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Effects of Chromium,Vanadium and Austenite Deformation on Transformation Behaviors of High-strength Spring Steels

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Journal of Iron and Steel Research International 2016年第12期23卷 1323-1332页

作者： Gang NIU Yin-li CHEN hui bin WU Xuan WANG Mao-fang ZUO zhi-jun XU Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Engineering Research Institute University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation Beijing 100083China

The phase transformation behavior during continuous cooling of high-strength spring steels containing different amounts of Cr was studied. Furthermore, the effects of combining Cr with V as well as austenite deformation on the transformation kinetics were investigated in the method of dilatometry and metallography hardness. The re suits showed that, with the increase of Cr, the pearlite transformation field was enlarged, the ferrite transformation field was narrowed, and the entire phase field shifted to the right. With the addition of V, the start transformation temperature of undercooling austenite （Ar3） was gradually increased, but the ferrite and pearlite transformation fields were not affected. Besides, the minimum critical cooling rate of martensilic transformation was also reduced. In addition, the dynamic continuous cooling transformation （CCT） curve moves to the top left compared with the static CCT curve. The transformed microstructures showed that the addition of V and the deformation not only refined the overall transformed microstructures but also reduced the lamellar spacing of pearlite. The alloying elements Cr and V promoted the Vickers hardness. However, the effect of Cr on the Vickers hardness of martensite was stronger and the influence of V on that of pearlite was stronger. Moreover, the Vickers hardness affected by the austenite deformation was more complex and strongly depended on the transformed microstructures.

关键词： spring steel phase transformation Chromium deformation microstructure

特殊拉格朗日型方程在超临界相位下的内部梯度估计

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数学杂志 2024年第2期44卷 107-112页

作者：李佳慧宁波大学数学与统计学院浙江宁波315211

本文研究了在超临界相位下的特殊拉格朗日型方程arctan{∆uIn−D^(2)u}=Θ(x),并建立了与特殊拉格朗日型方程相关的解的内部梯度估计.

关键词：内部梯度估计特殊拉格朗日型方程超临界相位

The Weighted Transience and Recurrence of Markov Processes

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Acta Mathematica Sinica,English Series 2007年第1期23卷 111-126页

作者： Min zhi ZHAO hui Zeng ZHANG Department of Mathematics Zhejing University Hangzhou 310027 P. R. China School of Computer and Computing Science Zhejiang University City College. Hangzhou 310015 P. R. China

Transience and recurrence are among the most important concepts in Markov processes. In this paper, we study the transience and recurrence for right processes with a given weight function, and characterize them by potentials, excessive functions, first hitting times and last exit times of the process. We also study the properties of recurrent states.

关键词： ω-recurrence ω-transience last exit time right process

基于随机森林模型的藏东南地区滑坡易发性评价及主控因素分析

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成都理工大学学报（自然科学版） 2024年第2期51卷 328-344页

作者：杜鹏陈宁生伍康林李志张瀛玉龙中国科学院、水利部成都山地灾害与环境研究所成都610041 西藏大学工学院拉萨850000 高原科学与可持续发展研究院西宁810016 中国科学院大学工程科学学院北京100049

为了获取藏东南地区的滑坡易发性分区、深入探究研究区滑坡发育的主控因素。本文采用随机森林模型对藏东南地区的滑坡易发性进行研究。首先通过现场调查、遥感解译和文献查询等手段,共发现研究区滑坡306处,其次使用频率比模型(FR)对研... 详细信息

为了获取藏东南地区的滑坡易发性分区、深入探究研究区滑坡发育的主控因素。本文采用随机森林模型对藏东南地区的滑坡易发性进行研究。首先通过现场调查、遥感解译和文献查询等手段,共发现研究区滑坡306处,其次使用频率比模型(FR)对研究区易发性做快速评判,在其低易发区进行非滑坡样本的选取,使得随机森林模型得到较好的原始数据集,并通过计算权重来制作研究区易发性图,分析滑坡发生的主控因素,最后绘制ROC曲线和计算线下曲线的面积(AUC)对模型的准确性进行验证。模型预测结果显示,研究区高易发区主要集中在易贡藏布、帕隆藏布交汇处和雅鲁藏布江大拐弯的地方。在对特征重要性因素排序中,前三分别是断层密度、高程和坡度,模型的AUC=0.940,因此有较好的准确性。根据结果分析,研究区因长期受到构造作用影响,地质构造复杂,东西两侧均是巨型断层,南侧为喜马拉雅前缘断裂带,断裂带发育,尤其在高易发区断层纵横交错,多重挤压造成岩石破碎,节理发育。因此,易贡藏布、帕隆藏布交汇处和雅鲁藏布江大拐弯区域为滑坡灾害高易发区具有合理性。该模型对藏东南地区滑坡的发生和灾害的治理提供了理论依据,对该地区防灾减灾提供了理论支撑。

