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Investigation of influence factors on CO_(2) flowback characteristics and optimization of flowback parameters during CO_(2) dry fracturing in tight gas reservoirs

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Petroleum Science 2023年第6期20卷 3553-3566页

作者： xiao-mei zhou Lei Li Yong-Quan Sun Ran Liu Ying-Chun Guo Yong-Mao Hao Yu-Liang Su National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shengli Oil Field Dongsheng Jinggong Petroleum Development(GROUP)Stock Co. Ltd.Dongying257000ShandongChina Exploration and Development Research Institute of Shengli Oilfield Company SinopecDongying257000ShandongChina

CO_(2) dry fracturing is a promising alternative method to water fracturing in tight gas reservoirs,especially in water-scarce areas such as the Loess *** CO_(2) flowback efficiency is a critical factor that affects the final gas production ***,there have been few studies focusing on the flowback characteristics after CO_(2) dry *** this study,an extensive core-to-field scale study was conducted to investigate CO_(2) flowback characteristics and CH_(4) production ***,to investigate the impact of core properties and production conditions on CO_(2) flowback,a series of laboratory experiments at the core scale were ***,the key factors affecting the flowback were analyzed using the grey correlation method based on field ***,taking the construction parameters of Well S60 as an example,a dual-permeability model was used to characterize the different seepage fields in the matrix and fracture for tight gas *** production parameters after CO_(2) dry fracturing were then *** results demonstrate that CO_(2) dry fracturing is more effective than slickwater fracturing,with a 9.2%increase in CH_(4) *** increase in core permeability plays a positive role in improving CH_(4) production and CO_(2) *** soaking process is mainly affected by CO_(2) diffusion,and the soaking time should be controlled within 12 *** the flowback pressure gradient results in a significant increase in both CH_(4) recovery and CO_(2) flowback ***,an increase in CO_(2) injection is not conducive to CH_(4) production and CO_(2) *** on the experimental and field data,the important factors affecting flowback and production were comprehensively and effectively *** results show that permeability is the most important factor,followed by porosity and effective *** flowback efficiency and the influence of proppant reflux,the injection volume should

关键词： CO_(2)fracturing Tight gas reservoir Fracturing fluid flowback Parameter optimization

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Automatic removal of false image stars in disk-resolved images of the Cassini Imaging Science Subsystem

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Research in Astronomy and Astrophysics 2020年第7期20卷 93-102页

作者： Qing-Feng Zhang Zhi-Cong Lu xiao-mei zhou Yang Zheng Zhan Li Qing-Yu Peng Shun Long Wei-Heng Zhu Department of Computer Science Jinan UniversityGuangzhou 510632China Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China

Taking a large number of images,the Cassini Imaging Science Subsystem(ISS)has been routinely used in *** ISS images,disk-resolved objects often lead to false detection of stars that disturb the camera pointing *** aim of this study was to develop an automated processing method to remove the false image stars in disk-resolved objects in ISS *** method included the following steps:extracting edges,segmenting boundary arcs,fitting circles and excluding false image *** proposed method was tested using 200 ISS *** experimental results show that it can remove the false image stars in more than 95%of ISS images with disk-resolved objects in a fully automatic manner,i.e.,outperforming the traditional circle detection based on Circular Hough Transform(CHT)by 17%.In addition,its speed is more than twice as fast as that of the CHT *** is also more robust(no manual parameter tuning is needed)when compared with *** proposed method was also applied to a set of ISS images of Rhea to eliminate the mismatch in pointing correction in automatic *** results showed that the precision of final astrometry results can be improve by roughly 2 times that of automatic procedure without the *** proved that the proposed method is helpful in the astrometry of ISS images in a fully automatic manner.

关键词： methods:data analysis techniques:image processing techniques:telescopes stars:imaging

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Modulatory effects of acupuncture on brain networks in mild cognitive impairment patients

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Neural Regeneration Research 2017年第2期12卷 250-258页

作者： Ting-ting Tan Dan Wang Ju-ke Huang xiao-mei zhou Xu Yuan Jiu-ping Liang Liang Yin Hong-liang Xie Xin-yan Jia Jiao Shi Fang Wang Hao-bo Yang Shang-jie Chen Department of Rehabilitation Medicine Shenzhen Baoan Hospital Southern Medical University Shenzhen Guangdong Province China Shenzhen Baoan Hospital Southern Medical University Shenzhen Guangdong Province China Department of Radiologgy Shenzhen Baoan Hospital Southern Medical University Shenzhen Guangdong Province China Department of Neurology Shenzhen Baoan Hospital Southern Medical University Shenzhen Guangdong Province China Tianjin Medical University Tianjin China

