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Numerical simulation of melt flow and temperature field during DC casting 2024 aluminium alloy under different casting conditions

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China Foundry 2024年第4期21卷 387-396页

作者： jin-chuan Wang Yu-bo Zuo Qing-feng Zhu jing Li Rui Wang Xu-dong Liu Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Engineering Research Center of Advanced Materials Preparing Technology Ministry of EducationShenyang 110819China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Casting speed,casting temperature and secondary cooling water flow rate are the main process parameters affecting the DC casting *** parameters significantly influence the flow and temperature fields during casting,which are crucial for the quality of the ingot and can determine the success or failure of the casting *** simulation,with the advantages of low cost,rapid execution,and visualized results,is an important method to study and optimize the DC casting *** the present work,a simulation model of DC casting 2024 aluminum alloy was established,and the reliability of the model was ***,the influence of casting parameters on flow field and temperature field was studied in detail by numerical simulation *** show that with the increase of casting speed,the melt flow becomes faster,the depths of slurry zone and mushy zone increase,and the variation of slurry zone depth is greater than that of mushy *** an increase in casting temperature,the melt flow rate increases,the depth of the slurry zone becomes shallower,and the depth of the mushy zone experiences only minor *** simulation results further indicate that the increase of the flow rate of the secondary cooling water slightly reduces the depths of both slurry and mushy zone.

关键词： aluminium DC casting flow field temperature field numerical simulation

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Experimental investigation on pyrolysis products and pore structure characteristics of organic-rich shale heated by supercritical carbon dioxide

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Petroleum Science 2024年第4期21卷 2393-2406页

作者： Bai-Shuo Liu chuan-jin Yao Jia-Long Qi Ya-Qian Liu Liang Xu jing-Xuan Hou State Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)) Ministry of Education School of Petroleum Engineering China University of Petroleum (East China)

The efficient pyrolysis and conversion of organic matter in organic-rich shale,as well as the effective recovery of pyrolysis shale oil and gas,play a vital role in alleviating energy *** state of carbon dioxide（CO2） in the pyrolysis environment of shale reservoirs is the supercritical *** unique supercritical fluid properties not only effectively heat organic matter,displace pyrolysis products and change shale pore structure,but also achieve carbon storage to a certain *** samples were made into powder and three sizes of cores,and nitrogen（N2） and supercritical carbon dioxide（ScCO2）pyrolysis experiments were performed at different final pyrolysis *** properties and mineral characteristics of the pyrolysis products were studied based on gas chromatography analysis,Xray diffraction tests,and mass spectrometry ***,the pore structure characteristics at different regions of cores before and after pyrolysis were analyzed using N2adsorption tests to clarify the impact of fracturing degree on the pyrolysis *** results indicate that the optimal pyrolysis temperature of Longkou shale is about 430℃.Compared with N2,the oil yield of ScCO2pyrolysis is *** pyrolysis oil obtained by ScCO2extraction has more intermediate fractions and higher relative molecular *** ScCO2can effectively improve the pore diameter of shale and its effect is better than that of *** micropores are produced in shale after pyrolysis,and the macropores only are generated in ScCO2pyrolysis environments with temperatures greater than 430℃.The pore structure has different development characteristics at different pyrolysis temperatures,which are mainly affected by the pressure holding of volatile matter and products *** to the surface of the core,the pore development effect inside the core is *** the decrease in core size,the pore diameter,specific surface area,and pore volume of cores all increase after pyrolysis.

关键词： Organic-rich shale Supercritical carbon dioxide In-situ pyrolysis Pore structure Core size and region

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Effectiveness of Histopathological Examination of Ultrasound-guided Puncture Biopsy Samples for Diagnosis of Extrapulmonary Tuberculosis

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Biomedical and Environmental Sciences 2024年第2期37卷 170-177页

作者： GU Wen Fei SHI Xia MA Xin YU Jun Lei XU jin chuan QIAN Cheng Cheng HU Zhi Dong ZHANG Hui Shanghai Public Health Clinical Center Fudan UniversityShanghai 201508China School of Laboratory Medicine and Life Science Wenzhou Medical UniversityWenzhou 325000ZhejiangChina Department of Laboratory Medicine Zhejiang Putuo HospitalZhoushan 316100ZhejiangChina Zhongshan Hospital Fudan UniversityShanghai 200032China

