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Spleen volume is associated with overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt in patients with portal hypertension

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World Journal of Gastrointestinal Surgery 2024年第7期16卷 2054-2064页

作者： Chun-Juan Zhao Chao Ren Zhen Yuan Guo-Hui Bai Jin-Yu Li Long Gao Jin-Hui Li Ze-Qi Duan dui-Ping Feng Hui zhang College of Medical Imaging Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Radiology The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Occupational Health School of Public HealthShanxi Key Laboratory of Environmental Health Impairment and PreventionNHC Key Laboratory of PneumoconiosisMOE Key Laboratory of Coal Environmental Pathogenicity and PreventionShanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Oncological and Vascular Intervention The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Shanxi Provincial Clinical Research Center for Interventional Medicine The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina First Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Shanxi Key Laboratory of Intelligent Imaging and Nanomedicine The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Intelligent Imaging Big Data and Functional Nano-imaging Engineering Research Center of Shanxi Province The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina

BACKGROUND Portal shunt and immune status related to the spleen are related to the occurrence of hepatic encephalopathy(HE).It is unknown whether spleen volume before transjugular intrahepatic portosystemic shunt(TIPS)is related to postoperative *** To investigate the relationship between spleen volume and the occurrence of *** This study included 135 patients with liver cirrhosis who underwent TIPS,and liver and spleen volumes were elevated upon computed tomography *** Kaplan-Meier curve was used to compare the difference in the incidence rate of HE among patients with different spleen *** and multivariate Cox regression analyses were performed to identify the factors affecting overt HE(OHE).Restricted cubic spline was used to examine the shapes of the dose-response association between spleen volumes and OHE *** The results showed that 37(27.2%)of 135 patients experienced OHE during a 1-year follow-up *** with preoperative spleen volume(901.30±471.90 cm3),there was a significant decrease in spleen volume after TIPS(697.60±281.0 cm^(3))in OHE *** the severity of OHE increased,the spleen volume significantly decreased(P<0.05).Compared with patients with a spleen volume≥782.4 cm^(3),those with a spleen volume<782.4 cm^(3) had a higher incidence of HE(P<0.05).Cox regression analysis showed that spleen volume was an independent risk factor for post-TIPS OHE(hazard ratio=0.494,P<0.05).Restricted cubic spline model showed that with an increasing spleen volume,OHE risk showed an initial increase and then decrease(P<0.05).CONCLUSION Spleen volume is related to the occurrence of OHE after *** spleen volume is an independent risk factor for post-TIPS OHE.

关键词： Hepatic encephalopathy Transjugular intrahepatic portosystemic shunt Spleen volume Portal hypertension Cirrhosis

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塔式起重机起吊全过程力学特性研究

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兰州理工大学学报 2024年第4期50卷 55-59页

作者：张堆学兰州路域产业综合开发有限公司甘肃兰州730000

针对塔式起重机起吊过程中稳定性问题,以某型号平头塔式起重机为研究对象,对起吊全过程的静力学和瞬时动力学展开了研究.利用有限元静力学,探究了在静风工况和正常工况下塔式起重机不同起吊位置和不同起吊重量与位移响应的关系.结果表明... 详细信息

针对塔式起重机起吊过程中稳定性问题,以某型号平头塔式起重机为研究对象,对起吊全过程的静力学和瞬时动力学展开了研究.利用有限元静力学,探究了在静风工况和正常工况下塔式起重机不同起吊位置和不同起吊重量与位移响应的关系.结果表明,静力学分析时塔式起重机在静风工况和正常工况下具有相近的变化幅值和趋势,且风载荷对塔式起重机的位移响应影响显著.同时,在惯性力作用下,基于瞬态动力学分析了起吊加速度不同时塔式起重机的位移响应.结果表明:在60 m幅度处与30 m幅度处起吊时最大位移响应相差71.8 mm,平均位移响应相差63.4、63.6、64和64.1 mm,二者具有相近的波动幅值和变化趋势,说明缓慢起吊时位移响应对起吊位置不敏感;此外,二者位移响应均呈现起伏趋势,说明在起吊过程中明显存在塔机晃动现象.

