Characteristics and dynamics analysis of Populus euphratica populations in the middle reaches of Tarim River

Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.

Population Characteristics and Future Population Countermeasures for the Studied Counties in Tibet, China

Focusing on the 18 counties along “One River and Two Tributaries” region, and based on the data from China 3nl, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3nl population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown, fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3nl population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education.

Evaluation of Material-based Development of China Using GIS Methods

Regional development is a course of accumulation based on many factors, which is directly related to resources utilization and conversion. And material wealth production and accumulation embody the outcome of regional development. Thus, focusing on material wealth, regional development can be evaluated from resources and perspective of resources conversion. Taking the infrastructural level, transportation accessibility and economic development level into full account, the concept of "material-based development" was presented and the material-based development index (MDI) model was established. By using the MDI model, geographic information system technology and mathematic methods, this article then calculated MDI of each county and province of China in 2005 and systematically evaluated the material-based development of China at county and provincial scales, so as to bring some scientific references and policy-making supports to the population development function oriented zoning and population spatial distribution planning of China. The result showed that: (1) At county scale, the material-based development of counties within China in 2005 was significantly different, in which there were 1876 counties belonging to the mid-level material-based development and accounted for 78.10% of the total. The numbers of high-level and low-level counties were 144 and 382 and accounted for 6.00% and 15.90% respectively, demonstrating a spindle shape in general. The spatial distribution of material-based development was unbalanced, and it was much better in southeastern part of the line of "Daxinganling–Yinshan-Liupanshan–southeast edge of Qinghai–Tibet Plateau" than that of northwestern. Furthermore, there were also differences of the sub-index between different material-based development levels. Therefore, for different regions, key issues and measures adaptable to local condition should be prioritized and taken in order to realize regional balance development. (2) At provincial scale, there was also significant difference between each province and the spatial distribution of it was "high in the east, low in the west" in general. It meant that the capacity of natural resources attraction and conversion of east China was better than that of west China. The infrastructure level was the main factor ac- counting for the differences of material-based development levelsamong provinces. As a result, our government should make great efforts to improve infrastructure condition, especially the western part of China, so as to narrow the gap between the western part and the eastern part to realize the coordinated development within different regions and rapidly socio-economic development of China.

Influence of land use change on the waterbird community of Sihwa Lake,Republic of Korea

Background:Land use and development alter mudflat and wetland habitat availability,although mudflats and wetlands provide important stopover habitats for shorebirds during the spring and autumn migrations and support communities of ducks and geese during the winter months in the Republic of Korea.This study investigated land use changes around Sihwa Lake(Republic of Korea)and evaluated the effect of these changes on waterbird community characteristics.Methods:We conducted a land-use-change analysis at the medium-resolution level using land cover maps for 2001,2007,2009,and 2014.Also,a tidal stream survey was conducted in Sihwa Lake and the surrounding reclaimed mudflats every season for 10 years(2003-2012)to identify the seasonal and interannual variations in waterbird species composition.To determine the total annual waterbird species and population counts,species diversity index,and interspecies variations,a TRIM(trends and indices for monitoring data)analysis was used.Results:Wetland area decreased more than 10%while agricultural land,barren land,and grassland area increased more than 10%due to continuous reclamation activities around Sihwa Lake.Barren land later turned into agricultural land or other land use.Sixty-three species and 566,623 individuals were recorded.The number of species,population size,and species diversity index by year and by species showed decreasing trends that were more marked in spring and summer.Furthermore,seasonal and annual variations in waterbird species composition showed decreasing trends in dabbling ducks,herons,grebes,and shorebirds but diving ducks displayed increasing trends.In particular,shorebirds were reduced to a greater extent than other waterbird species because of the reduction and simplification of the intertidal zone,and shallow waters caused by reclamation and road construction.Conclusions:Increased development and construction around Sihwa Lake has altered migratory shorebird populations with a general decline in species diversity and population size.The greatest decline was observed in wading birds,while diving duck populations showed increasing trends.

