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A Method to Estimate the Steganographic Capacity in DCT Domain Based on MCUU Model

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Wuhan University Journal of Natural Sciences 2016年第4期21卷 283-290页

作者： MAO Jiafa huang Yanhong NIU Xinxin XIAO Gang ZHU linan SHENG Weiguo Department of Computer Science and Technology Zhejiang University of Technology Information Security Center Beijing University of Posts and Telecommunications

In order to estimate maximum steganographic capacity of discrete cosine transform（DCT） domain in JPEG image, this paper presents a method based on the maximize capacity under undetectable model（MCUU）. We analyze the relation between steganographic capacity and affecting factors（image size, steganography operator, loading band, embedding intensity and image complexity）. Then we design a steganography analyzer architecture and a steganographic algorithm which can dynamically increase the steganographic capacity. Compared with other methods of embedding capacity estimation in DCT domain, the proposed methods utilizes general steganalysis methods rather than one specific steganalysis technique and takes five essential factors into account, which improves the commonality and comprehensiveness of capacity estimation, respectively. The experimental results show that steganographic capacity for quantization index modulation（QIM） is almost twice that of spread spectrum（SS） based on MCUU model.

关键词： maximize capacity under undetectable(MCUU) model steganographic capacity steganography steganalysis image complexity

指南临床适用性评价的影响因素分析:一项横断面研究

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中国循证医学杂志 2024年第1期24卷 29-35页

作者：刁莎刘峥石雨晴李思雨曾力楠易秋莎李海龙许慧中王锡雄黄修森杨稀策黄超王强张伶俐四川大学华西第二医院药学部成都610041 四川大学华西第二医院循证药学中心成都610041 国家药品监督管理局药物制剂体内外相关性技术研究重点实验室成都610041 出生缺陷与相关妇儿疾病教育部重点实验室成都610041 四川大学华西临床医学院成都610041 四川大学华西药学院成都610041 东台市人民医院江苏盐城224200 钦州市第一人民医院广西钦州535099 四川大学华西医院成都610041 国家卫生健康委医疗管理服务指导中心北京100044 四川大学华西医院中国循证医学中心成都610041

目的探索指南临床适用性的影响因素,为更好地制订、实施指南提供建议。方法计算机检索CNKI数据库,搜集2015—2020年由中华医学会、中国医师协会发布的临床指南。随机抽取61部,每部指南均由来自东、中、西部的医务人员采用指南临床适用... 详细信息

目的探索指南临床适用性的影响因素,为更好地制订、实施指南提供建议。方法计算机检索CNKI数据库,搜集2015—2020年由中华医学会、中国医师协会发布的临床指南。随机抽取61部,每部指南均由来自东、中、西部的医务人员采用指南临床适用性评价工具(2.0版)共同评价。对统计资料进行描述,组间比较采用t检验或秩和检验或卡方检验;采用逐步Logistic回归筛选指南临床适用性各领域和总体标准化评分的影响因素。结果回收有效问卷6904份,涵盖26省119家医疗机构。调查对象越熟悉指南、指南推荐意见与患者及家属意愿越相符,指南临床适用性的总体标准化评分越高。此外,调查对象越熟悉指南,各领域标准化评分越高;医疗机构越重视指南的依从性,可行性标准化评分越高。结论为改善指南临床适用性,指南制订者应重视推荐意见是否符合患者及家属的意愿,医疗机构应重视医务人员对指南的依从性,同时医务人员应熟悉指南推荐意见。

关键词：指南临床适用性影响因素横断面研究

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指南临床适用性评价指标体系的系统评价

中国循证医学杂志 2024年第1期24卷 61-68页

作者：石雨晴刁莎曾力楠易秋莎李海龙杨稀策何苗郭家平黄超王强张伶俐四川大学华西药学院成都610041 四川大学华西第二医院药学部成都610041 四川大学华西第二医院循证药学中心成都610041 国家药品监督管理局药物制剂体内外相关性技术研究重点实验室成都610041 出生缺陷与相关妇儿疾病教育部重点实验室成都610041 四川大学华西医院成都610041 黄石市中心医院(湖北理工学院附属医院) 湖北黄石435000 赣南医学院第一附属医院江西赣州341000 国家卫生健康委医疗管理服务指导中心北京100044 四川大学华西医院中国循证医学中心成都610041

