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引黄滴灌灌水器流道水流模拟及堵塞成因研究

中国农村水利水电 2024年第6期 140-149页

作者：谭启轩翟英剑吴文勇李秀梅胡雅琪李子明河北农业大学城乡建设学院河北保定071000 中国水利水电科学研究院北京100084 新疆兵团勘测设计院集团股份有限公司新疆乌鲁木齐830000

为探究大田引黄滴灌系统灌水器流道的堵塞机理,以减少大田灌水器系统堵塞,根据山西运城尊村灌区泥沙特点利用SolidWorks绘图软件进行灌水器流道的建模设计,以大田滴灌实际工程条件设置仿真参数,采用Ansys Fluent仿真软件进行不同型号灌... 详细信息

为探究大田引黄滴灌系统灌水器流道的堵塞机理,以减少大田灌水器系统堵塞,根据山西运城尊村灌区泥沙特点利用SolidWorks绘图软件进行灌水器流道的建模设计,以大田滴灌实际工程条件设置仿真参数,采用Ansys Fluent仿真软件进行不同型号灌水器流道的仿真计算模拟。研究此灌水器的压力、流速、湍动能等湍流特性以及颗粒的运动轨迹,揭示其内部流动机理。灌水器内部流体域压力随流道单元线性降低,并且压降梯度与流道单元数量线性相关;主流区流体更新快,泥沙不易发生沉积,流道旋涡区以及储水槽倒角部位是泥沙发生沉积的主要部位;流道高速区以外的其他区域以及储水槽部位整体湍流动能较低,水流无法形成或维持湍流状态,不利于泥沙运移,从而形成堵塞。模拟结果表明,灌水器内部结构流体域流速、湍流动能以及流线等分析均表明在灌水器流道部分的低速区和储水槽部位的倒角和边壁处是发生泥沙颗粒沉积的主要部位。

关键词：灌水器堵塞水力性能数值模拟

Management status of type 2 diabetes mellitus in tertiary hospitals in Beijing： gap between guideline and reality

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Chinese Medical Journal 2012年第23期125卷 4185-4189页

作者： li ming-zi JI li-nong MENG Zhao-lin GUO Xiao-hui YANG Jin-kui LU Ju-ming LUE Xiao-feng HONG Xu Department of Endocrinology and Metabolism Peking UniversityPeople's Hospital Beijing 100044 China Department of Endocrinology and Metabolism Xiamen UniversityZhongshan Hospital Xiamen Fujian 361004 China Department of Endocrinology and Metabolism Peking UniversityFirst Hospital Beijing 100034 China Department of Endocrinology and Metabolism Beijing TongrenHospital Capital Medial University Beijing 100730 China Department of Endocrinology and Metabolism Chinese People'sLiberation Army General Hospital Beijing 100853 China Department of Endocrinology and Metabolism Beijing MilitaryCommand General Hospital Beijing 100700 China Department of Endocrinology and Metabolism Beijing FriendshipHospital Capital Medial University Beijing 100050 China

Background Diabetes has become one of the most common chronic diseases and the third leading cause of death in China. Many programs have been initiated at national and local levels to address the illness. However, the effect of these programs in daily outpatient clinics is still unclear. The objective of this study was to investigate the management status of type 2 diabetes mellitus （T2DM） and factors associated with it in diabetes clinics of tertiary hospitals in Beijing. Methods A cross-sectional survey was conducted in six tertiary hospitals in Beijing. Control criteria were defined based on 2007 China guideline for type 2 diabetes （CGT2D）. Results A sample of 1151 patients, age （60.8±9.2） years, and with a median disease duration of 7.3 years was included. The hemoglobin Alc （HbAlc） mean level was （7.15±1.50）%, the percentage of patients achieving the targets for HbAlc was 37.8%, blood pressure 65.6%, triglyceride （TG） 48.8%, high-density lipoprotein （HDL） 59.2%, low-density lipoprotein （LDL） 34.0%, and total cholesterol （TC） 42.0%. The factors independently associated with glycemic control were diabetes duration （odds ratio （OR） = 0.95; 95% confidence interval （CI）： 0.919-0.982, P 〈0.01）, body mass index （BMI）（OR=0.914, 95% CI： 0.854-0.979, P=0.01） and smoking （OR=0.391, 95% Ch 0.197-0.778, P〈0.01）. The factors independently associated with blood pressure control were BMI （OR=0.915, 95% Ch 0.872-0.960, P 〈0.01） and male gender （OR=0.624, 95% CI： 0.457-0.852, P 〈0.01）. The factor independently associated with LDL control was education level （OR=1.429, 95% Ch 1.078-1.896, P=0.013）. Conclusions The management status of T2DM patients in tertiary hospitals in Beijing has improved remarkably. However, there is still room for further improvement to reach the guideline target. Long diabetes duration, high BMI, smoking, male gender and low education level were independently associated with poor metabolic control.

