Relationship between hypertriglyceridemic-waist phenotype and clustering of cardiovascular risk factors in middle and aged population

Objective To explore the relationship between hypertriglyceridemic-waist(HTWC)phenotype and clustering of cardiovascular risk factors in middle and aged population.Methods A community-based cross-sectional survey was conducted in 5 communities of Chengdu city from 2013-10 to 2014-05 and 1004 subjects from(40-79)years of age were investigated.HTWC was de-

Systematic study of cluster radioactivity within the generalized liquid drop model

Cluster radioactivity is studied within the generalized liquid drop model(GLDM),in which the shell correction energy,pairing energy,and cluster preformation factor are considered.The calculations show significant improvements and can reproduce the experimental data within a factor of 8.04 after considering these physical effects.In addition,the systematic trend of the cluster preformation factors is discussed in terms of the N_(p)N_(n)scheme to study the influence of the valence proton-neutron interaction and shell effect on cluster radioactivity.It is found that log10Pcis linearly related to N_(p)N_(n).This is in agreement with a recent study[L.Qi et al.,Phys.Rev.C 108,014325(2023)],in which log10Pc,obtained using different theoretical models and treatment methods than those used in this study,also had a linear relationship with N_(p)N_(n).Combined with the work by Qi et al.,this study suggests that the linear relationship between log10Pcand N_(p)N_(n)is model-independent and both the shell effect and valence proton-neutron interaction play essential roles in cluster radioactivity.An analytical formula is proposed to calculate the cluster preformation factor based on the N_(p)N_(n)scheme.In addition,the cluster preformation factors and the cluster radioactivity half-lives of some heavy nuclei are predicted,which can provide a reference for future experiments.

计及多点电池储能系统的电网二次调频协同控制

在“碳达峰•碳中和”国家能源战略变革背景下,大规模可再生能源的加速并网加剧了电力系统对于快速调频资源需求的迫切性,如何充分发挥以电池储能系统(battery energy storage systems,BESS)为代表的新型快速资源在电网调频中的作用是解决该问题的关键。首先,为满足电网各类型调频资源在自动发电控制(automatic generation control,AGC)系统中的接入监视与分类决策需求,提出“域-群-机”三级控制模型架构;然后,从BESS的荷电状态(state of charge,SOC)主动管理出发,提出基于改进的动态调频容量(dynamic available AGC,DAA)的多元集群协同控制策略,以及引入SOC影响因子的多点BESS功率分配策略;最后,结合实际电网的持续扰动工况及模拟跳机扰动工况进行仿真分析,验证了文中所提控制策略的有效性。文中所提策略不但可以显著改善各单点BESS的SOC一致性,而且能够提升电网调频品质。

Spectrum-effect relationship between HPLC fingerprints and bioactive components of Radix Hedysari on increasing the peak bone mass of rat

The traditional Chinese medicine of Radix Hedysari plays an important role in invigorating gas for ascending, benefiting blood for promoting production of fluid, and promoting circulation for removing obstruction in collaterals, which is consistent with the principle of treatment for osteoporosis. This study is designed to investigate the bioactive components on increasing peak bone mass (PBM) by exploring the spectrum-effect relationship between chromatography fingerprints and effect. Multiple indicators are selected to evaluate the pharmacological activity. In fingerprints, 21 common peaks are obtained, five of which are identified. Furthermore, gray relational analysis (GRA) is a quantitative method of gray system theory and is used to describe the correlation degree of common peaks and pharmacological activities with relational value. 21 components are then divided into three different regions, of which ononin and calycosin play an extremely significant role in increasing PBM. In addition, factor analysis and hierarchical cluster analysis (HCA) are used to screen the optimal producing area for Radix Hedysari. This provides a comprehensive and efficient method to improve the quality evaluation of Radix Hedysari, confirming the bioactive components for PBM-enhancement and further develop its medicinal value.

