近25 a 银川市城市化进程中热力景观格局演变分析

Abstract： Based on the Landsat images and statistical data，in this paper the urbanization process and thermal landscape dynamics of Yinchuan City were analyzed． The objectives of this study were as follows: ① To analyze the spatial and dynamic characteristics of urban thermal landscapes based on the landscape pattern index; ② To assess the influence of the urbanization process on the thermal landscapes; ③ To understand the relationship between the land use pattern and the land surface temperature ( LST) based on the distribution index． The results showed that there was a significant heat-island effect in Yinchuan City，and the high temperature area was consistent with the built-up area and the unused land． LST declined from the downtown to the suburbs，and an obvious difference of the dynamic characters of the thermal landscapes could be identified at the different stages of urbanization． LST for various land use had obvious discrepancies，the mean LST for the land use types was in a descending order of unused land，construction land，green land and water body． Different land use types had different thermal distribution at different stages of urbanization． The land use pattern influenced the urban thermal environment，especially the spatial distribution of green land and unused land affected LST more significantly

长江口邻近海域夏季大中型浮游动物物种多样性、年际变化及其影响因素

利用2014—2016年毎年7月在长江口邻近海域进行的大面调查所采集的浮游动物样品,对该海域夏季大中型浮游动物的种类组成及种数平面分布进行了分析,同时结合环境参数,研究了种类组成、种数平面及年际变化的影响因素.研究结果表明:长江口邻近海域3年共鉴定大中型浮游动物165种,隶属7个门的17个类群;桡足类和水螅水母类是每年夏季优势类群;调查区大中型浮游动物种类分布大致呈现近岸低、远岸高、南部高于北部的特征;大中型浮游动物种类数没有明显的年际变化,但是种类组成有明显的年际更替.Pearson相关性分析结果显示:盐度、温度和溶解氧是影响大中型浮游动物种类数平面分布的主要环境因素;复杂的水文环境及台风过境的剧烈影响可能是造成该区域大中型浮游动物种类组成年际变化的主要原因.国家自然科学基金(41676133,J1310037);;福建省自然科学基金(2016J01196);;国家海洋局近岸海域生态环境重点实验室项目;;厦门大学校长基金(20720170077);厦门大学大学生创新创业训练计划项目(201610384120,103842017046

MRI 在阿尔茨海默病与血管性痴呆中的鉴别价值

【目的】对比阿尔茨海默病（AD）和血管性痴呆（VaD）的脑区体积及脑白质高信号（WMH）差异，并探究 MRI 对 AD 与 VaD 的鉴别诊断价值。【方法】回顾性分析 35 例 VaD 和 74 例 AD 患者的临床资料和 MRI 影像资料。利用AccuBrainTM 提取不同脑区及WMH 的体积测量值，并利用视觉评分量表评估所有患者WMH；比较AD与VaD 脑区体积及WMH  差异，鉴别诊断采用主成分分析（PCA）和logistic  回归模型两种方法，最后评价各指标的诊断效能。【结果】①AD 组颅内总体积、脑实质、脑灰质、脑白质、海马、杏仁核、下丘脑、额叶（左、右）、枕叶（左、右）、颞叶（左、右）、顶叶（左、右）、海马（左、右）、杏仁核（左、右）、下丘脑（左、右）体积均较VaD 组减小，且差异具有统计学意义（P<0.05）；②深部WMH（DWMH）视觉评分在AD 和VaD 患者之间的差异具有统计学意义（P= 0.015）；并且VaD 组WMH 绝对与相对体积高于AD 组，差异均具有统计学意义（P<0.05）；③经过PCA 后发现重要的参数有8 个，分别为脑实质、海马、杏仁核、下丘脑、额叶（左）、枕叶（左）、颞叶（左）、顶叶（左）；基于logistic 回归分析，形成了包括杏仁核、WMH 绝对体积和枕叶（左）组成的鉴别模型。④其中鉴别模型效能最佳，鉴别 AD 与VaD 的敏感度为81.1%，特异度为74.3%。【结论】VaD 与AD 患者部分脑区体积及WMH 严重程度具有显著差异。脑MRI 对鉴别VD 与AD 具有较高的价值

Simultaneous determination of 7 nucleosides in Asterias rollestoni using reversed-phase high performance liquid chromatography