Functional magnetic resonance imaging has been widely used to investigate the effects of acupuncture on neural activity. However, most functional magnetic resonance imaging studies have focused on acute changes in brain activation induced by acupuncture. Thus, the time course of the therapeutic effects of acupuncture remains unclear. In this study, 32 patients with amnestic mild cognitive impairment were randomly divided into two groups, where they received either Tiaoshen Yizhi acupuncture or sham acupoint acupuncture. The needles were either twirled at Tiaoshen Yizhi acupoints, including Sishencong（EX-HN1）, Yintang（EX-HN3）, Neiguan（PC6）, Taixi（KI3）, Fenglong（ST40）, and Taichong（LR3）, or at related sham acupoints at a depth of approximately 15 mm, an angle of ± 60°, and a rate of approximately 120 times per minute. Acupuncture was conducted for 4 consecutive weeks, five times per week, on weekdays. Resting-state functional magnetic resonance imaging indicated that connections between cognition-related regions such as the insula, dorsolateral prefrontal cortex, hippocampus, thalamus, inferior parietal lobule, and anterior cingulate cortex increased after acupuncture at Tiaoshen Yizhi acupoints. The insula, dorsolateral prefrontal cortex, and hippocampus acted as central brain hubs. Patients in the Tiaoshen Yizhi group exhibited improved cognitive performance after acupuncture. In the sham acupoint acupuncture group, connections between brain regions were dispersed, and we found no differences in cognitive function following the treatment. These results indicate that acupuncture at Tiaoshen Yizhi acupoints can regulate brain networks by increasing connectivity between cognition-related regions, thereby improving cognitive function in patients with mild cognitive impairment.

关键词： nerve regeneration mild cognitive impairment Alzheimer's disease neuroimaging resting-state functional magnetic resonance imaging brain network acupuncture Tiaoshen Yizhi neural regeneration

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磁致伸缩复合材料有效性能的变分渐近细观力学模型

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复合材料学报 2017年第3期34卷 574-581页

作者：钟轶峰李潇梅宝平周小平重庆大学土木工程学院重庆400045 山地城镇建设与新技术教育部重点实验室(重庆大学) 重庆400045

基于一种新颖的建模方法——变分渐近均匀化理论,建立了磁致伸缩复合材料的细观力学模型,以准确预测材料的有效属性和局部应力、磁通密度分布。从建立磁致伸缩复合材料的总磁焓入手,将总磁焓中的场变量精确解表示为平均值和波动函数之... 详细信息

基于一种新颖的建模方法——变分渐近均匀化理论,建立了磁致伸缩复合材料的细观力学模型,以准确预测材料的有效属性和局部应力、磁通密度分布。从建立磁致伸缩复合材料的总磁焓入手,将总磁焓中的场变量精确解表示为平均值和波动函数之和。根据最小势能原理,利用细宏观尺度比作为小参数对约束条件下总磁焓求驻值(最小化)建立细观力学模型。为分析实际工程中的微观结构,利用有限元离散技术实现构建模型的数值模拟。CoFe_2O_4/环氧树脂复合材料数值算例结果表明:构建的模型可准确预测磁致伸缩复合材料的有效属性和局部场分布,并可扩展到其他多相复合材料的有效属性和局部场分析中。

关键词：磁致伸缩复合材料细观力学有限元变分渐近法均匀化

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成年女性压力性尿失禁诊疗的临床实践指南内容分析

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中国现代医学杂志 2015年第32期25卷 78-83页

作者：周晓美刘晓双柳韦华泰山医学院护理学院山东泰安271000

目的总结成年女性压力性尿失禁(SUI)诊断和治疗的循证证据和推荐意见。方法以关键词压力性尿失禁/尿失禁(UI)、临床实践指南/最佳实践/共识,检索美国指南网(NGC)、Cochrane图书馆(CL)、JBI循证卫生保健数据库、Medline、中华人民共和国... 详细信息