Objective To evaluate the diagnostic value of histopathological examination of ultrasound-guided puncture biopsy samples in extrapulmonary tuberculosis(EPTB).Methods This study was conducted at the Shanghai Public Health Clinical Center.A total of 115patients underwent ultrasound-guided puncture biopsy,followed by MGIT 960 culture(culture),smear,Gene Xpert MTB/RIF(Xpert),and histopathological *** assays were performed to evaluate their effectiveness in diagnosing EPTB in comparison to two different diagnostic criteria:liquid culture and composite reference standard(CRS).Results When CRS was used as the reference standard,the sensitivity and specificity of culture,smear,Xpert,and histopathological examination were(44.83%,89.29%),(51.72%,89.29%),(70.11%,96.43%),and(85.06%,82.14%),*** on liquid culture tests,the sensitivity and specificity of smear,Xpert,and pathological examination were(66.67%,72.60%),(83.33%,63.01%),and(92.86%,45.21%),*** examination showed the highest sensitivity but lowest ***,we found that the combination of Xpert and histopathological examination showed a sensitivity of 90.80%and a specificity of 89.29%.Conclusion Ultrasound-guided puncture sampling is safe and effective for the diagnosis of *** with culture,smear,and Xpert,histopathological examination showed higher sensitivity but lower *** combination of histopathology with Xpert showed the best performance characteristics.

关键词： Extrapulmonary tuberculosis Diagnosis Biopsy Histopathological examination Puncture samples

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Vertebral Artery Stenting for Acute Multiple Cerebral Infarctions Caused by Vertebral Artery Dissection After Massage:A Case Report

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Chinese Medical Sciences Journal 2024年第2期39卷 149-154页

作者： Ying-Xue Cui chuan-jin Song Xue-Si Hou Gui-Lin Liu Xu Ji Shao-Song Wang Department of Neurology Beijing Hospital of Traditional Chinese MedicineCapital Medical UniversityBeijing 100010China

Vertebral artery dissection is a rare pathology that can cause ischemic stroke in young *** massage,especially improper pulling manipulation,is a cause of vertebral artery *** present a case of 32-year old woman who developed acute multiple posterior circulation ischemic cerebral infarctions as a result of left vertebral artery V4 segment dissection after receiving neck *** underwent emergency vertebral artery stent implantation at the site of the *** were relieved the day after *** patient recovered without adverse complications or endovascular restenosis in the following year.

关键词： vertebral artery dissection acute ischemic stroke stent implantation endovascular therapy

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Verifying hierarchical network nonlocality in general quantum networks

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Chinese Physics B 2024年第7期33卷 199-208页

作者：杨舒媛侯晋川贺衎 College of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

Recently, a class of innovative notions on quantum network nonlocality(QNN), called full quantum network nonlocality(FQNN), have been proposed in Phys. Rev. Lett. 128 010403(2022). As the generalization of full network nonlocality(FNN), l-level quantum network nonlocality(l-QNN) was defined in arxiv. 2306.15717 quant-ph(2024). FQNN is a NN that can be generated only from a network with all sources being non-classical. This is beyond the existing standard network nonlocality, which may be generated from a network with only a non-classical source. One of the challenging tasks is to establish corresponding Bell-like inequalities to demonstrate the FQNN or l-QNN. Up to now, the inequality criteria for FQNN and l-QNN have only been established for star and chain networks. In this paper, we devote ourselves to establishing Bell-like inequalities for networks with more complex structures. Note that star and chain networks are special kinds of tree-shaped networks. We first establish the Bell-like inequalities for verifying l-QNN in k-forked tree-shaped networks. Such results generalize the existing inequalities for star and chain networks. Furthermore, we find the Bell-like inequality criteria for l-QNN for general acyclic and cyclic networks. Finally, we discuss the demonstration of l-QNN in the well-known butterfly networks.

关键词： full network nonlocality hierarchical network nonlocality tree network

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Trend of robot-assisted surgery system in gastrointestinal and liver surgery: A bibliometric analysis

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World Journal of Gastrointestinal Surgery 2024年第9期16卷 3008-3019页

作者： Ze-chuan jin Zi-Qiang Wang Colorectal Cancer Center West China HospitalSichuan UniversityChengdu 610000Sichuan ProvinceChina Colorectal Cancer Center Department of General SurgeryWest China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND Robot-assisted gastrointestinal and liver surgery has been an important development direction in the field of surgery in recent years and it is also one of the fastest developing and most concerning fields in surgical *** To illustrate the major areas of research and forward-looking directions over the past twenty-six *** Using the Web of Science Core Collection database,a comprehensive review of scholarly articles pertaining to robot-assisted gastrointestinal and liver surgery was researched out between 2000 and *** used Citespace(Version 6.2.4)and Bibliometrix package(Version 4.3.0)to visualize the analysis of all publications including country,institutional affiliations,authors,and *** In total,346 articles were *** Endoscopy had with the largest number of publications and was cited in this *** United States was a core research country in this *** University was the most productive *** current focus of this field is on rectal surgery,long-term prognosis,perioperative management,previous surgical experience,and the learning *** The scientific interest in robot-assisted gastrointestinal and liver surgery has experienced a significant rise since *** study provides new perspectives and ideas for future research in this field.

