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通过建立计算预制装配式型钢混凝土（PSRC）梁抗剪承载力的智能模型，在一定程度上提高了计算精度与适用性。基于BP人工神经网络算法，通过对影响PSRC梁抗剪承载力的相关参数进行梳理，选取14个主要影响参数作为输入层，以试算法确定隐含层节点数为5，初步构建了3层结构人工神经网络系统；以收集的76组试验数据作为学习样本，对构建的神经网络系统进行训练，建立了对PSRC梁及SRC梁抗剪承载力计算的N14-5-1智能模型。使用智能模型对6个PSRC梁构件及6个SRC梁构件进行抗剪承载力计算，并通过与规范公式计算结果、试验结果的对比分析，证明了智能模型具有良好的计算精度及较好的泛化能力，具有一定的工程参考意义。运用Garson算法对输入参数进行敏感性分析，结果表明箍筋间距、型钢屈服强度、箍筋屈服强度、型钢腹板含钢率对抗剪承载力影响较大。随着研究试验的开展，在收集更多具有代表性的试验数据以扩充学习样本后，可对智能模型进一步优化。

目的 探讨动脉内溶栓（intra-arterial thrombolysis，IAT）治疗视网膜中央动脉阻塞（central retinal artery occlusion，CRAO）患者的临床特征及功能性视觉恢复情况。 方法 纳入2018年1月—2023年8月西北大学附属第一医院神经内科和神经眼科连续收治的非动脉炎性CRAO患者，根据入院后是否进行IAT治疗分为IAT组和非IAT组。功能性视觉定义为 视力≥20/100。比较分析两组患者的临床特征和不同时间段（入院、出院时和出院1个月时）功能性视觉恢复情况。 结果 共纳入131例（131只眼）非动脉炎性CRAO患者，男性93例（71.0%），平均年龄为（61.6±12.6）岁， 其中IAT组57例（43.5%），非IAT组74例（56.5%）。与非IAT组患者相比，IAT组患者年龄更低[（58.4±12.5）岁 vs.（64.1±12.2）岁，P=0.011]、合并卒中病史者比例更低[10（17.5%）vs. 25（33.8%）， P=0.037]、发病至就诊时间更短[10.0（6.0～24.0）h vs. 55.0（20.2～162.0）h，P＜0.001]、醒后发病者比例更高[26（45.6%）vs. 15（20.3%），P=0.002]和患侧颈内动脉血管状态更佳（无狭窄∶轻度狭窄∶中-重度狭窄∶闭塞=41∶7∶7∶2 vs. 32∶11∶21∶10，P=0.006）。IAT组患者出院1个月时功能性视觉比例较非IAT组患者更高[25（43.9%）vs. 18（24.3%），P=0.018]，而入院和出院时差异无统计学意义 （P＞0.05）。多因素logistic回归分析显示，IAT组患者出院1个月时的功能性视觉较非IAT组患者显著改善（OR 3.24，95%CI 1.08～9.69，P=0.036）。IAT组患者术中发生眼动脉痉挛2例（3.5%）、穿刺部位皮肤出血2例（3.5%）和新发脑栓塞（均为无症状性栓塞）事件4例（7.0%）。 结论 是否进行IAT治疗的CRAO患者部分临床特征存在差异，IAT治疗可显著提高CRAO患者出院1个月时的功能性视觉，且手术安全性较好。提示临床医师需重视CRAO患者的IAT治疗，以期改善患者的视觉功能。 Abstract: Objective To investigate the clinical characteristics and functional visual recovery of patients with central retinal artery occlusion (CRAO) treated with intra-arterial thrombolysis (IAT). Methods The non-arteriotic CRAO patients admitted to the Department of Neurology and Neuro-ophthalmology of the First Affiliated Hospital of Northwest University from January 2018 to August 2023 were included. They were divided into IAT group and non-IAT group according to whether IAT was performed after admission. Functional vision is defined as visual acuity≥20/100. The clinical features and functional visual recovery at different time periods (admission, discharge and 1 month after discharge) were compared and analyzed between the two groups. Results A total of 131 patients (131 eyes) with non-arteriotic CRAO were included, including 93 males (71.0%) with a mean age of (61.6±12.6) years. There were 57 patients (43.5%) in IAT group and 74 patients (56.5%) in non-IAT group. Compared with patients in non-IAT group, patients in IAT group had younger age [(58.4±12.5) years vs. (64.1±12.2) years, P=0.011], lower proportion of stroke history [10 (17.5%) vs. 25 (33.8%), P=0.037], shorter time from onset to visit [10.0 (6.0-24.0) h vs. 55.0 (20.2-162.0) h, P0.05). Multivariate logistic regression analysis showed that the functional vision of CRAO patients in the IAT group at 1 month after discharge was significantly improved compared with those in the non-IAT group (OR 3.24, 95%CI 1.08-9.69, P=0.036). In the IAT group, ophthalmic artery spasm occurred in 2 cases (3.5%), skin bleeding at the puncture site in 2 cases (3.5%), and new cerebral embolism (all asymptomatic embolism) occurred in 4 cases (7.0%). Conclusions Some clinical features of CRAO patients who were treated with or without IAT were different. IAT can significantly improve the functional vision of CRAO patients at 1 month after discharge, and the surgical safety is good. This suggests that clinicians should pay more attention to IAT in CRAO patients in order to improve their visual function.