Estimating index of population trend by re-sampling techniques （jackknife and bootstrap） and its application to the life table study of rice leaf roller, Cnaphalocrocis medinalis （Lepidoptera： Pyralidae）

Taking a published natural population life table of rice leaf roller, Cnaphalocrocis medinalis （Lepidoptera： Pyralidae）, as an example, we estimated the population trend index, I, via re-sampling methods （jackknife and bootstrap）, determined its statistical properties and illustrated the application of these methods in determining the control effectiveness of bio- agents and chemical insecticides. Depending on the simulation outputs, the smoothed distribution pattern of the estimates of I by delete-1 jackknife is visually distinguishable from the normal density, but the smoothed pattern produced by delete-d jackknife, and logarithm- transformed smoothed patterns produced by both empirical and parametric bootstraps, matched well the corresponding normal density. Thus, the estimates of I produced by delete-1 jackknife were not used to determine the suppressive effect of wasps and insecticides. The 95% percent confidence intervals or the narrowest 95 percentiles and Z-test criterion were employed to compare the effectiveness of Trichogrammajaponicum Ashmead and insecticides （powder, 1.5% mevinphos ＋ 3% alpha-hexachloro cyclohexane） against the rice leaf roller based on the estimates of I produced by delete-d jackknife and bootstrap techniques. At a = 0.05 level, there were statistical differences between wasp treatment and control, and between wasp and insecticide treatments, if the normality is ensured, or by the narrowest 95 percentiles. However, there is still no difference between insecticide treatment and control. By Z-test criterion, wasp treatment is better than control and insecticide treatment with P-value 〈 0.01. Insecticide treatment is similar to control with P-value 〉 0.2 indicating that 95% confidence intervals procedure is more conservative. Although similar conclusions may be drawn by re-sampling techniques, such as the delta method, about the suppressive effect of trichogramma and insecticides, the normality of the estimates can be checked and guaranteed, and the correlation among sequential life stages of rice leaf roller is also considered in the estimation. Judged by the P-values from Z-test, the delta method is more conservative.

中国区域物流差异发展趋势分析——基于Theil指数的实证研究

在开放经济格局下,我国经济发展的区域间差异明显,相应地,区域间物流水平在一定程度上也明显不同。研究国内区域间物流差异的发展趋势,对改进物流工作和了解国内经济发展的区域性差异有实际参考意义。本文利用2009~2018年全国31个省级区域的时序数据,结合Theil指数模型构建了分析区域物流差异发展的计量分析体系。结合区域经济发展的相关指标数据,深入分析了区域间物流差异发展趋势的情况。研究结果表明:2009~2018年期间,我国东、中、西部地区物流发展差异性不断扩大,受到资源禀赋、政策颁布实施情况、区域经济发展水平、市场开放度的差异等方面的影响,区域物流差异发展明显,各地区应首先关注物流发展的内部差异问题,再考虑向外部拓展发展,不同区域要结合自身物流业发展实际情况寻找适合的机遇,继而提高本区域物流产业的整体竞争力。

基于德温特专利数据的MOFs材料的研究现状及发展态势分析

基于德温特专利数据(DII),应用专利计量方法研究金属有机框架(MOFs)材料的研究现状及发展趋势。在DII数据库中检索1963年至2016年12月31日的MOFs专利记录1356条,采用汤森路透开发的分析软件(TDA)对采集的专利数据进行分析和研究,并借助可视化的分析工具,从专利总体态势、专利权人、专利技术领域和MOFs专利在中国的申请情况等方面进行分析。为我国相关领域的研究者提供具有一定价值的技术文献信息,也为我国加快MOFs材料技术创新、增强专利成果转化等提供参考。

Common Species Distribution Models in Biodiversity Analysis and Their Challenges and Prospects in Application

Species distribution models have been widely used to explore suitable habitats of species,the impact of climate change on the distribution of suitable habitats of species,and the construction of ecological reserves.This paper introduced species distribution models commonly used in biodiversity analysis,as well as model performance evaluation indexes,challenges in the application of species distribution models,and finally prospected the development trend of research on species distribution models.

数字经济时代流动人口创业生态系统建构的区域差异与协调研究

基于空间计量模型和协调发展指数的方法,对2000—2022年中国31个省份的流动人口创业生态系统建构的区域差异与协调研究进行了实证分析。研究结果表明:流动人口创业生态系统指数呈现出东高西低、沿海高内陆低的空间分布特征,且存在显著的空间自相关性和空间溢出效应;数字经济指数对流动人口创业生态系统有显著的正向影响;流动人口创业生态系统的供给、需求、资源和环境4个子系统对协调发展指数的影响均为正向且显著,其中环境因素的影响最大;协调发展指数对流动人口创业的质量和效益的影响为正向且显著。据此,提出加大对数字经济的投入和支持、加强对流动人口创业的区域协调和合作、加强对流动人口创业的环境优化和改善等政策建议。

基于CNKI指数的高校图书馆阅读推广研究热点和发展趋势分析

本文以中国知网CNKI为数据源,以国内高校图书馆阅读推广的开展为研究主题,通过举例具体介绍CNKI指数分析方法的运用,对检索结果文献从学术关注度、关注文献、学科分布、机构分布、相关词分析等五个方面进行数据分析,通过CNKI指数的多维度分析进一步探讨国内高校图书馆阅读推广研究热点和发展趋势。