关键词： Bibliometric analysis Robot-assisted surgery system Gastrointestinal surgery Liver surgery Citespace

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基于Rényi-α熵的参数化纠缠度量

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物理学报 2024年第4期73卷 37-46页

作者：戴伟鹏贺衎侯晋川太原理工大学数学学院太原030024

与各种非参数化纠缠度量相比,参数化纠缠度量显示了其优越性.并发纠缠被广泛用于描述量子实验中的纠缠.作为一种纠缠度量,它与特定Rényi-α熵有关.本文提出了一种基于Rényi-α熵的参数化两体纠缠度量,命名为α-对数并发纠缠.与现有的... 详细信息

与各种非参数化纠缠度量相比,参数化纠缠度量显示了其优越性.并发纠缠被广泛用于描述量子实验中的纠缠.作为一种纠缠度量,它与特定Rényi-α熵有关.本文提出了一种基于Rényi-α熵的参数化两体纠缠度量,命名为α-对数并发纠缠.与现有的参数化度量不同,首先定义了纯态的度量,然后推广到混合态.进一步验证了α-对数并发纠缠满足纠缠度量3个条件.展示了对纯态的度量是容易计算的,然而对于混合态,解析计算只适用于特殊的双量子位态或特殊的高维混合态.因此,本文致力于建立一般两体态α-对数并发纠缠的一个下界.令人惊讶的是,这个下界是这个混合态的正部分转置判据和重排判据的函数.这表明了3种纠缠度量之间的联系.有趣的是,下界依赖于与具体态相关的熵参数.这样我们可以选择适当的参数α,使得Gα(ρ)≫0用于特定态ρ的实验纠缠检测.此外,计算了isotropic态的α-对数并发纠缠的表达式,并给出了d=2时isotropic态的解析表达式.最后,讨论了α-对数并发纠缠的的单配性.建立了两个量子比特系统中并发纠缠和α-对数并发纠缠之间的函数关系,然后得到了该函数的一些有用性质,并结合Coffman-Kundu-Wootters(CKW)不等式,建立了关于α-对数并发纠缠的单配性不等式.最终证明了单配性不等式对于α-对数并发纠缠是成立的.

关键词：参数化度量 Rényi-α熵纠缠度量并发纠缠

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2022年泸定M_(S)6.8地震震前区域变形背景及同震形变特征

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地震地质 2024年第3期46卷 645-664页

作者：徐晶季灵运刘传金中国地震局第二监测中心西安710054 地震动力学国家重点实验室中国地震局地质研究所北京100029

文中利用Sentinel-1 SAR影像获取了2022年泸定6.8级地震的震间形变场(2014—2020年)和同震形变场,估算了泸定地震的震间断层滑动速率、闭锁深度和同震滑动分布,分析了此次地震对周边断裂的影响,并进一步探讨泸定地震的发震构造和磨西断... 详细信息

文中利用Sentinel-1 SAR影像获取了2022年泸定6.8级地震的震间形变场(2014—2020年)和同震形变场,估算了泸定地震的震间断层滑动速率、闭锁深度和同震滑动分布,分析了此次地震对周边断裂的影响,并进一步探讨泸定地震的发震构造和磨西断裂及其周边断裂的未来地震发生趋势。震间InSAR形变场及InSAR和GNSS融合的三维形变场结果显示了2022年泸定地震发震断层的长期滑动特征,滑动速率为(5.9±1.8)mm/a,主要表现为剪切变形明显且应变集中的特征,震前磨西断裂存在明显闭锁,具有强震发生背景。同震滑动分布反演结果表明,此次泸定地震是以左旋走滑为主的高倾角走滑地震,最大滑动量可达1.71m,最大滑动位于10km深处。基于文中获得的同震滑动分布计算了同震位错效应引起的断层面上的库仑应力变化,结果显示磨西断裂南段的地震破裂段形成应力影区,而在此次地震中未破裂的北段的库仑应力显著升高,同时,折多塘断裂南东部分、安宁河断裂带石棉—冕宁段北西部分、大凉山断裂竹马段南东部分和公益海段南东部分的断层面库仑应力显著增加。2022年泸定地震的发震构造为鲜水河断裂带的磨西断裂,此次泸定地震的发生并没有完全降低鲜水河断裂带的地震风险,仍需重点关注磨西断裂未破裂段及其周边具有大地震发生背景的强震破裂空段。

