Optimal acquisition price management in a remanufacturing system

Return items received from end customers for remanufacturing is uncertain in nature. In this paper, we considered that return demand function is uncertain and sensitive to the acquisition price and the availability of used products in the market. A mathematical model was developed to investigate the impact of the availability of return items in the market on acquisition price management. Here, three different methods of collection of return items from the market are considered: direct method, indirect method and coordinated method. A numerical study was conducted to illustrate the mathematical model, and an extensive sensitivity analysis was carried out for the three different methods of collection to examine the impact of market size and the available dependency factor on acquisition price and the channel profit. The results show that the total channel profit increases when the acquisition price increases for the direct method of collection. Furthermore, the results reveal that the total channel profit increases when the market size increases for the coordinated method of collection compared with the other two methods of collection.     

The Intensity of Wildfires in Fire Emissions Estimates

Russian Journal of Ecology - A method for estimating direct wildfire emissions that considers fire intensity based on infrared radiation data from the Terra/MODIS satellite is proposed. In Siberia,...     

太湖湿地生态系统服务功能价值评估

随着生物资源价值估算方法的日益成熟,生态系统的服务评估成为生态系统研究的热点。运用市场价值、影子工程、碳税法等方法对太湖湿地生态系统的物质生产功能、环境调节功能和文化社会功能等直接与间接价值进行评估。结果表明：太湖湿地生态系统具有巨大和多重服务价值,总价值为112.39×10⁸元。其中,生态环境调节与维护功能价值最大,占总服务价值的48.98%;其次是物质生产与供给功能,占29.1%;文化社会功能最小,占21.91%。通过对9项子功能进行评估得出,调蓄洪水的功能价值最大,约占26.23%,供水功能其次,约占24.56%,气候调节功能,约占18.23%,科研教育价值约占13.16%,植被资源生产功能价值最小,约占0.09%。此项研究首次定量评估了太湖湿地生态系统的服务功能价值,研究成果对于认识太湖湿地的价值,有针对性地保护太湖湿地具有现实意义。     

长江上游输沙模数分布图的制作及其空间分异特征初步分析

针对一般编制输沙模数图所存在的问题,提出了一种主要基于侵蚀量加权平均绘制输沙模数图的方法。利用1956~1987年152个水文站输沙资料和其他相关数据,将各水文站观测数据插补延长到同样的长度,通过侵蚀量加权空间插值制作了长江上游输沙模数分布图。交叉检验结果显示利用本文方法得到的输沙模数插值结果要优于直接插值法的结果。所绘制的输沙模数图显示长江上游高产沙区主要集中于两个条带：一个是从北向南沿陇南和川滇山地延伸,另一个是从秦巴山地向东南,过川中丘陵北部,至黄陵背斜。同时,该图也揭示出在低产沙区存在局部高产沙斑块或条带;在高产沙区则存在局部低产沙斑块。充分反映了长江上游强烈的产沙空间变异性。     

湖北省咸宁市光伏电站太阳能资源评价

为了对无太阳辐射观测的咸宁市进行并网光伏电站太阳能资源综合评价,拟采用水平面太阳辐射气候学推算方法和倾斜面辐射换算方法,即根据武汉站历史资料分月建立总辐射量和直接辐射量与日照百分率的推算方程推算出咸宁逐月太阳辐射各分量,分析其时间变化、资源丰度和稳定性,并基于Klein提出的散射辐射各向同性的假设,计算出该地不同倾斜面年总辐射量和最佳倾角。结果表明：咸宁地区近50 a（1961~2009年）水平面太阳总辐射年总量为4 0914 MJ/m2,该地区属于太阳能资源丰富区,该地辐射形式等级处于散射辐射较多(C)等级,且太阳能资源年变化稳定度较高。正南朝向斜面接受总辐射年总量最大的条件下其最佳倾角为18°,该倾角下斜面年总辐射量为4 2246 MJ/m2,比水平的值高出33%。设计容量为1 500 kWp的光伏阵列若按最佳倾角和方位角安装,每年可发电约132×106 kW·h。太阳辐射各分量的合理推算与多个评价指标的联合应用为光伏电站规划设计提供了科学依据,也为今后类似工作提供了样本。     

上海经济的直接物质投入和市内物质消耗

本文尝试对上海经济的直接物质投入和市内物质消耗进行初步的核算和分析,目的是促进上海"十一五"期间的循环经济发展和管理.采取的核算方法主要依据是欧盟统计局的<物质流账户及指标--方法导则>,而针对地区物质流核算的难点和上海的实际,也采用了一些估算方法.对核算的结果进行分析后表明,上海的物质自给率非常低,而直接物质投入1990-2005年总体上量现不断增长的态势,2005年达到45 564.95万t;人均直接物质投入已经相当高,2005年为33.50 t/人(以户籍人口计),1996年后已经高于1992-1996年发达国家中的较高水平;物质投入的生态效率比较低,每吨直接物质投入产出2005年为2 009.04元/t,2001年约为汉堡大都市区的1/5.     