关键词：塔式起重机风载荷静力学分析瞬态动力学分析

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基于多源遥感及气象数据的河流非光学活性水质参数反演模型研究

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遥感技术与应用 2024年第1期39卷 120-133页

作者：兑紫璇王卿王敏张璟顾倩荣中国科学院上海高等研究院低碳转化科学与工程重点实验室碳数据与碳评估中心上海201210 中国科学院大学北京100049 上海市环境科学研究院上海200233 江苏省司法警官高等职业学校江苏南京212008

针对传统河流水质监测成本高、地面监测站点稀疏等问题,基于哨兵2卫星多光谱遥感数据,结合MODIS地表温度、植被指数、气溶胶光学厚度数据产品,以及ERA5气象数据产品中的地表风速数据,以非光学活性参数溶解氧(DO)、化学需氧量(COD)和氨氮... 详细信息

针对传统河流水质监测成本高、地面监测站点稀疏等问题,基于哨兵2卫星多光谱遥感数据,结合MODIS地表温度、植被指数、气溶胶光学厚度数据产品,以及ERA5气象数据产品中的地表风速数据,以非光学活性参数溶解氧(DO)、化学需氧量(COD)和氨氮(NH_(3)-N)的地面水质监测站的监测数据为参照,采用支持向量回归(SVR)、随机森林(RF)和多层感知机(MLP)3种机器学习方法,通过对比实验选出每种水质参数最优反演模型及其对应的输入特征组合。模型性能测试实验结果表明,利用多源遥感及气象数据反演出的DO、COD以及NH_(3)-N的决定系数(R^(2))分别为0.896、0.781、0.529,均方根误差(RMSE)分别为0.263 mg/L、0.383 mg/L、0.061 mg/L。与仅使用哨兵2卫星多光谱遥感数据的反演结果相比,R^(2)分别提高了7.04%、19.05%、18.34%,RMSE分别降低了34.58%、37.42%、14.08%。表明多源遥感及气象数据对提高DO、COD以及NH_(3)-N水质参数反演准确性有重要意义。最后,模型鲁棒性评估实验表明,当模型训练数据的代表性与全局数据较为接近时,训练的模型具有较好的时空鲁棒性。

关键词：机器学习多源遥感数据溶解氧化学需氧量氨氮水质反演模型

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基于多层耦合网络的装备保障体系级联失效及抗毁性分析

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指挥与控制学报 2024年第1期10卷 67-80页

作者：张帅周伟白光晗兑红炎陶俊勇国防科技大学智能科学学院装备综合保障技术重点实验室长沙410073 解放军32256部队广州510630 郑州大学管理工程学院郑州450001

为准确描述装备保障体系结构特征与毁伤失效流程,进而提升装备保障体系功能与抗毁能力,基于杀伤层、保障层和储供层构建装备保障体系的多层耦合网络模型。基于杀伤链给出装备维修保障链与储供保障链的特征和典型样式,在此基础上,提出考... 详细信息

为准确描述装备保障体系结构特征与毁伤失效流程,进而提升装备保障体系功能与抗毁能力,基于杀伤层、保障层和储供层构建装备保障体系的多层耦合网络模型。基于杀伤链给出装备维修保障链与储供保障链的特征和典型样式,在此基础上,提出考虑装备保障体系多层耦合网络特性的级联失效模型与节点重要度评估方法。给出对应的网络抗毁性评估指标。仿真结果表明,考虑级联失效的多层耦合网络模型能较好地反映遭受攻击时整个装备保障体系的性能变化情况,所提出的使命任务节点重要度能准确识别关键节点。与传统网络抗毁性指标相比,杀伤链数量对节点失效产生的装备保障体系抗毁性变化更加敏感。

关键词：装备保障体系网络抗毁性多层耦合网络级联失效节点重要度

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不同比例硫酸铵替代尿素对玉米根际土壤环境及微生物群落的影响

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环境科学 2024年第6期45卷 3584-3594页

作者：张延慧刘宇韩莹董馨宇郭探文闫秋艳闫双堆山西农业大学资源环境学院太谷030801 山西农业大学小麦研究所临汾041000 山西农业大学农业资源与环境国家级实验教学示范中心太谷030801

为了探究工业副产物硫酸铵以不同比例替代尿素做为氮肥施入土壤后对土壤养分以及微生物群落的影响,进行了盆栽玉米试验.试验采用完全随机设计方法,共设置5个处理:CK(不施肥)、U_(10)S_(0)(100%尿素)、U_(8)S_(2)(80%尿素+20%硫酸铵)、U_... 详细信息