目的总结成年女性压力性尿失禁(SUI)诊断和治疗的循证证据和推荐意见。方法以关键词压力性尿失禁/尿失禁(UI)、临床实践指南/最佳实践/共识,检索美国指南网(NGC)、Cochrane图书馆(CL)、JBI循证卫生保健数据库、Medline、中华人民共和国卫生部网站及中国生物医学文献数据库等。采用内容分析法,对检索出的相关临床实践指南进行文献内容分析。结果共纳入11个临床实践指南,对成年女性SUI的诊断和治疗方面总结出具体的循证证据和推荐意见。结论应结合我国实际和最佳证据,构建适合本土成年女性SUI诊疗的临床实践指南。

关键词：压力性尿失禁诊断治疗临床实践指南内容分析法

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环境保护税税率与地区浮动标准设计研究

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当代财经 2016年第11期 23-31页

作者：王有兴杨晓妹周全林东北财经大学产业组织与企业组织研究中心辽宁大连116025 安徽财经大学国际经济贸易学院江西南昌330013 安徽财经大学财政与公共管理学院安徽蚌埠233030 江西财经大学财税与公共管理学院江西南昌330013

根据"污染者付费"原则,运用环境治理成本分摊法,从国家层面和地区层面对我国工业废水和废气税率的合意水平进行测度,定量分析地区浮动税率的参考区间。结果表明,排污费收入较低,无法满足环境治理支出需要;工业废水和废气的测算税率是实... 详细信息

根据"污染者付费"原则,运用环境治理成本分摊法,从国家层面和地区层面对我国工业废水和废气税率的合意水平进行测度,定量分析地区浮动税率的参考区间。结果表明,排污费收入较低,无法满足环境治理支出需要;工业废水和废气的测算税率是实际执行征收标准及《征求意见稿》中税率的9.7倍和5.28倍;东部、中部、西部及东北部地区工业废水和废气的税率设置应有不同程度的提高,且东部地区税率应高于其他地区。为实现绿色发展、保证环境保护税法顺利出台,政府应循序渐进分阶段逐步提高环境保护税税率水平、定期发布地区浮动税率参考指数、科学设定加征和减征梯度。

关键词：环境保护税税率设计地区浮动税率排污费

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掺铍GaAs量子阱的光致荧光

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物理学报 1993年第5期42卷 864-865页

作者：程文芹梅笑冰周均铭刘玉龙朱恪中国科学院物理研究所北京100080

测量了掺铍的,阱宽约为10nm的GaAs量子阱在4.2K的光致荧光。掺杂浓度分别为1×10^(17)和5×10^(18)cm^(-3)。测量结果表明:对于无规掺杂,局域在阱中心的铍的状态密度与导带电子从n=1量子能级到阱中心中性铍的跃迁概率的乘积大于对应于... 详细信息

测量了掺铍的,阱宽约为10nm的GaAs量子阱在4.2K的光致荧光。掺杂浓度分别为1×10^(17)和5×10^(18)cm^(-3)。测量结果表明:对于无规掺杂,局域在阱中心的铍的状态密度与导带电子从n=1量子能级到阱中心中性铍的跃迁概率的乘积大于对应于介面铍的乘积。另外,实验结果也表明:当掺杂浓度升高时,由于带隙收缩的影响,阱中心铍的电离能减小。

关键词：砷化镓量子阱光致发光荧光铍

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人类微小病毒B19感染与川崎病的关系

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实用儿科临床杂志 2004年第4期19卷 281-282页

作者：束晓梅杨平周华遵义医学院第一附属医院儿科贵州遵义563003

目的　探讨人类微小病毒B19感染与川崎病 (KD)的关系。方法　对 6 0例KD患儿及 4 2例健康儿童进行近期B19感染检查 ,包括B19DNA检查、间接免疫荧光法检测B19表面蛋白抗原。结果　 6 0例KD患儿中B19DNA阳性 6例 (10 .0 % ) ,对照组阳性 2... 详细信息

目的　探讨人类微小病毒B19感染与川崎病 (KD)的关系。方法　对 6 0例KD患儿及 4 2例健康儿童进行近期B19感染检查 ,包括B19DNA检查、间接免疫荧光法检测B19表面蛋白抗原。结果　 6 0例KD患儿中B19DNA阳性 6例 (10 .0 % ) ,对照组阳性 2例 (4 .8% ) ,两组差异无显著意义 (χ2 =0 .94　P >0 .0 5 )。但B19DNA阳性 6例中 ,1岁患儿两组阳性率差异有统计学意义 (P 0 .0 5 )。

关键词：微小病毒B19 感染川崎病聚合酶链式反应间接免疫荧光

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Effects of hypoxia,hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 in hepatic stellate cells

