基于能值方法的承德市农业生态系统分析

用能值理论和方法对承德市农业生态系统的能值投入结构和产出特征进行分析,计算了典型能值指标,并与其他地区进行比较,以对系统的可持续性进行评估.结果表明:承德市农业生态系统自然投入可更新能值流量的稳定性影响承德市农产品产量;人力输入在总能值投入中占比例较高,尚未摆脱传统农业模式.农作物产出中粮食产出能值比例较高,消费者对淀粉类粮食的需求仍然旺盛.承德市农业生态系统能值指标分析表明其生产效率和开发程度较低,每单位无偿环境资源的利用只相应投入了较少的购买能值,且有进一步开发利用的潜力.     

基于系统动力学的黑龙江省农业生态系统能值分析

农业生态系统为人类提供生存和发展的基本产品,构建可以独立核算的农业生态系统模型对科学评价区域农业状况有重大意义.该研究借助系统动力学方法,构建基于能值投入、产出及综合评价性指标的农业生态系统SD模型,对黑龙江省农业生态系统发展状况及时间变化特征进行了分析与预测,同时对系统进行灵敏性测试.结果表明:(1)黑龙江省农业生态系统能值投入及产出均呈持续增加趋势,但系统可持续性能逐年降低;(2)黑龙江省过度依赖种植业及畜牧业,导致区域生产力稳定性的波动降低;(3)区域农业生态系统对自然因素的响应较弱,对人为因素的响应较为明显,可知人为因素对黑龙江省农业生态系统影响较大.该研究为黑龙江省今后农业投入产出结构的调整提供了依据.     

基于能值的开封市农业生态系统投入产出分析

在能值分析的基础上,运用1990～2003年开封市农业生态系统能值的投入与产出数据,建立开封市农业生态系统投入产出生产函数模型,并进行定量分析与评价.结果表明,劳动力的边际生产力相对较高,化肥与农业机械动力边际生产力较低,水资源投入的边际生产力为负,开封市农业生态系统能值产出及各生产要素能值投入均处于收益递减阶段.同时揭示了农业生态系统不同时段能值产出与各生产要素能值投入之间的内在联系,为优化开封市农业生态系统结构提供了科学依据.     

三峡库区家庭农业生态系统能值分析

对三峡库区家庭农业生态系统中的各种物质、能量、货币在系统投入与产出的过程中进行了能值分析,对家庭农业生态系统及其亚系统能量的投入与产出进行了能值评价,通过能值指标分析了辅助能投入结构、辅助能投入比例以及家庭农业生态系统、种植亚系统和养殖亚系统的能值产投比,提出了家庭农业生态系统能流的调控措施．     

基于能值分析的山西省生态经济系统可持续发展评价

本文采用奥多姆(Odum H T)的能值分析方法,针对山西省2000年～2016年生态经济系统的主要能值投入与产出、运行效率以及环境负荷作了系统分析,并通过构造生态经济系统能值评估体系分析区域实体经济发展的整体趋势及可持续性.结果表明:山西省经济发展状况仍然十分滞后,主要由于工业与煤炭资源息息相关,产业单一,抗风险能力差.从2000年到2016年,可更新资源能值量基本保持在3.56E+22sej,无显著变化差异;人均能值量从1.94E+15sej提升到2.66E+15sej;环境负荷率(ELR)从0.77提升到1.74;生态经济系统能值投资率从0.59提升到1.07.能值可持续指标从3.44降到1.10,可持续性有所改善.     

基于能值分析的区域生态经济发展研究——以承德为例

生态经济系统的能量流动、转化过程经过自然和人类经济社会,能值可用于表达自然、环境与经济的关系.根据能值理论,从能值资源的投入和产出、区域环境压力及可持续发展状况3个方面考虑建立能值指标体系,分析2004—2011年承德生态经济发展状况.结果表明,承德经济增长速度较快,但平均消耗81.02%的不可更新资源及其产品,且81.41%—88.26%为本地资源.进口能值比率虽然呈现增加趋势,但占总能值用量的比例在16.33%以下.生态经济系统能值利用强度增大,环境压力加大,系统可持续发展能力在不断下降.应该结合京津水源地保护与生态屏障建设要求,加强京津冀区域间合作发展,增加进口能值流量,降低对本地资源的开发利用强度,促进生态文明建设.     

