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Experiment and Numerical Simulation of Free Water Jet by a Central-body Nozzle

Chinese Journal of Mechanical Engineering 2010年第6期23卷 797-804页

作者： yang minguan zhang feng kang can gao bo School of Energy and Power Engineering Jiangsu University Zhenjiang 212013 China

The recent research about cavitation jet mainly focuses on the organ-pipe nozzle and triangular nozzle. The research content mainly includes the optimized design about the structure of nozzles, the observation and flow analysis about the cavitation jet in the water, and the theory of rock attacked by the cavitation jet, while the energy characteristic of the free jet is not studied yet. In China, the research about the central-body nozzle is almost empty. For the purpose of studying the energy characteristic and the structure of free water jet discharged from central-body nozzle, an experiment with phase Doppler particle anemometry（PDPA） technology is carried out to measure the free water jet flow, which is produced by a central-body nozzle under the jet pressure of 15 MPa. While five sections with different axial distances from the nozzle outlet are selected for data process and analysis, the axial and radial velocity and the droplets of the particle size are studied. Meanwhile, numerical calculation of corresponding flow field is conducted by using volume of fluid（VOF） multiphase model, and the jet flow feature is discussed. The experimental and calculating results show that the axial velocity of high speed jet flow dissipates slowly in the air, and the core area and diffused area are discovered. The diameter of droplet in the core area is small, and jet energy is concentrated, while in the diffusion area, water is mingled with ambient air and radial velocity is relatively large. Obvious low-pressure area exists behind the central body and potential cavitation may occur in that area. The proposed research reveals the energy characteristic of free jet discharged from central-body nozzle, provides the theoretical basis for preestimating erosion feature of the central-body nozzle and also the theoretical foundation for revealing the mechanism of erosion.

关键词： central-body nozzle free water jet phase Doppler particle anemometry(PDPA) energy characteristic VOF model

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Achieving ultralow leakage current in Schottky-MIS cascode anode lateral field-effect diode based on AlGaN/GaN HEMT

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Science China(Information Sciences) 2025年第1期68卷 379-385页

作者： Fangzhou WANG Changhong gao Guojian DING Cheng YU Zhuocheng WANG Xiaohui WANG Qi feng Ping YU Peng ZUO Wanjun CHEN yang WANG Haiqiang JIA Hong CHEN bo zhang Zeheng WANG Songshan Lake Materials Laboratory School of Microelectronics Southern University of Science and Technology State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Manufacturing Commonwealth Scientific and Industrial Research Organisation

In this paper,we design and fabricate a Schottky-metal-insulator-semiconductor（MIS） cascode anode GaN lateral field-effect diode（CA-LFED） to achieve ultralow reverse leakage current(ILEAK).The device based on AlGaN/GaN highelectron-mobility-transistor（HEMT） includes a normally-off MIS-controlled channel that is cascoded with a high barrier height Schottky *** reverse bias,the high electric-field is effectively prevented by the normally-off MIS-controlled channel *** with the high barrier height Schottky contact,this feature significantly suppresses the *** by the device fabrication,the CA-LFED with high breakdown voltage（BV）>600 V shows an ultralow ILEAKof 3.6×10-9A/mm as well as a low forward voltage drop（VF） of 2.2 *** performance suggests that the CA-LFED can be a promising candidate for ultralow ILEAKand better VF-ILEAKtrade-off GaN power diode applications.