Equilibrium and kinetic Si isotope fractionation factors and their implications for Si isotope distributions in the Earth's surface environments

Several important equilibrium Si isotope fractionation factors among minerals,organic molecules and the H_4SiO_4 solution are complemented to facilitate the explanation of the distributions of Si isotopes in Earth's surface environments.The results reveal that,in comparison to aqueous H_4SiO_4,heavy Si isotopes will be significantly enriched in secondary silicate minerals.On the contrary,quadra-coordinated organosilicon complexes are enriched in light silicon isotope relative to the solution.The extent of ^(28)Si-enrichment in hyper-coordinated organosilicon complexes was found to be the largest.In addition,the large kinetic isotope effect associated with the polymerization of monosilicic acid and dimer was calculated,and the results support the previous statement that highly ^(28)Sienrichment in the formation of amorphous quartz precursor contributes to the discrepancy between theoretical calculations and field observations.With the equilibrium Si isotope fractionation factors provided here,Si isotope distributions in many of Earth's surface systems can be explained.For example,the change of bulk soil δ^(30)Si can be predicted as a concave pattern with respect to the weathering degree,with the minimum value where allophane completely dissolves and the total amount of sesquioxides and poorly crystalline minerals reaches their maximum.When,under equilibrium conditions,the well-crystallized clays start to precipitate from the pore solutions,the bulk soil δ^(30)Si will increase again and reach a constant value.Similarly,the precipitation of crystalline smectite and the dissolution of poorly crystalline kaolinite may explain the δ^(30)Si variations in the ground water profile.The equilibrium Si isotope fractionations among the quadracoordinated organosilicon complexes and the H_4SiO_4solution may also shed light on the Si isotope distributions in the Si-accumulating plants.

国家级城市群规划对要素跨省流动的影响研究

在发展城市群和加快建设全国统一大市场的政策导向下,以京津冀、长三角、珠三角、成渝及长江中游城市群为样本,基于百万条原始数据整理得到五大城市群2010—2018年的经济要素流动网络,采用多期双重差分模型检验国家级城市群规划对要素跨省流动的影响。研究结果表明:(1)城市群规划显著促进了技术、资本、人口要素的跨省流动;(2)城市群规划促进技术、资本要素跨省流动的中介机制是降低城市间的市场分割程度以及缩小城市间的市场制度差异,但这两个机制对于人口要素不显著;(3)城市间信息要素流动规模越大,城市群规划越能提升其他经济要素的流动规模;(4)国家级城市群规划有利于技术和资本要素的跨省双边流动,但加剧了人口要素的单向“虹吸”。据此,各级政府应当坚持以人为本的原则,充分重视城市文化的辐射能力,积极推动区域间市场一体化,更好地培育、发展国家级城市群。

物流产业集群对制造业全要素生产率的影响及其城市异质性

物流企业在一定空间集聚所形成的物流产业集群,能够通过促进地区要素流通、优化资源配置,以提升城市制造业全要素生产率。基于2012—2019年中国284个地级及以上城市的面板数据,建立空间计量模型实证检验物流产业集群对制造业全要素生产率的影响。研究结果显示,物流产业集群能够显著提升城市制造业全要素生产率。异质性分析结果表明,东部和西部城市的物流产业集群显著提升了制造业全要素生产率,中部城市作用则相反;在特大城市和小城市这一作用显著为正;产业阶段处于工业化后期的城市中物流产业集群具有显著的提升作用。机制分析结果表明,物流产业集群的发展会通过提升物流业专业化水平和物流业制造业产业协同度对制造业全要素生产率呈正向促进作用。

黄河流域文化产业集群时空格局与空间溢出效应研究

基于2005—2020年黄河流域62市面板数据,从集群规模、联系度和专业化3个维度匹配构建文化产业集群水平指标体系,采用莫兰指数(Moran’s I)和空间杜宾模型,在厘清空间溢出效应作用机制与路径的基础上,探究黄河流域文化产业集群时空格局及空间溢出效应影响因素。结果表明:(1)2005—2020年黄河流域文化产业集群指数均值由0.07上升为0.21,整体呈“正三角”型分布模式。(2)城市间文化产业集群发展水平不均衡,存在明显的“虹吸效应”,各解释变量对溢出效应影响效果差异显著。(3)空间溢出效应与地理距离有明显的相关性,当地理距离达到500 km时,正向的空间溢出效应最强,超过850 km时,空间溢出效应逐渐消失,总体呈倒“U”型趋势。基于上述分析,为加快黄河流域文化产业集群发展,提高区域竞争力,缩小地区发展差距,提出加强区域协同合作、把握城市更新进程、避免同质化竞争等建议。

