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以某奥体中心体育场钢结构屋盖为研究对象，对其加固及施工方案进行了分析。首先进行模型反建，并对该屋盖在施加新增荷载后的内力及变形进行分析，明确了需要加固的杆件范围。在此基础上，采用有限元软件对结构开展精细化分析，确定了包含加强节点、杆件和结构的加固方案，有效地改善了结构的传力体系，提高了结构的承载能力并降低了结构在使用荷载下的应力和变形。针对钢屋盖的不同部位，分别通过预应力锚索、增大截面和设置刚性圆管等方式进行加固，保证结构安全且满足建筑要求。除此之外，还对该加固方案对应的施工过程进行了有限元模拟，可为实际施工提供参考。经省运会工程实践验证，本项目的加固方法简单有效。

为了解哈尼梯田鸟类群落结构及多样性构成，探讨不同农田类型和不同季节中鸟类群落变化特征。2019年7月—2020年4月，采用样线法对哈尼梯田4个季节分别进行鸟类专项调查。结果显示：共记录到鸟类86种，隶属10目37科，其中包括国家二级重点保护野生动物4种，分别是褐翅鸦鹃（Centropus sinensis）、小鸦鹃（C.bengalensis）、普通鵟（Buteo japonicus）和红隼（Falco tinnunculus）；中国脊椎动物红色名录近危（NT）物种1种，即银耳相思鸟（Leiothrix argentauris）；数据缺乏（DD）1种，为蓝喉拟啄木鸟（Psilopogon asiatica）。雀形目（Passeriformes）鸟类最多，共计27科69种。繁殖鸟类共74种，占鸟种数的86%，东洋种43种，占繁殖鸟类的58%，其余是广布种。居留类型以留鸟为主，64种，占74%，夏候鸟和冬候鸟各记录到10种。不同农田微生境类型下，旱田的丰富度、Shannon-Wiener多样性指数、Pielou均匀度指数和G-F指数均高于水田，但Shannon-Wiener指数（F=0.206，p>0.05）和Pielou均匀度指数（F=0.211，p>0.05）差异不显著。不同季节Shannon-Wiener指数（F=1.515，p>0.05）和Pielou均匀度指数（F=0.805，p>0.05）差异也不显著，优势度春季和冬季较高，夏季和秋季较低，相似性指数夏季和冬季最高，春季和秋季较低。从鸟类优势种来看，以人类伴生鸟类和适应人为干扰活动的鸟类为主要优势种。研究结果既掌握了哈尼梯田鸟类资源现状，还为开展农业生态系统的生物多样性服务功能提供基础数据。

目的基于简单易得的临床资料，开发并验证２型糖尿病（T2DM）患者并发威胁视力的视网膜病变（VTDR）的风险预测模型，为基层医院提供便捷有效的预测工具，以便早期识别和转诊高危人群。方法使用2017年至2020年广州糖尿病眼病研究中T2DM患者临床数据构建列线图预测模型。使用Logistic回归分析VTDR的影响因素并建立模型，受试者工作特征曲线（ROC）、Hosmer-Lemeshow检验、校准曲线、决策曲线（DCA）用于评价模型的性能。使用k折交叉验证得到的平均ROC下面积对模型进行内部验证，使用东莞眼科研究数据对模型进行外部验证。结果建模集共纳入患者2 161例，并发VTDR者135例（6.25%）。年龄（P＜0.001，OR=0.927，95%CI：0.898~0.957）、体质量指数（P＜0.001，OR =0.845，95%CI：0.821~0.932）与VTDR负相关，糖尿病病程（P＜0.001，OR=1.064，95%CI：1.035~1.094）、是否使用胰岛素（P =0.045，OR =1.534，95%CI：1.010~2.332）、收缩压（P＜0.001，OR =1.019，95%CI：1.008~1.029）、糖化血红蛋白（P＜0.001，OR =1.484，95%CI：1.341~1.643）和血清肌酐（P＜0.001，OR =1.017，95%CI：1.010~1.023）与VTDR正相关，均被纳入模型。ROC提示建模集和验证集中该模型预测VTDR发生的曲线下面积分别为0.797和0.762；Hosmer-Lemeshow检验（P＞0.05）及校准曲线表明预测概率与观测概率具有较高一致性；DCA表明模型在建模集和验证集中均能产生净效益。结论年龄、糖尿病病程、是否使用胰岛素、体质量指数、收缩压、糖化血红蛋白和血清肌酐是VTDR的独立影响因素，基于上述变量构建的列线图模型有良好的预测效力，可以为基层医院早期识别和转诊VTDR提供科学依据，值得应用推广。

