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HYDRODYNAMIC ANALYSIS OF SUCK-IN PULSED JET IN WELL DRILLING

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Journal of Hydrodynamics 2011年第1期23卷 34-41页

作者： WANG Rui-he du yu-kun NI Hong-jian MA Lin College of Petroleum Engineering China University of Petroleum Dongying 257061 China

The development of new drilling methods is important for the exploration and production of oil *** pulsed jet is a drilling technology of high *** article proposes a new concept of suck-in pulsed jet with self-excited oscillation,by which a full use of the hydraulic power can be made in the annular space.A hydrodynamic analysis of suck-in pulsed jet with self-excited oscillation is carried out by numerical simulations and rock-breaking *** is shown that with the jet,a negative pressure zone will be formed in the oscillation cavity to ensure automatic sucking of enough annular fluids and the formation of an efficient pulsed *** rock-breaking and pressure testing results have verified the reliability of the numerical *** research provides a basis for the development of the pulsed jet drilling technology.

关键词： drilling methods numerical simulation pulsed jet rock-breaking suck-in

Validation of the Simplified Chinese-character Version of the International Physical Activity Questionnaire-Long Form in Urban Community-dwelling Adults:a Cross-sectional Study in Hangzhou,China

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Biomedical and Environmental Sciences 2017年第4期30卷 255-263页

作者： REN Yan Jun SU Meng LIU Qing Min TAN Ya yun du yu kun LI Li Ming Lyu Jun Department of Chronic Non-communicable Disease Control and Prevention Hangzhou Center for Disease Control and Prevention National Clinical Research Center of Cardiovascular Diseases State Key Laboratory of Cardiovascular DiseaseFuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical College Department of Epidemiology and Biostatistics School of Public HealthPeking University

Objective To assess the test-retest reliability and criterion validity of the Simplified Chinese-character version of the International Physical Activity Questionnaire Long form （IPAC）.-L） in urban community-dwelling adults in Hanghzou, China. Methods A total of 158 eligible participants aged 25-59 years from 6 neighbourhoods in two central districts of Hangzhou completed the IPAQ-L questionnaire twice within a 7-day interval. Half of the subjects wore pedometers during the first 7 days. Test-retest reliability was examined by comparing the first （Day 1） and the second （Day 9） survey of IPAQ-L Criterion validity was assessed by comparing IPAO,-L with pedometer data. Results Modest to good test-retest reliability was found with intraclass correlation coefficients of 0.67 for total PA, 0.37 to 0.73 for specific dimensions, and 0.56 to 0.71 for different intensities of PA. Total PA measured by IPAO.-L was moderately correlated with exercise levels （partial r = 0.27, P = 0.020） and walking distance （partial r = 0.31, P = 0.007）, which were measured by a pedometer, after adjusting for gender, age, educational attainment and employment status. Conclusion Our results indicate that the IPAO.-L is a reliable and validated measure for assessing physica activity levels in this population and possibly the adult population in other mainland Chinese cities.

关键词： PAO. Long form China Physical activity Reliability Validity Pedometer

Laparoscopic liver resection utilizing the ventral avascular area of the inferior vena cava:A retrospective cohort study

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World Journal of Gastroenterology 2025年第1期31卷 42-57页

作者： kun Huang Zhu Chen Heng Xiao Hai-Yang Hu Xing-yu Chen Cheng-You du Xiang Lan Department of Hepatobiliary Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400000China Department of General Surgery Mianyang Hospital of Traditional Chinese MedicineMianyang 621000Sichuan ProvinceChina

BACKGROUND Laparoscopic liver resection(LLR)can be challenging due to the difficulty of establishing a retrohepatic tunnel under *** the third hepatic hilum before parenchymal transection often leads to significant liver mobilization,tumor compression,and bleeding from the short hepatic veins(SHVs).This study introduces a novel technique utilizing the ventral avascular area of the inferior vena cava(IVC),allowing SHVs to be addressed after parenchymal transection,thereby reducing surgical complexity and improving outcomes in in situ *** To introduce and evaluate a novel LLR technique using the ventral avascular area of the IVC and compare its short-term outcomes with conventional *** The clinical cohort data of patients with pathologically confirmed hepatocellular carcinoma or intrahepatic cholangiocarcinoma who underwent conventional LLR and novel LLR between July 2021 and July 2023 at the First Affiliated Hospital of Chongqing Medical University were retrospectively *** novel LLR,we initially separated the caudate lobe from the IVC using dissecting forceps along the ventral avascular area of the ***,we transected the parenchyma of the left and right caudate lobes from the caudal side to the cephalic side using the avascular area as a ***,we addressed the SHVs and finally dissected the root of the right hepatic vein or left hepatic *** short-term postoperative outcomes and oncological results of the two approaches were evaluated and *** A total of 256 patients were included,with 150(58.59%)undergoing conventional LLR and 106(41.41%)undergoing novel *** novel technique resulted in significantly larger tumor resections(6.47±2.96 cm vs 4.01±2.33 cm,P<0.001),shorter operative times(199.57±60.37 minutes vs 262.33±83.90 minutes,P<0.001),less intraoperative blood loss(206.92±37.09 mL vs 363.34±131.27 mL,P<0.001),and greater resection volume(345.11±31.40 mL vs 264.38±31.98 mL,P<0.001)comp

