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Experimental and Numerical Evaluation of the Cavitation Performances of Self-Excited Oscillating Jets

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1883-1901页

作者： Yuanyuan zhao Fujian zhao Guohui li Wei Xu Xiuli Wang School of the Environment and Safety Engineering Jiangsu UniversityZhenjiang212013China Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang212013China GongQing institute of Science and Technology Jiujiang332020China School of Energy and Power Engineering Jiangsu UniversityZhenjiang212013China

Self-excited oscillating jets(SOJ)are used in several practical *** performances are significantly affected by structural parameters and the target *** this study,a geometric model of the SOJ nozzle accounting for multiple structural parameters is introduced,then the related cavitation performances and the optimal target distance are investigated using a Large-Eddy Simulation(LES)*** are also provided about an experiment,which was conducted to validate the simulation *** analyzing the evolution of the vapor volume fraction at the nozzle outlet,a discussion is presented about the effect of the aforementioned structural parameters on the cavitation performances and the target *** is shown that the distribution of cavitation clouds at the outlet of the SOJ nozzle displays a non-monotonic trend(first increasing,then decreasing).Under working conditions with an inlet pressure of 4 MPa,a SOJ nozzle outlet/inlet diameter ratio(D_(1./D_(2))of {1.,and a chamber diameter ratio(D/L)close to 1.8,the nozzle outlet cavitation performance attains a *** optimal structural parameters correspond to the optimal target distance,which is near 50 *** experiments have revealed that the SOJ nozzle with the above parameters displays a good cavitation erosion effect at the target distance of 50 mm,in satisfactory agreement with the numerical simulation results.

关键词： Self-excited oscillating nozzle cavitating jet target distant LES cavitation

Validation and performance of three scoring systems for predicting primary non-function and early allograft failure after liver transplantation

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Hepatobiliary & Pancreatic Diseases International 2024年第5期23卷 463-471页

作者： Yu Nie Jin-Bo Huang Shu-Jiao He Hua-Di Chen Jun-Jun Jia Jing-Jing li Xiao-Shun He Qiang {1. General Surgery Center Department of Hepatobiliary Surgery IIResearch Center for Artificial Organ and Tissue EngineeringGuangzhou Clinical Research and Transformation Center for Artificial LiverInstitute of Regenerative MedicineZhujiang HospitalSouthern Medical UniversityGuangzhou 510515China Organ Transplant Center the First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology Guangzhou 510080China Guangdong Provincial International Cooperation Base of Science and Technology Guangzhou 510080China Division of Hepatobiliary Pancreatic Surgery the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Background: Primary non-function(PNF) and early allograft failure(EAF) after liver transplantation(LT) seriously affect patient outcomes. In clinical practice, effective prognostic tools for early identifying recipients at high risk of PNF and EAF were urgently needed. Recently, the Model for Early Allograft Function(MEAF), PNF score by King's College(King-PNF) and Balance-and-Risk-Lactate(BAR-Lac) score were developed to assess the risks of PNF and EAF. This study aimed to externally validate and compare the prognostic performance of these three scores for predicting PNF and EAF. Methods: A retrospective study included 720 patients with primary LT between January 201. and December 2020. MEAF, King-PNF and BAR-Lac scores were compared using receiver operating characteristic(ROC) and the net reclassification improvement(NRI) and integrated discrimination improvement(IDI) analyses. Results: Of all 720 patients, 28(3.9%) developed PNF and 67(9.3%) developed EAF in 3 months. The overall early allograft dysfunction(EAD) rate was 39.0%. The 3-month patient mortality was 8.6% while 1.year graft-failure-free survival was 89.2%. The median MEAF, King-PNF and BAR-Lac scores were 5.0(3.5–6.3),-2.1.-2.6 to-1.2), and 5.0(2.0–1..0), respectively. For predicting PNF, MEAF and King-PNF scores had excellent area under curves(AUCs) of 0.872 and 0.891. superior to BAR-Lac(AUC = 0.830). The NRI and IDI analyses confirmed that King-PNF score had the best performance in predicting PNF while MEAF served as a better predictor of EAD. The EAF risk curve and 1.year graft-failure-free survival curve showed that King-PNF was superior to MEAF and BAR-Lac scores for stratifying the risk of EAF. Conclusions: MEAF, King-PNF and BAR-Lac were validated as practical and effective risk assessment tools of PNF. King-PNF score outperformed MEAF and BAR-Lac in predicting PNF and EAF within 6 months. BAR-Lac score had a huge advantage in the prediction for PNF without post-transplant variables. Proper use