绿色GDP理论基础与核算思路探讨

在可持续发展理论的冲击下，绿色GDP核算受到了学术界的广泛关注。本文讨论了绿色GDP植算的概念、意义及相关理论基础，并且进一步提出，绿色GDP核算在方法上存在直接测算与间接测算两种思路。理论上进两种思路各有利弊，但从实践上看，这两种核算方法都迁存在不少的难点。     

WASP富营养化水质模型在GIS中的完全集成研究

模型与GIS的结合是水质模拟研究的发展趋势,但完全集成方式面临许多技术难点。通过分析WASP富营养化模型的原理,剖析其程序源代码的核心,并对其核心算法进行重新编程开发。把GIS擅长的工作完全交给GIS、把模型擅长的工作完全交给模型,模型从底层对GIS属性数据库进行直接读写,GIS对模型的起始和中间过程直接控制,实现了WASP富营养化水质模型在GIS中的完全集成。完全集成后,为WASP增加LH OAT全局参数敏感性分析功能。LH OAT全局参数敏感性分析方法集成了LH抽样与随机OAT方法的优点,在随机OAT的基础上融入LH抽样法,保证参数敏感性分析的强壮性及有效性。但LH OAT方法必须依靠复杂的计算机程序来实现,因为没有通用程序而限制了其推广应用。为此我们设计了LH OAT方法的通用程序,提高了水质模拟的性能和应用范围。这为模型与GIS的完全集成研究提供了成功案例和问题解决的新思路     

北京市生产性土地的部门关联效应分析

本文基于生态足迹的投入产出模型,利用改进的HEM方法和北京市2007年投入产出表及相关数据,计算生产性土地的部门关联效应指标,对北京市9部门块土地资源关联效应进行了分析.研究结果表明:土地资源纵向总效应超过直接消耗的部门块主要由制造业、建筑业和服务业等部门构成;采选业部门块有更大的土地资源转让潜力;其他部门块都要从本部门块以外获取土地资源,导致各部门块的外部后向关联及外部前向关联都很大.本文认为:生产性土地的关联效应实际上是经济系统部门间土地资源需求的转移,最终需求总量不变,其结构调整就不会对土地资源总量产生影响;改进的HEM方法结合生态足迹最终需求,分析直接土地资源消耗数量,分解影响部门土地资源的组成因素,可以更直接、明确地量化部门间以及部门内部土地资源的关联关系;如果能够以实物型投入产出表代替货币型投入产出表,可以更加科学地反映经济系统中各产业部门土地资源的关联特性.     

秦岭自然保护区群保护成本计量研究

秦岭自然保护区群在我国生物多样性保护方面发挥了重要作用,学术界一直缺乏保护成本计量的研究。本研究在界定秦岭自然保护区群成本的概念及分析其内涵的基础上,综合运用专家咨询法及文献参考方法,建立了秦岭自然保护区群保护成本计量指标体系,利用市场价值法、等效替代法以及机会成本法等方法,对秦岭自然保护区群保护生物多样性的投入进行了成本计量及分析。结果表明:秦岭自然保护区群在保护生物多样性投入方面,总货币量约29.72亿元人民币,其中直接保护成本为2.59亿元;间接保护成本为2.00亿元;与周边区域密切相关的机会成本为25.13亿元。其中,机会成本的计量模型多样化,在学术界存在较多争议,但是,最终每种模型都能反映出机会成本的内涵的货币量,可以表达出我国政府为建立秦岭自然保护区群而付出的无形代价。     

基于物质流分析的江苏省区域生态效率评价

物质流分析被认为是适用于生态效率评价的重要工具和方法之一,但应用于区域生态效率评价的研究尚较少。根据生态效率理论、物质流分析理论与方法,建立了基于物质流账户的3个层面的区域生态效率评价指标：区域直接生态效率、区域总生态效率、整体生态效率。以江苏省为例,全面评价了 1995~2005年江苏省不同层面的生态效率,结果表明：（1）江苏省区域直接生态效率远高于我国同期水平。区域总生态效率和整体生态效率相对较低,分别仅为区域直接生态效率 15%~22%和 7%~8%左右;（2）1995~2005年,区域直接生态效率呈先上升后下降趋势,原因在于物质生产率未有显著提高以及近年来重工业在产业结构中比重的增加;（3）整体生态效率的变化趋势与区域直接生态效率类似,原因主要是近年江苏省对区外物质和资源的进口量显著增加;（4）区域总生态效率则表现为先快速上升后缓慢上升的趋势。在对研究结果及成因进行分析和讨论的基础上,提出了提高区域生态效率的建议.     

