3E系统视角下能源结构合理度评价研究

针对传统的能源结构评价方法多是重指标轻评价的局限性,提出了一种基于3E系统视角的熵权–集对分析评价方法.文章首先以DPSIR模型为基础构建了能源结构合理度评价指标体系.然后通过熵权集对分析评价模型实证分析,对我国30年的能源结构合理度进行评价.结果表明,熵权–集对评价方法能够很好的拟合我国能源结构合理度变化趋势;提高能源结构合理度需从能源、经济和环境三管齐下;政府应增加对固定资产的投资,严格控制能源价格的同时坚持实行低碳经济政策,保护环境,从而保证经济与能源、环境系统的可持续同步发展.

基于“能源-经济-环境模型”的能源结构合理度分析

我国的能源瓶颈突出表现为结构性矛盾。笔者以能源经济学为理论支撑,从低碳经济发展对能源结构的要求角度,提出了社会经济发展、能源发展规划、环境等3个维度,分析了各个维度的构成要素,运用SPSS16.0对每个要素进行单样本T检验,确定了15个测评指标。运用层次分析法确定了各个指标的权重,构建了能源-经济-环境模型,并以此模型对2002年～2008年我国能源结构合理度进行了实证分析,发现此阶段我国能源结构合理度变化趋势呈"U"状,即先降后升;能源结构在满足社会经济发展需求上的得分呈上升趋势,而在能源发展规划执行力度、环境改善等方面的得分呈下降趋势。

城市土地利用结构合理度及影响因素分析——以京津冀地区为例

基于改进后的熵权TOPSIS法,对京津冀地区的城市土地利用结构合理度进行评价;运用地理加权回归模型探索驱动因子对京津冀地区城市土地利用结构合理度影响程度的差异.结果表明:1)京津冀地区的城市土地利用结构合理度在空间上具有连续性,呈现出以北京、天津为中心,石家庄为次中心向外递减的趋势.2)同一影响因素对京津冀不同地区的城市土地利用结构合理度影响存在差别,呈现出地域性差异.人口密度对京津冀西南地区影响最大,对京津冀东北地区影响最小;人均第二产业占GRP比重对京津冀东北地区影响最大,对京津冀西南地区影响最小;人均社会消费零售总额对京津冀西部地区的影响大于东部地区;人均科学技术支出对京津冀东部地区的影响大于西部地区;人均地区生产总值的影响呈现出北高南低的特征.3)不同地区城市土地利用结构合理度的影响因素不同,经济发展和科学技术因素是城市土地利用结构合理度的首要影响因素,于不同地区的空间差异性,影响因素对各个不同地区的城市土地利用结构合理度的影响次序和影响程度异质性明显.

北京市进出口商品结构的变动及合理度分析

基于2002年和2007年北京市投入产出表数据,利用投入产出模型,分别计算并分析比较了北京市进出口商品结构及其支柱产业和瓶颈产业的匹配程度,以及北京市进出口商品结构合理度的变动情况。结果表明:2002—2007年,北京市出口商品结构朝着更加合理的方向和趋势发展,而进口商品结构不尽合理。从整体看,北京市进出口贸易在支持国民经济的发展中还没有充分发挥作用,进出口商品结构有待进一步优化。

零售业结构与外贸结构关联匹配的影响因素分析

我国零售业结构与外贸结构匹配度越高,说明国内市场与国际市场的重合度越高,因而越能发挥规模经济效应,使我国零售业以较低成本实现高速发展。然而,目前我国仍未制定提升零售业结构与外贸结构匹配度的有效方案。因此,本文采用GMM估计法探究了零售业结构与外贸结构关联匹配的影响因素,旨在为匹配度提升方案的制定提供参考依据。结果表明:随着零售贸易占比增长,我国零售业结构与外贸结构错位程度加深,而外资企业外贸额能在一定程度上缓解这种错位。在非线性关系检验中,外资企业外贸额、零售业结构高级度与外贸商品结构关联匹配、零售贸易占比、零售业结构高级度与外贸方式结构关联匹配、外资企业外贸额、零售业结构合理度与外贸商品结构关联匹配存在非线性关系。

