基于生态足迹的咸阳市适度人口研究

一个区域生态适度人口的确定取决于区域生态承载力与区域人口对生态资源的需求。首先介绍了生态足迹模型的基本概念和计算方法,其次计算了咸阳市1999-2006年的生态足迹和实际利用的生态承载力,并在此基础上估算了咸阳市1999-2006年的态适度人口。结果表明：在1999-2001年之间,咸阳市实际人口从467.12万一直增加到477.32万;咸阳市生态适度人口从188.86万一直增加到195.40万。在2002-2006年之间,咸阳市实际人口从481.66万一直增加到499.69万;咸阳市生态适度人口从177.43万一直下降到138.04万。总之,咸阳目前已经出现了过度人口和生态赤字,咸阳市具有相对较大的人地矛盾,生态赤字较大,目前的人口规模是非常不合理的。最后提出咸阳市未来可持续发展的可选途径。     

合肥市生态足迹动态分析

生态足迹作为度量区域生态可持续性的方法已经得到越来越广的应用,是城市可持续发展的重要指标。该文利用合肥市2000—2004年数据,分别计算了当地生态足迹、生态承载力、生态赤字以及万元GDP生态足迹。结果表明合肥市生态足迹呈上升趋势且大大高于当地的生态承载力,生态赤字现象严重。人均生态赤字由2000年的1.7041hm2/人增长到2004年的2.10108hm2/人。生态供需平衡依赖其他地区的生态输入。而万元GDP生态足迹则呈下降趋势,由2000年的2.545955减少为2004年的1.791977,表明在工业、经济的增长过程中对资源的利用率和效率有所提高。     

Regional population growth rate differences: note

"This note investigates regional population growth in the U.S. for 1959-84, taking into account four city sizes and three time periods. It is found that the growth is largest in city size (0.5-1.0) million and (1.0-2.0) million. Over time, the growth is largest in the less urbanized regions." The note aims to supplement the findings of Daniel Garnick and is based on data from the U.S. Bureau of Economic Analysis.     

山东省耕地变化与人口增长及经济发展间的关系初探

选择GDP增长率、人口增长率和耕地面积减少率作为主要分析指标,分析了1978—2000年山东经济增长,人口增长和耕地面积减少之间的关系,并选用1991—2000年的数据以市为单位探讨了区域差异。发现改革开放以来的20几年,耕地面积大量减少的时间和经济过热的增长阶段基本同步,具体受固定资产投资规模的牵动。认为经济增长是耕地面积减少的主要宏观驱动因子。     

1951—2012年河南省气候变化对冬小麦和玉米产量的影响

在分析河南省1951—2012 年历史气候变化背景下,对冬小麦和玉米不同生长时期对应的气候要素变化对其产量的影响进行定量研究。利用国家气象局网站提供的历史气象数据,基于Matlab 和Surfer 8.0 绘制年平均气温和降水量的小波系数实部等值线图。通过用二次函数拟合趋势产量,将冬小麦和玉米的历年气象产量分离出来。之后利用SPSS进行逐步回归分析,建立以气候产量为因变量,不同生长时期的气候要素为自变量的回归模型。结果表明：（1）河南省年降水量在其变化过程中存在多时间尺度特征,小波波幅中心在36~58 年、15~35 年以及8~14 年这3 类时间尺度上正负交替出现,存在周期性的变化规律。在18 年尺度上,年均气温到2012 年处于升高状态。（2）冬小麦全生育期内,在其他自变量不变的情况下,越冬期降水量每增加1 mm,气象产量将减少0.221 万t;越冬期平均温度每增加1℃,气象产量将减少13.277万t;在冬小麦生长期第二阶段中,降水量每增加1 mm,气象产量将减少0.149万t。（3）在玉米全生育期内,保持其他自变量不变的前提下,营养生长期内降水量每增加1 mm,气象产量将减少0.003 万t;营养生长期平均温度每增加1℃,气象产量将减少6.389 万t;玉米生殖生长期间,降水量每增加1 mm,气象产量将减少0.159 万t。从总体上来看,温度和降水变化对气象产量的影响皆为负面影响,并且温度变化对粮食产量的影响比降水变化产生的影响显著得多。通过对2 个回归模型进行对比发现冬小麦比玉米具有更强的气候变化敏感性。     

