我国区域R&D强度与产业结构的灰色关联分析

在对我国各省份研究与发展强度现状进行分析的基础上,指出我国各省份之间的研究与发展强度具有很大的差异,然后利用灰色系统理论中的灰色关联模型分析了2000-2007年间我国31个省、市、自治区研究与发展强度与其第一产业、第二产业、第三产业和高科技产业之间的关联度.根据其关联度的大小,本文得到这样的结论,即我国各省份研究与发展强度的差异与其产业结构之间存在着密切的联系,其中高科技产业对研究与发展强度影响最大,第一产业对研究与发展强度的影响最小,各省的研究与发展强度受到其产业结构的限制.在此基础上,本文提出各省份在提高研究与发展强度的同时,我国各省份在制定科技研发政策的时候,必须立足于本省的产业结构,要具体情况具体分析,要将提高研究与发展强度与调整产业结构相结合,只有这样研究与发展资源才能够得到更好地利用,才能够真正提高各省份的科技创新能力.     

区域可持续发展指标体系与评价方法研究

本文探讨了区域可持续发展指标体系建立的指导原则和方法，分析了区域社会大系统的运行模式，在此基础上提出了区域可持续发展评价指标体系。     

土壤水分植被承载力研究成果在实践中的应用

论文以黄土高原半干旱区柠条林为例,探讨了土壤水分植被承载力研究成果在生产中的应用。结果表明,土壤水分植被承载力不仅是确定森林植被恢复目标、调控植物水关系的理论基础,而且是确定森林植被合理经营方向和利用强度的理论基础。如果人工林密度大于土壤水分承载力,需要对人工林进行疏伐;如果人工林密度小于土壤水分承载力,需要增加密度或改换植被类型。当人工林密度等于土壤水分承载力时,人工林可持续利用土壤水资源。土壤水分承载力时的柠条林可以作为薪炭林和放牧林经营。单位面积结实量与密度关系可用正态分布曲线描述。承载力时的柠条林不仅能有效地保持水土,而且能生产较多的种子,又是良好的蜜源植物,宜作为水土保持林经营。该研究结果可为人工植被恢复和可持续经营提供科技支撑。     

Rehabilitating China's Largest Inland River

Abstract:  Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica , which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20–45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources.     

Water budget and the consequent duration of canopy carbon gain in a teak plantation in a dry tropical region: Analysis using a soil–plant–air continuum multilayer model

A soil–plant–air continuum multilayer model was used to numerically simulate canopy net assimilation (A_n), evapotranspiration (ET), and soil moisture in a deciduous teak plantation in a dry tropical climate of northern Thailand to examine the influence of soil drought on A_n. The timings of leaf flush and the end of the canopy duration period (CDP) were also investigated from the perspective of the temporal positive carbon gain. Two numerical experiments with different seasonal patterns of leaf area index (LAI) were carried out using above-canopy hydrometeorological data as input data. The first experiment involved seasonally varying LAI estimated based on time-series of radiative transmittance through the canopy, and the second experiment applied an annually constant LAI. The first simulation captured the measured seasonal changes in soil surface moisture; the simulated transpiration agreed with seasonal changes in heat pulse velocity, corresponding to the water use of individual trees, and the simulated A_n became slightly negative. However, in the second simulation, A_n became negative in the dry season because the decline in stomatal conductance due to severe soil drought limited the assimilation, and the simultaneous increase in leaf temperature increased dark respiration. Thus, these experiments revealed that the leaflessness in the dry season is reasonable for carbon gain and emphasized the unfavorable soil water status for carbon gain in the dry season. Examining the duration of positive A_n (DPA) in the second simulation showed that the start of the longest DPA (LDPA) in a year approached the timing of leaf flush in the teak plantation after the spring equinox. On the other hand, the end appeared earlier than that of all CDPs. This result is consistent with the sap flow stopping earlier than the complete leaf fall, implying that the carbon assimilation period ends before the completion of defoliation. The model sensitivity analysis in the second simulation suggests that a smaller LAI and slower maximum rate of carboxylation likely extend the LDPA because soil water from the surface to rooting depth is maintained longer at levels adequate for carbon gain by decreased canopy transpiration. The experiments also suggest that lower soil hydraulic conductivity and deeper rooting depth can postpone the end of the LDPA by increasing soil water retention and the soil water capacity, respectively.     

