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两机一洞尾水调压室阻抗损失系数模型试验研究

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水电能源科学 2024年第2期42卷 161-165页

作者：周嘉伟胡定辉刘火箭刘志雄长江科学院水力学研究所湖北武汉430014 长江勘测规划设计研究有限责任公司湖北武汉430014

水电站引水发电系统中调压室的阻抗损失系数是影响机组过渡过程计算结果的重要因素,目前阻抗损失系数一般在行业规范推荐的范围内进行取值,往往与试验值有所偏差,不利于调压室体型的优化设计。通过采用大比尺的调压室水工模型,对两机一... 详细信息

水电站引水发电系统中调压室的阻抗损失系数是影响机组过渡过程计算结果的重要因素,目前阻抗损失系数一般在行业规范推荐的范围内进行取值,往往与试验值有所偏差,不利于调压室体型的优化设计。通过采用大比尺的调压室水工模型,对两机一洞型式的水电站阻抗式尾水调压室进行大流量条件下的水力学试验,研究不同水流流态和分流比对调压室阻抗损失系数的影响,分析控制工况下调压室的流入和流出阻抗损失系数,给出了调压室阻抗损失系数与分流比的拟合公式和关系曲线。研究结果填补了两机一洞型式的水电站尾水调压室阻抗损失系数试验的空白,可为此类调压室的水力计算分析提供依据。

关键词：两机一洞尾水调压室模型试验阻抗损失系数分流比

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数字普惠金融发展对城镇就业影响的实证研究

长春金融高等专科学校学报 2024年第3期 5-18页

作者：刘志雄张久玥广西民族大学经济学院广西南宁530007

为研究数字普惠金融发展对城镇就业的影响,选取我国31个省份2011—2021年的面板数据进行实证,并探究我国数字普惠金融发展对城镇就业影响的中介渠道。研究结果表明:首先,我国数字普惠金融发展能够带动城镇就业改善,但改善效果呈现地区... 详细信息

为研究数字普惠金融发展对城镇就业的影响,选取我国31个省份2011—2021年的面板数据进行实证,并探究我国数字普惠金融发展对城镇就业影响的中介渠道。研究结果表明:首先,我国数字普惠金融发展能够带动城镇就业改善,但改善效果呈现地区异质性,且低消费能力的地区和产业结构水平高的地区数字普惠金融发展对城镇就业的影响效果更为明显。其次,数字化程度和使用深度大于覆盖广度对城镇就业的改善效果。覆盖广度在东部地区效果明显,使用深度在中部和东部地区效果明显,覆盖程度在西部地区效果明显。最后,居民消费水平提升和产业结构升级在数字普惠金融发展对城镇就业的影响中发挥中介作用。因此,建议充分发挥数字普惠金融发展对城镇就业的带动作用,因地制宜推进区域数字普惠金融发展,提升居民消费水平并优化产业结构,健全数字普惠金融发展的监管机制。

关键词：数字普惠金融城镇就业中介效应异质性

广西科普能力建设与推进共同富裕的耦合协调研究

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边疆经济与文化 2024年第5期 23-30页

作者：刘志雄张久玥广西民族大学经济学院南宁530007

在科教兴桂战略、人才强桂战略和创新驱动发展战略扎实推进的过程中,探索广西科普能力建设与推进共同富裕二者的耦合协调关系非常重要。构建指标体系,基于2011—2020年的数据,采用耦合度模型和协调度模型对广西科普能力建设与推进共同... 详细信息

在科教兴桂战略、人才强桂战略和创新驱动发展战略扎实推进的过程中,探索广西科普能力建设与推进共同富裕二者的耦合协调关系非常重要。构建指标体系,基于2011—2020年的数据,采用耦合度模型和协调度模型对广西科普能力建设与推进共同富裕进行研究。提出四项建议:第一,广西需要继续加大科普工作力度,平衡科普各维度发展;第二,完善“科普发展-共同富裕”系统的耦合发展,提升广西科普发展与共同富裕二者之间协调效应;第三,利用科普带动共同富裕,以共同富裕反哺科普建设;第四,基于“1+1+4+3+N”目标任务体系推进科普建设。

关键词：科普能力共同富裕灰色关联度耦合协调熵权法

NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF THE NEW METHOD OF HORSESHOE VORTEX CONTROL

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Journal of Hydrodynamics 2010年第4期22卷 572-581页

作者： liu zhi-hua xiong Ying WANG Zhan-zhi WANG Song TU Cheng-xu Department of Naval Architecture and Ocean Engineering Naval University of Engineering Wuhan 430033 China China Jiliang University Hangzhou 310018 China

The horseshoe vortex generated around the sail-body junction of a submarine has an important influence on the uniformity of the submarine wake at the propeller *** this article,the horseshoe vortex is simulated by the Detached Eddy Simulation（DES） method,and a new method to control the horseshoe vortex by vortex control baffler is *** numerical simulation shows that a kind of attached vortex,with the rotation direction opposite to that of horseshoe vortex,is generated by the vortex control *** the attached vortex,the strength of the horseshoe vortex is significantly *** wind tunnel experiment on a submarine model is carried out,and the axial velocities at the propeller disc of the submarine with and without vortex control baffler are measured by a hot wire anemometer *** is shown from the experimental results that the vortex control baffler can enhance the uniformity of the wake at the propeller disc,which helps to improve the propeller *** engineering applicability of the vortex control baffler is discussed.