风电场功率预测的研究进展及发展趋势

风电场功率预测可以有效地帮助平衡系统电力供应和负荷需求,从而降低风电功率波动性和不确定性对电力系统稳定性的影响.随着风电接入电力系统比例的增加,如何准确地预测风电场发电功率成为一大难点,将影响风电场并网运行.由此,系统总结了近些年来国内外学者在风电场功率预测方面的研究进展.首先,以预测时间尺度、预测物理量、预测原理、预测特点为分类标准,对多种风电场功率预测方法进行了分类梳理,总结了各类预测方法的研究情况,阐述了其特点及应用场景,为预测模型的选择提供了参考.之后,从单点预测、概率预测、预测曲线的角度总结了预测效果的评价指标,并就评价指标的选择给出建议.最后,总结了当前风电场功率预测全过程遇到的影响预测准确性、实用性的关键因素,提出了未来风电场功率预测可能的发展趋势,为准确预测风电场功率及电网的稳定并网运行提供了参考.

人口高质量发展指数构建与国际评价研究

近半个世纪以来全球和中国的人口形势都发生了巨大变化,运用科学而简明的指标体系评价人口高质量发展状况及趋势有利于全球共同科学应对人口新常态对社会经济产生的巨大影响。在中国式现代化语境中,人口高质量发展的基本理论内涵是指人口总量、素质、结构和分布等要素有力支撑现代化发展和有助于实现人类自身的全面发展。运用专家咨询法和熵权法,从人口现代化发展和人的全面发展2个维度、5个分维度共选择12个指标构建人口高质量发展指数。实证研究显示人口素质、人口经济发展、人口生活质量、人口宜居环境、全民共享发展的最终权重系数分别为0.398 9、0.299 6、0.102 8、0.130 5和0.068 2。据此对世界有数据可得的国家和地区人口高质量发展情况进行测算,结果爱尔兰得分排名第一,中国排名第四十六。人口高质量发展指数均值由高到低依次为欧洲、大洋洲、北美洲、南美洲、亚洲和非洲。发达国家的人口高质量发展水平普遍高于发展中国家和最不发达国家。研究构建的人口高质量指数与既有相关国际指标具有一定的区分度,体现了人口高质量发展方面中国开放式的自主话语体系。世界人口高质量发展区域失衡与存在差异的关键影响因素仍然是经济发展水平。人口素质和人口经济发展是我国人口高质量发展的相对优势所在。

混凝动力学存在问题与研究趋势

对混凝动力学的研究和应用现状中存在问题进行了较为全面的分析,重点阐述了混凝动力学理论、混凝动力学控制指标等在应用研究中存在的问题;并在此基础上阐述了混凝动力学研究方法的发展趋势,以期推动混凝动力学研究的发展。

湖北省人口与国土空间协调发展策略研究

人口是一切经济社会活动的基础,人才更是第一资源。在新时代背景下,分析当前人口的变动特征和内涵,对于优化国土空间布局、促进人口与国土空间协调发展、推进湖北省社会经济可持续发展具有重要意义。基于人口统计数据分析,对湖北省人口结构转型与区域协调发展问题开展了研究。据此,提出人口与国土空间布局协调发展策略,通过优化空间布局、加强区域协同联动、推进新型城镇化等措施,为湖北省国土空间开发保护优化提供有益支撑。

2022年全球和中国胰腺癌发病及死亡分析

目的根据国际癌症研究机构发布的2022年全球癌症统计报告,结合性别、年龄和人类发展指数(HDI)等,分析2022年全球及中国胰腺癌的发病和死亡情况。方法全球185个国家和地区的胰腺癌数据来源于GLOBOCAN 2022数据库,HDI根据联合国开发计划署公布的《2022年人类发展报告》获取。将癌症数据按年龄、性别和HDI分层,描述全球及中国的胰腺癌流行情况。使用Pearson相关分析评估标化发病率(SIR)、标化死亡率(SMR)及死亡发病比(M/I)与HDI的相关性。结果2022年全球胰腺癌总发病人数为51.10万,在各癌种中位列第12位,SIR(4.7/10万)位列第15位;全球胰腺癌总死亡人数为46.74万,在各癌种中位列第6位,SMR(4.2/10万)位列第9位。中国胰腺癌总发病人数为11.87万,在中国各癌种中位列第10位,占全球胰腺癌总发病人数的23.22%,SIR(4.4/10万)位列中国各癌种的第13位;中国胰腺癌总死亡人数为10.63万,在中国各癌种中位列第6位,占全球胰腺癌总死亡人数的22.74%,SMR(3.9/10万)位列中国各癌种的第8位。全球及中国的男性胰腺癌发病人数、死亡人数、SIR和SMR均高于女性。胰腺癌SIR和SMR均与HDI呈正相关(r=0.77、0.77,均P<0.001),而M/I与HDI呈负相关(r=-0.43,P<0.001)。全球及中国的胰腺癌发病人数、死亡人数、SIR和SMR随年龄增长呈上升趋势,从45~49岁开始迅速增长。结论全球及中国胰腺癌疾病负担严重,胰腺癌的发病和死亡率随年龄增长呈上升趋势。男性的胰腺癌发病率和死亡率均高于女性。HDI与胰腺癌SIR和SMR呈正相关,而与M/I呈负相关。