基于生态足迹法的土地利用规划环境影响评价──以禹州市为例

随着经济社会的飞速发展,土地供给需求不平衡显得尤为明显,因此要合理规划用地。土地利用规划调整了区域内的土地利用结构及布局,可能会对该区域内的环境造成影响。为研究土地利用规划对环境的影响,笔者采用生态足迹法对河南省禹州市23个乡镇规划前期、规划中期和规划后期的总生态承载力和人均生态承载力进行了分析。结果表明:(1)禹州市的生态承载力由2005年的120062.95 hm~2增加到2009年的120933.45 hm~2,至2020年又增至123070.46 hm~2;(2)人均生态承载力除禹州市区和古城镇人口增长过快的地区下降外,其余地区的人均生态承载力都在规划实施后增加。可以得出结论,新一轮土地利用规划的实施对禹州市的环境是有益的,提高了全市的生态承载力。     

粤北山区县域土地利用对生态服务价值的影响

山区属于生态脆弱系统类型,为明确土地利用变化对其生态服务价值的影响,进行有利于城乡区域的生态环境保护及用地规划。本研究以韶关市仁化县为例,通过仁化县2000、2010、2020年的Landsat TM影像,运用RS和GIS软件分析仁化县近20年的土地利用变化状况,从生态服务价值的角度分析仁化县2000—2020年的用地变化对土地系统稳定性和生态系统服务价值的影响。结果表明：（1）仁化县各土地利用类型面积从大到小依次为林地、耕地、草地、水域和建设用地,20年间林地、耕地和草地在研究期内总体呈现先增加后下降的趋势,建设用地面积逐年上升,水域面积呈现先下降后增加的趋势;（2）2000—2020年仁化县土地利用程度指数呈增长趋势,土地利用结构信息熵值在0.76~0.82之间,土地利用结构稳定性增加,土地利用均衡度在0.47~0.51之间,且逐年增加;（3）仁化县土地利用类型的变化影响了生态服务价值的转变;2000—2020年仁化县整体生态服务价值呈现先减少后增加趋势,实际净增加39440.78万元;（4）在11个二级服务功能中,水文调节功能价值增加趋势明显,从2000年的342416.79万元增长到2020年的380556.19万元。本研究结果可以为山区的自然资源保护、经济和生态的可持续发展以及土地结构调整提供依据。     

重庆市涪陵区城镇化水平驱动机制分析及预测

本文在介绍重庆市涪陵区1998-2008年间城镇化水平现状的基础上,通过分析涪陵区城镇化发展的外在和内在驱动机制,对涪陵区城镇化趋势进行定性分析,最后再运用综合增长率法和剩余劳动力转移法分别预测出2015年和2020年的总人口和城镇常住人口,得出涪陵区在2015和2020年的城镇化水平。     

Biocontrol Methods in Cotton Management

The quantity of bio-laboratories and bio-factories in Uzbekistan increases every year.In 1970,there were only 4,in 1971,16,in 1985,710,in 1990,774,and in 2000,790.At present there are 864 biofactories and biolahoratories in our Republic,which produce trichograrnma,bracons,and golden eyes.Currently they make 9953.5 kg of trichogramma,2814.8 million individuals of bracon,and 3162.9 million individuals of goldeneyes.It has been achieved great successes in development and introduction of biological method of plant protection in our Republic at last time.In 1970,the area of this method was 2.6 thousand hectares,in 1971,12.5 thousand hectares,in 1985,3622 thousand hectares,in 1990,5919 thousand hectares,in 2000,7574 thousand hectares,and in 2007,10893 thousand hectares (85.7% of total crop area of our Republic).It will be planned to increase the biological method of plant protection in Uzbekistan by Program of integrated plant protection from pests, diseases and weeds in 2008.The big attention will be given to construction the new 83 bio-laborato-ries.     