目的系统评价全球指南临床适用性评价指标体系,为循证建立适用于我国诊疗环境的指南临床适用性评价指标体系提供依据。方法计算机检索PubMed、Embase、Cochrane Library、CNKI、WanFang Data和VIP数据库,搜集有关指南临床适用性评价指... 详细信息

目的系统评价全球指南临床适用性评价指标体系,为循证建立适用于我国诊疗环境的指南临床适用性评价指标体系提供依据。方法计算机检索PubMed、Embase、Cochrane Library、CNKI、WanFang Data和VIP数据库,搜集有关指南临床适用性评价指标体系的文献,检索时限均为建库至2022年11月。由2名研究员独立筛选文献、提取数据后,通过定性系统评价及主题分析法整理资料,形成评价条目池。结果共纳入82篇文献,获得指南临床适用性评价指标141个,其中第三级主题5个、分析性主题14个、描述性主题141个。第三级主题包括可获得性、可读性、可行性、可接受性和总体评价。可行性领域的影响因素包括医务人员因素、患者/患者家属因素、环境因素和指南因素。结论本研究系统性地梳理了指南临床适用性评价条目,为构建我国相关评价指标体系提供了循证参考。

关键词：指南临床适用性评价条目系统评价

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基于提采动作的便携式名优茶鲜叶采摘机

浙江农业学报 2024年第5期36卷 1161-1172页

作者：王洪成白子豪徐海浩徐凯黄阿龙王泽恩万菲张俐楠吴立群杭州电子科技大学机械工程学院浙江杭州310018

为缓解以龙井为代表的名优茶鲜叶采摘完全依赖人工的现状,提出一种基于鲜叶-老叶物理特性差异的鲜叶采摘方法,通过纯机械的弹性结构和柔性采摘单元实现鲜叶的自动化采摘。首先对鲜叶-老叶在生长高度、表观形态和茶叶茎断裂强度等物理特... 详细信息

为缓解以龙井为代表的名优茶鲜叶采摘完全依赖人工的现状,提出一种基于鲜叶-老叶物理特性差异的鲜叶采摘方法,通过纯机械的弹性结构和柔性采摘单元实现鲜叶的自动化采摘。首先对鲜叶-老叶在生长高度、表观形态和茶叶茎断裂强度等物理特性差异进行研究,作为采摘机结构和拉拔力参数设计的主要依据;在此基础上,受茶农手工采摘鲜叶时的“提采”动作启发,提出基于鲜叶上下表面摩擦力差异的鲜叶采摘机构,并对其进行采摘过程的动力学仿真分析;依据仿真结果,分别采用硅胶和特氟龙膜作为与鲜叶上下表面接触的柔性材料,结合动底板弹性结构、提供可调的拉拔力以避免采摘过程中鲜叶受损。茶园试验结果表明,当采摘力设置为3.0 N时采摘效果较好,鲜叶茎断裂位置取决于鲜叶茎断裂强度最小的位置,与人手工采摘时的断裂位置一致,鲜叶采净率约40%,老叶误采率约7%,茶叶损伤率约5%,采摘效率约1.44 kg·h^(-1)(相当于3个熟练采茶工)。该研究结果可为鲜叶的全自动机器采摘提供技术积累。

关键词：名优茶采茶机鲜叶老叶摩擦力

Structural Design and Dynamic Characteristics of Overloaded Horizontal Servo Cylinder for Resisting Dynamic Partial Load

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Chinese Journal of Mechanical Engineering 2019年第1期32卷 103-112页

作者： linan Ma Qingxue huang Lifeng Ma Qiangjun Ma Wenze Zhang Heyong Han Collaboration Innovation Center of Taiyuan Heavy Machinery Equipment Taiyuan University of Science and Technology Taiyuan University of Technology

