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针对含分布式电源（DG）的配电网动态重构问题，提出考虑配电网负荷需求与 DG 出力动态变化的配电网动态重构方案。首先，基于不同时段的负荷特性与最优网络结构的综合相似性，提出了一种改进层次聚类的时段划分方法。在此基础上，提出了遗传学习自适应粒子群优化算法，实现以网络损耗最小为优化目标的动态重构优化计算。针对基本粒子群算法中缺乏速度动态调节、易陷入局部最优等问题，提出基于粒子个体最优位置的遗传学习方案增加搜索多样性，提高算法的全局搜索能力，并引入自适应惯性权值和加速系数以满足不同时期的寻优要求。最后，以IEEE 33节点配电系统为例进行仿真，验证了所提方法的有效性和优越性。

泊松点过程（PPP）由于其理论可分析性和随机性而被广泛用于无线网络建模及分析,但实际基站部署并不是完全随机的,针对基站在空间上存在互斥的情况,文章采用泊松硬核过程（PHCP）建模异构蜂窝网络（HCN）,选择基于最大信干比（SIR）准则的基站接入方案,采用每层泊松SIR近似方法推导出了两层基于PHCP的HCN的近似覆盖率。仿真结果表明,该方法所产生的近似覆盖率为实际覆盖率的渐近下边界,并且PHCP网络的覆盖率优于PPP网络覆盖率,更适应于具有互斥性的实际基站部署。

慢光在未来全光网络通信中具有重要作用。文章提出一种基于零对比度光栅共振诱导透明效应的可实现平面外慢光滤波的设计,该设计兼具优良的透射滤波功能和慢光效应。分析了刻蚀深度和光栅周期对慢光滤波性能的影响,指出刻蚀深度影响波导层对共振诱导模式的束缚,刻蚀深度的改变将显著降低零对比度光栅的慢光滤波性能;而光栅周期主要影响入射光与波导模的相位匹配,选取不同光栅周期可在C波段实现对不同慢光滤波通道的选择。此外,研究了斜入射条件的模式劈裂效应,指出由于斜入射条件下非简并共振波导模的激发,±1级劈裂模式被激发,其虽然导致峰值透射的降低,但可以显著提高透射慢光的群折射率。该研究为慢光器件的设计提供了一种新的解决方案。

总高度530m的天津周大福金融中心塔楼采用带陡斜撑和环带桁架的钢管(型钢)混凝土框架-核心筒结构体系,存在超高、局部楼板不连续、竖向不规则等超限情况。通过采用SATWE和ETABS软件对结构进行了整体计算和弹性时程分析,采用ABAQUS软件进行了大震下动力弹塑性时程分析。根据概念设计和分析计算结果对关键构件和重要部位进行加强,并对关键构件进行了中震和大震下的性能化设计。结果表明,结构各项指标均满足规范要求,预设的性能目标均可达到,该结构设计安全可靠、经济合理,该结构体系、加强措施以及节点构造可供类似工程参考。

介绍了温州永强机场T2航站楼钢屋盖结构设计的主要工作。从方案配合阶段的建筑总体造型需求出发,阐述了整体上的结构体系比较和选择、屋盖竖向支承结构布置、天窗细部结构形式处理等等。结构设计方面,讨论了屋盖下部支承钢管混凝土柱及其节点设计、网架屋盖结构分析和幕墙钢结构等内容。工程的设计特点和设计思路历程可为类似公共建筑的结构设计提供参考。

武汉中心塔楼采用巨柱框架-核心筒-伸臂桁架体系。在设计过程中对伸臂桁架道数、位置、立面形式、截面的确定进行了分析研究;结合建筑、机电的要求进行了伸臂杆件入墙延伸段的设计,并针对不同墙厚条件设计了嵌入式和外包式两种伸臂桁架入墙节点形式;对伸臂桁架杆件与钢管混凝土柱连接的构造方式进行了比选,并结合施工过程分析探讨了伸臂杆件延迟封闭的必要性。最终选用了设置3道伸臂桁架的结构方案并确定了各道桁架的具体做法。

长沙冰雪世界项目依附废弃的矿坑建造,结合建筑师对造型的要求,利用深坑坑壁为岩体的地质条件,主体结构采用支承于矿坑坑壁的三组拱形桁架结构体系,拱形桁架最大跨度为180m。介绍了项目的工程概况、采用平面拱拟合曲面结构的确定过程、拱形桁架及其稳定系统的选型、拱脚基础与岩体的关系及其处理方式等内容,并结合工程特点详细阐述了在复杂边界条件下利用逆吊法进行形态创建的原理与流程。