关键词： Schottky-MIS cascode anode lateral field-effect diode (LFED) ultralow reverse leakage current ($I_{\rm{LEAK}}$) forward drop and reverse leakage trade-off AlGaN/GaN HEMTs

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Analysis of the anti-T2DM components in dichloromethane fraction of Schisandra sphenanthera and its mechanism

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Traditional Medicine Research 2025年第1期10卷 27-43页

作者： Shi-bo feng Hai-Hui Jiang Hui-Li kang Yi Jiang Hua-Wei zhang Xiao-Mei Song Yu-Ze Li Wen-Li Huang Dong-Dong zhang Chong Deng School of Pharmacy Shaanxi University of Chinese MedicineXianyang 712046China School of Pharmacy and Shaanxi Qinling Application Development and Engineering Center of Chinese Herbal Medicine Shaanxi University of Chinese MedicineXianyang 712046China Key Laboratory for Research and Development of“Qin Medicine”of Shaanxi Administration of Traditional Chinese Medicine Xianyang 712046China Shaanxi Key Laboratory of Research and Application of“Taibai Qi Yao” Xianyang 712046China

Background:The type 2 diabetes mellitus(T2DM)pharmacodynamic study of various parts of Schisandra sphenanthera was conducted in the previous stage,and it was found that dichloromethane extracted part(SDP)had a significant hypoglycemic ***,the components of SDP were analyzed,and the specific mechanism of its anti-T2DM was ***:We used a high-fat,high-sugar diet in combination with streptozotocin to induce a T2DM rat model,and the model rats were divided into two groups according to body weight and blood ***,oral glucose tolerance test,fasting blood glucose,low density lipoprotein cholesterol,superoxide dismutase,insulin,glycated hemoglobin,total cholesterol,nonesterified free fatty acids,alanine aminotransferase,high-density lipoprotein cholesterol,aspartate aminotransferase,malondialdehyde,and glutathione peroxidase were measured,organ indices were calculated,and pathological sections of pancreas and liver were *** 16S rRNA V3–V4 region of intestinal flora was sequenced to explore the effect of SDP on biochemical indicators and intestinal *** on the above indicators,the anti-T2DM mechanism of SDP in Schisandra sphenanthera was ***:After six weeks of administration,the biochemical indices of diabetic rats were diminished compared to the control *** SDP could significantly increase the gut microbialα-diversity index,resulting in significant changes in the flora of T2DM rats,with increased richness and diversity,reduced harmful flora,and significantly back-regulated the levels of acetic acid,propionic acid,and butyric ***:SDP can improve the symptoms associated with elevated blood glucose,dyslipidemia,elevated fasting insulin levels,and damaged glucose tolerance in *** against T2DM may be through the control of intestinal flora to normalize and exert anti-diabetic effect;its main active components may be lignans and terpenoids.

关键词： Schisandra sphenanthera T2DM intestinal flora HPLC

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Mechanism of calcium lignosulfonate in apatite and dolomite flotation system

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International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1697-1704页

作者： bo feng Liangzhu zhang Wenpu zhang Huihui Wang Zhiyong gao Jiangxi Key Laboratory of Mining Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China State Key Laboratory of Rare Metals Separation and Comprehensive Utilization Guangzhou 510600China

Since the physical and chemical properties of apatite and dolomite can be similar,the separation of these two minerals is ***,when performing this separation using the flotation method,it is necessary to search for selective *** experimental research was performed on the separation behavior of apatite and dolomite using calcium lignosulfonate as a depressant,and the mechanism by which this occurs was *** results show that calcium lignosulfonate has a depressant effect on both apatite and dolomite,but the depressant effect on dolomite is stronger at the same *** analysis shows that the adsorptive capacity of calcium lignosulfonate on dolomite is higher than that of apatite,which is due to the strong reaction between calcium lignosulfonate and the Ca sites on *** addition,there is a hydrogen bond between calcium lignosulfonate and dolomite,which further prevents the adsorption of sodium oleate to dolomite,thus greatly inhibiting the flotation of dolomite.

