307 research outputs found
(De-)activating the growth machine for redevelopment: the case of Liede urban village in Guangzhou
This research investigates the mechanism of urban village redevelopment in south China. Through a revised typology of place entrepreneurs based on the growth machine thesis and a case study of Liede village in central Guangzhou, it illustrates how land-based interests embedded in an imbalanced power relationship can (de-)activate urban village redevelopment. The study reveals that while urban villagers, as represented by the village collective, have entrenched interests in the redevelopment process, the city government â as monopolistic land manager and place entrepreneur â plays the deciding role in forging and halting a growth machine geared towards urban village redevelopment. Although developers are also part of the process, the (de-)activation of redevelopment growth machine/coalition in Guangzhou has largely been dominated by the city government. With a comparative view on the original growth machine model, it is hoped that this study would furnish both theoretical and practical thoughts for future research
Frontier Hyhrid Orbitals. I. Principles
The purpose of the present paper is to describe a method,
in quantitative sense, of discussing the isolobal analogy of fragments
(or molecules) proposed by Hoffmann. The »Frontier Hybrid
Orbitals (FHO)« are used to represent the directional, fronti er
orbitals of the central atom, which have the same meaning as the
»lobes« involved in the concept of isolobal analogy. The calculatio
n of Frontier Hybrid Orbitals (FHO\u27s) is based on the natural hybrid orbitals which are the eigenvectors of density matrix blocks. The overlap integrals, bonding capabillties, and valence orbital energy levels of the FHO\u27s of fragment s are also calculated. The relationship between FHO and the isolobal analogy is discussed in this paper
Frontier Hyhrid Orbitals. I. Principles
The purpose of the present paper is to describe a method,
in quantitative sense, of discussing the isolobal analogy of fragments
(or molecules) proposed by Hoffmann. The »Frontier Hybrid
Orbitals (FHO)« are used to represent the directional, fronti er
orbitals of the central atom, which have the same meaning as the
»lobes« involved in the concept of isolobal analogy. The calculatio
n of Frontier Hybrid Orbitals (FHO\u27s) is based on the natural hybrid orbitals which are the eigenvectors of density matrix blocks. The overlap integrals, bonding capabillties, and valence orbital energy levels of the FHO\u27s of fragment s are also calculated. The relationship between FHO and the isolobal analogy is discussed in this paper
A study of ab initio generalized valence bond theory: methodology, programming and applications
Please see thesis for abstract
Parametric Study on Self-centering Precast Concrete Frames with Hysteretic Dampers
The self-centering precast concrete frame structure combines the advantages of industrialization and low earthquake damage, and its energy dissipation capacity and seismic performance have always been the focus of research. This paper proposed a kind of self-centering precast concrete frame with hysteretic dampers (SCPCHD). Its modular design makes the energy dissipation device and components easy to repair and replace. In order to obtain the optimal design, the finite element models of SCPCHD frames with different layout types of post-tensioned (PT) tendons and different shapes of hysteretic dampers are established, and the elastoplastic dynamic time-history analyses are carried out. The results show that the layout types and vertical margin of PT tendons have little effect on the displacement response of the frame structure. Compared to linear PT tendons, polygonal PT tendons can better bear the bending moment of the beam and reduce the stress of longitudinal reinforcements in the beam. The reduce effect of shortening the vertical margin on the tensile damage of beam concrete is obvious in the frame with polygonal PT tendons, but not obvious in the frame with linear PT tendons. Rational design of the prestressing force also plays a crucial role in the energy dissipation capacity of SCPCHD frames
Frontier Hybrid Orbitals. II. Applications
In this paper, the frontier hybrid orbitals (FBO\u27s) of a series
of octahedral ML5 fragments are used to discuss the electronic
structure and the chemical bond of these fragments and the molecules built of these ML5 fragments. The bond orbitals which are
chosen as the linear combination of the fronti er hybrid orbitals .
of fragments are calculated and explain the electronic structure
and properties of molecules such as Mn(COl5L(L = B, CN, CB3,
Cl), M2Ll0,and XM2L\u2710built of ML5 fragments. The bond orbitals
of Mn-Mn in Mn2(COho and [Mn2Cll0r4are studied on the basis of FBO. And the three center bond of Cr-BCr in [(COl5Cr- B-Cr (CO)5l-ion is also discussed. The Cr-B-Cr bond is bent and the bond angles is found to be about 150°. Besides, Mn chemical shifts in Mn(CO)sL(L = B, CN, CB3,Cl) complexes are compaired with the overlap integrals between FBO of Mn(CO)5andL, showing that there is a consistent relationship between them
Diet Selection and Intake of Yak (\u3cem\u3eBos grunniens\u3c/em\u3e) in Warmâand ColdâSeason Paddocks of \u3cem\u3ePotentilla fruticosa\u3c/em\u3e Rangeland in Northern QinghaiâTibetan Plateau
Effect of Stocking Density of Yak (\u3cem\u3eBos grunniens\u3c/em\u3e) on Floral Diversity and Biomass of Rangeland in Northern QinghaiâTibetan Plateau
Influence of the initial angular distribution on strong-field molecular dissociation
Citation: Yu, Y. L., Zeng, S., Hernandez, J. V., Wang, Y. J., & Esry, B. D. (2016). Influence of the initial angular distribution on strong-field molecular dissociation. Physical Review A, 94(2), 6. doi:10.1103/PhysRevA.94.023423We study few-cycle, strong-field dissociation of aligned H-2(+) by solving the time-dependent Schrodinger equation including rotation. We examine the dependence of the final angular distribution, the kinetic energy release spectrum, and the total dissociation yield on the initial nuclear angular distribution. In particular, we look at the dependence on the relative angle theta(0) between the laser polarization and the symmetry axis of a well-aligned initial distribution, as well as the dependence on the delay between the "pump" pulse that prepares the alignment and the few-cycle probe pulse. Surprisingly, we find the dissociation probability for theta(0) = 90 degrees can be appreciable even though the transitions involved are purely parallel. We therefore address the limits of the commonly held "ball-and-stick" picture for molecules in intense fields as well as the validity of the axial recoil approximation
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