喀斯特地区都安瑶族自治县农业生态经济系统能值分析

收集都安瑶族自治县2004年相关统计资料,用能值法建立能值指标体系,通过能值投资率、能值自给率、环境负载指数、可持续利用指数和单位面积宏观经济价值产出5个指标分析评价都安县农业生态经济系统。结果显示,都安县能值投资率为5.46,能值自给率15.47%,环境负载指数5.53,可持续利用指数0.10,单位面积宏观经济价值产出1.5×105EM$.km-2.-a1。能值指标表明,都安农业生态经济系统能值利用技术水平较低,农业经济发展相对落后,但是系统生产效率较高,在获取经济输入能值方面具有优势;经济发展对环境资源的依赖程度较高,但是对资源环境带来的压力大;系统的可持续性较弱。都安农业生态经济系统进一步的发展应加强都安农业生态经济系统的对外开放程度,提高系统的能值反馈率;优化农业产业结构,发展生态农业,提高能值利用率;治理水土流失,提高土地生产力;合理运用当地条件,发展对外经济;控制人口增长,提高人口素质。     

中部地区农业现代化水平综合评价——以安徽省为例

以中部地区安徽省为例,构建农业现代化评价指标体系,运用多指标评价模型测度2000—2012年安徽省农业现代化水平,并从总体和结构两个维度对安徽省农业现代化水平区域差异特征进行了初步分析。结果表明,12000—2012年农业现代化总体从起步阶段向初步实现阶段过渡;农业投入水平、农业产出水平、农民生活水平均呈现增长态势,而农业生态水平呈微弱下降趋势;2预测可知2013—2020年区域农业现代化发展仍以持续上升为主,年均增长率达到0.87%;3皖江地区农业现代化水平最高为0.506,皖中地区、皖南地区农业现代化水平分别为0.451和0.402,而皖北地区水平最低仅为0.365;农业投入水平、农业产出水平、农民生活水平高值区主要分布在皖江、皖中地区,而农业生态水平高值区主要分布在皖南地区;最后,从完善农业基础设施、转变农业增长方式、提升农业市场水平等方面提出相关政策建议。     

能值-生态足迹模型支持的甘肃藏族高寒牧区可持续研究

运用改进的能值生态足迹模型,对2005-2013年甘肃藏族高寒牧区可持续发展状态进行了定量分析.改进的模型运用区域能值密度计算生态承载力和生态足迹,不仅克服了传统生态足迹模型的缺陷,而且能够更真实地反映研究区生态系统的供给能力和人类对资源的消耗状况.结果表明:9 a间玛曲县和碌曲县处于可持续发展状态,生态承载力还能够支撑生态足迹的增长;夏河县处于不可持续发展状态,生态足迹增长与生态承载力不平衡,不可持续性整体呈现增强的趋势;卓尼县处于不可持续发展状态,但2010年之后有好转的趋势;合作市和天祝县处于严重不可持续发展状态,不可持续性呈现不断增强的趋势.如何改善区域发展状态已经变得尤为迫切.结合能值密度和万元GDP生态足迹等指标,对各牧区可持续发展策略进行了有益探讨.     

基于能值分析的LID可持续性评价

明确不同LID(低影响开发,Low impact development)的可持续性是实现LID优化配置的关键。选取2014年汉中市兴汉新区雨水管理系统工程采用的5种LID实践:雨水花园、生态草沟、屋顶绿化、人工湿地和透水铺装,采用能值分析方法,通过能值产出(Y)、可更新百分比(PR)、能值产出率(EYR)、环境负载率(ELR)和环境可持续指数(ESI)5项指标,分析其建设期和运营期的各种能值投入,评价其可持续性。结果表明,建设期所有LID的可持续性较差,运营期由于LID能够产生多种生态系统服务能值,增加了其持续性。比较而言,雨水花园和生态草沟的可持续较高,其次是屋顶绿化和人工湿地,透水铺装的可持续性最低。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that