关键词： Primary non-function Early allograft failure Risk predicting model liver transplantation

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热处理污泥联合间歇梯度曝气实现短程硝化

中国环境科学 2024年第7期44卷 3719-3728页

作者：李冬张景昭曾凡旭李柱张杰北京工业大学水质科学与水环境恢复工程北京市重点实验室北京100124 哈尔滨工业大学城市水资源与水环境国家重点实验室黑龙江哈尔滨150090

提出了一种结合热处理污泥和间歇梯度曝气的新策略.在为期1.0d的实验中,探索了联合策略对氨氧化细菌(AOB)和亚硝酸盐氧化细菌(NOB)的影响.并在此基础上,以排泥比为主要变量,进一步优化短程硝化运行的长期稳定性.结果显示,在未添加外部... 详细信息

提出了一种结合热处理污泥和间歇梯度曝气的新策略.在为期1.0d的实验中,探索了联合策略对氨氧化细菌(AOB)和亚硝酸盐氧化细菌(NOB)的影响.并在此基础上,以排泥比为主要变量,进一步优化短程硝化运行的长期稳定性.结果显示,在未添加外部碳源的条件下,间歇梯度曝气(DO:2.0mg/L//DO:1.2mg/L//DO:0.5mg/L)可以快速恢复因热处理而活性降低的AOB,并在5d内亚硝酸盐氮积累率(NAR)达到80%以上.在稳定运行阶段,比氨氧化速率(SAOR)和比亚硝酸盐氧化速率(SNPR)分别为30.1.和6.69mg N/(gVSS⋅h),氨氮出水浓度低于0.1.g/L,亚硝酸盐和硝酸盐的出水浓度分别为53.42和8.01.g/L.进一步研究表明,排泥比设置为1.的反应器相较于排泥比分别为0.5%和1.5%的反应器,展现出更高的NAR(88.96%)和稳定性.

关键词：短程硝化间歇梯度曝气热冲击定期排泥

Online Load Operating Mode of Oil Film Bearing in High Speed Wire Rolling Mill

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武汉理工大学学报 2006年第S2期28卷 682-685页

作者： li Yugui~({1.) PANG Siqing~1.HUANG Qingxue~2 WANG Jianmei~2 zhao Chunjiang~2 1.College of Machinery and Vehicle Engineering,Beijing institute of Technology,Beijing 1.0081.china 2.College of Material and Science Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,china College of Machinery and Vehicle Engineering Beijing Institute of TechnologyBeijing 100081China College of Material and Science Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China College of Machinery and Vehicle Engineering Beijing Institute of TechnologyBeijing 100081China College of Material and Science Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China

To study the mechanism of burnt damage of oil film bearing in high-speed wire rolling mill,reasonable tempera- ture sensors are designed and calibrated,pressure block of rolling mill has been transformed into pressure *** tempera- ture and load of oil film bearing in a domestic precision rolling F1. have been ***,a large sum of valuable test data was *** distributions rules of pressure and temperature under continuous online rolling state are recorded in detail. Theoretical and experimental results are beneficial to damage mechanism of oil film bearing,thus its service life could be pro- ***,such results could provide an important reference for online test and control.

关键词： oil film bearing damage mechanism online test

Boosting rate performance of layered lithium-rich cathode materials by oxygen vacancy induced surface multicomponent integration

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Journal of Energy Chemistry 2024年第5期92卷 250-262页

作者： Youyou Fang Yuefeng Su Jinyang Dong Jiayu zhao Haoyu Wang Yun Lu Bin Zhang Hua Yan Feng Wu Lai Chen Beijing Key Laboratory of Environmental Science and Engineering School of Material Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 401120China Yibin libode New Materials Co. Ltd.Yibin 64400SichuanChina School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina Engineering Research Center of the Ministry of Education for Advanced Battery Materials Central South UniversityChangsha 410083HunanChina