Numerical investigation on the cluster effect of an array of axial flow fans for air-cooled condensers in a power plant

The aerodynamic behavior of tens of axial flow fans incorporated with air-cooled condensers in a power plant is different from that of an individual fan.Investigation of the aerodynamic characteristics of axial flow fan array benefits its design optimization and running regulation.Based on a representative 2600 MW direct-dry cooling power plant,the flow rate of each fan and the overall flow rate of the fan array are obtained in the absence of ambient wind and at various wind speeds and directions,using CFD simulation.The cluster factor of each fan and the average cluster factor of the fan array are calculated and analyzed.Results show that the cluster factors are different from each other and that the cluster effect with ambient wind is significantly different from the cluster effect with no wind.The fan at the periphery of the array or upwind of the ambient wind generally has a small cluster factor.The average cluster factor of the array decreases with the increasing wind speeds and also varies widely with wind direction.The cluster effect of the axial flow fan array can be applied to optimize the design and operation of air-cooled condensers in a power plant.

人口流入城市肺结核流行特征、时空分布及其社会影响因素分析

目的探讨人口流入城市肺结核流行特征、时空聚集性及社会影响因素。方法通过中国疾病预防控制信息系统收集宁波市2013-2015年肺结核发病数据,并进行描述流行病学分析。使用SaTScan9.1.1对街道/乡镇级发病数据进行时空扫描分析。利用ArcMap10.2对分析结果进行可视化展示。结果宁波市2013-2015年累计报告肺结核12 109例,发病率呈逐年下降趋势,外地户籍病例占比逐年上升。男女比例为2.07∶1(8162/3947),各年龄组均有发病,其中15-34岁、65岁及以上发病率高,15-54岁年龄组占比73.95%,职业分布以农民、家政家务及待业、民工、工人为主。时空聚集性扫描共发现6个聚集区,其中一类聚集区分布在中心城区及其周边,二类聚集区分布在工业园区。与非聚集区相比,发病聚集区的流动人口占比(t=2.88,P=0.01)、省外流入人口占比(t=7.46,P=0.00)、人口密度(t=3.37,P=0.00)均较高,而人均公园绿地面积较低(t=-2.39,P=0.03)。结论人口流入城市的中心城区及其周边、工业园区是肺结核疫情高发区和聚集区。人口密度和流动人口高是发病聚集的重要影响因素。

基于因子分析的景观指数筛选与分区研究

以泾河流域为例,在总结前人研究的基础上,筛选出7个一致性较好的景观指数,应用相关性分析和因子分析对其进行了筛选,并据此对研究区进行了分区。结果表明:面积加权平均分维数与面积变化具有较高的相关性,予以剔除。其余景观指数可以用景观分布与斑块形状因子和景观破碎化因子2个公因子代替,并据此将泾河流域32个县市分成3个类型区,分别处于流域的上游、中下游和下游地区,表现出一定的分布规律。

一种基于改进群组AHP法的指标权重确定方法

针对传统群组AHP聚类分析法没有考虑同类专家意见差异的不足,提出了一种改进的群组AHP赋权方法。在确定出各个专家权重系数的基础上,通过计算群体一致度系数和个体差异性系数,将同类专家评价意见之间的差异性表示出来并利用线性加权法将各个专家权重向量综合为最终指标权重向量。实例验证的结果表明了该方法的科学性与实用性。

基于神经网络的岩体边坡稳定性的灰色聚类空间预测法及其应用

针对岩体边坡稳定性与影响因素之间的非线性关系 ,提山了基于神经网络的岩体边坡稳定性的灰色聚类空间预测法。结合实例仿真分析 ,表明该方法能较好地处理岩体边坡稳定性与影响因素之间的灰色非线性关系 ,同时 ,能比较准确地预测岩体边坡的稳定性。