建立圆形、正方形、圆端形、六边形钢管混凝土柱在火灾下的有限元模型,利用现有试验结果验证有限元模型。基于该模型,研究保护层种类、保护层厚度、截面形状和截面周长等参数对钢管混凝土柱耐火极限的影响。分析表明,试件耐火极限随着保护层厚度和截面周长的增加而增大。厚涂型涂料的防火效果优于砂浆的防火效果。在长细比和截面周长相同的情况下,圆端形钢管混凝土柱的耐火极限高于圆形钢管混凝土柱;六边形钢管混凝土柱的耐火极限优于方钢管混凝土柱;绕强轴破坏的耐火极限略低于绕弱轴破坏的情况。基于周长等效原则,可将圆端形(或六边形)钢管混凝土柱视为圆形(或正方形)钢管混凝土柱进行抗火设计。

四轴飞行器控制活动杆件或装水酒杯平衡是一项难度系数极大的任务，所构成的模型称为四轴飞行器—倒立摆不倒平衡控制系统。基于这种特殊形式的倒立摆不倒平衡控制模型，在X-Z平面简化为线性不倒模型进行分析，建立其动力学模型，并结合滑模控制的算法，设计系统的控制器并进行仿真实验。利用滑模控制算法对四轴飞行器—倒立摆不倒平衡控制系统进行控制，实验结果表明，其表现出了优异的不倒稳定性。

2002年11月20日,笔者与荣成市野生动物保护站的同志在大天鹅自然保护区进行鸟类调查时,发现了3只黑脸琵鹭在此栖息。 调查时正于退潮,黑脸琵鹭正在浅水处觅食。保护区三面环海,生物多样性十分丰富,是众多水禽的迁徙停歇地和越冬地。当时与黑脸琵鹭同时混居的还有大天鹅、黑雁、白额雁、绿头鸭、花脸鸭、针尾鸭等鸟类8000余只。 该鸟通体白色,嘴基、额、脸、眼先、眼周,往下一直到喉,

利用聚丙烯酰胺凝胶垂直板电泳法对产后30小时死亡的大熊猫幼仔的七种组织（心肌、肝、肾、骨骼肌、肺和肾上腺）的LDH同工酶的酶谱进行了分析。结果显示,其酶谱与成体大熊猫尸体组织的酶谱基本一致,也呈现出明显的组织特异性。同时进一步提供了七种组织对应酶带的迁移率基本一致,幼仔肝脏的LDH2含量较多及小肠的LDH同工酶酶谱等新资料。此外实验还证实经急冻（-20℃）保留一段时间的大熊猫幼仔组织器官的LDH同工酶酶谱较稳定,可做电泳分析。大熊猫（Ailuropoda melanleuca）是世界珍稀动物之一,我国的国宝。近年来,对大熊猫研究主要有野外生态调查、形态解剖、人工驯化及饲养繁殖,还有少量生化方面的研究,其中主要是血清学的研究。由于大熊猫的新鲜整体和组织材料难以得到,冯文和等曾对成体大熊猫尸体组织的LDH同工酶进行了研究。本文对出生后30小时死亡的大熊猫幼仔的七种组织的LDH同工酶进行分析,旨在探讨大熊猫幼仔与成体LDH同工酶酶谱的异同及整体冰冻贮存对组织同工酶的影响。