Natural radioactivity in phosphates, phosphogypsum and natural waters in Morocco

The contents of natural radionuclides (uranium, actinium and thorium series) were measured in sedimentary phosphate rock samples using high-resolution gamma spectrometry. Data obtained for uranium content (ppm) were compared with the results obtained by a method based on the measurements using solid-state nuclear track detectors (SSNTD) in the same samples. The potential leaching of radionuclides from sedimentary phosphate rock during the industrial production of the phosphoric acid was studied. The process of leaching of the radioisotopes from phosphogypsum was discussed. A method for the direct alpha counting of 226Ra thin source, elaborated by the deposition of Ra from aqueous solutions on manganese oxides film deposited on polyvinyl support, have been developed and applied for the determination of 226Ra in natural water samples. The results show that only the water sample from the mine area reveals the presence of 226Ra at a level of about 0.2 Bq l-1.     

Determination of depleted uranium in environmental samples by gamma-spectroscopic techniques

The military use of depleted uranium initiated the need for an efficient and reliable method to detect and quantify DU contamination in environmental samples. This paper presents such a method, based on the gamma spectroscopic determination of 238U and 235U. The main advantage of this method is that it allows for a direct determination of the U isotope ratio, while requiring little sample preparation and being significantly less labor intensive than methods requiring radiochemical treatment. Furthermore, the fact that the sample preparation is not destructive greatly simplifies control of the quality of measurements. Low energy photons are utilized, using Ge detectors efficient in the low energy region and applying appropriate corrections for self-absorption. Uranium-235 in particular is determined directly from its 185.72 keV photons, after analyzing the 235U-226Ra multiplet. The method presented is applied to soil samples originating from two different target sites, in Southern Yugoslavia and Montenegro. The analysis results are discussed in relation to the natural radioactivity content of the soil at the sampling sites. A mapping algorithm is applied to examine the spatial variability of the DU contamination.     

Development of a rapid method for direct detection of tet(M) genes in soil from Danish farmland

A method for direct detection of antibiotic resistance genes in soil samples has been developed. The tetracycline resistance gene, tet(M), was used as a model. The method was validated on Danish farmland soil that had repeatedly been treated with pig manure slurry containing resistant bacteria. The tet(M) gene was directly detected in 10-80% of the samples from the various farmland soils and could be detected in all samples tested after selective enrichment. To validate the obtained results, the method was applied to garden soil samples where lower prevalence of resistance was found. RESULT: A detection limit of 10(2)-10(3) copies of the tet(M) gene per gram of soil (in a Bacillus cereus group bacterium) was achieved. tet(M) gene was detected in soil samples with the highest prevalence on farmland treated with pig manure slurry.     

海南省环境经济系统的物质流特征与演变

本文运用物质流分析( MFA)和IPAT分析方法,对海南省环境经济系统1990 -2008年间的物质输入与输出进行研究,并与同期广东省数据进行对比分析.结果表明:1990 - 2008年间,海南省环境经济系统直接物质输入呈上升趋势,1990 - 2007年间增长速度平缓,年均增长6.88％,而区域过程排放呈下降趋势,年均降低0.95％;19年间,除个别年份外,海南省物质输入强度、输出强度及物质输入效率均低于同期广东省水平,1994年以前,海南省物质输出效率明显低于同期广东省水平,1995年开始逐渐接近同期广东省水平.对以上结果进行分析,可揭示我国唯一的热带岛屿省份——海南省的物质流特征与演变规律,能够为区域循环经济与可持续发展提供科学决策,促进海南生态省、新型工业省和国际旅游岛的建设.     