建立了罗氏海盘车中7种核苷化合物的反相高效液相色谱分析测定方法。采用超声波辅助提取,选用两根不同的C18色谱柱串联,以甲醇和0.2%(体积分数)乙酸/水溶液为流动相梯度洗脱分离。优化的色谱条件为:柱温为室温,检测波长为260nM,流速为0.8Ml/MIn,进样量为20μl。结果表明,7种核苷化合物在一定的浓度范围内线性关系良好,次黄嘌呤和胸苷的线性范围为0.65~40Mg/l,尿苷、黄嘌呤和肌苷的线性范围为0.80~40Mg/l,胸腺嘧啶的线性范围为1.15~40Mg/l,鸟苷的线性范围为0.50~40Mg/l。样品中7种核苷化合物的加标回收率为90.00%~105.00%,相对标准偏差为0.72%~3.23%。该方法操作简便、灵敏度高、重复性好,回收率高,适用于罗氏海盘车中7种核苷类成分的同时分析,也可用于罗氏海盘车的质量控制和综合评价。A method for the simultaneous determination of 7 nucleosides in Asterias rollestoni was devel-oped using reversed-phase high performance liquid chromatography ( RP-HPLC) .Analytes were extracted by ultrasonic-assisted extraction and separated on two different C18 columns,which were connected in se-ries,under the gradient elution with the mobile phases of methanol and 0.2% ( v/v) acetic acid/water at room temperature.The chromatographic conditions were as follows: flow rate,0.8 mL/min; detection wavelength,260 nm; injection volume,20 μL.Under the optimized conditions,good linear relationships between the values of mass concentrations and the peak areas of hypoxanthine,uridine,xanthine,thy-mine,inosine,guanosine and thymidine were observed in the ranges of 0.65-40,0.80-40,0.80-40,1.15-40,0.80-40,0.50-40,and 0.65-40 mg/L,respectively.The relative standard devia-tions were around 0.72%-3.23% and the recoveries were around 90.00%-105.00%.The results showed that the developed method is sensitive,accurate and reproducible.It is suitable for the analysis of nucleosides in Asterias rollestoni with high recoveries and it is expected to be used for the quality control and evaluation of Asterias rollestoni.国家自然科学基金项目(20905017);海洋公益性行业科研专项(200705011;200805039);海洋局青年基金项目(2010140);海洋一所基本科研业务专项(GY-022008T32;2010G25);中国科学院实验海洋生物学重点实验室开放基金课

People's Sense of Gain in Poverty Alleviation: An Empirical Study of the Case in Guangxi Ethnic Areas

精准扶贫思想是新时代中国特色社会主义思想的重要组成部分,也是马克思主义反贫困理论中国化的最新贡献。本研究以广西7个乡镇613户贫困户为对象进行问卷调查,运用SPSS25.0对民族地区精准扶贫过程中贫困群体的人民获得感相关问题进行实证研究。研究发现:政府承诺与政府信任对人民获得感都有显著的正向促进作用,即政府承诺和政府信任越高,人们就越容易产生获得感。而且政府信任在政府承诺与人民获得感之间发挥着部分中介作用。本研究从贫困群体的物质与精神需求层面去分析问题,为政府更好地处理精准扶贫中的问题提供经验依据。The thought of poverty alleviation is a key part of the thought on socialism with Chinese characteristics for a new era. It is a latest contribution to the poverty elimination theory of the Marxism. The paper makes an empirical study of relative issues of the people-in-poverty's sense of gain in the poverty alleviation with SPSS 25.0, for which 613 poverty-stricken households in 7 towns were selected to finish the questionnaire survey. The study shows the governments' commitment and trust play a positive role in increasing people's sense of gain. The higher the governments' commitment and trust lead to people's higher sense of gain. Another finding is the governments' trust plays an intermediary role between the governments' commitment and people's sense of gain. The study makes analysis in the perspective of poor people's material and spiritual needs and provide experience for the government to handle the problems in the poverty alleviation in a better way.：广西哲学社会科学规划研究课题(18FGL008)； 广西壮族自治区“八桂学者”项目(BGXZ2015003

Mechanism of Soil Potassium Loss by Erosion in Loess Area

根据有关文献资料,从形态、有效性、与侵蚀的关系、影响因素和流失模型等方面,对黄土区土壤钾素径流流失机理的研究作一综述。文章指出进一步深入研究黄土区土壤钾素径流流失机理十分必要

耗能梁段布置方式对含可更换剪切型耗能梁段的高强钢框筒结构抗震性能的影响

针对传统钢框筒结构地震耗能差、震后修复难度大和难以实现"强柱弱梁"的设计理念等问题,提出了一种新型高层钢结构体系——含可更换剪切型耗能梁段的高强钢框筒结构(HSS-FTS)。为研究耗能梁段布置方式对HSS-FTS抗震性能的影响,设计了30层的HSS-FTS系列算例并建立其有限元模型,依据提出的耗能梁段布置原则,给出了6种不同的耗能梁段布置方式。验证了有限元建模的合理性,对有限元模型分别进行反应谱分析、静力Pushover分析和动力弹塑性时程分析。分析结果表明:HSS-FTS改善了传统钢框筒结构的耗能能力,主要依靠耗能梁段塑性剪切变形耗散地震能量。不同的耗能梁段布置方式对结构的基底剪力、层间侧移角、承载能力、耗能能力、剪力滞后效应、塑性铰发展模式以及震后残余层间侧移角均有显著影响,但对结构的整体抗侧刚度影响较小。耗能梁段采用间隔布置3跨或连续布置5跨时,HSS-FTS在强震下的层间侧移角分布均匀,没有薄弱层出现,对震后残余层间侧移角的控制效果更为显著,且具有优良的耗能能力和理想的整体失效模式

扬矿管在海水中的整体运动分析

在对扬矿管进行受力分析的基础上，运用有限元的方法将5000m扬矿管等分成20个两节点梁单元，将梁单元受力简化，推导出梁单元运动方程。将单元总装成整体结构，并将节点力加到具体节点上，得出整体结构运动方程，用ADINA得到扬矿管整体运动的动态响应解。分析扬矿管的整体运动过程，扬矿管的横向、纵向振动及变形与各因素的关系，其结果可作为扬矿管设计和操作控制的依据。同时提出减小扬矿管变形和振动的措施