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delta工艺中Inconel 718合金中δ相的演变机制

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金属学报 2009年第12期45卷 1451-1455页

作者：张海燕张士宏程明中国科学院金属研究所沈阳110016

针对Inconel 718合金的delta工艺,采用金相显微镜、扫描电镜和定量X射线衍射技术研究了变形温度为950℃、应变速率为0.005 s^(-1)的等温压缩变形中δ相的演变机制.结果表明:在变形前的加热和保温阶段,时效处理过程中晶内析出的颗粒/短... 详细信息

针对Inconel 718合金的delta工艺,采用金相显微镜、扫描电镜和定量X射线衍射技术研究了变形温度为950℃、应变速率为0.005 s^(-1)的等温压缩变形中δ相的演变机制.结果表明:在变形前的加热和保温阶段,时效处理过程中晶内析出的颗粒/短棒状δ相全部溶解消失,δ相含量由8.14%降低为7.05%;在变形过程中δ相发生了溶解,含量由7.05%进一步降低为5.14%;由于变形断裂和溶解断裂的综合作用,片层/长针状δ相发生球化,由片层/长针状δ相转变为颗粒/短棒状δ相;在变形量最大的芯部,片层/长针状δ相全部消失,颗粒/短棒状δ相分布于晶内与晶界.

关键词： Inconel 718合金 delta 工艺 δ相变形球化

The comprehensive evaluation on resource environmental bearing capacity of central cities in the Yellow River delta-A case study on Dongying City

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Journal of Groundwater Science and Engineering 2017年第4期5卷 354-363页

作者： WANG Kui-feng XU Meng CHEN Xiao-man Shandong Institute and Laboratory of Geological Sciences Key Laboratory of Geological Process and Resource Utilization of Metallic Minerals in ShandongKey Laboratory of Gold Mineralization Process and Resource Utilization Subordinate to the Ministryof Land and ResourceJinan 250013China Key Laboratory of Assessing Resource Environmental bearing capacity Ministry of Land and Resources(Chinese Academy of Land and Resource EconomicsChina University of Geosciences in Beijing)Beijing 101149China School of Civil Engineering Shandong UniversityJinan 250061China Guangdong Research Center for Geoanalysis GuangzhouGuangdong Province 510080China

Dongying City, which is the most important central city in the Yellow River delta, is located in the estuary of the Yellow River. With a short land formation time, ecological environment is very weak in this area. To realize the sustainable economic development of the Yellow River delta, resource environment and resource environmental bearing capacity(REBC) must be improved. This study builds assessment system of regional REBC through resource and economic characteristics in Yellow River delta and uses principal component analysis(PCA) method to evaluate REBC of five counties and districts in Dongying City in 2011-2015 on the dimensions of time and space. Results show that, on the time dimension, Guangrao County is ranked first, Dongying district second for four years and Hekou and Kenli districts with lower ranks in 2012-2015, indicating that more attention needs to be paid to REBC of Hekou and Dongying districts and these two districts should be included into key monitoring areas. From space scale, REBC in five counties and districts has been gradually improving. In order to further develop REBC in Dongying City, measures such as intensifying protection of urban ecological environment and developing circular economy, etc. should be implemented.

关键词： Resource environmental bearing capacity Dongying City Comprehensive evaluation Yellow River delta

Spatial-temporal analysis of wetland landscape pattern under the influence of artificial dykes in the Yellow River delta

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Chinese Journal of Population,Resources and Environment 2013年第2期11卷 109-117页

作者： Xin Fu Gaohuan Liu Siyue Chai Chong Huang Fadong Li State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchCAS Graduate University of Chinese Academy of Sciences Yucheng Comprehensive Experiment Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchCAS

The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal *** is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal *** study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt *** results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the *** dykes created conditions for the development of artificial ***,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period.

关键词： artificial dykes coastal wetland coastal zone of the Yellow River delta landscape pattern spatial-temporal analysis

Institutions and water governance in the Okavango delta, Botswana

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Chinese Journal of Population,Resources and Environment 2019年第1期17卷 67-78页

作者： Reniko Gondo Oluwatoyin Dare Kolawole Joseph E. Mbaiwa Okavango Research Institute University of Botswana Maun Botswana

The goals of Integrated Water Resources Management (IWRM) can be achieved by embracing the principles of distributive governance, which places both customary and statutory water institutions on the same pedestal in the governance of water resources. As culture and traditions constitute intangible aspects of water resources management in rural Africa, the recognition of water governance systems grounded in local norms, which correspond better with the aspirations of local water users as against the expert-knowledge systems is desirable. Following the introduction of the statutory institutions in postcolonial Africa, customary institutions, which were once effective in regulating water resources became relegated to the background in those countries, including Botswana . Adopting a critical literature review approach, this article employs the concept of legal pluralism to analyze the institutional factors that create the disharmony between cultural and statutory water governance and management institutions. Findings indicate that water has been abstracted from its social nature and transformed into a tradable economic good. Ultimately, the local meanings and images encoded in water as a nature-given resource are overlooked, thus generating conflicts in water governance. The paper recommends the adoptions of legal pluralism under which water institutions need to embrace both customary and statutory institutions.

