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The Formation and Major Breakthroughs of the Theory of Socialist Market Economy
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作者 Li Tieying Member of the Political Brteau of the Central Commitrtee of the Communist Party of China,and President of the Chinese Academy of Social Sciences. 《经济研究参考》 1999年第B0期21-54,共34页
① Without a correct reform theory, there can be no successful reform practice. Since the Communist Party of China (CPC) convened the Third Plenary Session of the 11 th Central Committee (December, 1978), a fundamenta... ① Without a correct reform theory, there can be no successful reform practice. Since the Communist Party of China (CPC) convened the Third Plenary Session of the 11 th Central Committee (December, 1978), a fundamental reason for the tremendous achievements China has scored is that it has had the guidance of Deng Xiaoping Theory. Broad and pro- 展开更多
关键词 The formation and Major Breakthroughs of the theory of Socialist Market Economy CPCC
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A application of the theory of underground water net work formation and evolution in the forecast of water inrush from coal floor
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《Global Geology》 1998年第1期70-71,共2页
关键词 NET A application of the theory of underground water net work formation and evolution in the forecast of water inrush from coal floor
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Accurate Modeling of the Spiral Bevel and Hypoid Gear with a New Tooth Profile
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作者 LI Yun-song ADAYI Xieeryazidan DING Han 《Computer Aided Drafting,Design and Manufacturing》 2014年第3期32-38,共7页
Distinguishing with traditional tooth profile of spiral bevel and hypoid gear, it proposed a new tooth profile namely the spherical involute. Firstly, a new theory of forming the spherical involute tooth profile was p... Distinguishing with traditional tooth profile of spiral bevel and hypoid gear, it proposed a new tooth profile namely the spherical involute. Firstly, a new theory of forming the spherical involute tooth profile was proposed. Then, this theory was applied to complete parametric derivation of each part of its tooth profile. For enhancing the precision, the SWEEP method used for formation of each part of tooth surface and G1 stitching schema for obtaining a unified tooth surface are put forward and made the application in the accurate modeling. Lastly, owing to the higher accuracy of tooth surface of outputted model, it gave some optimization approaches. Given numerical example about the model can show that this designed gear with spherical involute tooth profile can achieve fast and accurate parametric modeling and provide a foundation for tooth contact analysis (TCA) in digitized design and manufacture. 展开更多
关键词 spiral bevel and hypoid gear formation theory spherical involute tooth profile MODELING
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Curvature and Size Effects on Reactivities of Mono-to Octa-vacancies in a(5,5) Single-walled Carbon Nanotube 被引量:1
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作者 贾桂霄 李磊 +3 位作者 王晓霞 孙松松 包金小 安胜利 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第4期621-630,共10页
Defect curvature was developed based on our previously proposed direction curvature theory. Defect curvature, as a universal criterion, was used to identify vacancy formation energies E_f of mono-vacancies to octa-vac... Defect curvature was developed based on our previously proposed direction curvature theory. Defect curvature, as a universal criterion, was used to identify vacancy formation energies E_f of mono-vacancies to octa-vacancies in a(5,5) tube. An ab initio calculation results showed that E_f decreased with increasing the defect curvature K_(V_s)(s = 1~8). The structures with removed carbon atoms along zigzag chain or the tubular axis were the most stable in each kind of Vs, because their corresponding K_(V_s) was the largest. In addition, local product structures disturbed the variation rule of E_f as K_(V_s). There was an odd-even oscillation rule in the smallest E_f among each kind of Vs as the s value and vacancies V2, V4 and V6 were more stable. The stabilities of the related vacancy structures were confirmed by two dissociation processes. 展开更多
关键词 defect curvature atomic vacancies vacancy formation energies density functional theory
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Ionization state of cosmic hydrogen by early stars and quasars
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作者 Xiao-Chun Mao1,2 1 National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2009年第6期665-681,共17页
Cosmic hydrogen is reionized and maintained in its highly ionized state by the ultraviolet emission attributed to an early generation of stars and quasars. The Lyα opacity observed in absorption spectra of high-redsh... Cosmic hydrogen is reionized and maintained in its highly ionized state by the ultraviolet emission attributed to an early generation of stars and quasars. The Lyα opacity observed in absorption spectra of high-redshift quasars permits more stringent constraints on the ionization state of cosmic hydrogen. Based on density perturbation and structure formation theory, we develop an analytic model to trace the evolution of the ionization state in the post-overlap epoch of reionization, in which the bias factor is taken into account. For quasars, we represent an improved luminosity function by utilizing a hybrid approach for the halo formation rate that is in reasonable agreement with the published measurements at 2 ≤ z ≤ 6. Comparison with the classic Press-Schechter mass function of dark matter halos, we demonstrate that the biased mass distribution indeed enhances star formation efficiency in the overdense environment by more than 25 per cent following the overlap