中国区域教育竞争力与区域经济竞争力的关联分析——兼复胡咏梅教授等

教育竞争力是区域经济竞争力的关键和重要内容 ,一个地区经济竞争力的强弱最终体现于其教育竞争力的强弱。本文在回复胡咏梅教授等提出问题的基础上 ,采用因子分析、相关分析、回归和Granger因果分析等方法 ,多侧面、定量地对中国各省级区域教育竞争力和区域经济竞争力进行了综合评估 ,探求了二者之间的关联关系和相关程度 ,以及区域教育竞争力对区域经济竞争力的贡献 ,并验证了区域教育竞争力与经济竞争力之间关联的密切程度和因果关系 ,得出了相应的结论和建议。

资源枯竭型城市产业转型成效分析

本文采用因子分析对我国15个资源枯竭型城市转型效果进行测度,并采用聚类分析法对各城市转型成效进行分类,发现各市之间整体转型成效差异较大,其中生产要素和科技水平对资源枯竭型城市转型成效的影响最大。从单个主因子得分来看,多个城市在转型过程中积累了各自的优势。

基于灰色模糊聚类法的发电企业竞争力分析

通过构建发电厂竞争力及其作用因素的评价指标体系,提出了对发电厂竞争力进行评价和分类的系统方法。首先,运用灰色理论方法计算了发电厂竞争力的作用因素与其综合竞争力的灰色关联度,在此基础上建立了描述发电厂间相似程度的特征向量空间;然后,运用模糊聚类方法,对作用因素对竞争力的影响具有相同或相似特性的发电厂进行分类,为发电集团提供决策依据;最后,利用一家发电集团下属的13家发电厂的实际数据,证实了该方法的科学性与可行性。

水泥乳化沥青混合料初期强度影响因素及机理

为了探究水泥乳化沥青初期强度影响因素,进行了水分损失试验、掺加材料需水率试验、马歇尔稳定度试验、孔隙率测定试验以及扫描电镜试验。在聚类分析理论基础上,研究了粉煤灰、硅粉、水泥和乳化沥青掺量,以及养护条件、孔隙率、水分损失对混合料初期强度的影响。研究结果表明:随着粉煤灰掺量、硅粉掺量、孔隙率以及水分损失的增加,水泥用量减少,混合料的马歇尔稳定度不断降低。养护条件对混合料初期强度没有显著影响。内部空间结构松散程度和黏结状态是影响混合料初期强度的主要因素,粉煤灰、硅粉、乳化沥青的掺加使微观结构面变得松散,影响混合料的整体强度。养护条件的变化并不能显著改善微观结构面的黏结状态。混合料的初期强度影响因素中,影响程度依次为:水泥掺量>孔隙率>12 h水分损失>硅粉掺量>乳化沥青掺量>粉煤灰掺量。

我国各省市老龄事业发展现状的比较研究

在构建分析指标体系的基础上,运用因子分析和聚类分析对我国31个省市养老事业发展状况进行了实证研究,并进行了排序和分类。结果发现各省市在老龄事业不同方面的发展程度不同,存在着严重的不均衡问题,且大体可以分为4个发展水平。文末,在实证分析的基础上对我国老龄事业的发展提出了相关建议。

风化作用元素迁移与金富集机制研究——以国内外典型红土型金矿床为例

以国内外典型红土型金矿床为例,采用质量平衡和地质统计分析方法,探讨了风化作用元素迁移与金富集机制。研究表明,元素迁移与风化强度有关。风化作用较弱时,以淋滤FeO、MgO、CaO、Na2O、K2O等组分为主;风化作用较强时,A l2O3、Fe2O3、SiO2亦发生大量迁移。Au富集主要有两种方式:其一,Au从载金矿物中活化后被表生矿物吸附,随着其它组分的淋失而逐步残余富集;其二,Au随FeO、MgO、CaO、Na2O、K2O等组分一起淋滤,而在风化壳下部被低价铁锰离子还原富集。

创意产业集群空间集聚效应的影响要素分析

在创意产业集群空间集聚效应影响要素梳理的基础上,基于问卷调研数据,采用因子分析和回归分析相结合的方法,实证分析创意产业集群空间集聚效应的影响要素及其对集聚效应的具体影响。研究发现:设施条件、政务环境、企业互动、区域网络、创新系统、文化环境、消费需求对创意产业集群空间集聚效应的正向影响显著,其影响的重要性程度由大到小依次为创新系统、文化环境、政务环境、区域网络、消费需求、设施条件、企业互动。由此,提出创意产业集群空间集聚的创新发展策略。