港珠澳大桥珠海口岸位于人工填岛上,针对其特殊的环境,介绍了珠港旅检楼钢屋盖体系的确定过程,提出需重视钢结构防腐、金属屋面抗风等内容。分析结果表明,支撑钢屋盖的局部关键柱破坏引起屋盖的局部破坏,未引起连续性倒塌,但局部破坏的影响仍较大,设计应对可能受到攻击的部位采取加强措施。大跨结构设计中应根据屋盖分块提升施工方案进行施工模拟分析,并基于施工成形状态进行正常使用阶段的设计复核,确保施工及使用阶段结构的安全。

Copyright of Chinese Journal of Aesthetic & Plastic Surgery is the property of Chinese Journal of Aesthetic & Plastic Surgery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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With the development of intelligent robot navigation technology, much more attention has been paid on the research of path planning. An improved gray wolf optimization (GWO) algorithm was proposed for local optimum and slow convergence seed in robot path planning. Firstly, a two-dimensional spatial model was used to imitate the path planning process of robots. In the global search process, a dynamic perturbation coefficient and nonlinear decreasing control parameters(which are improved from linear decreasing) were proposed in the formula of position updating for the aim of enhancing global search performance. Then, considering the diversity of gray wolf population and local mining ability of the algorithm, a reverse learning selection strategy was introduced, which led to the improvement of convergence accuracy of the algorithm. The testing data from eight common functions has shown the effectiveness of the improved algorithm. Finally, a comparative experiment has been made among the improved gray wolf optimization algorithm, the original gray wolf optimization algorithm and particle swarm optimization algorithm, and the data has shown that the average path distance is shortened by 11. 99%, 7. 79% and 5. 78%, and iteration times is reduced by 75. 63%, 59. 78% and 43. 67%, respectively in simple, general and complex environments, which indicates the effectiveness in optimal distance planning and obstacle avoidance of this improved algorithm. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

羊水细胞培养是进行产前诊断遗传性疾病的重要方法之一,它可以预测子宫内胎儿的发育情况,检出胎儿是否有先天性遗传缺陷,以便及早作出合适的处理。 近几年来,国内外文献陆续报道成功地应用羊水细胞培养技术为临床提供新的产前诊断途径。羊水细胞培养方法繁多,国内一般较多采用简易羊水细胞培养方法,但迄今尚未能广泛应用于临床。本室于1979年3月份开始抽取中期引产孕妇的羊水细胞培养。现初步小结如下。

甾体激素长效口服避孕药在临床上使用越来越广泛。停药后再度妊娠,对子代有无影响,国外学者仍有不少争论。国内文献报道不多。为此,我们自1977年始对曾服长效复方18甲基炔诺酮避孕药(简称复方18甲)的妇女,停药后及其妊娠分娩的子代进行淋巴细胞染色体培养分析。

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Natural Disasters is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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To explore the influencing factors of respiratory function exercise behavior in patients with chronic obstructive pulmonary disease (COPD), and to construct a nomogram prediction model. 112 COPD patients in our hospital from March 2021 to March 2023 were selected, and patients were divided into low compliance group (n=68) and high compliance group (n=44) according to their respiratory function exercise behavior. The influencing factors of low compliance of respiratory function exercise behavior in COPD patients were analyzed by univariate analysis and multivariate logistic regression analysis, and a prediction model was constructed, the predictive value of the model was analyzed by receiver operating characteristic (ROC). Age≥ 60 years old, on the job, no family support, dyspnea after activity, high disease uncertainty, and low exercise self-efficacy were independent risk factors for low compliance of respiratory function exercise in COPD patients (P<0.05). The area under the curve (AUC) of age, on the job, family support, dyspnea after activity, disease uncertainty, exercise self-efficacy and nomogram prediction model were 0.645, 0.645, 0.717, 0.600, 0.660, 0.672 and 0.908 respectively, the prediction model had higher predictive value for low compliance of respiratory function exercise in COPD patients, when the cut-off value was 0.498, the sensitivity was 0.912 and the specificity was 0.795. The internal validation of the Bootstrap method (B=1000) showed that the predicted curve after the correction of the deviation was basically coincident with the ideal line, and the consistency index (C-index) was 0.816, indicating that the prediction ability of the model was better. The decision curve shows that the threshold probability range was 0.01~0.92, and the net return rate was>0. Age≥ 60 years old, on the job, no family support, dyspnea after activity, high uncertainty of disease, and low exercise self-efficacy are independent risk factors for low compliance of respiratory function exercise in COPD patients. The predictive model can help to assess exercise compliance and develop interventions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Clinical Neurosurgery / Linchuang Shenjingwaike Zazhi is the property of Editorial Board of Journal of Clinical Neurosurgery and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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This study conducts numerical simulations to analyze the influence of the distance between roadway and fault fracture zone on the stability of excavation roadway surrounding rock during parallel roadway excavation with using the drilling and blasting method in the Julong Copper Mine. Numerical simulation models are established for different distances between roadway and fault fracture zone, and the variations in the displacement field, stress field, and plastic zone are analyzed. The numerical simulation results show that when the distance between roadway and fault fracture zone is 1 m and 4 m, the fault fracture zone has a significant impact on the stability of the surrounding rock of the roadway, with the maximum displacement values of the roadway side wall being 6. 19 cm and 1. 13 cm respectively. The maximum principal stress is concentrated in the left side surrounding rock of the roadway, with lesser stress in the right side surrounding rock. Horizontal stress is concentrated at the intersection of the surrounding rock and the fault fracture zone, and plastic deformation occurs within the fault fracture zone. When the distance between the roadway and the fault fracture zone is 7 m and 10 m, the influence of the fault fracture zone on the stability of the surrounding rock of the roadway is minor, with the maximum principal stress and horizontal stress approximately symmetrically distributed along the centerline of the influence, and no plastic deformation occurs within the fault fracture zone. [ABSTRACT FROM AUTHOR]