关键词： type 2 diabetes management status, tertiary hospitals

Fine Mapping and Cloning of the Grain Number Per-Panicle Gene (Gnp4) on Chromosome 4 in Rice (Oryza sativa L.)

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Agricultural Sciences in China 2011年第12期10卷 1825-1833页

作者： ZHANG Zhan-ying li Jin-jie YAO Guo-xin ZHANG Hong-liang DOU Hui-jing SHI Hong-li SUN Xing-ming li zi-chao Key Laboratory of Crop Heterosis and Utilization Ministry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement ChinaAgricultural University Beijing 100193 P.R.China

Grain number per-panicle is one of the most important components for rice yield. Spikelets on the primary and secondary branches determine the grain number per-panicle in rice. In this study, we identified a natural mutant, gnp4, lack of lateral spikelet on the secondary branches in the field condition. In addition, the Gnp4 and Lax1-1 double mutant showed dramatically reduced secondary branches and spikelets in panicle at reproductive stage, and tillers at vegetative stage. By map-based cloning approach, and using four F2 segregating populations, the Gnp4 gene was finally mapped to a 10.7-kb region on the long arm of chromosome 4 in rice. In this region, only one gene was predicted, and genomic DNA sequencing of the 10.7-kb region showed no nucleotide differences between the mutant and wild type. Interestingly, we found that the methylation level of several cytosines in the promoter CpG islands region of the predicted gene in gnp4 were different from the wild type. Thus, we propose that the DNA methylation changes at these sites may induce to decrease expression level of Gnp4, consequently, resulting in phenotypic variation.

关键词： rice gnp4 laxl-1 grain number per-panicle methylation

Solidification crack characteristics and sensitivity of peritectic steel

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Journal of Iron and Steel Research International 2024年第7期31卷 1668-1679页

作者： Ya-qiang li Jian-hua liu zi-ming Wang Ying-ying li Yang He Xiao-wei li Department of Automotive Engineering Hebei Vocational University of Technology and EngineeringXingtai 054000HebeiChina Hebei Special Vehicle Modification Technology Innovation Center Hebei Vocational University of Technology and EngineeringXingtai 054000HebeiChina Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China School of Petroleum and Natural Gas Engineering Changzhou UniversityChangzhou 213164JiangsuChina

The characteristics and sensitivity of solidification cracks in peritectic steels were investigated using directional solidifi-cation *** cracks were observed in both hypoperitectic steels(12CrlMoV,15CrMo)and hyper-peritectic steel(20CrMo)during solidification at growth velocities of 15,50,and 80 pm/*** the dendritic boundaries,sulphide precipitates were found,promoting crack *** on the statistical analysis of interdendritic cracks in peritectic steels,the area ratio(RA)of interdendritic cracks in a directional solidification structure was proposed to evaluate the crack sensitivity of peritectic ***,the crack sensitivities of peritectic steels(12CrlMoV,15CrMo,and 20CrMo)were tested,evaluated,and compared with the surface crack rates of three types of steels produced from a steel *** results demonstrated that RA was in good agreement with that of the steel plant,and the crack sensitivity of 12CrlMoV steel was the strongest,followed by that of 15CrMo and 20CrMo ***,RA can be used to evaluate the crack sensitivity of peritectic steel.

关键词： Peritectic steel-Directional solidification Growth velocity Dendritic structure Solidification crack Crack sensitivity

Supramolecular polymer network constructed by a functionalized polyimidazolium salt derived from metal-carbene template approach

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Science China Chemistry 2024年第4期67卷 1224-1228页

作者： ming-ming Gan zi-En Zhang Yi-Fan Zhang Heng Zhang li-Ying Sun Ying-Feng Han Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China

In this study,we present a supramolecular templating approach for constructing polyimidazolium salt containing crown ether and cyclobutane *** strategy involves the formation of metal-carbene templates,photochemical cycloaddition,and subsequent demetallation of metal *** by the host-guest chemistry between crown ether units and ammonium salts,we successfully fabricated a supramolecular polymer SPN1,which features imidazolium receptors and cyclobutane *** obtained SPN1 demonstrates outstanding reversible stimulus-response,antibacterial behavior and conductivity.