of ionized bubbles. In addition, an alternative way is introduced to derive robust estimates of the mean free path for ionizing photons. In our model, star-forming galaxies are likely to dominate the ionizing background radiation beyond z = 3, and quasars contribute equally above a redshift of z ~ 2.5. From 5 ≤ z ≤ 6, the lack of evolution in photoionization rate can thus be explained by the relatively flat evolution in star formation efficiency, although the mean free path of ionizing photons increases rapidly. Moreover, in the redshift interval z ~ 2 - 6, the expected mean free path and Gunn-Peterson optical depth obviously evolve by a factor of ~ 500 and ~50 respectively. We find that the relative values of critical overdensities for hydrogen ionization and collapse could be 430% at z ≈2 and 2% at z ≈6, suggesting a rapid overlap process in the overdense regions around instant quasars following reionization. We further illustrate that the absolute estimates of the fraction of neutral hydrogen computed from theoretical models may not be important because of comparable uncertainties in the computation. 展开更多
关键词 COSMOLOGY theory -- formation galaxies -- quasars general -- diffuse radiation -- intergalactic medium
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A Review of Glass and Crystallizations of Glass-Ceramics
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作者 Ali S. Alzahrani 《Advances in Materials Physics and Chemistry》 CAS 2022年第11期261-288,共28页
The fundamental science behind glass and glass-ceramics in relation to research including syntheses, processing, characterization and applications are critically reviewed in this paper. The crystalline structure of th... The fundamental science behind glass and glass-ceramics in relation to research including syntheses, processing, characterization and applications are critically reviewed in this paper. The crystalline structure of the crystalline phases/s investigated in the literature is also discussed. Throughout this paper, the scene is set toward the overall picture of the rationale behind the choice of a glass system. Additionally, earlier reviews do not include the most recent literature in this fast-moving field. The main methods of synthesizing glasses and glass-ceramics are explained and described in relation to their applications. The paper concludes with recommendations for future research. 展开更多
关键词 Glass formation Theories CRYSTALLIZATION GLASS-CERAMICS Processing of Powder and Bulk Glasses
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Comparative DFT Study of [Mg(CHZ)_3](ClO_4)_2 and [Mg(CHZ)_3](NO_3)_2(CHZ=Carbohydrazide)
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作者 聂西度 黄辉胜 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第4期679-683,共5页
The molecular geometry,electronic structure,thermochemistry and infrared spectra of [Mg(CHZ)3](ClO4)2 and [Mg(CHZ)3](NO3)2 were comparatively studied using the Heyd-Scuseria-Ernzerhof(HSE) screened hybrid de... The molecular geometry,electronic structure,thermochemistry and infrared spectra of [Mg(CHZ)3](ClO4)2 and [Mg(CHZ)3](NO3)2 were comparatively studied using the Heyd-Scuseria-Ernzerhof(HSE) screened hybrid density functional with 6-31G** basis set.The experimental results show that the complexes have six-coordinated octahedron feature,and the metal-ligand interactions are predominantly ionic in nature.The calculated heats of formation predict that [Mg(CHZ)3](NO3)2 is more stable than [Mg(CHZ)3](ClO4)2.Detailed NBO analyses indicate that the ligand-anion interaction plays an important role in the stability for these two energetic complexes.Moreover,the stretching vibration frequencies of N-H bonds shift to lower wave number compared to the free CHZ ligand,which are caused by the delocalizations from N-H bond orbital to lone-pair electron antibond orbital of magnesium. 展开更多
关键词 energetic complex carbohydrazide density functional theory electronic structure heats of formation
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The Formation and Main Breakthroughs of the Theory of a Socialist Market Economy-In Celebration of the Twentieth Anniversary of the Third Plenary Session of the Eleventh Central Committee of the Communist Party of China
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《Social Sciences in China》 1999年第4期5-25,192,共22页
关键词 In OPEN The formation and Main Breakthroughs of the theory of a Socialist Market Economy-In Celebration of the Twentieth Anniversary of the Third Plenary Session of the Eleventh Central Committee of the Communist Party of China
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Theoretical study on the formation mechanism of polychlorinated dibenzothiophenes/thianthrenes from 2-chlorothiophenol molecules 被引量:1
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作者 Xiaoqing Yu Jiamin Chang +2 位作者 Xian Liu Wenxiao Pan Aiqian Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第4期318-327,共10页
Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes(PCDT/TAs),sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans(PCDD/Fs), has been well-documented to occur via ra... Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes(PCDT/TAs),sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans(PCDD/Fs), has been well-documented to occur via radical–radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol(2-CTP) as a model compound for chlorothiophenols,we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self-and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene(1-MCTA), 1,6-dichlorothianthrene(1,6-DCTA), 4,6-dichlorodibenzothiophene(4,6-DCDT)and 1,6-dichlorodibenzothiophene(1,6-DCDT). The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists. 展开更多
关键词 Polychlorinated dibenzothiophenes/thianthrenes formation mechanism Phenyl radicals Thiophenoxyl diradicals Density functional theory study
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