关键词： Botswana customary institutions legal pluralism Okavango delta statutory

Arsenic distribution and source in groundwater of Yangtze River delta economic region, China

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Journal of Groundwater Science and Engineering 2017年第4期5卷 343-353页

作者： ZHOU Xun School of Environment Studies China University of Geoscience Nanjing Center China Geology Survey

This thesis focuses Arsenic(As) distribution and occurrence in groundwater of Yangtze River delta economic region, East China. 2019 groundwater samples were collected to analyze 26 chemical compositions, including As. The Principal Component Analysis(PCA) was used to find out As source in groundwater. The results show that average As concentration in groundwater of this study is 9.33 μg/l, and maximum As concentration is up to 510 μg/l. The variation coefficient is 314.34%. High arsenic phreatic water(>10 μg/l) distributes along the Yangtze River and its estuary. Weak hydrodynamic conditions, wide p H value variation range and deteriorating environment are dominating factors, especially in Yangtze River delta. The PCA suggests that arsenic in phreatic water is mainly of natural origin. Part of arsenic may directly originate from sediment organics and be related to organics decomposition.

关键词： Groundwater Arsenic Distribution Source Yangtze River delta economic region

Estimation on wetland loss and its restoration potential in Modern Yellow River delta,Shandong Province of China

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Chinese Journal of Population,Resources and Environment 2015年第4期13卷 365-372页

作者： Baolei Zhang Le Yin Shumin Zhang Kai Liang College of Population Resources and EnvironmentShandong Normal University Institute of Regional Economic Research Shandong University of Finance and Economics

Wetland is one of the most important ecosystems with varied functions and structures,and its loss has been a major *** loss in Modem Yellow River delta(MYRD) becomes a serious environmental problem,so its restoration attracts a great deal of attention from academia and *** article proposes a GIS-based multi-criteria comprehensive evaluation methodology for potential estimation of wetland restoration,using MYRD as an *** model uses four kinds of data(hydrology,terrain,soil,and land use) and could be adapted by planners for use in identifying the suitability of locations as wetland mitigation sites at any site or *** the application of the model in the MYRD,the research developed a lost wetland distributed map taking the better wetland situation of 1995 as the reference,and elevated the overall distribution trends of wetland restoration potential based on wetland *** results indicated that the total area of wetland loss from 1995 to 2014 was 568.12 km^2,which includes 188.83 km^2 natural wetland and 21.80 km^2 artificial wetland,*** areas of lost wetland with low,middle,and high resilience ability are 126.82 km^2,259.92 km^2,and 119.59 km^2,occupying 25.05%,51.33%,and 23.62%,*** high-restoration-potential wetland included98.47 km^2 of natural wetland and 21.12 km^2 of artificial wetland,which are mainly bush,reed,and *** highrestoration-potential wetland is mainly distributed in the vicinity of Gudong oil field,the Yellow River delta protected areas,and the eastern sides of Kenli county and Dongying city.

关键词： wetland loss restoration potential comprehensive evaluation Modern Yellow River delta

SARS-CoV-2 delta突变株感染者核酸复阳的临床特征和传染性分析及其机制研究

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SARS-CoV-2 Delta突变株感染者核酸复阳的临床特征和传染性分析及...

作者：唐婧艳广州医科大学

学位级别：硕士

研究背景SARS-CoV-2,简称新冠病毒,造成新冠肺炎(COVID-19)的持续暴发给全球公共卫生带来了严重威胁。自新冠肺炎暴发以来,大量患者达到出院标准出院,出于疫情防控的特殊需求,我国制定了出院后继续进行14天隔离管理和健康状况监测的规定... 详细信息