关键词： metal-carbene template crown ether polyimidazolium salt host-guest chemistry

Integrating machine learning and CALPHAD method for exploring low-modulus near-β-Ti alloys

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Rare Metals 2024年第1期43卷 309-323页

作者： Hao Zou Yue-Yan Tian li-Gang Zhang Ren-Hao Xue zi-Xuan Deng ming-ming Lu Jian-Xin Wang li-Bin liu School of Computer Science and Engineering Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Traditional theoretical and empirical calculation methods can guide the design of β-and metastable β-alloys for bio-titanium. However, it is still difficult to obtain novel near-β-Ti alloys with low modulus. This study developed a method that combines machine learning with calculation of phase diagrams(CALPHAD) to facilitate the design of near-β-Ti alloys. An elastic modulus database of Ti–Nb–Zr–Mo–Ta–Sn system was constructed first, and then three features(the electron to atom ratio, mean absolute deviation of atom mass, and mean electronegativity) were selected as the key factors of modulus by performing a three-step feature selection. With these features, a highly accurate model was built for predicting the modulus of near-β-Ti alloys. To further ensure the accuracy of modulus prediction, machine learning with the elastic constants calculated was leveraged by CALPHAD database. The root mean square error of the well-trained model can be as low as 6.75 GPa. Guided by the prediction of machine learning and CALPHAD, three novel near-β-Ti alloys with elastic modulus below 50 GPa were successfully designed in this study. The best candidate alloy(Ti–26Nb–4Zr–4Sn–1Mo–Ta) exhibits an ultra-low modulus(36.6 GPa) after cold rolling with a thickness reduction of 20%. Our method can greatly save time and resources in the development of novel Ti alloys, and experimental verifications have demonstrated the reliability of this method.

关键词： Near-β-Ti alloy Machine learning Calculation of phase diagram Low-modulus alloy Feature selection

NUDT5 promotes the growth,metastasis,and Warburg effect of IDH wild-type glioblastoma multiforme cells by upregulating TRIM47

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Asian Pacific Journal of Tropical Biomedicine 2024年第2期14卷 82-92页

作者： zi-Fa Zhang Shu-ming liu Neurosurgery Department Shanxi Bethune HospitalTaiyuanShanxi Province030022China Shanxi Academy of Medical Sciences TaiyuanShanxi province030022China Emergency Department Taiyuan People’s HospitalTaiyuanShanxi Province030021China

Objective:To explore the regulatory mechanism of NUDT5 in glioblastoma multiforme(GBM).Methods:GEPIA database was used to predict the expressions of NUDT5 and tripartite motif family proteins 47(TRIM47)in GBM ***-qPCR and Western blot analyses were performed to examine NUDT5 expression in GBM ***-229 cell proliferation,migration as well as invasion were estimated by CCK-8,colony formation,wound healing,and Transwell assays following interference with *** assay,L-lactic acid kit,glucose detection kit,and ATP detection kit were applied for the detection of glycolysis-related ***-immunoprecipitation experiment was carried out to verify the relationship between NUDT5 and ***:GEPIA database showed that NUDT5 expression was significantly increased in GBM *** the expression of NUDT5 in GBM cells significantly suppressed the viability,proliferation,invasion,migration,and glycolysis of GBM ***,TRIM47 was highly expressed in GBM cells and interacted with *** of TRIM47 partially reversed the inhibitory effect of NUDT5 downregulation on the proliferation,metastasis,and glycolysis of GBM ***:NUDT5 promotes the growth,metastasis,and Warburg effect of GBM cells by upregulating *** NUDT5 and TRIM47 can be used as targets for GMB treatment.

关键词： Glioblastoma multiforme NUDT5 TRIM47 Growth Metastasis Warburg effect

Implications for fault reactivation and seismicity induced by hydraulic fracturing

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Petroleum Science 2024年第2期21卷 1081-1098页

作者： zi-Han Sun ming-Guang Che li-Hong Zhu Shu-Juan Zhang Ji-Yuan Lu Chang-Yu Jin Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina Research Institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China The Exploration and Development Research Institute of Daqing Oilfield limited Company Daqing163458HeilongjiangChina

Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as

关键词： Hydraulic fracturing Coulomb failure stress Rate-and-state fraction model linear stability analysis Critical stiffness Seismically induced fault

Semi-supervised remote sensing image scene classification with prototype-based consistency

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Chinese Journal of Aeronautics 2024年第2期37卷 459-470页

作者： Yang li Zhang li zi WANG Kun WANG Qifeng YU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Deep learning significantly improves the accuracy of remote sensing image scene classification,benefiting from the large-scale ***,annotating the remote sensing images is time-consuming and even tough for *** neural networks trained using a few labeled samples usually generalize less to new unseen *** this paper,we propose a semi-supervised approach for remote sensing image scene classification based on the prototype-based consistency,by exploring massive unlabeled *** this end,we,first,propose a feature enhancement module to extract discriminative *** is achieved by focusing the model on the foreground ***,the prototype-based classifier is introduced to the framework,which is used to acquire consistent feature *** conduct a series of experiments on NWPU-RESISC45 and Aerial Image Dataset(AID).Our method improves the State-Of-The-Art(SOTA)method on NWPU-RESISC45 from 92.03%to 93.08%and on AID from 94.25%to 95.24%in terms of accuracy.

关键词： Semi-supervised learning Remote sensing Scene classification Prototype network Deep learning