成大天鹅自然保护区位于山东半岛最东端的荣成市境内,保护区南、北、东三面濒,临黄海,由众多港湾和浅海滩涂组成,总面积10500hm2,属野生动物及湿地生态系统类型自然保护区。该保护区属暖温带季风型湿润气候区,四季分明,光照充足,雨热同期。年平均气温11.1℃,是山东沿海年均气温

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Underground pipelines will be damaged under the action of external loads and human factors, resulting in ground collapse. To investigate the impact of particle shape on ground subsidence following pipeline breakage, numerical simulations strata subsidence were conducted by PFC-2D. About 3 kinds of coarse particle shapes were defined by PFC-2D, and the effects of particle shapes on formation loss, surface settlement and collapse form were analyzed. The simulation results show these as follou's. The time required for the classification is shortest when particles of different shapes reach the same degree of settlement at the center. The relative motion angle is defined to distinguish between particles that are relatively stationary during collapse. It is determined that the range of the soil stratum affected increases as the particle shape becomes more regular. There are variations in the sliding contact rate and cumulative rotation angle of particles among different particle shapes, which may result in different particle movement modes and, therefore, different ground subsidence mechanisms. There study findings are useful in preventing ground subsidence. [ABSTRACT FROM AUTHOR]

To optimize the concentrate grade in the beneficiation process of non-ferrous metals, a fusion algorithm combining fuzzy logic (FL) and immune genetic algorithm(IGA) was developed. Based on this fusion algorithm, a detection model for the beneficiation of non-ferrous metals was constructed to detect and optimize the concentrate grade. Comparative test results show that the data recall rate of the IGA-FL fusion algorithm is 99.7 %, with a computation speed of 16.7 bps. The average detection accuracy of the model based on this algorithm is 97.3 %, with a detection time of 1.8 s. After applying the detection model based on the IGA-FL fusion algorithm, the concentrate grade of non-ferrous metal beneficiation reached 70.5 %, indicating that this model can optimize the concentrate grade effectively. [ABSTRACT FROM AUTHOR]

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In order to ensure the safe operation of urban logistics UAVs in the free flight scenario, the required separation for UAVs should be equipped. Gas model and position error probability model were adapted, and method for determining the free flight separation of UAVs covering conflict detection and resolution mechanism was proposed. Firstly, gas model was used to evaluate the conflict frequency of UAVs, and the collision probability when the conflict occurs were calculated by considering air traffic characteristics, conflict detection and resolution mechanism, route structure as well as air traffic service capability. Total collision probability was obtained by synthesizing the two values. Finally, the safety target level is benchmarked and the required separation for free flight of urban logistics UAV was calculated. Using this method, taking the free flight of UAV in a certain operating space as an example, the required separation was calculated. The research results provide a feasible method for the formulation of urban logistics UAV separation minima. The method can also be used to guide the CDR response mechanism to reduce the collision probability after the separation is breached. [ABSTRACT FROM AUTHOR]

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The implicit modeling method offers the advantage of automating the modeling process and has been successfully applied to automatic modeling of shallow geological formations. However, the automatic integrated modeling remains challenging for mine areas with multiple deep and complex geological formations such as intrusive rocks, faults and goaf. Based on the HRBF implicit modeling method, this paper proposes the implicit modeling feature vector extraction method for the coal seam, intrusive rocks, goaf, faults and other structures in the mining area, and designs the implicit integration method between the structural model and the strata model, enabling the topology‑consistent integrated modeling of complex geological formations in the coal mine area. A case study of Jinan Subway Line 8 shows that this method can realize the implicit modeling of intrusive rocks, gobs and faults, which provides auxiliary support for decision‑making and ensures safety in the construction of urban rail transit projects. [ABSTRACT FROM AUTHOR]

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