为了探究工业副产物硫酸铵以不同比例替代尿素做为氮肥施入土壤后对土壤养分以及微生物群落的影响,进行了盆栽玉米试验.试验采用完全随机设计方法,共设置5个处理:CK(不施肥)、U_(10)S_(0)(100%尿素)、U_(8)S_(2)(80%尿素+20%硫酸铵)、U_(6)S_(4)(60%尿素+40%硫酸铵)和U_(0)S_(10)(100%硫酸铵).应用常规方法进行土壤基本理化性质以及玉米植株干重的测定,通过Illumina Nova Seq平台进行微生物测序.结果表明:①在玉米的各个生育期,施肥处理土壤p H(7.85~8.15)与CK(8.1~8.21)相比都有所下降,并且随着硫酸铵比例的增加p H呈不断下降的趋势;②在玉米各生育期土壤碱解氮含量随着硫酸铵比例的增加呈逐渐增加的趋势,U_(0)S_(10)处理比CK和U_(10)S_(0)处理分别提高了30.56%~63.68%和13.22%~38.43%;有机碳含量变化趋势为:U_(8)S_(2)>U_(6)S_(4)>U_(0)S_(10),但除苗期以外其他生育期添加硫酸铵的处理都仍高于U_(10)S_(0)处理;③所有的施肥处理蛋白酶活性都高于对照,并且随着玉米的不断生长和硫酸铵比例的增加蛋白酶活性逐渐增强,U_(0)S_(10)处理在玉米各生育期都高于U_(10)S_(0)处理,提高了10.54%~100%;各施肥处理土壤蔗糖酶活性范围为0.04~0.24 mg·(g·24 h)^(-1),并在所有生育期U_(0)S_(10)处理都显著高于U_(10)S_(0)和CK处理,分别提高了20.32%~99.16%、24.31%~79.33%;④所有施肥处理的玉米根际细菌和真菌物种丰富度都低于CK处理,U_(10)S_(0)处理仅低于CK,硫酸铵替代尿素的3个处理细菌群落物种多样性趋势为:U_(8)S_(2)>U_(0)S_(10)>U_(6)S_(4),真菌为:U_(6)S_(4)>U_(8)S_(2)>U_(0)S_(10);⑤U_(0)S_(10)和U_(10)S_(0)处理玉米植株干重最大,分别比CK处理提高了39.47%和36.16%,U_(0)S_(10)处理高于U_(10)S_(0)处理但差异不显著;Pearson模型表明相关环境变量对土壤根际真菌和细菌物种丰富度和多样性有一定影响,其中p H值和土壤碱解氮含量是影响微生物物种多样性的最主要因素.综上,在石灰性褐土的玉米种植中,以一定比例硫酸铵替代尿素比单施尿素更能提高土壤养分,在一定程度上影响了玉米生长及根际微生物群落,并且有更大的产出.

关键词：硫酸铵 pH 碳氮养分土壤酶活性根际微生物

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装备体系可靠性概念、建模与预计方法研究

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系统工程与电子技术 2024年第6期46卷 1975-1985页

作者：陈志伟张罗庚方晓彤袁远崔巍巍兑红炎洪东跑西北工业大学无人系统技术研究院陕西西安710129 西安现代控制技术研究所陕西西安710065 中国船舶集团有限公司综合技术经济研究院北京100081 北京航空航天大学可靠性与系统工程学院北京100191 国防科技大学智能科学学院湖南长沙410073 中国运载火箭技术研究院北京100076 郑州大学管理学院河南郑州450001

武器装备体系执行任务复杂多样,其可靠性直接影响装备战备完好性与效能。传统可靠性建模与预计方法未充分考虑装备体系组成系统之间的资源共享与信息融合特征,难以满足现代化装备体系化和集群化需求。因此,分析给出装备体系可靠性相关概... 详细信息

武器装备体系执行任务复杂多样,其可靠性直接影响装备战备完好性与效能。传统可靠性建模与预计方法未充分考虑装备体系组成系统之间的资源共享与信息融合特征,难以满足现代化装备体系化和集群化需求。因此,分析给出装备体系可靠性相关概念,并提出了一种基于广义有效OODA(observation,orientation,decision,action)环的装备体系可靠性建模与预计方法。首先,对装备系统与体系可靠性相关概念进行辨析,分析装备体系可靠性、维修性、测试性、保障性和安全性概念内涵。其次,考虑装备体系节点异质性与连边有向性,建立资源与信息共享条件下的装备体系OODA网络模型。然后,考虑装备体系节点与通信链路的随机、蓄意攻击失效和重构策略,提出基于广义OODA环的装备体系可靠性建模与预计方法。最后,以100个无人机组成的无人装备体系为对象验证所提方法的有效性与实用性,进而提升其作战效能。

关键词：装备体系有效OODA环 OODA网络模型可靠性建模可靠性预计

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Importance measure of system reliability upgrade for multi-state consecutive k-out-of-n systems

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Journal of Systems Engineering and Electronics 2012年第6期23卷 936-942页

作者： HonQvan dui Shubin si Zhiqiang Cai Shudong Sun Yingfeng zhang School of Mechatronics Northwestern Polytechnical University Xi'an 710072 P. R. China

Importance measures in reliability systems are used to identify weak components in contributing to a proper function of the system. Traditional importance measures mainly concerned the changing value of the system reliability caused by the change of the reliability of the component, and seldom considered the joint effect of the probability distribution, improvement rate of the object component. This paper studies the rate of the system reliability upgrading with an improvement of the component reliability for the multi-state consecutive k-out-of-n system. To verify the multi-state consecutive k-out-of-n system reliability upgrading by improving one component based on its improvement rate, an increasing potential importance （IPI） and its physical meaning are described at first. Secondly, the relationship between the IPI and Birnbaum importance measures are discussed. And the IPI for some different improvement actions of the component is further discussed. Thirdly, the characteristics of the IPI are analyzed. Finally, an application to an oil pipeline system is given.

