检索结果-南通市图书馆

Numerical investigation of the interaction of the turbulent dual-jet and acoustic propagation

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

Chinese Physics B 2017年第2期26卷 294-304页

作者： Yi-Ming Li Bao-Kuan Li Feng-Sheng Qi xi-chun wang School of Metallurgy Northeastern University Shenyang 110819 China

In order to study the interaction between two independent jets, a three-dimensional（3D） transient mathematical model is developed to investigate the flow field and acoustic properties of the two-stream jets. The results are compared with those of the single-stream jet at Mach number 0.9 and Reynolds number 3600. The large eddy simulation（LES） with dynamic Smagorinsky sub-grid scale（SGS） approach is used to simulate the turbulent jet flow structure. The acoustic field is evaluated by the Ffowcs Williams–Hawkings（FW-H） integral equation. Considering the compressibility of high-speed gas jets, the density-based explicit formulation is adopted to solve the governing equations. Meanwhile, the viscosity is approximated by using the Sutherland kinetic theory. The predicted flow characteristics as well as the acoustic properties show that they are in good agreement with the existing experimental and numerical results under the same flow conditions available in the literature. The results indicate that the merging phenomenon of the dual-jet is triggered by the deflection mechanism of the Coanda effect, which sequentially introduces additional complexity and instability of flow structure. One of the main factors affecting the dual-jet merging is the aperture ratio, which has a direct influence on the potential core and surrounding flow fluctuation. The analysis on the noise pollution reveals that the potential core plays a fundamental role in noise emission while the additional mixing noise makes less contribution than the single jet noise. The overall sound pressure level（OASPL） profiles have a directive property, suggesting an approximate 25° deflection from the streamwise direction, however, shifting toward lateral direction of about 10° to 15° in the dual-jet. The conclusion obtained in this study can provide valuable data to guide the development of manufacturing-green technology in the multi-jet applications.

关键词： dual-jet jet entrainment acoustic characteristic Coanda effect

Successful treatment of accessory breast cancer with endocrine therapy

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2017年第1期18卷 70-75页

作者： chun-xi wang Shu-li GUO Li-na HAN Department of General Surgery Hainan Branch of Chinese PLA General Hospital Beijing 100853 China State Key Laboratory of Intelligent Control and Decision School of Automation Beijing Institute of Teehnology Beijing 100081 China Department of Cardiovascular Internal Medicine Nanlou Branch of Chinese PLA General Hospital Beijing 100853 China

Accessory breast cancers in males are extremely rare, and only a few cases have been reported in the literature. In this paper, an 87-year-old male patient was diagnosed with an accessory breast cancer by means of computed tomography （CT）, magnetic reso- nance imaging （MRI）, positron emission tomography- computed tomography （PET-CT）, and immuno- histochemistry based on needle biopsy, and has un- dergone successful resection and postoperative ad- juvant endocrine therapy. He was the oldest male patient with an accessory breast cancer reported in the Chinese Hospital Knowledge Database and PubMed literature from 1975 to 2015.

关键词：副乳腺癌高龄男性内分泌治疗

Deciphering Water Oxidation Catalysts:The Dominant Role of Surface Chemistry over Reconstruction Degree in Activity Promotion

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第3期17卷 340-354页

作者： Li An Jianyi Li Yuanmiao Sun Jiamin Zhu Justin Zhu Yeow Seow Hong Zhang Nan Zhang Pinxian xi * Zhichuan JXu chun‑Hua Yan State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceFrontiers Science Center for Rare IsotopesCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000People’s Republic of China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Faculty of Materials Science and Energy Engineering Institute of Technology for Carbon NeutralityShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Key Laboratory of Electromagnetic Materials and Devices National Center for International Research On Photoelectric and Energy MaterialsSchool of Materials and EnergyElectron Microscopy CenterYunnan UniversityKunming 650091People’s Republic of China State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030People’s Republic of China Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU‑HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryPeking UniversityBeijing 100871People’s Republic of China

Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution *** surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity ***,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is *** substituting Fe content influences both current change tendency and surface reconstruction ***_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)*** reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based ***,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term ***,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction *** effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface *** finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.