The rapid development of electric vehicles and portable energy storage systems demands improvements in the energy density and cost-effectiveness of lithium-ion batteries,a domain in which lithium-rich layered cathode(LLO)materials inherently ***,these materials face practical challenges,such as low initial Coulombic efficiency,inferior cycle/rate performance,and voltage decline during cycling,which limit practical *** study introduces a surface multi-component integration strategy that incorporates oxygen vacancies into the pristine LLO material li1.2Mn_(0.6)Ni_(0.2)O_(2).This process involves a brief citric acid treatment followed by calcination,aiming to explore rate-dependent degradation *** induced surface oxygen vacancies can reduce surface oxygen partial pressure and diminish the generation of O_(2)and other highly reactive oxygen species on the surface,thereby facilitating the activation of li ions trapped in tetrahedral sites while overcoming transport ***,the formation of a spinel-like phase with 3D li+diffusion channels significantly improves li^(+)diffusion kinetics and stabilizes the surface *** optimally modified sample boasts a discharge capacity of 299.5 mA h g^(-1.at a 0.1.C and 251.6 mA h g^(-1.at a 1.C during the initial activation cycle,with an impressive capacity of 222.1.mA h g^(-1.at a 5 *** notably,it retained nearly 70%of its capacity after 300 cycles at this elevated *** straightforward,effective,and highly viable modification strategy provides a crucial resolution for overcoming challenges associated with LLO materials,making them more suitable for practical application.

关键词： lithium-ion battery Layered lithium rich cathode Surface multicomponent integration Rate-dependent degradation and li^(+) diffusion kinetics

藏南冈底斯岩基东段中新世中酸性高Sr/Y比岩浆岩的地球化学特征及成因探讨

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岩石学报 2019年第6期35卷 1627-1646页

作者：徐倩曾令森高家昊高利娥王亚飞胡昭平赵令浩自然资源部深部动力学重点实验室中国地质科学院地质研究所北京100037 中国地质科学院国家地质实验测试中心北京100037

藏南冈底斯带广泛发育中新世中酸性高Sr/Y比岩浆岩,对该类型岩石的成因研究可为藏南后碰撞岩浆活动提供良好的记录和约束。通过对冈底斯带东段中酸性岩浆岩进行锆石U-Pb年代学研究表明,该中酸性岩浆岩形成于1.~1.Ma,为中新世时期;全岩... 详细信息

藏南冈底斯带广泛发育中新世中酸性高Sr/Y比岩浆岩,对该类型岩石的成因研究可为藏南后碰撞岩浆活动提供良好的记录和约束。通过对冈底斯带东段中酸性岩浆岩进行锆石U-Pb年代学研究表明,该中酸性岩浆岩形成于1.~1.Ma,为中新世时期;全岩地球化学数据表明岩浆岩具有高SiO2含量(> 64%),高钾富钠,高Sr、低Y和高Sr/Y比,轻稀土富集、重稀土亏损且较平坦的特征,显示出埃达克质岩的地球化学亲缘性;与冈底斯带中段~1.Ma埃达克质闪长玢岩脉相比,冈底斯带东段的中新世岩浆岩具有更高的K含量;锆石Hf同位素分析结果表明,中新世中酸性岩浆岩具有正的且变化较大的εHf(t)值(+1. 2^+1.. 4);全岩(La/Yb)N值对中新世地壳厚度的估算结果为77~84km,处于壳幔边界处。综合上述数据分析表明,冈底斯带东段中新世中酸性高Sr/Y岩浆岩的成因为拉萨地块加厚下地壳(占主体的新生下地壳+少量古老地壳)的部分熔融,并在源区残留了石榴子石和角闪石,造成熔融的热量来源可能为拉萨地体岩石圈根部拆沉导致的热扰动。

关键词：中新世高Sr/Y比值中酸性岩石新生下地壳冈底斯岩基西藏

Physics package based on intracavity laser cooling ^(87)Rb atoms for space cold atom microwave clock

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chinese Physics B 2024年第7期33卷 22-26页

作者：邓思敏达任伟项静峰赵剑波李琳张迪万金银孟艳玲蒋小军李唐刘亮吕德胜 Aerospace Laser Technology and System Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Mechanics Chinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation,microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2×1.^(-􀀀1.) τ^(-1.2) with a Ramsey linewidth of 1..5 Hz, and a better performance is predicted with a 1.Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.