为研究超出规范范围材料强度的高强钢管高强混凝土短柱承载力在规范范围外拓展应用的相关问题，搜集61组试验及有限元数据，利用神经网络智能技术研究了在不同的截面尺寸、高强材料、含钢率、偏心率和长细比等影响因素下的高强钢管高强混凝土短柱的极限承载力及荷载-位移曲线，将承载力预测结果与规范EC4、规范ACI及规范GJB 4142—2000的计算结果进行了对比分析，并预测了试件的荷载-位移曲线，对各阶段各模型的切线刚度进行了分析研究。研究结果表明：所述规范可以在一定程度上继续延伸使用，而神经网络智能模型不仅与试验数据吻合度较高、精确度高，还考虑了规范没有考虑的约束效应减弱及两种材料强度匹配程度对承载力的影响，承载力会随着混凝土强度和钢材强度的提高而减缓增强速度；神经网络智能模型非常适合用于预测高强钢管高强混凝土短柱承载力，可以为实际工程和规范延伸拓展提供设计参考；神经网络智能模型相比于现有组合构件应力-应变理论公式会更加简便准确，以切线刚度的对比结果可知，其可以更加准确地反映和再现轴压作用下高强钢管高强混凝土短柱荷载-位移曲线的特征，对构件的力学性能研究有一定的参考作用。

为了寻找一种耗费人力更少、预测效果更好的外伸端板半刚性钢结构连接节点的弯矩-转角（M-θr）关系模型，提出将智能模型引入对该种半刚性连接节点M-θr曲线的预测。首先对现有钢结构梁柱半刚性连接节点M-θr关系经典模型进行了评述，采用其中的幂函数模型对一组试验做了计算并与试验结果进行对比；然后用非线性有限元法对外伸端板半刚性钢结构连接节点进行了计算，并把分析所得M-θr曲线与试验曲线做了比较分析；基于大量试验数据，研究确定了对该种半刚性连接节点M-θr性能影响较大的11个主要参数，并用MATLAB数值计算软件建立了智能模型，对外伸端板半刚性钢结构连接节点的M-θr关系进行了预测，将预测结果与试验值对比。最后发现智能模型不论是定性的曲线变化趋势、还是定量的数值大小，都优于现有幂函数模型和非线性有限元分析，具有更好的可靠性、实用性。所得结论，可为该类半刚性钢结构连接节点M-θr关系研究提供新的思路。