When an output curve force is applied to a horizontal servo cylinder with a heavy load, the piston rod bears a dynamic partial load based on the installation and load characteristics, which significantly a ects the frequency response and control accuracy of the servo cylinder. Based on this partial load, increased friction can lead to cylinder bore scu ng, leakage, lack of output power, or even system failure. In this paper, a novel asymmetric static-pressure support structure is proposed based on the principle of hydrostatic support. The radial component force of a dynamic partial load is balanced by cooperation between the support oil cushion of the variable hydraulic pressure support structure, oil cushion of the supportive force, and the damper. Adaptive control of the servo cylinder piston rod, guide sleeve, and piston, as well as the cylinder oil film friction between lubricated surfaces is achieved. In this paper, theoretical design and analysis of the traditional hydrostatic bearing structure and novel structure are presented. A hydraulic dynamic shear scissor is used as a research target to derive a structural dynamic model. Comparative simulations are performed using Matlab Simulink. Additionally, flow field analysis of the novel structure is performed, which verifies the rationality and feasibility of the proposed structure and system.

关键词： Dynamic partial load Servo cylinder Asymmetrical static-pressure support structure Bearing characteristics

Morphometric measurement of the patella on 3D model reconstructed from CT scan images for the southern Chinese population

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Chinese Medical Journal 2014年第1期127卷 96-101页

作者： Shang Peng Zhang linan Hou Zengtao Bai Xueling Ye Xin Xu Zhaobin huang Xu Center for Translational Medicine Research and Development Shenzhen Institutes of Advanced Technology Chinese Academy ofSciences Shenzhen Guangdong 518055 China

Background Due to racial differences in the morphology of the knee joint and due to most prostheses available in the market being designed using measurements from Caucasians,the objective of this study was to provide the morphometric data of the patella for the southern Chinese population for total knee arthroplasty （TKA）,patellar resurfacing,and prostheses *** The CT slices of the knee joint were obtained from both knees of 40 Chinese volunteers （20 females,20 males,and age from 20-25 years） by performing a computer tomographic scan.A 3D model was reconstructed by Mimics software based on the computed tomography *** metrical characteristics were measured by digital *** analysis was performed with the SPSS statistical *** The mean,standard deviation and P values of measurements and ratios were calculated using *** dimensions showed a significant gender difference with P＜0.05,but the six variables of the left and right knees had no statistical significance with P＞*** addition,we studied the relationship between six couples （H-W,H-T,H-HAF,W-T,W-HAF,T-HAF） of the four variables （H：height,W：width,T：thickness and HAF：height of articulating facet） that were measured,which showed a significant *** Examination of the southern Chinese population revealed that males have larger patellae than *** both genders,comparing data between left and right knees shows no statistically significant *** with Westerners in previous studies,the patella in our study was thin and *** was a good linear regression correlation between measurements of the *** indirect measurement method on 3D models makes it easy to obtain anatomical data,and the results can provide a region and gender specific database for morphometric measurements of the oatella,and can be helpful for designing implants suited for southern Chinese patients.

关键词： morphometric measurement patella 3D model computed tomography southern Chinese population

基于电感耦合等离子体-串联质谱技术测定乳制品中26种无机元素

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乳业科学与技术 2024年第4期47卷 19-24页

作者：刘丽南王岩吴春敏王芳高镯曹梦杨琳琳张春林黄建辉河北省食品检验研究院河北省食品安全重点实验室国家市场监管重点实验室(特殊食品监管技术)特殊食品安全与健康河北省工程研究中心河北石家庄050227

建立电感耦合等离子体-串联质谱测定乳制品中26种无机元素的分析方法。在串联质谱条件下,选择无气模式、碰撞气(He)模式及反应气(H_(2)、O_(2)、NH_(3)/He)模式,分别对26种元素进行测定并筛选出最优测定模式。结果表明:每种元素在选用... 详细信息