关键词： submarine Detached Eddy Simulation (DES) method vortex control baffler horseshoe vortex attached vortex wind tunnel experiment

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四大家鱼幼鱼下行行为及流场偏好研究

水生态学杂志 2024年第4期45卷 117-124页

作者：王渊洋李鸿柯森繁王继保刘雁石小涛谭均军刘志雄三峡大学水利与环境学院湖北宜昌443002 湖北省鱼类过坝技术国际科技合作基地湖北宜昌443002 长江三峡技术经济发展有限公司北京101100 三峡大学三峡库区生态环境部工程研究中心湖北宜昌443002 长江水利委员会长江科学院湖北武汉430014

探究典型江河半洄游性鱼类的摄食、育肥等下行洄游需求,可为鱼类下行通道的设计与评价提供技术支撑。以全长5~13 cm四大家鱼(青鱼、草鱼、鲢、鳙)幼鱼为研究对象,通过构建模型实验,在进口流速为0.2 m/s时,分析同一水流环境下鱼类的运动... 详细信息

探究典型江河半洄游性鱼类的摄食、育肥等下行洄游需求,可为鱼类下行通道的设计与评价提供技术支撑。以全长5~13 cm四大家鱼(青鱼、草鱼、鲢、鳙)幼鱼为研究对象,通过构建模型实验,在进口流速为0.2 m/s时,分析同一水流环境下鱼类的运动行为,开展其下行过程中应用水力条件的行为响应及流场偏好研究。结果表明:(1)青鱼、草鱼、鲢、鳙幼鱼的下行成功率分别为58.3%、78.6%、74.5%、87.2%,下行轨迹主要集中在主流区域;(2)四大家鱼幼鱼多表现为主动下行行为,鳙幼鱼的直接下行率最高(88.5%),青鱼、鲢幼鱼分别为60.0%、56.2%,草鱼幼鱼发生延迟下行的概率(56.3%)大于直接下行率(43.8%);(3)实验鱼对不同流速范围的选择存在差异性,四大家鱼幼鱼在同一水力环境条件下的下行行为选择存在一定的规律性,青鱼、草鱼、鲢、鳙幼鱼的共同偏好流速为0.228~0.454 m/s,共同偏好紊动能为0.0014~0.0023 m^(2)/s^(2)。

关键词：四大家鱼下行行为流场模拟流场偏好

Structures and magnetic properties of several novel lanthanide coordination polymers based on thiophene-2,5-dicarboxylic acid

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Science China Chemistry 2012年第6期55卷 1073-1078页

作者： REN Jia liu Yue CHEN zhi xiong Gang ZHAO Bin Department of Chemistry Nankai University Tianjin 300071 China

Eight novel lanthanide complexes： {Ln（TDA）I.5（H20）2 },, （Ln = Pr（la）, Nd（2a）） and { Ln（TDA）（Ac）（H2O）}n （Ln = Pr（1）, Nd（2） Eu（3）, Gd（4）, Tb（5）, Dy（6）; TDA = Thiophene-2,5-dicarboxylic acid anion） have been constructed by hydrothermal reaction. Structural analyses reveal that complexes Ia and 2a belong to the space group C2/c, exhibiting three-dimensional （3D） frame- works. Complexes 1-6 with P2t/c space group were prepared in the presence of excessive ammonium acetate, giving rise to interesting 3D frameworks different from those of la and 2a. Magnetic property studies of 4-6 reveal the weak antiferromag- netic interaction exists between adjacent Gd3＋ in 4. The complex 6 displays rather rare slow magnetization relaxation behavior in 3D frameworks.