通过建立计算预制装配式型钢混凝土（PSRC）梁抗剪承载力的智能模型，在一定程度上提高了计算精度与适用性。基于BP人工神经网络算法，通过对影响PSRC梁抗剪承载力的相关参数进行梳理，选取十四个主要影响参数作为输入层，以试算法确定隐含层节点数为5，初步构建了三层结构人工神经网络系统；以收集的76组试验数据作为学习样本，对构建的神经网络系统进行训练，建立了对PSRC梁及SRC梁抗剪承载力计算的N14-5-1智能模型。使用智能模型对6个PSRC梁构件及6个SRC梁构件进行抗剪承载力计算，并通过与规范公式计算结果、试验结果的对比分析，证明了智能模型具有良好的计算精度、及较好的泛化能力，具有一定的工程参考意义。运用Garson算法对输入参数进行敏感性分析，结果表明箍筋间距、型钢屈服强度、箍筋屈服强度、型钢腹板含钢率对抗剪承载力影响较大。随着研究试验的开展，在收集更多具有代表性的试验数据以扩充学习样本后，可对智能模型进一步优化。

Objective To understand the fall risk and fall status of the elderly living in an island community, to explore the influencing factors of falls, and to provide basis for the formulation of health education program. Methods The self-made general information questionnaire and the revised Fall-risk Self-assessment Questionnaire (FSQ) were used. Results The scale had good reliability and validity for the elderly in the island community. Totally 300 participants were recruited and investigated, and the incidence of falls was 26. 67%. Protective factors of falls included using walking aids, believing in that falls could be prevented and taking exercise regularly. The three main items associated with risk of falls included abnormal sensation of lower limbs, difficulty in walking faster and feeling of unstable walking sometimes. Conclusion The high incidence of falls in the elderly in the island community is related to the poor muscle strength and balance ability of lower limbs. Community medical staff should strengthen health education, improve the elderly people’s awareness of fall prevention, and reduce the risk of falls, so as to reduce the occurrence of falls. (目的 了解某海岛社区老年人跌倒风险与跌倒现状, 探讨发生跌倒的影响因素, 为健康教育方案的制定提供依据。方法 采用自制的一般资料调查表和修改后的老年人跌倒风险自评量表进行调查。结果 该量表用于海岛社区老年人信效度良好。共300例老年人参与调查, 跌倒发生率为26. 67%(80/300)。跌倒保护因素: 使用助行器、认为跌倒可以预防和规律锻炼。跌倒风险因素中阳性率排前三位的因素: “下肢感觉异常”、“走路加快速度时感到困难”和“有时侯, 我感到行走不稳定”。结论 海岛社区老年人跌倒发生率高与下肢肌力和平衡能力差有关。社区医务人员应加强健康教育力度, 提高老年人防跌倒意识, 降低跌倒风险, 以减少跌倒发生。)

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Objective The aim is to study the corrosion behavior of N80 tubing material and TP125V casing material commonly used in shale gas wells in Sichuan and Chongqing areas. Methods The corrosion effects of flowback water, on-site slick water and laboratory prepared slick water on N80 and TP125V steel were compared by weight-loss method and electrochemical method. Results The corrosion rate in the flowback water environment was the highest and in the laboratory prepared slick water was the lowest. Conclusions The overall corrosion rate of N80 and TP125V materials in the flowback water environment is not only higher than that in the on-site slick water or the laboratory prepared slick water, but also the pitting is more serious. [ABSTRACT FROM AUTHOR]

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Objective · To understand boys' pubertal timing in school in two urban districts of Chongqing and explore the relationship between pubertal timing and physical activity or sleeping time. Methods · Using a stratified random cluster sampling, 3 403 boy students (10-18 year-old) were selected and completed the physical examination and questionnaire survey. 1 282 participants experiencing first spermatorrhea were chosen as research objects. According to age of first spermatorrhea, the objects were divided into on-time group (964 cases) and later group (318 cases). Results · The composition of weekly high (χ2=11.488, P=0.009), medium (χ2=7.829, P=0.050) physical activity and daily sleeping time (χ2=17.803, P=0.000) in two groups were significantly different. Controlling covariates (age, height and weight), compared with boys in on-time group, later group boys were less likely to engage in 5-7 days (OR=0.596, 95% CI: 0.367-0.967) and 3-4 days (OR=0.590, 95% CI: 0.370-0.941) high physical activity every week, and 9-11h (OR=0.207, 95% CI: 0.088-0.489) sleep every day. Conclusion · The age of first spermatorrhea in boys might be associated with the intensity of weekly physical activity and daily sleeping time. [ABSTRACT FROM AUTHOR]