关键词： atomic clock microgravity microwave cavity space station frequency stability

2000—2020年中国青饲料播种面积及其供需驱动因素的时空格局

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地理学报 2024年第7期79卷 1804-1823页

作者：杨彤赵雯莉董金玮李愈哲李之超王洁齐雯丽毕健张戈丽中国农业大学土地科学与技术学院北京100093 中国农业大学生物学院北京100093 中国科学院地理科学与资源研究所北京100101 中国农业大学草业科学与技术学院北京100093 兰州大学资源环境学院兰州730000

高产、优质的青饲料对于国家畜牧业发展和食物供给至关重要。然而,当前对于青饲料播种面积时空变化格局及其阶段性特征、区域差异以及影响因素等尚未清楚。本文基于省级面板数据分析了2000—2020年青饲料种植的时空格局变化,结合MODIS-... 详细信息

高产、优质的青饲料对于国家畜牧业发展和食物供给至关重要。然而,当前对于青饲料播种面积时空变化格局及其阶段性特征、区域差异以及影响因素等尚未清楚。本文基于省级面板数据分析了2000—2020年青饲料种植的时空格局变化,结合MODIS-NPP产品和统计数据,揭示了饲料供给与需求对青饲料播种面积的影响。结果表明:①2020年中国青饲料播种面积为21.9×1.^(3)hm^(2),仅占农作物播种面积的1.3%,其中牧业地区占全国的59%。②2000年以来青饲料播种面积经历了快速增长(2000—2003年,464.2×1.^(3)hm^(2)/a)、快速下降(2004—2009年,-399×1.^(3)hm^(2)/a)和缓慢增长(201.—2020年,64.3×1.^(3)hm^(2)/a)3个时期。牧业地区主导了全国青饲料播种面积的变化。③饲料供需因素最多可以解释92%的青饲料播种面积变化。其中,饲料需求每增加1.t,青饲料播种面积最高增加900 hm^(2)。秸秆草饲料产量与青饲料互为补充,以负效应为主(偏回归系数介于-1.2~-0.5之间)。天然草饲料产量则对青饲料播种面积变化影响较小。此外,生态工程和农业政策等因素通过调控奶业、草牧业和种植业对青饲料播种面积的变化有重要影响。本文结果可为制定粮食安全、生态环境保护和作物结构调整等相关政策措施提供科学支持。

关键词：青饲料时空格局播种面积饲料供需中国

li_({1.)Mn_(0.54)Ni_(0.1.)Co_(0.1.)O_(2)正极材料的Ga_(2)O_(3)包覆改性及电化学性能

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无机化学学报 2024年第6期40卷 1105-1113页

作者：刘新朋赵刘洋李泓漪陈雅图吴爱民李爱魁黄昊大连理工大学材料科学与工程学院辽宁省能源材料及器件重点实验室大连116024 陕西煤业化工技术研究院有限责任公司西安710065 大连理工大学电气工程学院大连116024

首先采用共沉淀方法制备富锂锰基正极材料li_({1.)Mn_(0.54)Ni_(0.1.)Co_(0.1.)O_(2)原始样品(P-LRMO),然后通过简单的湿化学法以及低温煅烧方法对其进行不同含量Ga_(2)O_(3)原位包覆。透射电子显微镜(TEM)以及X射线光电子能谱(XPS)结... 详细信息

首先采用共沉淀方法制备富锂锰基正极材料li_({1.)Mn_(0.54)Ni_(0.1.)Co_(0.1.)O_(2)原始样品(P-LRMO),然后通过简单的湿化学法以及低温煅烧方法对其进行不同含量Ga_(2)O_(3)原位包覆。透射电子显微镜(TEM)以及X射线光电子能谱(XPS)结果表明在P-LRMO表面成功合成了Ga_(2)O_(3)包覆层。电化学测试结果表明:含有3%Ga_(2)O_(3)的改性材料G3-LRMO具有最优的电化学性能,其在0.1.倍率(电流密度为25 mA·g^(-1.)下首圈充放电比容量可以达到270.1.mAh·g^(-1.,在5C倍率下容量仍能保持1.7.4 mAh·g^(-1.,优于未改性材料的90.7 mAh·g^(-1.,表现出优异的倍率性能。G3-LRMO在1.倍率下循环200圈后仍有1.0.7 mAh·g^(-1.的容量,容量保持率由未改性前的72.9%提升至85.6%,证明Ga_(2)O_(3)包覆改性能有效提升富锂锰基材料的循环稳定性。并且,G3-LRMO在1.倍率下循环1.0圈后,电荷转移阻抗(Rct)为1.7.7Ω,远低于未改性材料的251.5Ω,表明Ga_(2)O_(3)包覆层能提高材料的电子传输速率。

关键词：锂离子电池富锂锰基正极材料 Ga_(2)O_(3)包覆电化学性能