关键词： thiophene-2 5-dicarboxylic acid lanthanide complexes slow magnetic relaxation

Applied anatomy for pituitary adenoma resection

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Chinese Medical Journal 2011年第15期124卷 2269-2274页

作者： liu Liang liu zhi-xiong liu Yun-sheng liu Jing-fang ZENG Yu ZENG zhi-cheng WANG Miao WANG Hao ZENG Chang-ming JIANG Xing-jun HEN Xin YANG Shu-guang Department of Neurosurgery Xiangya Hospital Central South University Changsha Hunan 410008 China Department of-Anatomy and Neurobiology Xiangya School of Medicine Central South University Changsha Hunan 410013 China Department of Neurosurgery People＇s Hospital Ningxiang County Changsha Hunan 410600 China Department of Neurosurgery the Third Hospital Ningxiang County Changsha Hunan 410600 China Department of Neuroscience TCM Hospital of Ningxiang County Changsha Htman 410600 China

Background Pituitary adenomas are common intracranial tumors, with a rising incidence in China. Excision is a mainstay therapy for this disease, and is often carried out via transfr0ntal, transsphenoidal or transpterional approaches. However, few studies have systematically addressed the regional anatomy involved in these microsurgical procedures. The present study attempted to establish some key anatomic measurements relevant to pituitary adenoma resection based on cadaver and computer tomography （CT） image studies. Methods Head specimens from 30 randomly selected formalin-fixed adult cadavers were used for anatomical analysis. Measurements were made on the base of the skull following removal of brain structures above the pituitary gland, and on the mid-sagittal plane of the cranium. Parameters were designed by considering the 3 above-mentioned common microsurgical approaches, and obtained on each head using a sliding caliper. Multi-level CT images from 30 individuals were also used for distance measurements between landmark structures that are relevant to these surgeries. All data were subjected to statistical analysis using the SPSS 11.5 software. Results There was statistically significant difference （P〈0.05） of distance measured on cadavers relative to CT images in 3 sets of measurements related to the transfrontal surgical approach, i.e., distances from the midpoint of superciliary arch superior border to the cranial entrance of internal carotid arteries （ICAs）, the opposite side entrance of ICA and to the genu of ICA. While regional anatomical analyses were carried out according to the transpterional approach, statistically significant difference was also found in 3 sets of distance measurements between cadaver and CT image data, with regard to the distances between the pterion and some landmark structures around the pituitary. Conclusions The present study provides key anatomical and CT image measurements involving the 3 conventionally used surgical approach

关键词： pituitary neoplasms surgical approach applied anatomy

Leaching kinetics of low-grade copper ore with high-alkality gangues in ammonia-ammonium sulphate solution

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Journal of Central South University 2012年第1期19卷 77-84页

作者： liu zhi-xiong YIN Zhou-lan HU Hui-ping CHEN Qi-yuan School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China College of Chemistry and Chemical Engineering Jishou UniversityJishou 416000China

The leaching kinetics of low-grade copper ore with high-alkality gangues was studied in ammonia-ammonium sulphate *** main parameters,such as ammonia and ammonium sulphate concentrations,particle size,solid-to-liquid ratio and reaction temperature,were chosen in the *** results show that the increase of temperature,concentrations of ammonia and ammonium sulphate is propitious to the leaching rate of copper *** leaching rate increases with the decrease of particle size and solid-to-liquid *** leaching rate is controlled by the diffusion through the ash layer and the activation energy is determined to be 25.54 kJ/mol.A semi-empirical equation was proposed to describe the leaching kinetics.

关键词： leaching kinetics ammonia-ammonium sulphate solution low-grade copper ore high-alkality gangues

Defects in the grain interiors of 3 mol%yttria-stabilized tetragonal zirconia polycrystal ceramics with 0.25 wt%alumina

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Journal of Advanced Ceramics 2024年第4期13卷 469-477页

作者： Yan xiong Lian Luo Yao Cheng zhi liu Qi liu Weimin Wang Wei Ji School of Materials&Chemical Engineering Hubei Province Key Laboratory of Green Materials for Light IndustryHubei University of TechnologyWuhan 430068China Fujian Institute of Research on the Structure of Mater Chinese Academy of SciencesFuzhou 350002China Jiangxi Provincial Engineering Research Center for Multifunction Zirconia Materials Jiangxi Size Materials Co.Ltd.Jiujiang 332500China State Key Laboratory of Advance Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

The presence of high-density defects is rarely observed in bulk 3 mol%yttria-stabilized tetragonal zirconia polycrystal(3Y-TZP)ceramics obtained through conventional pressureless *** the present work,fine-grained dense 147 nm 3Y-TZP ceramics were prepared by pressureless sintering of commercial 0.25 wt%alumina-doped zirconia powders at 1300℃.A novel discovery was reported in which large amounts of defects were present in the grain interiors of the *** phenomenon was further examined using three types of powder samples,and the reasons for defect formation were investigated by microstructural characterization using high-resolution transmission electron microscopy(HRTEM)analysis and Rietveld *** results confirmed the essential dependence of the defect formation on the alumina *** authors attributed the defect formation to the significant difference in ionic radii of the solvent and solute during the dissolution of alumina into the zirconia *** sintering kinetics were proposed to be enhanced by the presence of substantial defects,which consequently favored the low-temperature sintering of the alumina-doped zirconia ceramics.

关键词： 3 mol%yttria-stabilized tetragonal zirconia polycrystal(3Y-TzP)ceramics alumina addition microstructure defect