建立电感耦合等离子体-串联质谱测定乳制品中26种无机元素的分析方法。在串联质谱条件下,选择无气模式、碰撞气(He)模式及反应气(H_(2)、O_(2)、NH_(3)/He)模式,分别对26种元素进行测定并筛选出最优测定模式。结果表明:每种元素在选用合适的测定模式下能够获得线性良好的标准曲线,相关系数均大于0.9990;26种无机元素的检出限范围为0.00003361~0.04371 mg/kg,加标回收率在95.50%~104.21%之间,11次重复分析的相对标准偏差3.94%;6种乳制品中含量较高的元素为Na、Mg、K、Ca、P、Fe、Zn,而重金属元素Cr、As、Cd、Pb的含量较低,均低于国家标准的限量要求。该方法样品前处理简单、灵敏度高、检出限低,测定结果准确,可用于乳制品中无机元素的检测。

关键词：电感耦合等离子体-串联质谱乳制品无机元素干扰消除原位质量法

西部地区生态状况变化及生态系统服务权衡与协同

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地理学报 2022年第1期77卷 182-195页

作者：牛丽楠邵全琴宁佳黄海波中国科学院地理科学与资源研究所中国科学院陆地表层格局与模拟重点实验室北京100101 中国科学院大学资源与环境学院北京100049

西部大开发战略实施20年以来,一系列重大生态建设工程使得西部地区的生态状况和生态服务发生了重要变化,本文分析西部地区生态状况变化及其生态服务时空变化特征,并运用相关分析法研究其服务功能权衡协同关系。研究发现西部地区2000—2... 详细信息

西部大开发战略实施20年以来,一系列重大生态建设工程使得西部地区的生态状况和生态服务发生了重要变化,本文分析西部地区生态状况变化及其生态服务时空变化特征,并运用相关分析法研究其服务功能权衡协同关系。研究发现西部地区2000—2019年间:①聚落和湿地生态系统面积显著增加,草地有逐年下降趋势。②植被覆盖度呈波动上升趋势,存在年际差异且空间差异较大。③水源涵养服务有轻微下降趋势,下降区域主要分布在藏东南地区、三江源西部地区、喀斯特石漠化地区等;土壤保持服务波动中呈上升趋势,上升区域主要黄土高原地区、川滇西部地区、藏西北地区、藏东南地区等;防风固沙服务呈下降趋势,大幅下降区域主要位于内蒙古中西部地区、西藏和北疆部分地区。④生态系统供给与水源涵养、土壤保持主要为协同关系,与防风固沙主要为权衡关系且分布在农牧交错带地区。⑤生态工程区内生态系统服务协同程度大于非工程区。定量评估生态系统服务变化及其权衡协同关系有助于进行科学化生态管理,最大化生态效益。

关键词：生态系统服务权衡协同关系西部地区西部大开发

Potential land for plantation of Jatropha curcas as feedstocks for biodiesel in China

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Science China Earth Sciences 2010年第1期53卷 120-127页

作者： WU WeiGuang 1,2,3,huang JiKun 1,3 & DENG XiangZheng 1,3 1 Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 2 Department of Economics and Management,Zhejiang Forestry University,linan 311300,China 3 Center for Chinese Agricultural Policy,Chinese Academy of Sciences,Beijing 100101,China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Department of Economics and Management Zhejiang Forestry University Linan China Center for Chinese Agricultural Policy Chinese Academy of Sciences Beijing China

As a renewable energy,biofuel has attracted great attention in China and the rest of *** with the national food security,China recently has shifted its biofuel development priority from grain-based to non-grain-based biofuels,including forest-based biodiesel,since *** curcas is one of major biodiesel ***,there is rising debate on availability of land for expanding Jatropha curcas *** overall goal of this paper is to evaluate potential land for Jatropha curcas used as feedstock for biodiesel in *** on remote sensing data on land use,data on meteorological,soil and land slope,and suitable environment for Jatropha curcas plantation,this study uses Agro Ecological Zone method and considers social-economic constraints to evaluate potential suitable land for Jatropha curcas plantation in China's major Jatropha curcas production region,Southwest *** results show that while there are some potential lands to expand Jatropha curcas areas,amount of these lands will hardly meet the government's target for Jatropha curcas-based biodiesels development in the *** may need to reconsider its long-term targets on the development of Jatropha curcas-based biodiesels.

关键词： biodiesel Jatropha curcas potential land suitability evaluation Southwest China