湖北省水资源供需平衡及其承载力

以湖北省为研究区域,运用水资源负载指数和水资源供需平衡模型,采用数理统计方法,定量计算和分析了湖北省近年来的水资源供需平衡态势以及湖北省市域尺度的水资源开发潜力;在水土平衡分析、水资源供需状况评价与水资源开发潜力评价的基础上,从资源平衡关系入手,采用水资源承载指数等指标,对2000—2012年省域与市域2个层面的水资源平衡状况进行了定量研究。结果表明：湖北省人均水资源量居全国平均水平。湖北省属于水资源利用程度较高、开发利用条件较好、水资源开发潜力较大的省区。湖北省水资源承载力有限,随着未来人口的增加以及工农业的快速发展,在现有的水资源量基础上,水资源短缺将会成为湖北省中东部城市的发展瓶颈。     

运轮1号玉米群体轮回选择改良效果

种质资源遗传基础狭窄是制约玉米育种的重要因素,而群体轮回选择是拓宽玉米资源遗传多样性的重要方法。以具有中国reid 血缘的8 个自交系组成的群体和美国坚秆种质群体BSSS 杂交后经过一轮混合授粉形成运轮1 号玉米群体。3 轮混合选择后,以昌7-2 为测验种分析了运轮1号群体的产量性状的配合力。结果表明,群体内单株间产量配合力差异显著,遗传变异较丰富。从138 个测交种中筛选出20 个较优良的对应自交单株作为新一轮轮回选择的亲本。预计新一轮合成群体产量配合力将提高11.6%,灌浆脱水速率较对照优越,其他农艺性状也得到相应改良。     

Regional Innovation Systems: Implications for Nonmetropolitan Areas and Workers in the South

ABSTRACT A public policy response to global competition is the creation of a geographic concentration of innovative activity (regional innovation systems [RIS]) that will enhance metropolitan economic development through knowledge spillovers, product development, and new firm spin‐offs. This article identifies three types of RIS in the thirteen southern states based on a cluster analysis of twenty indicators of innovative and entrepreneurial activity. Next, regression analysis is used to determine if the 1990–2000 growth rates of nonmetro county population, employment, and earnings were related to proximity to an RIS after controlling for other county characteristics associated with local economic development. The research findings indicate that nonmetro counties near an RIS experienced more rapid population and employment growth; however, changes in nonmetro growth rates varied by type of regional innovation system. In addition, proximity to an RIS had a stronger impact on nonmetro population change than on nonmetro job growth.     

种植密度对适宜机械化栽培高粱品种产量及生理特性的影响

以适宜机械化种植的高粱品种辽杂37和晋杂34为试验材料,分别对6个密度处理的产量、产量构成因素、叶面积指数、叶绿素含量、光合速率及群体透光率进行了测定与分析。结果表明：辽杂37和晋杂34均在密度为13.5万株/hm ²时产量最高,分别可达10 551.0和10 324.5kg/hm ²。其中辽杂37在12.0万~15.0万株/hm ²、晋杂34在12.0万~13.5万株/hm ²密度时穗数、穗粒数和穗粒重协调效果较好,可保持较高产量水平。当密度达到15.0万株/hm ²时,随着密度的继续增加将导致群体光合速率和透光率大幅度下降,影响干物质积累和产量形成。     

沙地冬小麦灌浆特点和水肥对灌浆的影响

对不同品种，不同砂土类型和不同水肥条件的冬小麦粒形成及灌浆强度测定表明，沙地冬小麦灌浆特点主要表现为灌浆期短（一般１５～１７天）灌浆强度较高，但开花至成熟历时天数少（３０天左右）千粒重低，小麦旗叶单位面积干重与千粒重呈极显著负相关，倒二，倒三叶单位面积干重与千粒重相关不显著；茎秆上部三节间单位面积干重与千粒重均呈极显著负相关，沙地不麦增灌水量，难以显著提高灌浆强度，灌溉应做到少量多次。增施有机肥料     

Method of Gradual Advance for Town Development

The economical construction and development of China can't be separated from the development of rural economy.Due to appearance and development of rural enterprises,surplus labor force of rural areas was accepted, agricultural economy had been developed and farmers' income enhanced. The traditional agriculture had been reconstructed. The construction and development of small cities and towns are connected with the development of rural economy and accelerate the development of city economy. The construction of small cities and towns can have congregation effect and scale benefit. The industry structure of country will be optimized in whole, management cost will be cut down, energy consumption will be reduced, pollution will be lowered and labor productivity will be increased. In this paper, the importance of town construction in economic development of China is elaborated. The achievement and problem in town construction are summarized. A method of gradual advance for town development is put forward and the problems that must be handled in town development are pointed out.     