时序数据分析下的生态环境变化监测与发展趋势预测

生态环境监测与发展趋势预测已经成为城镇可持续发展关注的重点问题之一,对于平衡生态环境与城镇化发展具有重要意义。鉴于传统生态环境评价方法难以体现其客观性及有效性,本文基于长时序卫星遥感图像数据应用于生态环境变化评估的优势,结合遥感生态指数与卷积神经网络模型评价乌鲁木齐的生态环境时空变化并预测未来发展趋势。

The trends of migration in China, 1949-2019

Based on relevant policy documents and census data,the authors analyze the characteristics and trends of China’s population migration since the founding of People’s Republic of China(PRC)in 1949.The study finds that over the past 70 years,population migration in China has exhibited distinct stage-specific characteristics.From the founding of PRC to the period of reform and opening-up that got underway in 1978,China witnessed a shift from free population movement to restricted population movement,as well as a shift from population movement driven by the recovery of national economy to that driven by political reasons.With the launch of the reform and opening-up policy,China’s population migration entered an entirely new stage of development,exhibiting the following trends:(1)population migration was highly active,and there were changes in the size of the migrant population;(2)with regard to the direction of migration,rural to urban migration remained the dominant pattern,but the proportion of urban to urban migrants also rose;(3)with regard to the choice of destination,inter-provincial migrants were increasingly concentrated in the coastal areas of Eastern China,whilst the large cities in the Central and Western China were more favored by intra-provincial migrants;(4)the distances inter-provincial migrants traveled increased;(5)migration was motivated mainly by economic factors,yet the importance of social factors was on the rise;and(6)the educational level of migrants went up significantly and the sex ratio gradually became balanced.Accordingly,we must gain a deeper understanding of the trends and characteristics of population migration,taking into consideration the interrelationship between population migration and socioeconomic development.To begin,the equalization of basic public services and thorough-going reform of the household registration system can contribute to the development of a new urbanization strategy.

广东省人口发展现状特征及趋势研究(下)

以2020年第七次全国人口普查资料为基础和2020年年末广东省人口为基期,借助PADIS-INT软件,运用队列要素法,代入人口预测参数,对广东未来30年人口规模和结构进行了预测,得出高、中、低三种方案。针对广东人口发展趋势,提出树立保持第一动力,增强第二动力,稳定第三动力的人口总量发展战略;提高全要素生产率,提升劳动人口质量,变常住人口大省为人才强省;开展针对性人才引入,逐步优化人口性别结构;做好人口发展规划和评估预案,推动人口平衡协调健康发展等可操作性的政策建议。

钻屑瓦斯解吸指标测定取样装置研究现状

随着我国煤与瓦斯突出预测技术日益完善,煤与瓦斯突出事故得到极大改善,但开采深度增加导致煤层结构日趋复杂,煤与瓦斯突出事故仍时有发生。取样装置是采用钻屑指标法预测煤与瓦斯突出的基础,目前普遍存在因为钻机振动、钻屑飞扬而取样困难的问题,特别是我国煤层逐渐呈现出松软和急倾斜特征。总结了煤矿用钻屑瓦斯解吸指标测定取样装置的研究现状,阐述了其工作特点及未来发展趋势。

高职食品检验检测技术专业课程体系的构建

当前,如何将职业标准有效融入高职课程体系是高职院校亟待解决的问题。本文以食品检验检测技术为例,通过分析行业发展动态,对接相关职业标准,构建包含四级指标的高职毕业生能力指标体系,在此基础上,通过能力的课程映射,构建“平台+模块”的课程体系。该课程体系的构建对培养适应行业需要的高素质技术技能型人才具有重要意义。