关键词： apatite dolomite calcium lignosulfonate depression mechanism

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Effect of the volute tongue cut on pressure pulsations of a low specific speed centrifugal pump

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Journal of Hydrodynamics 2020年第4期32卷 758-770页

作者： Ning zhang bo gao Bin Xia Qi-feng Jiang School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China School of Mechanical Technology Wuxi Institute of TechnologyWuxi 214121China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China

The volute tongue,as the crucial component inducing rotor-stator interaction,is detrimental to unsteady pressure pulsations of centrifugal *** the present paper,to investigate the effect of the volute tongue cut on pressure pulsations of a low specific speed centrifugal pump,three volute tongues are obtained through twice cuts,named cases 1,2,*** measuring points are evenly mounted on periphery of the volute casing to obtain unsteady pressure signals using high response *** amplitudes at the blade passing frequency fBPF and root mean square(rms)values in 0 Hz-500 Hz frequency band are applied to evaluate the cutting *** show that pressure spectrum is significantly affected by the volute tongue cut,especially for the component at *** different measuring points,influences of the volute tongue cut on three cases are not *** nns values,it is evident that cutting the volute tongue will lead to pressure energy increasing for most of the concerned measuring points,especially for the points at the far away region from the volute ***,from comparison with the original shape case 1,the averaged increment of the twenty points is more than 20%.So it is concluded that for this type centrifugal pump,cutting the volute tongue is not reasonable considering low pressure pulsation requirement.

关键词： Centrifugal pump volute tongue cut pressure pulsation spectrum analysis

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Electropolymerization of Ni(salen) on carbon nanotube carrier as a capacitive material by pulse potentiostatic method

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Science China Chemistry 2012年第7期55卷 1338-1344页

作者： LI JianLing gao Fei zhang YaKun kang FeiYu WANG XinDong YE feng yang Jun State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China China Electric Power Research Institute Beijing 100192China Department of Material Science and Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of SciencesBeijing 100080China

The composites of poly[Ni（salen）] and multi-walled carbon nanotube （MWCNT） were synthesized by pulse potentiostatic method. The composites were characterized by field emission scanning electron microscopy, Fourier transform infrared spectra, and electrochemical impedance spectroscopy. The wrapping of carbon nanotubes with poly[Ni（salen）] varied significantly with anodic pulse duration. Variance of structure of poly[Ni（salen）] caused by anodic pulse duration affected the ability of absorption to solvent molecules or solvated ions, which was indicated by v （C≡N） intensity. The ability to store/release charge of poly[Ni（salen）] caused by redox switching was evaluated in the form of low-frequency capacitance. Correlations of chargetransfer resistance/ionic diffusion resistance with potential and anodic pulse duration were investigated.

关键词： poly[Ni(salen)] carbon nanotubes potential pulse electrochemical impedance spectroscopy

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圆柱水射流中的能量分布与统计特征

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排灌机械工程学报 2011年第2期29卷 160-164页

作者：康灿杨敏官张峰高波江苏大学能源与动力工程学院江苏镇江212013

在13,15,17 MPa压力下,采用相位多普勒粒子分析仪(PDPA)对自由圆柱水射流的轴向速度、轴向脉动速度和液滴粒径进行测量,对通过射流场中不同位置测量体的单个液滴特征进行统计分析,以获得单个液滴的轴向速度和对应的液滴数的相关特征,进... 详细信息

在13,15,17 MPa压力下,采用相位多普勒粒子分析仪(PDPA)对自由圆柱水射流的轴向速度、轴向脉动速度和液滴粒径进行测量,对通过射流场中不同位置测量体的单个液滴特征进行统计分析,以获得单个液滴的轴向速度和对应的液滴数的相关特征,进而分析射流束中的能量分布.研究结果表明:在相同压力条件下,不同轴向截面上的轴向速度分布呈现一定的相似性,截面边缘处的轴向速度梯度较大;截面边缘处的轴向脉动速度较大,且随射流压力增加,轴向脉动速度增大.对位于中间点的测量体,具有较高速度的液滴占据绝大多数;对边缘处的测量体,液滴速度谱较宽.在不同轴向截面上,随射流压力的变化,对应位置的统计关系变化规律不同.在设定的第1采样时段内,在各中心点处测量体内采集到的有效液滴数相差不大.但穿越边缘点测量体的有效液滴数随射流压力和截面位置的变化极不规则.