关键词： Laparoscopic liver resection Inferior vena cava Retrohepatic tunnel Short hepatic veins Complex liver tumors Intraoperative bleeding control

兰索拉唑微丸口崩片的制备及崩解时间测定方法考察

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中国医院药学杂志 2018年第20期38卷 2115-2118,2127页

作者：缪宇梅杨鑫杜宇坤杜青河北医科大学河北石家庄050017

目的:制备兰索拉唑微丸口崩片,考察崩解时间的测定方法。方法:采用粉末直接压片法制备口崩片,并以填充剂、崩解剂及润滑剂的种类和用量作为考察因素,通过单因素试验和正交试验结果确定最优处方。崩解时间的测定方法分别为药典法Ⅰ、药... 详细信息

目的:制备兰索拉唑微丸口崩片,考察崩解时间的测定方法。方法:采用粉末直接压片法制备口崩片,并以填充剂、崩解剂及润滑剂的种类和用量作为考察因素,通过单因素试验和正交试验结果确定最优处方。崩解时间的测定方法分别为药典法Ⅰ、药典法Ⅱ和改良法,将3种方法的结果进行比较,选择合适的测定方法用于处方筛选。结果:用改良法测定崩解时间可以较好区分不同处方间的差别。口崩片的优化处方为30%兰索拉唑微丸,59%微晶纤维素102,5%交联羧甲基纤维素钠,5.5%甘露醇,0.5%硬脂富马酸钠。结论:改良法适用于处方筛选时对崩解时间的测定,优化处方制备的口崩片崩解迅速。

关键词：兰索拉唑口崩片崩解时间崩解剂

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活体肺癌组织玻璃化保存的研究

生物化学与生物物理进展 2021年第9期48卷 1096-1103页

作者：李嘉慧杜羽琨余科科邢杰周新丽上海理工大学生物系统热科学研究所上海200093 上海交通大学附属胸科医院上海200030

保存活体的肺癌组织将为肺癌发病基因筛查和靶向药物筛选等体外实验研究提供更完整的样本信息.本文对活体肺癌组织的玻璃化保存方法进行研究,首先采用针浸法玻璃化保存单块肺癌组织,对所需低温保护剂的浓度和平衡时间进行了优化;其次采... 详细信息

保存活体的肺癌组织将为肺癌发病基因筛查和靶向药物筛选等体外实验研究提供更完整的样本信息.本文对活体肺癌组织的玻璃化保存方法进行研究,首先采用针浸法玻璃化保存单块肺癌组织,对所需低温保护剂的浓度和平衡时间进行了优化;其次采用冻存管对多块肺癌组织样本进行玻璃化保存,对低温保护剂溶液体积以及平衡时间进行了优化;最后对慢速冷冻、不加低温保护剂快速冷冻、玻璃化冷冻3种冷冻方法的冻存效果进行比较并通过低温显微分析其冰晶损伤机理.结果表明,20%EG+20%DMSO+0.5 mol/L海藻糖作为低温保护剂,在平衡溶液和玻璃化溶液分别加载3 min和1 min时,针浸法和0.25 ml冻存管内玻璃化冻存,复苏后组织活力最高,分别约为79.96%与80.44%.免疫组化显示玻璃化保存肺癌组织经过复苏后,相比慢速冷冻和无保护剂快速冷冻,组织结构损伤较小,组织内细胞TUNEL阳性表达较少.低温显微结果表明,玻璃化保存组织内部及周围只出现少量细小冰晶,而慢速冷冻、快速冷冻组织皆出现明显冰晶.