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Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Metal nanoclusters (NCs) are stable aggregates at the molecular level, consisting of several to hundreds of metal atoms bound together by physical or chemical interaction. These nanoclusters exhibit unique physicochemical properties that have garnered significant attention in various fields, including biology, catalysis, sensing, and drug delivery. In the field of catalytic reactions, atomically precise metal nanoclusters have acted as an archetypical model for elucidating the structural evolution and structure-property relationship of nanomaterials. However, due to the factors such as the uncertainty of the growth mechanism, the complexity of the crystallization process, and the inherent poor stability, the cluster research faces some challenges in the precise synthesis, structural analysis as well as the comprehension of catalytic reaction mechanism which hinder the full exploration and understanding of these fascinating properties of clusters. Recent years, mass spectrometry (MS) has emerged as a crucial tool in biomolecular analysis and the detection of organic reaction intermediates due to its high sensitivity, high resolution, and fast response. In cluster chemistry, the researchers have also introduced this technique into the study of metal nanoclusters with precise atomic numbers, which have played an important role in the synthesis of clusters and the analysis of their structures as well as reaction mechanisms. The ion source, as the "heart" of the MS, can ionize the analyte and then be detected by MS. Currently, the main ionization methods used for cluster analysis are electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). These two "soft" ionization techniques can obtain the quasi-molecular ion peaks of the clusters without destroying the structure of the clusters, thus determining the composition of the clusters. In addition, MS enables real-time characterization of the reaction process in solution, allowing for online monitoring of complex reaction components, providing an experimental basis for synthesis processes and catalytic reaction mechanisms of metal clusters. Notably, gas-phase ion-molecule reactions can provide catalytic primitive steps and reaction kinetics enabling in-depth analysis of microscopic reaction mechanisms at a strictly molecular level. For the structural characterization of clusters, tandem mass spectrometry (MS/MS) combined with quantum chemical calculation provides a powerful tool to study and understand the structural evolutions of clusters. By comparing and verifying the experimental and computational results, the correlation between the catalyst structure and its performance can be established, deepening our understanding of the catalytic reaction mechanism and process. This paper was focused on the latest development of soft ionization MS in monitoring intermediates of cluster synthesis, structure analysis, and catalytic reaction mechanism, and the emerging directions in this fascinating area of research were highlighted. [ABSTRACT FROM AUTHOR]

To remediate recoverable cultivated land resources in a more scientific manner, a method to evaluate arability on recoverable cultivated land using the XGBoost algorithm is proposed. This study defined independent variables in four dimensions: natural, spatial, economical, and engineering, which were further indicated by 36 specific factors including elevation, slope grade, national nature, and aggregated area. A binary classification between recoverable cultivated land and cultivated land was then defined. According to the importance, Pearson′s collinearity, and index correlation, 21 variables and their weighted P value were obtained. The weighted P value of the influencing factors was relatively stable. For the four influencing factors, natural factors had the largest weight, followed by spatial and engineering factors, while the socio-economic factors were the smallest. In addition, the accuracy of our method reached 91.87%, showing generalization ability and robustness. Based on the above model, the suitable tillage potential of recoverable arable land in Xiangyin County was predicted, and the following understandings were obtained: The cultivation potential of the central and western plains in the county was significantly better than that in the eastern mountainous areas. The suitable cultivation potential of uncultivated and recoverable plots in recoverable arable land is higher than that of engineering restored plots, these plots were good renovation plots, which can be restored as cultivated land in priority. From the perspective of specific land types, the cultivation potential of ponds was the greatest, followed by sparse forest land. The assessment of the suitability of cultivated land for restoration should be performed as a decision basis. Moreover, it is necessary to conduct remediation of recoverable cultivated land in a reasonable and orderly manner. In addition, we should carry out refined monitoring of cultivated land“non-grain”and implement differentiated compensation policies to curb cultivated land“non-grain”. [ABSTRACT FROM AUTHOR]