云南地区种子植物东亚分布成分的地理分布格局

植物区系分析是理解植被起源、性质和分布的基础.本研究利用大尺度的区系分布信息,结合地理信息系统平台和统计分析方法,探讨了云南地区种子植物东亚分布成分的地理分布格局以及"田中线"的生物地理意义.结果表明,东亚分布成分及其亚型所占比重均随着纬度的升高呈递增趋势.在经度梯度上,中国-日本植物分布亚型所占的比重从东到西呈递减趋势,而中国-喜马拉雅分布亚型所占比重的经度格局则与此相反.东亚分布成分在云南地区的扩散方向以由北到南为主,其次为经度梯度上的双向迁移.与过去的研究不同,本研究结果表明,东亚分布成分在云南地区的起源中心更可能为滇西北.我们未能证实"田中线"对中国-喜马拉雅分布亚型的分布具有限制意义,但对东亚分布成分(总体)和中国-日本分布亚型在云南地区的分布具有严格的限制意义.     

突发事故危害期估算模式研究

针对大气环境突发事故造成的危害,在高斯扩散模式基础上,引入危害半径变化与时间及危害期变化与横风向距离呈线性关系的假设,得出危险源附近各处受危险源突发事故危害的危害时间长短（危害期）一系列定量估算公式,使用方便,结果精确,为环境风险评价提供了有效的工具,可广泛应用于环境风险评价与管理、风险工程设计、风险责任保险等各个领域与事故应急计划制定、事故抢险工作实施.     

以沙湖为例探究宁夏内陆封闭型湖泊水体污染原因

为研究西北地区封闭式湖泊水质恶化原因及水体污染物迁移转化规律,以宁夏沙湖为研究对象,对沙湖2012—2017年水体污染物总量变化趋势及沙湖周边地表水环境质量进行分析。研究结果表明:沙湖水环境质量变化主要由内源性污染和外源性输入造成,其中内源性污染源主要为沙湖沉积物污染物释放,沙湖水体沉积物通过孔隙水向沙湖水体转移的CODMn、CODCr、TP、TN、氟化物分别占水体总污染物的6.4%、6.6%、16.6%、14.2%、31.4%;沙湖外源性污染源主要为黄河补水和农垦集团稻田等面源污染,其中黄河补水向沙湖 转移的 CODMn、CODCr、TP、TN、氟化物分别占沙湖水体污染物总量的49%、30%、279%、99%、13%,沙湖周边面源性污染通过渗透作用向沙湖水体输入的CODMn、CODCr、TP、TN、氟化物分别占沙湖水体污染物总量的23%、18%、52%、34%、19%,外源性污染物输入占沙湖水体污染物总量CODMn、CODCr、TP、TN、氟化物分别为72%、48%、331%、133%、32%,但由于水体自身净化作用, TP和TN已大幅度降解。     

京津冀秋冬季工业生产热异常遥感监测探讨

为全面、客观掌握工业生产热排放对大气污染的影响,利用遥感手段分析了2018—2019年秋冬季京津冀工业生产热排放及其同比变化。结果显示:2018—2019年秋冬季,京津冀地区工业热异常点数量及秋冬热异常点辐射功率(FRP秋冬)较上年同期明显增加,工业生产活动规模及强度同比有所扩大,区域PM2. 5浓度呈增长趋势。根据FRP秋冬分布特点可将京津冀工业生产分为3类,密集型、分散型和稀少型。工业生产密集型城市FRP秋冬通常 1 500 MW,较为典型的城市如唐山、邯郸,FRP秋冬可达2 000 MW以上甚至上万MW,这些城市的空气质量也相对较差;保定是工业生产分散型城市,该城市热异常点增长显著,FRP秋冬也可达2 000 MW以上,但空间分布分散;工业生产稀少型城市热异常点较少且空气质量相对较好。     

环鄱阳湖旅游圈旅游经济联系与区域发展策略

旅游圈是推进区域旅游发展的有效载体,对区域内各地区间旅游经济关系产生重要影响。以资源主导型的环鄱阳湖区域为例,根据该区域旅游经济现状,以该研究区5个地级市所属的国家3A级及以上67个旅游景区为研究对象,从景区景观质量引力指数、旅游规模和交通可达性对传统引力模型进行修正,测度2003~2015年各地区间旅游经济联系强度及其演变情况,揭示环鄱阳湖区域旅游经济联系总量呈现出快速增长且联系紧密、区域差异较明显、交通作用逐渐增强等特征。在此基础上,提出构建环鄱阳湖旅游圈区域旅游发展的基本模式,以及圈内各地旅游经济联系的思路,形成多极核的网络化结构旅游圈层格局,并演进为区域旅游圈的一般结构模式,为推进区域旅游可持续发展提供借鉴。