关键词： 2022年泸定地震鲜水河断裂带震间形变同震滑动分布库仑应力变化地震危险性

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三维荧光光谱结合IGOA-SVM分类鉴别油类污染物

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光谱学与光谱分析 2024年第4期44卷 1031-1038页

作者：程朋飞朱燕萍潘金燕崔传金张怡徐州工程学院电气与控制工程学院江苏徐州221018 华北理工大学电气工程学院河北唐山063210

溢油污染是一种典型的环境污染形式,通过多重渠道危害着生物多样性和人类自身安全。因此,针对油类污染物自身组成成分及其特性,采用多种方法相结合的方式,对其进行实时、精确、高效的检测对生态环境监测具有重要意义。三维荧光光谱分析... 详细信息

溢油污染是一种典型的环境污染形式,通过多重渠道危害着生物多样性和人类自身安全。因此,针对油类污染物自身组成成分及其特性,采用多种方法相结合的方式,对其进行实时、精确、高效的检测对生态环境监测具有重要意义。三维荧光光谱分析法以其检测精度高、实时性好、操作简便、干扰性小等优势在荧光类物质检测领域应用十分广泛。三维荧光光谱结合支持向量机等算法在物质分类鉴别和浓度预测方面取得较好的成效,但仍存在收敛速度慢、易陷入局部最优等缺陷。将三维荧光光谱与改进蚱蜢优化支持向量机算法(IGOA-SVM)相结合,提出一种对油类污染物分类鉴别的新方法。首先,以0.1 mol·L-1十二烷基硫酸钠溶液作为溶剂,将0#柴油、95#汽油和煤油以不同浓度配比配制成0#柴油和95#汽油、0#柴油和煤油两组分混合样本20个和18个,三组分混合样本20个,各取一半为训练集和测试集。然后,采用F-7000荧光光谱仪采集混合溶液的荧光数据,分析三种油的标准溶液及配制的混合溶液,发现荧光光谱均在一定范围内存在不同程度的重叠现象,仅利用光谱检测无法准确鉴别。最后,结合混沌初始化、精英优化算法和差分进化算法对蚱蜢优化算法进行改进,提取激发波长270 nm,发射波长270~450 nm范围内的荧光峰数据作为训练的输入值,以三种分类标签作为输出,将数据分别输入到蚱蜢优化支持向量机算法(GOA-SVM)、粒子群优化支持向量机算法(PSO-SVM)和遗传优化支持向量机算法(GA-SVM)中进行训练,IGOA-SVM模型在收敛速度、稳定性和跳出局部最优能力上明显优于GOA-SVM、PSO-SVM和GA-SVM,为油类污染物的准确鉴别提供了一种新思路。

关键词：三维荧光光谱改进蚱蜢优化算法支持向量机石油类污染物

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Sharing quantum nonlocality in the noisy scenario

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Chinese Physics B 2024年第1期33卷 199-211页

作者：杨舒媛侯晋川贺衎 College of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

It was showed in [Phys. Rev. Lett. 125 090401(2020)] that there exist unbounded number of independent Bobs who can share quantum nonlocality with a single Alice by performing sequentially measurements on the Bob's half of the maximally entangled pure two-qubit state. However, from practical perspectives, errors in entanglement generation and noises in quantum measurements will result in the decay of nonlocality in the scenario. In this paper, we analyze the persistency and termination of sharing nonlocality in the noisy scenario. We first obtain the two sufficient conditions under which there exist n independent Bobs who can share nonlocality with a single Alice under noisy measurements and the noisy initial two qubit entangled state. Analyzing the two conditions, we find that the influences on persistency under different kinds of noises can cancel each other out. Furthermore, we describe the change patterns of the maximal nonlocality-sharing number under the influence of different noises. Finally, we extend our investigation to the case of arbitrary finite-dimensional systems.

关键词： Bell nonlocality quantum measurement quantum noise

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