关键词：肺癌组织玻璃化保护剂加载冷冻载体

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和函数图像的盒维数的一个注记

韶关学院学报 2020年第12期41卷 14-17页

作者：杜玉坤广东茂名幼儿师范专科学校理学院广东茂名525200

主要研究两个函数和的图像的盒维数.定义连续函数图像,并给出连续函数图像的盒维数,利用连续函数图像的初等性质,对闭区间I上的两个连续函数,当这两个函数在该闭区间上图像的盒维数都存在且不相等时,那么这两个函数的和在该闭区间上图... 详细信息

主要研究两个函数和的图像的盒维数.定义连续函数图像,并给出连续函数图像的盒维数,利用连续函数图像的初等性质,对闭区间I上的两个连续函数,当这两个函数在该闭区间上图像的盒维数都存在且不相等时,那么这两个函数的和在该闭区间上图像的盒维数是存在的,且等于这两个函数图像盒维数的最大值.证明两个连续函数满足一致与反一致s阶赫尔德条件时,两个连续函数和图像的盒维数等于其中任何一个连续函数图像的盒维数.

关键词：盒维数函数图像连续函数

Targets capture by distributed active swarms via bio-inspired reinforcement learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 210-221页

作者： kun Xu yue Li Jun Sun Shuyuan du Xinpeng Di yuguang Yang Bo Li Institute of Biomechanics and Medical Engineering Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua University Institute of Nuclear and New Energy Technology Tsinghua University Shanghai Aerospace Control Technology Institute Shanghai Key Laboratory of Aerospace Intelligent Control Technology College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Natural swarms arranged from cells to herds are usually decentralized but display intriguing collective intelligence in coordinating individuals across large scales to efficiently achieve their common goals. Learning from nature may provide new strategies for controlling collective dynamics of synthetic swarms to accomplish specific functions. Here, we present a bioinspired computational framework that steers distributed active swarms to collectively capture and merge targets via reinforcement learning. We exploit collective milling structures of natural herds to cage the targets, and adopt a switching control policy inspired by sperms' chiral dynamics to optimize the trajectories of individuals, through which the active swarms can selforganize to enclose single or multiple distant targets in a dynamical, adaptive and scalable manner. There exists a critical swarm size, beyond which the excessive competition between agents would generate large mechanical forces, leading to capture instability but enabling the transition from short-distance to long-distance merging capture of multiple targets. This work provides physical insights into distributed active swarms and could offer a multilevel, decentralized strategy toward controlling swarm robotics in wide applications such as bio-medical devices, machine immunity, and target clearance.

关键词： swarm intelligence robotics multi-tasks artificial intelligence bionics

环空流体吸入式自激振荡脉冲射流大涡模拟研究

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水动力学研究与进展（A辑） 2009年第4期24卷 455-462页

作者：杜玉昆王瑞和倪红坚中国石油大学石油工程学院山东东营257061

发展新型破岩钻井技术对于促进油气田高效开发具有重要意义,高压水射流是提高破岩钻井效率的一个重要手段,脉冲射流是一种高效射流形式。为了充分利用井底水力能量,提出了一种环空流体吸入式脉冲射流的技术构想。基于自激振荡原理设计... 详细信息

发展新型破岩钻井技术对于促进油气田高效开发具有重要意义,高压水射流是提高破岩钻井效率的一个重要手段,脉冲射流是一种高效射流形式。为了充分利用井底水力能量,提出了一种环空流体吸入式脉冲射流的技术构想。基于自激振荡原理设计了相应射流调制工具,并对工具的流场和动力学特性进行了大涡模拟研究。研究结果分析揭示了环空流体吸入式自激振荡脉冲射流调制的机理,并发现合理的水力结构可以在振荡腔内实现局部负压,使得环空流体被吸入,参与调制生成高效脉冲射流。与非吸入式脉冲射流相比,吸入式脉冲射流振荡更加剧烈,破岩能力更强。研究结果得到了实验验证,为实际钻井工具的研制和相关工艺技术的开发提供了依据。

关键词：破岩钻井水力能量吸入式脉冲射流大涡模拟

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城市体力活动相关建成环境的评价工具进展

中华流行病学杂志 2011年第6期32卷 632-635页

作者：苏萌杜宇坤吕筠李立明北京大学医学部公共卫生学院流行病与卫生统计学系 100191

体力活动水平是影响个体健康重要的、可干预的因素之一。经常进行体力活动能够有效减少诸多慢性病，如心血管疾病等发病风险。建成环境（built environment）指人为建设改造的各种建筑物、场所，尤其指那些可以通过政策、人为行为改变... 详细信息

体力活动水平是影响个体健康重要的、可干预的因素之一。经常进行体力活动能够有效减少诸多慢性病，如心血管疾病等发病风险。建成环境（built environment）指人为建设改造的各种建筑物、场所，尤其指那些可以通过政策、人为行为改变的环境。近年来，国外研究者越来越多关注建成（物理）环境对个体体力活动水平的影响。

关键词：建成环境评价体力活动