关键词：藏东南地区随机森林模型滑坡易发性断层密度

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Clostridium difficile infection following colon subtotal resection in a patient with gallstones: A case report and review of literature

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World Journal of Gastrointestinal Surgery 2024年第9期16卷 3048-3056页

作者： Feng Ke Zhen-Hua Dong Fan Bu Cheng-Nan li Qi-Tong He zhi-Cheng liu Ji Lu Kai Yu Da-Guang Wang He-Nan Xu Chang-Tao Ye Department of General Surgery Affiliated Hospital of Changchun University of Chinese MedicineChangchun 130000Jilin ProvinceChina Department of Gastrointestinal Surgery The First Hospital of Jilin UniversityChangchun 130061Jilin ProvinceChina Department of Plastic and Aesthetic Surgery The First Hospital of Jilin UniversityChangchun 130061Jilin ProvinceChina Department of Encephalopathy Rehabilitation Chaoyi HospitalYanbian Korean Autonomous PrefectureYanji 133000Jilin ProvinceChina Department of Urology The First Hospital of Jilin UniversityChangchun 130061Jilin ProvinceChina

BACKGROUND Clostridium difficile(***)infection(CDI)is a rare clinical disease caused by changes in the intestinal microenvironment,which has a variety of causes and a poor prognosis,and for which there is no standardized clinical *** SUMMARY A patient experienced recurrent difficulty in bowel movements over the past ***,symptoms worsened within the last ten days,leading to a clinic visit due to *** patient was subsequently referred to our ***,the patient was diagnosed with obstructed colon accom-panied by *** antibiotics were administered both before and after surgery to prevent *** the fourth day post-surgery,symptoms of CDI *** cultures confirmed the presence of *** *** involved a combination of vancomycin and linezolid,resulting in the patient's successful recovery upon ***,the patient failed to adhere to the prescribed medication after discharge and was discovered deceased during a follow-up two months *** CDI is the leading cause of nosocomial post-operative care,with limited clinical cases and poor patient prognosis,and comprehensive clinical treatment guidelines are still *** infection can be triggered by a variety of factors,including intestinal hypoxia,inappropriate antibiotic use,and bile acid circulation *** patients with chronic bowel disease and related etiologies,prompt preoperative attention to possible CDI and preoperative bowel preparation is *** and prolonged medication should be maintained in the treatment of CDI to prevent recurrence of the disease.

关键词： Cholecystolithiasis Clostridium difficile Bile acid circulation Intestinal microenvironment Case report

Zr基非晶破片对碳纤维复合靶及后效铝靶的侵彻试验研究

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高压物理学报 2024年第2期38卷 128-137页

作者：贾杰智小琦郝春杰李劲郭璐柳星河中北大学机电工程学院山西太原030051 晋西工业集团山西太原030027

Zr基非晶破片是一种新兴的活性高效毁伤元,其着靶速度达到一定阈值时会发生燃烧反应并破碎,从而大幅提高其后效毁伤能力。为研究Zr基非晶破片对碳纤维增强复合材料的侵彻破坏机理及后效毁伤能力,利用弹道枪加载球形破片,分别以496.4~1 0... 详细信息

Zr基非晶破片是一种新兴的活性高效毁伤元,其着靶速度达到一定阈值时会发生燃烧反应并破碎,从而大幅提高其后效毁伤能力。为研究Zr基非晶破片对碳纤维增强复合材料的侵彻破坏机理及后效毁伤能力,利用弹道枪加载球形破片,分别以496.4~1 085.8 m/s、571.4~1 103.9 m/s的速度范围撞击8和6 mm厚的碳纤维复合靶,并布置2 mm厚LY12铝靶板作为后效靶,以比较破片在不同工况下的后效毁伤能力。实验结果表明:碳纤维靶受活性破片冲击时,其迎弹面的破坏形式主要是压缩失效与剪切失效的耦合破坏,其背弹面的破坏形式主要是拉伸失效破坏与层间的脱粘分裂;随着破片着靶速度的提高,碳纤维靶板的压剪耦合破坏比例逐渐增加,拉伸断裂与分层现象逐渐减弱;破片对于8和6 mm厚碳纤维靶的弹道极限速度分别为351.9、264.6 m/s;相同着靶速度下,8 mm厚碳纤维靶的后效毁伤面积大于6 mm厚碳纤维靶的后效毁伤面积,两者之间的差异随着着靶速度的提高而逐渐减小;破片冲击等厚度碳纤维靶时,破片的后效毁伤能力随着靶速度的提高而增强。

关键词： Zr基非晶合金碳纤维增强复合材料后效毁伤能力活性破片

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高工作温度碲镉汞红外探测器杜瓦结构研究

激光与红外 2024年第7期54卷 1081-1085页

作者：张利明李艳红冯志攀宋淑芳付志凯王冠张磊中国电子科技集团公司第十一研究所北京100015

随着第三代红外探测器技术的快速发展,高工作温度红外探测器成为重要的发展方向。本文报道了在高工作温度碲镉汞红外探测器杜瓦结构小型化、低功耗、高可靠性方面的研究进展。通过杜瓦结构的优化设计,搭配旋转整体式低温制冷机K562S sho... 详细信息

