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201.
202.
吴会松 《新疆大学学报(理工版)》1998,15(2):26-29
本文在对当前原型法中的数据驱动分析的基础上,提出了一种新的原型化开发方法:“自适应原型化开发方法”。该方法可用于构造具有高度自适应能力的、易维护的应用系统。 相似文献
203.
京杭运河(杭州段)旅游资源及其旅游功能开发研究 总被引:7,自引:0,他引:7
从分析运河杭州段旅游资源的空间分布特征入手,对其旅游开发条件进行了评价,揭示了杭州城市旅游业发展与运河间的相互关系,提出运河杭州段旅游开发的功能定位与形象策划,并对运河各区段的旅游开发方向提出了建设的性的总体构想。 相似文献
204.
T. Aoyama N. Maeda 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(2):157-168
The induced Chern-Simons term for a paired electron state is calculated in the
quantum Hall system by using a field theory on the von Neumann lattice.
The coefficient of the Chern-Simons term, which is the Hall conductance,
has not only the usual term proportional to a filling factor due to
P (parity) & T (time reversal) symmetry breaking
but also correction terms due to P & T & U(1) symmetry breaking.
The correction term essentially comes from the Nambu-Goldstone
mode and depends on an infrared limit.
It is shown that the correction term is related to a topological number of a gap function
in the momentum space. 相似文献
205.
Sambhu N Datta 《Pramana》1993,41(4):345-362
A set of indigenously developed computer programs for ab-initio Hartree-Fock calculations on both closed- and open-shell molecules
have been described. These programs have been written for calculations using GTO basis sets. Integral formulae have been taken
from Taketaet al [8]. Structures and functions of the programs have been discussed. These programs have been extensively tested. Molecular
integrals over GTO basis sets have been chosen for tests and as numerical examples in this paper. Results of calculations
using very accurate minimal bases have been given for methane. Time taken for these computations in a CDC Cyber 180/840 machine
has been indicated. Trends in the calculations have also been illustrated by employing 4-gaussian expansions for the STO’s
and by varying the basis size for LiH and BH+.
An erratum to this article is available at . 相似文献
206.
黄瓜(Cucumis sativus L.)子叶发育过程中谷氨酰胺合成酶同工酶的变化 总被引:1,自引:0,他引:1
采用Native-PAGE和活性染色的方法检测黄瓜种子萌发和子叶发育过程中GS同工酶的类型和活性,以期了解同工酶在子叶发育过程中的作用,在下种子中,只观察到一种不同于GS1和GS2形式的同工酶随着发育过程迅速消失,在种子萌发和子叶发育过程中,子叶GS1活性先于GS2出现,而且两者活性均很快升高;子叶绿化后GS2是主要的,外源氮素能硅著增强它的活性;子叶发育后期这两种同工酶活性逐步下降,在真叶发育中,同样观察到两种GS同工酶,以GS2为主.在暗转光后,GS2明显被诱导;而当光/暗转换后,GS1活性在子叶和真叶中均显著增加.GS同工酶活性随发育以及环境条件的变化而改变的现象与它们在代谢上的功能需要是一致的。 相似文献
207.
The evolution of several structural characteristics during isothermal heat treatment of poly(p-phenylene terephthalamide) was studied. In this work, heat treatment was interrupted after different treatment times, with the specimens immediately quenched to room temperature. These specimens were then characterized by tensile testing, wide- and small-angle x-ray scattering, and optical microscopy. Structural parameters obtained from these measurements relate to crystal perfection (via the paracrystalline axial distortion parameter), axial crystallite size, transverse crystallite size, degree of chain misorientation, and degree of pleating. Structural and mechanical parameters were then plotted against heat-treatment time to obtain kinetic isotherms for each parameter. The kinetics of the removal of chain misorientation parallels that of tensile modulus increase under all conditions. Of the other structural parameters, only the kinetics of pleat removal mimics that of modulus change, indicating that pleat removal is the effective cause of increased chain alignment and thereby of increased axial stiffness. ©1995 John Wiley & Sons, Inc. 相似文献
208.
J.C. Califano A. Uribe J.L. Chang C.L. Becker J.J. Napier V. Kishore D. Zhou G. Love K. Gernhardt J.C. Tolle 《Tetrahedron》2005,61(37):8821-8829
Oligomers of arginine, such as octa-d-arginine amide, are excellent transporters for active drugs through cell membranes and tissue. The synthesis of octa-d-arginine amide, as the nonahydrochloride salt, was approached via a solution phase synthetic route involving the preparation of an octa-d-ornithine intermediate, which was then converted into the desired octa-d-arginine compound through a guanidinylation step. The multi-step synthesis was carried out at pilot scale, resulting in the preparation of 700 g of the target molecule. No chromatographic purification was needed at any step of the process. 相似文献
209.
D. Vencatachellum 《Journal of Optimization Theory and Applications》1998,96(1):175-189
This paper compares the outcomes of strategic and nonstrategic research and development (R&D). Firms undertake cost-reducing R&D in an environment where benefits accrue from their rivals' R&D via a common pool of knowledge. We demonstrate that multiple suboptimal equilibria exist; under these conditions, growth models which do not consider strategic interactions will overestimate or underestimate the growth rate. 相似文献
210.
R&;D Incentives and Market Structure: Dynamic Analysis 总被引:2,自引:0,他引:2
We investigate dynamic R&D for process innovation in an oligopoly where firms invest in cost-reducing activities. We focus on the relationship between R&D intensity and market structure, proving that the industry R&D investment increases monotonically with the number of firms. This Arrowian result contradicts the established wisdom acquired from static games on the same topic.The authors thank Jeroen Hinloopen and George Leitmann for useful comments and discussions 相似文献