进口结构优化与外贸增长方式转变的相关性研究——基于投入产出表的实证分析

本文基于投入产出表,借助外贸产品结构合理度指标,通过实证检验,不仅分析了当前我国进出口商品结构的优化情况,而且验证了进口结构优化对外贸增长方式转变具有正向促进作用,并提出了实行创新导向型进口结构优化战略的政策建议。

江苏省服务业规模和结构升级协调发展的时空特征

论文运用产业结构高级度指数、合理度指数和耦合协调模型等考察了江苏省2013—2019年服务业规模和结构升级协调发展的时空特征,结构表明:(1)服务业规模、结构高级度和结构合理度都呈现苏南>苏中>苏北的格局,高级度的南北差距逐渐拉大,而合理度的南北差距逐年缩小。(2)服务业规模和结构高级度和合理度间的协调发展水平逐年上升,但协调水平较低。(3)协调发展的问题区域主要集中在苏北地区,由规模滞后产生的区域问题较多。

外贸产品结构的合理性分析

本文利用投入产出分析中的影响力系数和推动力系数的概念,确定国民经济中的支柱产业和瓶颈产业,根据出口、进口产品对国民经济系统的不同作用,分析外贸产品结构的合理性,提出了外贸产品结构合理度指数的计算公式。

不同范式下贸易利益的内涵和可持续发展下贸易利益的衡量

文章说明:随着理论前提的不同和经济现实的发展,贸易利益的内涵也会不同。传统贸易理论强调追求狭义的经济贸易利益,而未考虑环境污染、自然资源等对国际贸易格局和利益的影响;贸易和环境冲突范式下,南北国家因为各自不同的环境观和发展观而产生迥然不同的贸易利益观;通过将环境成本内部化来协调贸易和环境间的冲突,方能使南北双方贸易利益的不平衡状态回归到双赢状态。进而提出,在贸易和环境协调前提下,用绿色贸易结构合理度和绿色收入贸易条件来衡量低碳经济环境下真实的贸易利益。

Syntheses and calculation of( E)-4-chloro-4'-ethoxystilbene and( E)-4,4'-dichlorostilbene

（E） -4-chloro-4＇ -ethoxystilbene （2a） and （E） -4, 4＇ - dichlorostilbene （2b） were synthesized by the Witting-Homer reaction. The crystals of 2a and 2b were prepared through solvent evaporation and characterized by the single-crystal X- ray diffraction. Molecular structure analysis confirms the E- configuration of C=C bond. The crystal of 2a reveals an orthorhombic and space group Pna21 structure while 2b shows a monoclinic and space group P21/c structure. The electronic structures of 2a and 2b were optimized at B3LYP/6-311 ＋ ＋ G （d, p） level. The Hirshfeld surface and fingerprint plot indicate close O-H and C1-H contacts and π-π stacking in 2a and 2b. Molecular electrostatic potential shows that the O and C1 atoms of 2a and C1 atoms of 2b have the minimum energies and they are more likely to be attacked by electrophiles in reaction. Frontier molecular orbitals analysis demonstrates that the △ELuMO_HOMO of 2a and 2b are 3.85 and 3.91 eV, respectively.

Satisficing as an Account of Kuhnian Rationality

The lack of an account of rationality in The Structure of Scientific Revolutions was a lacuna which Thomas Kuhn acutely felt. In this paper, I argue that Herbert Simon＇s notion of ＂satisficing＂ provides a formally well-developed and empirically well-established theory of rationality that fits well with Kuhn＇s general characterization of science. I start by considering two rival interpretations of the problem of Kuhnian rationality and introduce Simon＇s notion of satisficing. In Section 3, I show how satisficing can be used to interpret paradigm, change, rational theory-choice, relativism, and progress. On this account, Kuhnian scientists are not irrational. Rather they employ the same computational mechanism which allows humans to play chess.

First-principles investigation of cohesive energy and electronic structure in vanadium phosphides

First-principles calculations based on the density-functional theory were employed to study the crystal structure of vanadium phosphide compounds,such as V3P,V2P,VP,VP2 and VP4. Cohesive energy of five types of vanadium phosphide compounds was calculated to assess their structural stability. The charge density distribution and densities of states of vanadium phosphides were discussed to study further their electronic structures. The results show that the structure of metal-rich compounds is considerably more stable than the phosphorus-rich compositions,and covalent bond exists between the V and P atoms of V3P,V2P,VP,VP2 and VP4.