关键词： system reliability multi-state consecutive k-out-of-nsystem improvement Birnbaum importance.

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Analytical solutions for deep tunnels in strain-softening rocks modeled by different elastic strain definitions with the unified strength theory

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Science China(Technological Sciences) 2022年第10期65卷 2503-2519页

作者： SUN ZhenYu zhang DingLi FANG Qian dui GuanSuo CHU ZhaoFei Key Laboratory for Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China School of Civil Engineering Wuhan UniversityWuhan 430072China

This paper presents the analytical solutions for the responses of tunnels excavated in rock masses exhibiting strain-softening behavior. Since previous analyses give little consideration to the effect of the intermediate principal stress on the strain-softening rock behavior, the unified strength theory was introduced to analyze the tunnel response. Four cases of different definitions of the elastic strain in the softening and residual regions, used in the existing solutions, were considered. The tunnel displacements,stresses, radii of the softening and residual zones and critical stresses were deduced. The proposed solutions were verified by comparing with numerical simulations, model tests and existing solutions. Furthermore, the solutions of the four cases were compared with each other to investigate the influence of the elastic strain expressions on the tunnel responses. The results showed that the intermediate principal stress coefficient b has a significant effect on the tunnel displacements, stress fields, and plastic radii. Parametric studies were performed to analyze the influences of the softening and residual dilatancy coefficients,softening modulus and residual strength on the tunnel responses. The parametric analysis indicated that the existing models should be carefully evaluated in the analysis of tunnels constructed through average-quality rocks;the proposed solutions outperformed the existing models in solving the mentioned problem.

关键词： analytical solution elastic strain definition unified strength theory strain-softening intermediate principal stress model test

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The chemical characteristics of different sodium iron ethylenediaminetetraacetate sources and their relative bioavailabilities for broilers fed with a conventional corn‑soybean meal diet

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Journal of Animal Science and Biotechnology 2024年第2期15卷 826-843页

作者： Shengchen Wang Bingxin Wu Ling Zhu Weiyun zhang Liyang zhang We Wu Jiaqi Wu Yun Hu Tingting Li Xiaoyan Cui Xugang Luo College of Animal Science and Technology Yangzhou UniversityYangzhou 225000People’s Republic of China Mineral Nutrition Research Division State Key Laboratory of Animal NutritionInstitute of Animal ScienceChinese Academy of Agricultural SciencesBeijing 100193China

Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for *** iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand ***,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains ***,the chemical characteristics of 12 NaFeEDTA products were *** these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were *** bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of *** NaFeEDTA sources varied greatly in their chemical *** Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe ***,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and *** on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,***

关键词： Broilers Chelation strengths Fe-containing enzymes NaFeEDTA Relative bioavailabilities

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Preparation and characterization of Bi2O3/XNBR flexible films for attenuating gamma rays

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Nuclear Science and Techniques 2018年第7期29卷 152-163页

作者： Yi-Chuan Liao dui-Gong Xu Peng-Cheng zhang Institute of Materials China Academy of Engineering PhysicsJiangyou 621907China Science and Technology on Surface Physics and ChemistryLaboratory Jiangyou 621908China

A bismuth oxide(Bi_2O_3)-dispersed carboxylated nitrile butadiene rubber(XNBR) flexible film was prepared as a flexible lead-free material for gamma ray(c-ray)***,obtaining a uniform and stable dispersion of Bi_2O_3 in carboxylated nitrile butadiene rubber latex(XNBRL) is a challenge due to sedimentation induced by the remarkable density ***,this challenge was approached by reducing the Bi_2O-3 particle radius,increasing the viscosity of the latex,and adding a *** experimental results confirmed that Bi2 O3 was well dispersed in the XNBRL in the concentration range of 30–70 wt%.The mechanical properties demonstrated that the Bi_2O_3/XNBR flexible films had a good resistance to oil,acid,alkali,and hot *** linear attenuation coefficients of the Bi_2O_3/XNBR flexible films obtained from the experiments were in good agreement with the calculated *** attenuation efficiencies of the Bi_2O_3/XNBR flexible films with different thicknesses and Bi_2O_3 contents were investigated for a few different γ-ray *** results showed that the Bi_2O_3/XNBRflexible films have wide application prospects for low-energy γ-ray attenuation.

关键词： gamma 电影光线 Bi2O3 丁二烯橡胶粒子半径机械性质分散剂

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