关键词： Oxygen evolution reaction Perovskite oxides Doping Activation and reconstruction

Computed Tomography Angiography in Diagnosis and Treatment of Splenic Artery Aneurysm

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

Chinese Medical Journal 2016年第3期129卷 367-369页

作者： chun-xi wang Shu-Li GUO Li-Na Han Yang Jie Hai-Di Hu Jing-Ru Cheng Miao Yu Yue-Yong xiao Tai Yin Fu-Tao Chu Fa-Qi Liang Department of General Surgery Chinese PLA General Hospital Beijing 100853 China State Key Laboratory of Intelligent Control and Decision School of Automation Beijing Institute of Technology Beijing 100081 China Department of Cardiovascular Internal Medicine Nanlou Branch of Chinese PLA General Hospital Beijing 100853 China Department of CT Radioactive Intervention Chinese PLA General Hospital Beijing 100853 China Department of Vascular Surgery First Clinical Hospital of China Medical University Shenyang 110001 China

Splenic artery aneurysm, without obvious symptoms, is a direct threat to the patient＇s life, once it ruptures as hemorrhagic *** examinations have been the main diagnostic methods of splenic artery aneurysm, including ultrasound, computed tomography （CT）, magnetic resonance imaging, and digital subtraction angiography （DSA）.Although various inspective methods have their own advantages and disadvantages, abdominal CT examination is the most comprehensively applied method in clinical *** representative images of splenic artery aneurysm from a relatively large number of patients examined by CT are presented in this study.

关键词： Aneurysm Resection Computed Tomography Angiography Splenic Artery Aneurysm

Ni-catalyzed cross-electrophile alkyl-alkyl coupling reactions

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Li-Xu You Lan Tian chun-Ling Guo Shun-xi Li Yu-Cheng Liu Yu-Long Li Wei Shu College of Chemistry and Environmental Engineering Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan Sichuan University of Science and Engineering Guangming Advanced Research Institute Shenzhen Grubbs Institute Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and Technology

Introducing saturated carbon-carbon bonds into organic molecules significantly increases the three-dimensional configuration,thus altering the physical and chemical properties as well as the functions of molecules. Transition-metal-catalyzed carboncarbon cross-couplings represent one of the most straightforward, efficient and modular alternatives to build saturation in a single step. However, the efficient construction of alkyl-alkyl bonds remains a formidable challenge due to the precise manipulation of multiple alkyl metallic intermediates as well as associated competitive side reactions and selectivity control. Over the past years, Ni-catalyzed cross-coupling under reductive conditions has gained more and more attention for alkyl-alkyl crosscoupling partially attributing to the low-valent state of metal centers under reducing conditions, which suppresses the competitive β-hydride elimination process, thus facilitating the formation of alkyl-alkyl bonds. In this review, the initiative and progress of Ni-catalyzed cross-electrophile alkyl-alkyl cross-coupling, including the efforts in racemic and enantioselective formation of alkyl-alkyl bonds, have been summarized and discussed. Moreover, the challenges and further opportunities in this area have also been discussed.

关键词：

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于RBF网络的制冷压缩机热力性能计算

上海交通大学学报 2001年第8期35卷 1172-1174页

作者：詹涛张春路王昔林丁国良上海交通大学制冷与低温工程研究所上海200030

在对制冷压缩机的热力性能进行建模和仿真计算时 ,运用多层感知器网络虽然可以收到较传统热力计算模型更好的效果 ,但也存在着诸多缺点 .通过引入径向基函数 (RBF)网络替代多层感知器网络 ,较好地克服了这些缺点 .

关键词：制冷压缩机热力性能人工神经网络径向基函数热力计算电功率

银杏达莫注射液联合氯吡格雷治疗急性冠脉综合征的临床研究

在线全文

学校读者我要写书评

暂无评论

现代药物与临床 2017年第10期32卷 1859-1863页

作者：邱军杰雷肖蠢王西辉西安医学院第二附属医院心内科陕西西安710038

目的探讨银杏达莫注射液联合硫酸氢氯吡格雷片治疗急性冠脉综合征的临床疗效。方法选取2016年3月—2017年3月在西安医学院第二附属医院进行治疗的急性冠脉综合征患者78例为研究对象,根据所有患者用药的差别分为对照组和治疗组,每组各39... 详细信息

