首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   43篇
  免费   1篇
化学   12篇
晶体学   1篇
力学   5篇
数学   19篇
物理学   7篇
  2022年   1篇
  2021年   4篇
  2019年   1篇
  2018年   2篇
  2016年   2篇
  2015年   3篇
  2013年   4篇
  2012年   2篇
  2011年   1篇
  2010年   4篇
  2009年   4篇
  2008年   4篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2000年   3篇
  1999年   1篇
  1994年   2篇
  1992年   1篇
  1989年   1篇
  1979年   1篇
排序方式: 共有44条查询结果,搜索用时 31 毫秒
1.
2.
Studied is a cylindrical reservoir consisting of three layers: a water-containing bottom layer, and two oil-containing top layers from whose upper layer oil is produced. For its solution, a corrected version of the finite Hankel transform for Neumann-Neumann boundary conditions was used together with numerical inversion of the Laplace transform. The effects of the water zone on the unsteady state pressure in the reservoir were evaluated at distances away from the well and at the well-bore itself. We found that the vertical pressure drop increases gradually with time and is more significant in the vicinity of the well-bore. For constant production and at any time t, smaller reservoirs experience higher pressure drops than larger ones. For the reservoir investigated, we found that for nondimensional time t Dw <104 the presence of a second fluid (water) has no effect on the pressure drop. Of all the formation and fluid properties investigated, porosity has the largest effect on pressure.Nomenclature c 1, c 2 Oil and water compressibilities, vol/vol/atm, vol/vol/psi - h Height of water zone from bottom of reservoir, cm, ft - h D h/r w , non-dimensional - H Height of reservoir, cm, ft - H D H/r w, non-dimensional - J 0, J 1 Bessel functions of the first kind, zero and first-order - K r2, K r1 Oil and water zones, horizontal permeabilities, darcies, md - K z2, K z1 Oil and water zones, vertical permeabilities, darcies, md - k 1 n=1, 2, 3... - k 2 n=1, 2, 3... - k 1,0 - k 2,0 - p(r, z, t) P(r, z, 0)–P(r, z, t), atm, psi - P(r, z, t) Pressure at any layer in the reservoir, atm, psi - P(r, z, 0) Initial pressure at any layer in the reservoir, atm, psi - P D , non-dimensional - q Constant production rate of well, cc/sec, barrels/day - r Radius of reservoir, cm, ft - r D r/r w , non-dimensional - r e Drainage radius, cm, ft - r eD re/r w , non-dimensional - r w Well-bore radius, cm, ft - t Time, sec, hr - Dw (k r2 t)/( 2 2 c 2 r w 2 ), non-dimensional - Y 0, Y 1 Bessel functions of the second kind, zero and first-order - z Distance z measured vertically upward from bottom of reservoir, cm, ft - Z D z/r w , non-dimensional - z 1 Height of the bottom of the producing layer, cm, ft - z 1D z 1/r w , non-dimensional - z 2 Height of the top of the producing layer, cm, ft - z 2,D z 2/r w , non-dimensional - n nth positive root of equation (18) - 1 k z1/k r1, non-dimensional - 2 k z2/k r2, non-dimensional - 1 1 1 c 1/k r1, hydraulic diffusivity of layer I - 2 2 2 c 2/k r2, hydraulic diffusivity of layers II and III - 2, 1 Viscosity of oil and water, cp, cp - n n /r w , l/cm, l/ft - 2, 1 Porosity of oil and water-filled zones, fraction - ( 1/ 2) (k z2/k z1), non-dimensional  相似文献   
3.
Reaction of an arylmethyl halide with 3-amino-1,2,4-triazole ( 1 ) allows the preparation of the three N-aryl-methyl derivatives of 1 bearing the substituent on the heterocyclic nitrogen atoms. In basic medium (methoxide anion in DMF or methanol, or in benzene by phase transfer catalysis), the isomers 3 and 5 substituted at N-1 and N-2 respectively are obtained, while the isomer 4 is isolated from neutral medium (DMF). The isomers 3 and 4 may be also prepared by cyclization of appropriate formylguanidinium derivatives. 3-Arylmethylamino-1,2,4-triazoles 2 may be obtained through reaction of 3-chloro-1,2,4-triazole ( 6 ) with arylmethylamines. Photolysis of the N-arylmethyl-3-amino-1,2,4-triazoles 2-5 in methanol or water-methanol mixture, induces homolytic and heterolytic cleavage of the arylmethyl-C-N bond giving rise to 3-amino-1,2,4-triazole ( 1 ). Thus, compounds 2-5 with arylmethyl groups able to absorb solar light may be considered as potential photoactivatable herbicides.  相似文献   
4.
We associate a family of Hilbert spaces H q 2;(D) of analytic functions on the unit disk D=z :|z|<1 the q-continuous Gegenbauer polynomials C n (x;q) on the interval]–1;1[ and give a q-analogue of the unitary integral transform that Watanabe constructed from the Hilbert space L 2(]–1;1[;(1–x 2) dx onto the weighted Hilbert space H 2;(D).  相似文献   
5.
The intra-channel collision of optical solitons, with dual-power law nonlinearity, is studied in this paper by the aid of quasi-particle theory. The perturbation terms that are considered in this paper are the nonlinear gain and saturable amplifiers along with filters. The suppression of soliton-soliton interaction, in presence of these perturbation terms, is acheived. The numerical simulations support the quasi-particle theory. OCIS codes: 060.2310; 060.4510; 060.5530; 190.3270; 190.4370.  相似文献   
6.
7.
A new numerical method of solving integro-differential equations appearing in the theory of atomic and nuclear scattering systems has been devised. It is termed Singular Value Decomposition Method (SVD). It consists in expanding the exchange kernel into a number of separable terms by means of the Singular Value Decomposition and then iterating over the remainder. In this paper, we extend our SVD method to the scattering of low energy electron-helium which has been the subject of interest, both theoretically and experimentally. We compare our results with the Moments Method which is widely used. The Moments Method consists of making an expansion of the solution into an especially favorable basis that takes care of the non-exchange part of the Hamiltonian.  相似文献   
8.
The photocatalytic degradation of an azo reactive dye, Reactive Yellow 84 (RY84), in aqueous solutions using industrial titanium dioxide coated non-woven paper was studied. The experiments were carried out to investigate the factors that influence the dye photocatalytic degradation, such as adsorption, initial concentration of dye, temperature, and solution pH. The experimental results show that adsorption is an important parameter controlling the apparent kinetics constant of degradation. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model. The degradation was enhanced by the temperature and was favored in acidic pH range.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号