气象因子与地理因子对长江三峡库区雾的影响

为研究长江三峡库区气象因子与地理因子对雾情(能见度)的影响程度,定量描述以厘定影响雾发生的主要气象因子和地理因子,为能见度监测预报提供科学依据。选用2011~2012年长江三峡航道湖北宜昌至重庆宜宾段29个人工观测雾情台站资料和12个能见度观测仪资料,首先采用判别分析法寻找不同月份对雾情等级影响较大的气象因子,进一步采用通径分析法对量化的雾情资料分析地形地貌及气象因子对其的直接、间接影响程度。结果表明:常规气象要素对判断站点中雾和大雾的符合率在50%以上。风速、温度和湿度是影响秋末和冬季雾情等级的最主要气象因子。气象要素中的1 000 hPa湿度对能见度值的直接作用最大,通径系数为-0.518 2,而地理要素中山体与河面的落差对雾的滋生有间接作用。     

129I in the environment of the La Hague nuclear fuel reprocessing plant--from sea to land

In recent years, particular attention was paid to the long-lived radionuclides discharged with authorized low-level radioactive liquid and gaseous effluents by the nuclear spent fuel reprocessing plants of La Hague and Sellafield. The knowledge of (129)I (half-life=15.7 x 10(6) a) distribution in the environment is required to assess the radiological impact to the environment and population living in the area under the direct influence of La Hague NRP discharges. Measurement difficulties of (129)I in environmental matrices, where it is usually present at trace level, limited data published on (129)I activity levels in the European and more particularly in the French territory. Studies conducted to qualify a new alternative measurement method, direct gamma-X spectrometry with experimental self-absorption correction, led to test samples collected in the La Hague marine and terrestrial environment : seaweeds, lichens, grass, bovine thyroids, etc. All these results, often already published separately for analytical purposes and treated for intercomparison exercises, are presented here together in a radioecological manner. The levels of (129)I activity and (129)I/(127)I ratios in these samples show the spatial and temporal influence of the La Hague NRP in its local near-field environment as well as at the regional scale along the French Channel coast.     

中国森林公园旅游业发展的就业效应分析

发展旅游业是扩大就业的重要渠道。森林公园旅游业是中国森林旅游业的主体。本文首先概述了中国森林公园建设与发展状况,并基于林业统计年鉴数据,分析中国森林公园旅游业发展及直接就业效应,进而采用投入产出法对森林公园旅游业的间接就业效应进行了测算,最后总结全文并提出相关政策建议。研究结果表明:森林公园旅游业持续发展的就业效应可观。测算数据显示,2011-2020年森林公园旅游业的总体就业量为512.1万人,其中直接和间接就业量分别为238.5万人和273.6万人。     

Confidence interval estimation for pooled-sample biomonitoring from a complex survey design

The National Centers for Disease Control and Prevention (CDC) is using a weighted pooled-sample design to characterize concentrations of persistent organic pollutants (POPs) in the U.S. population. Historically, this characterization has been based on individual measurements of these compounds in body fluid or tissue from representative samples of the population using stratified multistage selection. Pooling samples before making analytical measurements reduces the costs of biomonitoring by reducing the number of analyses. Pooling samples also allows for larger sample volumes which can result in fewer left censored results. But because samples are pooled across the sampling design cells of the original survey, direct calculation of the design effects needed for accurate standard error and confidence interval (CI) estimation is not possible. So in this paper I describe a multiple imputation (MI) method for calculating design effects associated with pooled-sample estimates. I also evaluate the method presented, by simulating NHANES individual sample data from which artificial pools are created for use in a comparison of pooled-sample estimates with estimates based on individual samples. To further illustrate and evaluate the method proposed in this paper I present geometric mean and various percentile estimates along with their 95% CIs for two chemical compounds from NHANES 2005–2006 pooled samples and compare them to individual-sample based estimates from NHANES 1999–2004.     

基于高斯过程回归模型的洪涝灾害损失预测研究——以重庆市为例

快速准确的预测洪涝灾害各项损失是开展洪涝灾害应急管理工作的基础,而预测技术和方法则是洪涝灾害损失预测的核心与关键。从灾害风险构成因素和数据易获取性2方面构建了洪涝灾害损失评估指标体系,分别从致灾因子、孕灾环境、承灾体和应急能力4个方面选取了13项损失评估输入指标,提出基于高斯过程回归模型的洪涝灾害损失预测方法,并应用于重庆市洪灾受灾人数、农作物受灾面积和直接经济损失的预测。实例表明,高斯过程回归方法对上文提到的3种损失情况预测结果的残差平方和分别为0.99、0.1、12.67,拟合精度分别达到99.85%、99.97%、96.1%,相较于多层感知器神经网络和支持向量机等方法更具优越性。