目的探讨银杏达莫注射液联合硫酸氢氯吡格雷片治疗急性冠脉综合征的临床疗效。方法选取2016年3月—2017年3月在西安医学院第二附属医院进行治疗的急性冠脉综合征患者78例为研究对象,根据所有患者用药的差别分为对照组和治疗组,每组各39例。对照组口服硫酸氢氯吡格雷片,首次剂量300 mg/次,尔后75 mg/次,1次/d。治疗组在对照组基础上静脉注射银杏达莫注射液,20 m L加入到0.9%氯化钠注射液250 m L中,2次/d。两组均连续治疗14 d。观察两组的临床疗效,比较两组的心电图(ECG)疗效、心功能指标、心绞痛发作次数、心绞痛持续时间和血清学指标。结果治疗后,对照组和治疗组的总有效率和ECG有效率分别均为79.49%、94.87%,两组比较差异有统计学意义(P<0.05)。治疗后,两组LVEF和LVEDD显著升高,而LVEDV明显下降,同组治疗前后比较差异有统计学意义(P<0.05);且治疗组这些观察指标的改善程度明显优于对照组,两组比较差异具有统计学意义(P<0.05)。治疗后,两组心绞痛发作次数和持续时间明显降低,同组治疗前后比较差异有统计学意义(P<0.05);且治疗组这些观察指标明显低于对照组,两组比较差异具有统计学意义(P<0.05)。治疗后,两组血清hs-CRP、MMP-9、ET-1、TN-C水平明显降低,而NO水平明显升高,同组治疗前后比较差异有统计学意义(P<0.05);且治疗组这些观察指标的改善程度明显优于对照组,两组比较差异具有统计学意义(P<0.05)。结论银杏达莫注射液联合硫酸氢氯吡格雷片治疗急性冠脉综合征具有较好的临床疗效,可改善患者心功能和血管内皮功能,降低机体炎症反应,具有一定的临床推广应用价值。

关键词：银杏达莫注射液硫酸氢氯吡格雷片急性冠状动脉脉综合征心功能指标血清学指标

乙烷在Sb-Fe-O催化剂上的吸附及反应性能研究

在线全文

学校读者我要写书评

暂无评论

天然气化工—C1化学与化工 2002年第5期27卷 16-20页

作者：张春娥王希涛钟顺和天津大学化工学院天津300072

用共沉淀法制备了Sb Fe O催化剂 ,用BET、XRD、TEM、TPR、TPD、IR、微反等方法对催化剂的组成、结构、吸附性能及乙烷氧化反应性能进行了研究。实验结果表明 :用共沉淀法制备的Sb Fe O催化剂粒子为超细结构 ,粒子大小分布为 10～ 2 0nm ... 详细信息

用共沉淀法制备了Sb Fe O催化剂 ,用BET、XRD、TEM、TPR、TPD、IR、微反等方法对催化剂的组成、结构、吸附性能及乙烷氧化反应性能进行了研究。实验结果表明 :用共沉淀法制备的Sb Fe O催化剂粒子为超细结构 ,粒子大小分布为 10～ 2 0nm ,乙烷分子中的H吸附在催化剂表面的Lewis碱位Sb =O双键上的端基氧原子上 ,氧化产物为乙烯和碳氧化物 ,乙烯的选择性可达到 70

关键词：反应性能共沉淀法 Sb-Fe-O催化剂乙烷化学吸附氧化反应锑铁复合氧化物催化剂乙烯

在线全文

学校读者我要写书评

暂无评论

大下倾角电调基站天线移相器及馈电网络设计

微波学报 2010年第S2期26卷 200-203页

作者：江椿代喜望焦永昌陈晖蒋红义西安电子科技大学西安710071 东莞市晖速天线技术有限公司东莞523128

采用耦合串馈移相器和遗传算法天线赋形技术,设计了一个应用于GSM1800频段动态范围的基站天线。移相器通过串馈形式获得大下倾角所需要的移相量。实验表明,该移相器在整个频段内具有良好的幅度变化和插入损耗,所设计的基站天线在大下倾... 详细信息

采用耦合串馈移相器和遗传算法天线赋形技术,设计了一个应用于GSM1800频段动态范围的基站天线。移相器通过串馈形式获得大下倾角所需要的移相量。实验表明,该移相器在整个频段内具有良好的幅度变化和插入损耗,所设计的基站天线在大下倾角范围内具有很好的上旁瓣抑制和下倾角精度。

关键词：大下倾角串馈移相器基站天线遗传算法