随着第三代红外探测器技术的快速发展,高工作温度红外探测器成为重要的发展方向。本文报道了在高工作温度碲镉汞红外探测器杜瓦结构小型化、低功耗、高可靠性方面的研究进展。通过杜瓦结构的优化设计,搭配旋转整体式低温制冷机K562S short,制备出组件体积为80 mm×61 mm×39 mm,重量为212 g,启动时间为2.5 min,工作温度达到150 K的高工作温度中波碲镉汞红外探测器,并初步完成了组件可靠性试验验证,为高工作温度碲镉汞红外探测器的工程化应用奠定了一定的基础,对高工作温度碲镉汞红外探测器的小型化、低功耗、高可靠性研究具有一定的指导意义。

关键词：高工作温度碲镉汞红外探测器小型化低功耗可靠性

渤海曹妃甸低幅底水稠油油田特高含水期开发模式研究与实践

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中国海上油气 2024年第4期36卷 131-142页

作者：蔡晖李廷礼刘春艳袁志乾李子靳中海石油(中国)有限公司天津分公司天津300459

曹妃甸油田群为渤海规模最大的底水稠油油田,构造幅度低、油柱高度低、地层原油黏度大,经过十多年开发进入了特高含水期,目前采油速度低、水驱采收率低,亟需综合调整。通过室内实验与水驱模型推导,研究了底水稠油油藏水平井水脊特征与... 详细信息

曹妃甸油田群为渤海规模最大的底水稠油油田,构造幅度低、油柱高度低、地层原油黏度大,经过十多年开发进入了特高含水期,目前采油速度低、水驱采收率低,亟需综合调整。通过室内实验与水驱模型推导,研究了底水稠油油藏水平井水脊特征与水驱波及系数变化规律。结果表明,水平井开采过程中单区脊进严重、沿程驱替不均衡;水平井水驱波及系数“早期缓慢上升、后期持续增大”,这说明提高产液量可以提高水驱波及系数。在此基础上,提出了基于水脊演化规律的水平井网加密调整技术、融合构造与储层描述的水平井精准布井技术、基于孔隙有效动用的水平井大排量提液技术等关键技术,进而建立了特高含水期老区与新区并举、老井与新井交错、纵向分带、平面分区的水平井整体加密调整模式。按照本文模式调整后,油田储量动用程度提高了21.3个百分点,采油速度提高了1.3倍,水驱采收率提高了10.9个百分点,实现了特高含水期快速上产并持续稳产,为海上油田中长期持续稳产和高效开发提供借鉴。

关键词：底水油藏稠油水平井水脊开发模式采收率

Phosphoinositide-3-kinase regulatory subunit 4 participates in the occurrence and development of amyotrophic lateral sclerosis by regulating autophagy

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Neural Regeneration Research 2022年第7期17卷 1609-1616页

作者： Yue liu Cai-hui Wei Cheng li Wen-zhi Chen Yu Zhu Ren-Shi Xu Department of Neurology First Affiliated Hospital of Nanchang Medical CollegeJiangxi Provincial People’s HospitalAffiliated People’s Hospital of Nanchang UniversityNanchangJiangxi ProvinceChina

The development of amyotrophic lateral sclerosis(ALS)may be related to the abnormal alterations of multiple *** previous study revealed that the expression of phosphoinositide-3-kinase regulatory subunit 4(PIK3R4)was decreased in ***,the role of PIK3R4 in ALS pathogenesis remains *** study was the first to find that transfection of PC12 cells with small interfering RNA against the PIK3R4 gene significantly decreased the expression levels of PIK3R4 and the autophagy-related proteins p62 and ***,in vivo experiments revealed that the PIK3R4 protein was extensively expressed in the anterior horn,posterior horn,central canal,and areas surrounding the central canal in cervical,thoracic,and lumbar segments of the spinal cord in adult ***3R4 protein was mainly expressed in the neurons within the spinal lumbar ***3R4 and p62 expression levels were significantly decreased at both the pre-onset and onset stages of ALS disease in Tg(SOD1*G93A)1 Gur mice compared with control mice,but these proteins were markedly increased at the progression ***3 protein expression did not change during progression of *** findings suggest that PIK3R4 likely participates in the prevention of ALS *** study was approved by the Ethics Committee for Animal Care and Use of Jiangxi Provincial People’s Hospital,Affiliated People’s Hospital of Nanchang University(approval No.2020025)on March 26,2020.

关键词： amyotrophic lateral sclerosis autophagy LC3 p62 PC12 cell phosphoinositide-3-kinase regulatory subunit 4 spinal cord Tg(SOD1*G93A)1Gur mice