关键词：圆柱水射流相位多普勒粒子分析仪能量分布脉动速度穿越时间统计分析

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Ab-initio Investigation on Ion-associated Species and Association Process in NaNO_3 Solution

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Chemical Research in Chinese Universities 2010年第4期26卷 656-661页

作者： zhang Hao feng bo YU Jian-kang SUN Chia-chung State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changchun 130021 P. R. China Institute of Condensed State Physics Jilin Normal University Siping 136000 P. R. China

Some ion-associated species existed possibly in NaNO3 solution were investigated via the ab-initio method. The hydrated ion parings, triple and multiple ion clusters in NaNO3 solution are all analogous to those in Mg（NO3）2 system except that the bi-dentate structures can not be formed. Only one solvent-shared ion paring has larger v1-NO3^- frequency than the hydrated NO3^- ion. And all triple clusters with two hydrated Na^＋ ions and one NO3^- have larger v1-NO3^- frequency than the hydrated NO3^- ion. The ion association process in NaNO3 solution is predicted as free ions→solvent-separated ion pairings→solvent-shared ion pairings→solvent-shared triple ion clusters→contact triple ion clusters→contact multiple ion clusters→amorphous NaNO3, which is not analogous to that in MgSO4 but those in Mg（NO3）2 and Mg（ClO4）2 systems.

关键词： Quantum chemistry Sodium nitrate Ion-associated species Association process

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Friction and wear behavior of carbon fiber reinforced lithium aluminosilicate composites sliding against GCr15 steel

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Friction 2020年第6期8卷 1063-1072页

作者： Haibao MA Xin WU Long XIA Longnan HUANG Li XIONG Hua yang bo ZHONG Tao zhang Zhiwei yang feng gao Guangwu WEN School of Materials Science and Engineering Harbin Institute of Technology at WeihaiWeihai 264209China School of Science Lanzhou University of TechnologyLanzhou 730050China School of Materials Science and Engineering Shandong University of TechnologyZibo 255000China

Carbon fibers reinforced lithium aluminosilicate matrix composites(Cf/LAS)were prepared by slurry infiltration combined with a hot press *** friction,wear behavior,and wear mechanisms of Cf/LAS composites under dry sliding conditions were *** results show that the coefficient of friction(COF)initially increased with the increase in carbon fiber content,and reached the maximum value of 0.20 for the 33%Cf/LAS *** COF increased sharply with increasing sample temperature from RT to 300℃.The COF remained stable in the temperature range of 300–500℃.The two wear mechanisms of LAS glass-ceramics are fatigue wear and abrasive *** Cf/LAS composites demonstrate slight spalling and shallow *** results show that carbon fibers improve the mechanical properties and wear resistance of Cf/LAS composites.

关键词： unlubricated friction ceramics composites carbon fiber materials long fibers wear mechanisms

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New Spirostanol Sulfonate from the Rhizomes of Helleborus thibetanus(Ranunculaceae)

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Chemical Research in Chinese Universities 2010年第5期26卷 746-748页

作者： yang feng-ying SU Yan-fang zhang Xiao TU Guang-zhong gao Xiu-mei zhang bo-li School of Pharmaceutical Science and Technology Tianjin University Tianjin 300072 P R. China Tianjin Key Laboratory of TCM Chemistry and Analysis Tianjin University of Traditional Chinese Medicine Tianjin 300193 P R. China Beijing Institute of Microchemistry Beijing 100091 P R. China

A new spirostanol sulfonate, spirost-5,25（27）-dien-1β,3β-diol 1-sulfonate（1）, was isolated from the rhizomes of Helleborus thibetanus（Ranunculaceae）, and the structure was identified on the basis of a detailed... 详细信息

关键词： Helleborus thibetanus Ranunculaceae Spirostanol Sulfonate

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