The Doklam Standoff Crisis and the Future of Sino-Indian Relations

Doklam Standoff, a crisis of Sino-Indian bilateral relations, was a large-scale military deployment between China and India. The crisis reflects the newly forming distrust between the two countries that led to an outburst as a result of a series of conflicts over the past two years, which signifies that Sino-Indian relations are entering a new stage characterized by increasingly obvious structural conflict. On the surface, the Modi Administration designed the crisis to stop China from building border infrastructure, to pursue its own absolute security, to maintain South Asian order dominated by India, and to consolidate the basis of strategic cooperation among India, the United States and Japan. Ultimately, however, the British buffer zone theory, the Mandala theory, the Brahmin supremacy theory in traditional Indian culture and the US Monroe Doctrine have also shaped the mindset and behavioral patterns of the Modi Administration. Under the influence of seeking absolute security and its strategic culture, as well as the strong desire to be a great power, the assertive Modi Administration has obviously strengthened its precautionary measures and hostilities toward China. The relations between the two countries are becoming tense. In order to achieve the goal of ＂dragon and elephant dancing together＂, and to avoid the recurrence of crises like the Doklam Standoff, the two sides have to adhere to the two basic principles of viewing each other as opporttmities for development instead of threats to each other. The mindset of a zero-sum game should be abandoned, and efforts should be made to co-found mutual respect and win-win cooperation in areas of common interest.

Structural, thermodynamics and elastic properties of Mg_(17)Al_(12), Al_2Y and Al_4Ba phases by first-principles calculations

Structural stabilities, thermodynamics stabilities, elastic properties and electronic structures of Mgl7Al12, Al2Y and AlaBa phases were analyzed by first-principles calculations with Castep and Drool3 program based on the density functional theory. The calculated results of heat of formation indicate that AI2Y phase has the strongest alloying ability. The calculated thermodynamic properties show that the thermal stability of these compounds gradually increases in the order ofMgl7Al12, A12Y and Al4Ba phases. Y or Ba addition to the Mg-Al alloys could improve the heat resistance. The calculated bulk modulus B, shear modulus G, elastic modulus E and Poisson ratio v show that the adding Y or Ba to Mg-Al alloys could promote the brittleness and stiffness, and reduce tenacity and plasticity by forming Al4Ba and Al2Y phases. The calculated cohesive energy and density of state （DOS） show that Al2Y has the strongest structural stability, then AlaBa and finally Mg17Al12. The calculated electronic structures show that Al2Y has the strongest structure stability because of the strong ionic bonds and covalent bonds combined action.

Evolution of microstructure and high temperature tensile properties of as-extruded Ti Bw reinforced near-α titanium matrix composite subjected to heat treatments

The Ti Bw reinforced near-α titanium matrix composite（Ti-5.8 Al-3.4 Zr-4.0 Sn-0.4 Mo-0.4 Nb-0.4 Si-0.06 C） was successfully synthesized by powder metallurgy and hot extrusion route. The effects of solution and aging temperature on the microstructure and high temperature tensile properties of the composite were investigated. The results revealed that the fine transformed β phase can be obtained by the solution treatment at β phase region and aging treatment, no other precipitates were observed. The α2 phase（Ti3 Al） can be acquired when the solution treated at α＋β phase region followed by aging treatment. With increasing the aging temperature from 500 to 700℃ for 5 h, the size of α2 precipitates increases from about 5 to about 30 nm. The Ti Bw are stable without any interfacial reaction during the heat treatments. The high temperature tensile properties show that the composite performed by solution and aging treatment exhibits good strengthening effects. With increasing the aging temperature from 500 to 700℃, the strength of the composite increases at the expense of elongation due to the increment of α2 precipitates.The strength of the composite at 600℃ increases by 17% to 986 MPa after 1000℃/2 h/AC and 700℃/5 h/AC heat treatment.