苦荞新品种“川荞6号”的选育及栽培技术

川荞6号是中熟苦荞新品种，在西南地区生育期72~78d，出苗整齐、健壮，幼茎绿色，叶片大小中等，叶色深绿，花为绿白色、无香味。主茎节数11.5左右，株高100~110cm，有效分枝2~5个，花序柄短，结籽集中，籽粒饱满、长锥、暗灰色，平均单株粒重2.5~4.5g，千粒重22~24g，产量1800~2050kg/hm²。该品种是地方品种“额乌”变异单株通过系统选育而成的苦荞新品种，2020年12月通过重庆市种子行业协会组织相关专家进行田间鉴定，命名为“川荞6号”。2021年11月通过重庆种业协会农作物鉴定委员会鉴定，鉴定编号为“渝品审鉴202110”。     

基于GRNN算法的潜在产出与产出缺口估算模型

基于神经网络学习性、非参数估计的优势,建立估算经济潜在产出和产出缺口的广义回归神经网络（GRNN）模型,对中国产出缺口和潜在产出增速的1978—2015年数据进行估算、2016—2020年数据进行多步预测,实证分析较好地克服了生产函数法中由于事先假设确定的函数形式及选择不同函数结果不同的问题,并且所估算的潜在产出增速与经济增速具有较高的契合度。模型分析得出：中国经济增长速度大致维持在潜在产出增长率水平附近,便可实现通货膨胀率维持在合理水平,且较好地实现总体供需平衡的目的。     

A Trial Coexistence of New and Old: A Case Study of Shikumen House Reconstruction in Shanghai

As an architectural style from the growth period in Shanghai, Shikumen houses will influence the city image of Shanghai for a long time. Today, a further understanding of Shikumen houses will help us comprehend local characteristics and the meaning of city culture, to uphold the image of the city, and to keep the lifestyle lively. In this case study, we paid attention to city context. By proposing a method of partial preservation and partial reconstruction of a Shikumen house, we tried to realize humanistic communion space with different layers, such as an upright lane and aerial yard.     

Correlation Analysis of Digital City and Urban Sustainable Development

Digital city and its sustainable development is the new vision on city civilization in the 21st century, which will greatly change the life conception, style and level of the people. The relationship of Digital City and sustainable development will affect the orientation and speed of worldwide economic development. The concepts and the relationship of Digital City and sustainable development are analyzed and their harmony and collision are studied in this paper. It suggests that Digital City is an important component of Digital Earth and a result of new technology revolution as well as the inherent necessity to the implementation of sustainable development. Digital City and sustainable development will be vested with new connotations with the development of the city.     

Factors and Correlates of Employment Growth in the Canadian Urban System, 1971–1991

The objective of this paper is to examine a number of hypotheses concerning the factors or correlates of employment growth in the Canadian urban system—a set of 152 urban areas having populations of more than ten thousand inhabitants which comprises 77.4 percent of the national population. Do observed patterns of sectoral employment growth obey some sort of underlying logic? More specifically, do the rates of employment growth that are found in individual urban areas vary significantly according to one or more of the following attributes of an urban area: a) the region in which it is located; b) its population size; c) its relative proximity to a major metropolitan area; d) its socioeconomic characteristics? While approaches involving a, e and f yield promising results, it is clear that there are few immutable laws that permit one to predict where employment growth will occur within the urban system. Perhaps the most fundamental characteristic of the analyses conducted involves the instability of the results from one decade to another; one decade’s category of winners is often the other decade’s category of losers.