研究背景SARS-CoV-2,简称新冠病毒,造成新冠肺炎(COVID-19)的持续暴发给全球公共卫生带来了严重威胁。自新冠肺炎暴发以来,大量患者达到出院标准出院,出于疫情防控的特殊需求,我国制定了出院后继续进行14天隔离管理和健康状况监测的规定,部分康复者在隔离点观察或后期的居家隔离期间,出现了鼻咽拭子或肛门拭子或痰液等样本复检病毒核酸再次阳性(简称复阳)的现象。由于复阳者的传染性未知,复阳者需到定点医院接受隔离观察,患者因病毒核酸复阳问题长期留院或反复来院,加重了医疗负担,严重影响患者正常的生活并使COVID-19患者的管理复杂化。本研究重点对广州医科大学附属市八医院收治的SARS-CoV-2 delta突变株广州本土及入境复阳病例的临床特征、病毒学、流行病学等方面进行分析并研究接种疫苗和使用中和抗体治疗对病毒核酸复阳的影响以间接探索复阳发生的原因,这对于新冠肺炎防控管理、人群传播和了解该病自然史等具有至关重要的意义。第一部分SARS-CoV-2 delta突变株感染者核酸复阳的临床特征和传染性分析研究目的总结新冠病毒delta株感染者出院后病毒RNA复阳的特点,探究这部分人群是否对公共卫生构成传染风险及评估其自身恢复情况。研究方法1.横断面调查delta株感染者复阳率及其受年龄、性别、症状、基础疾病史等因素的影响,并比较分析复阳组与康复组入院时实验室检测指标的差异。2.通过采集复阳阶段患者的鼻咽拭子行活病毒培养实验,并对与复阳患者社区密切接触者进行流行病学调查,评估复阳患者的传染风险。3.统计分析复阳阶段患者的临床症状并采用AI评分定量分析肺部炎症程度及炎症好转速度,从而评估复阳阶段是否需要进一步治疗。研究结果***-CoV-2 delta株感染的158例本土患者中有77例(48.73%)复阳,679例入境患者中有437例(64.36%)复阳。复阳组与康复组在年龄、性别、症状和基础疾病史均无统计学差异(P值均>0.05)。入境的复阳组在入院时淋巴细胞、嗜酸性粒细胞、嗜碱性粒细胞较康复组低,乳酸脱氢酶和淀粉样蛋白A较高(P值均delta株感染后复阳现象是普遍存在的,实验室检测不能预测复阳的发生,复阳患者住院阶段病毒核酸峰值与康复者水平相当,其复阳阶段病毒RNA载量低、分离不出病毒、无社区传播事件发生、传染性风险小,复阳阶段绝大部分患者的肺炎进一步吸收且无明显临床症状,少数患者有轻微的临床症状,无需进一步延长住院治疗。第二部分SARS-CoV-2 delta突变株感染者核酸复阳的潜在机制研究研究目的比较不同SARS-CoV-2突变株的复阳率、发生复阳的组织部位,分析接种疫苗和使用中和抗体(BRII-196/198)治疗对复阳率的影响以进一步探索SARS-CoV-2 delta株RNA复阳的潜在机制。研究方法1.横向研究不同SARS-CoV-2突变株的复阳率、复阳发生的组织部位。2.统计分析接种疫苗对复阳率的影响,并用PBMC做转录组测序分析接种疫苗对个体免疫谱的影响。3.统计分析中和抗体的使用对复阳率的影响。研究结果***株感染者复阳率为61.41%(514/837)、Omicron株感染者复阳率为39.53%(119/301)、野生株的为7.27%(21/289)。与野生株RNA复阳主要出现在胃肠道(71%)不同,delta株RNA复阳绝大部分出现在上呼吸道(90%)。2.接种疫苗后delta株突破性感染者RBD-Ig G抗体水平显著高于未接种疫苗感染者,但疫苗突破性感染者复阳率并未降低(65.52%,266/406)。接种两针灭活疫苗突破性感染者中,复阳组和康复组的RBD-Ig G动态水平相似,复阳者与康复者住院天数无统计学差异(复阳者VS康复者住院天数:7.7

关键词： SARS-CoV-2 delta 复阳疫苗中和抗体 Omicron

基于轨迹晶格与综合动力灵巧度的delta机器人轨迹规划

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振动与冲击 2016年第22期35卷 31-37页

作者：郑坤明张秋菊江南大学机械工程学院江苏无锡214122 江苏省食品先进制造装备技术重点实验室江苏无锡214122

针对高速、柔性化delta机器人轨迹规划中的精度与振动稳定性问题,提出一种基于轨迹晶格与综合动力灵巧度的轨迹规划方法。首先,根据前期的研究工作,建立了含关节间隙的delta机器人系统完整弹性动力学模型;其次,定义了delta机器人综合动... 详细信息

针对高速、柔性化delta机器人轨迹规划中的精度与振动稳定性问题,提出一种基于轨迹晶格与综合动力灵巧度的轨迹规划方法。首先,根据前期的研究工作,建立了含关节间隙的delta机器人系统完整弹性动力学模型;其次,定义了delta机器人综合动力灵巧度,并基于此,提出了操作空间中微小晶格与轨迹晶格的概念;然后,以综合动力灵巧度为依据,考虑各种约束条件,在轨迹晶格中进行基于修正梯形模式的轨迹规划;最后,利用激光跟踪仪与动态信号采集设备,对提出的轨迹规划策略进行了实验分析。结果表明:所提出的轨迹规划策略能够精确、稳定地实现机器人的抓取与放置动作。

关键词： delta 机器人轨迹晶格综合动力灵巧度完整弹性动力学模型轨迹规划

Targeting glioblastoma with oncolytic adenovirus delta 24

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Neuroimmunology and Neuroinflammation 2015年第1期2卷 1-3页

作者： Konstantinos I.Tsamis George A.Alexiou Athanassios P.Kyritsis Department of Neurology Medical SchoolUniversity of Ioannina45500 IoanninaGreece

ONCOLYTIC VIRUSES Oncolytic viruses have been introduced in cancer treatment in the last two decades,offering new opportunities and hopes for ultimate *** studies had also tried to take advantage of the antineoplastic activity of natural viral species,but it was genetic engineering that led to the production of modified viral strains selectively infecting and killing neoplastic cells.[1]The two major characteristics of oncolytic viruses are their tropism for malignant cells and their augmented cytotoxicity.

关键词： cytotoxicity delta offering