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World Journal of Gastroenterology 2001年第5期7卷 647-651页

作者： Ping-Sheng Chen~(1,2) Wei-Rong Zhai~1 xiao-mei zhou~3 Jin-Sheng Zhang~1 Yue-E Zhang~1 Yu-Qin Ling~1 Ying-Hong Gu~1 1 Department of Pathology,School of Basic Medical Sciences,Fudan University,Shanghai 200032,China2 Ping-Sheng Chen now works in the Department of Pathology,School of Basic Medical Sciences the (former Nanjing Railway Medical College),Southeast University,Nanjing 210009,China3 Institute of Cancer Research,Shanghai 200032,China Department of Pathology School of Basic Medical Sciences Fudan University 138 Yixueyuan Road Shanghai 200032 China.

AIM: To study the effects of hypoxia, hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 (MMP-2) in hepatic stellate cells (HSC). METHODS: The expressions of MMP-2, tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) and membrane type matrix metalloproteinase-1 (MT1-MMP) in cultured rat HSC were detected by immunocytochemistry (ICC) and in situ hybridization (ISH). The contents of MMP-2 and TIMP-2 in culture supernatant were detected with ELISA and the activity of MMP-2 in supernatant was revealed by zymography. RESULTS: In the situation of hypoxia for 12h, the expression of MMP-2 protein was enhanced (hypoxia group positive indexes: 5.7 +/- 2.0, n=10; control: 3.2 +/- 1.0, n = 7; P<0.05), while TIMP-2 protein was decreased in HSC (hypoxia group positive indexes: 2.5 +/- 0.7, n = 10; control: 3.6 +/- 1.0, n = 7; P < 0.05), and the activity (total A) of MMP-2 in supernatant declined obviously (hypoxia group: 7.334 +/- 1.922, n = 9; control: 17.277 +/- 7.424, n = 11; P < 0.01). Compared the varied duration of hypoxia, the changes of expressions including mRNA and protein level as well as activity of MMP-2 were most notable in 6h group. The highest value(A(hypoxia)-A(control)) of the protein and the most intense signal of mRNA were in the period of hypoxia for 6h, along with the lowest activity of MMP-2. In the situation of hyperoxia for 12h, the contents (A(450)) of MMP-2 and TIMP-2 in supernatant were both higher than those in the control, especially the TIMP-2 (hyperoxia group: 0.0499 +/- 0.0144, n = 16; control: 0.0219 +/- 0.0098, n = 14; P < 0.01), and so was the activity of MMP-2 (hyperoxia group: 5.252 +/- 0.771, n = 14; control: 4.304 +/- 1.083, n = 12; P < 0.05), and the expression of MT1-MMP was increased. CONCLUSION: HSC is sensitive to the oxygen, hypoxia enhances the expression of MMP-2 and the effect is more marked at the early stage; hyperoxia mainly raises the activity of MMP-2.

关键词： Animals Cell Division Cell Hypoxia Cells, Cultured Gelatinase A Gene Expression Regulation, Enzymologic Hepatocytes Hyperoxia Metalloendopeptidases RNA, Messenger Rats Rats, Sprague-Dawley Research Support, Non-U.S. Gov't Tissue Inhibitor of Metalloproteinase-2

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一种ECC快速数字签名技术的硬件实现

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武汉理工大学学报 2009年第19期31卷 156-159页

作者：李成霞徐守志杨小梅周欢三峡大学电气信息学院宜昌443002

目前基于椭圆曲线的数字签名算法是信息安全领域的研究热点之一,用硬件实现数字签名有着广泛的应用前景。首先阐述了有限域上的椭圆曲线数字签名方案,其中标量乘运算是影响算法执行效率的一个重要因素。变长滑动窗口法是指窗口的长度随... 详细信息

目前基于椭圆曲线的数字签名算法是信息安全领域的研究热点之一,用硬件实现数字签名有着广泛的应用前景。首先阐述了有限域上的椭圆曲线数字签名方案,其中标量乘运算是影响算法执行效率的一个重要因素。变长滑动窗口法是指窗口的长度随着窗口中元素的具体划分而改变,因此提出用NAF和变长滑动窗口相结合的方法大大减少点加运算次数,并将其应用于基于TMS320VC5402的椭圆曲线数字签名。结果表明,签名运算速度得到很大的提高。

关键词：椭圆曲线数字签名标量乘硬件

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