associated with biological meanings.

关键词：精氨酸蛋白质包含域家庭尾巴生物

Orthogonal Frequency Division Multiplexing Adaptive Technology for Multinode Users of Seawater Channel Based on Inductively Coupled Mooring Chain

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

中国海洋大学学报:英文版 2023年第5期22卷 1243-1252页

作者： ZHENG Yu liU Yingjie REN Yuanhong FEI Chen ZHANG Shijiang li hongzhi School of life Sciences Tiangong UniversityTianjin 300387China School of Electronic&Information Engineering Tiangong UniversityTianjin 300387China National Ocean Technology Center Tianjin 300112China

As an important part of buoy-type ocean monitoring systems,the inductively coupled mooring chain solves the problem of data cotransmission through the multinode sensors that it carries,which is significant for the rapid acquisition of fish,hydrology,and other *** paper is based on a seawater channel transmission model with a depth of 300 m and a bandwidth of 2 *** orthogonal frequency division multiplexing(OFDM)technology is used to overcome the multipath effect of signal transmission on a seawater *** adaptive technology is integrated into the OFDM,and an improved joint subcarrier and bit power allocation algorithm is *** algorithm solves the problem of dynamic subcarrier allocation during the cotransmission of underwater multinode user data in seawater *** results show that the algorithm complexity can be reduced by 0.18126×10^(-2)s during one complete OFDM system data transmission by the improved greedy algorithm,and a total of 216 bits are transmitted by the *** normalized channel capacity can be improved by 0.012 bit s^(-1)Hz^(-1).At the bit error ratio(BER)of 10^(-3),the BER performance can be improved by approximately 6 d *** the numbers of users are 4 and 8,the improved algorithm increases the channel capacity,and the higher the number of users,the more evident the channel capacity improvement effect *** results of this paper have an important reference value for enhancing the transmission performance of inductively coupled mooring chain underwater multinode data.

关键词： inductively coupled mooring chain seawater channel multinode users OFDM adaptive technology

Experimental Research on the Mechanism of lift Amplification and Vibration Suppression of Lorentz Force

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2013年第2期9卷 110-116页

作者： ZHANG Hui FAN Baochun CHEN Zhihua li hongzhi li Baoming Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology

The Lorentz force generated by electromagnetic field on the surface of the cylinder in the electrolyte solution may modify the structure of the flow boundary layer effectively. The transient control process of Lorentz force is investigated experimentally for lift amplification and vibration suppression. The experiments are conducted in a rotating annular tank filled with a low-conducting electrolyte. A cylinder with an electro-magnetic actuator is placed into the electrolyte. The lift force of cylinder is measured using the strain gages attached to a fixed beam, and the flow fields are visualized by the dye markers. The results show that the upper vortex on the cylinder is suppressed, and the wake becomes a line and leans to the lower side under the action of upside Lorentz force while the lower vortex on the cylinder is suppressed and limited in a small region. Therefore, the value of lift increases with the variation of flow field. However, the vortexes on the cylinder are suppressed fully under the action of symmetrical Lorentz force which leads to the suppression of lift oscillation and then the vibration of cylinder are suppressed fully.

关键词： hydromechanics flow control Lorentz force vortex-induced vibration cylinder wake

Flow pattern and lift evolution of hydrofoil with control of electro-magnetic forces

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2009年第8期52卷 1364-1374页

作者： CHEN YaoHui FAN BaoChun CHEN ZhiHua li hongzhi National Key Laboratory of Transient Physics Nanjing University of Science&TechnologyNanjing 210094China

The initial responses and evolutions of the flow pattern and lift coefficient of a hydrofoil under the action of electro-magnetic (Lorentz) force have been studied experimentally and numerically, and trace particle methods are employed for them. With the introduction of BVF (boundary vortex flux), the quantitative relation among Lorentz forces, BVF and lifts is deduced. The influences of flow patterns on the hydrofoil lift coefficient have been discussed based on the BVF distribution, and the flow control mechanism of Lorentz force for a hydrofoil has been elucidated. Our results show that the flow pattern and lift of the hydrofoil vary periodically without any force. However, with the action of streamwise Lorentz forces, the separation point on the hydrofoil surface moves backward with a certain velocity, which makes the flow field steady finally. The streamwise Lorentz force raises the foil lift due to the increase of BVF intensity. On the other hand, Lorentz force also increases the hydrofoil surface pressure, which makes the lift decrease. However, the factor leading to the lift enhancement is determinant, therefore, the Lorentz force on the suction side can increase the lift, and the stronger the Lorentz force, the larger the lift enhancement. Our results also show that the localized Lorentz force can also both suppress the flow separation and increase the hydrofoil lift coefficient, furthermore, the Lorentz force located on the tail acts better than that located on the front.

关键词： Lorentz force hydrofoil wake flow control