全文获取类型
收费全文 | 545篇 |
免费 | 15篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 13篇 |
化学工业 | 137篇 |
金属工艺 | 18篇 |
机械仪表 | 12篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 23篇 |
轻工业 | 65篇 |
石油天然气 | 1篇 |
无线电 | 44篇 |
一般工业技术 | 158篇 |
冶金工业 | 24篇 |
原子能技术 | 1篇 |
自动化技术 | 57篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 15篇 |
2021年 | 30篇 |
2020年 | 17篇 |
2019年 | 21篇 |
2018年 | 36篇 |
2017年 | 24篇 |
2016年 | 24篇 |
2015年 | 11篇 |
2014年 | 16篇 |
2013年 | 51篇 |
2012年 | 26篇 |
2011年 | 42篇 |
2010年 | 30篇 |
2009年 | 21篇 |
2008年 | 23篇 |
2007年 | 23篇 |
2006年 | 12篇 |
2005年 | 18篇 |
2004年 | 14篇 |
2003年 | 6篇 |
2002年 | 11篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 9篇 |
1992年 | 1篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有564条查询结果,搜索用时 15 毫秒
1.
2.
3.
G
V Vijaya T Gireesh Gajanan S Bhat 《Journal of the science of food and agriculture》2002,82(5):493-496
The effect of enzymatic hydrolysis of proteins in milk using neutrase on the growth of the probiotic strain Bifidobacterium bifidus was evaluated by estimation of microbial growth, acidity, viscosity and flavour production. A significant increase in the growth of B bifidus was observed in neutrase‐hydrolysed milk. The setting time of bifidus‐cultured milk was advanced by about 12 h at 5% degree of hydrolysis. Enzymatic hydrolysis of proteins prior to cultivation also significantly increased the viscosity of the product. An approximately 60% increase in viscosity of the product was observed in neutrase‐hydrolysed milk. Production of steam‐volatile monocarbonyls as an indication of development of flavour was also higher in neutrase‐hydrolysed milk. The concentration of steam‐volatile monocarbonyls was 2.47 µmol per 100 ml in neutrase‐hydrolysed milk but only 1.84 µmol per 100 ml in control milk at the setting point of the curd. © 2002 Society of Chemical Industry 相似文献
4.
The Kerendan carbonate platform (Oligocene Berai Limestone) covers a subsurface area measuring approximately 11 by 16 km in the westernmost Kutei Basin, Central Kalimantan. Aggradation of the Kerendan platform occurred during a major Oligocene transgression, and is contemporaneous with aggradation and backstepping of the Barito shelf margin which was located approximately 30 km to the south. The Kerendan platform is approximately 1,000 m thick, and comprises three aggrading seismic sequences identified by the downlap of basinal strata at the platform margin and downlap of transgressive strata within the platform. Carbonate deposition started in the Late Eocene, and ended when the upper limestone sequence drowned and was covered with shale in the Late Oligocene (approximately 28.6 Ma). Three depositional areas can be distinguished in seismic sections: (1) a platform interior (lagoon); (2) a slightly raised platform rim (1–2 km wide); and (3) a basinward‐dipping platform margin and slope. The margin of the platform is identified by inflections on the seismic profiles where the relatively flat platform top begins to slope basinward. Depositional models from outcrops combined with core from three Kerendan wells were used to extrapolate depositional facies onto the seismically‐defined platform. Platform‐interior (lagoon) facies consist largely of fossiliferous wackestones and packstones, and porosities are generally lower than 5%. The platform rim is characterized by interbedded bioclastic wackestones, packstones, grainstones and boundstones, with grainstones increasing toward the platform margin. Porosity preferentially occurs in packstones, grainstones and boundstones. The platform‐rim deposits have greater porosity (5–13%) than the platform interior because the platform run is more grainstone‐rich, and because acidic waters compacting out of basinal shales concentrated dissolution near the platform margin. Pore types include vuggy porosity, microporosity within grains, and intercrystalline porosity in dolomite in the upper part of the platform rim. Different pore types have resulted in variable but locally very high permeabilities (greater than 100 mD). Permeabilities decrease with depth as vuggy pores decrease, and microporosity becomes dominant. 相似文献
5.
用辐射功率200W微波(2450MHz)处理6~16,明显促进离体黄瓜子叶生根.根长和根鲜重增加。不同辐射强度和辐服时间对离体黄瓜子叶生根有不同影响。用TTC法测定,微波处理后与根活力相关的OD值比对照体增加了。用温箱模拟FISO微波炉功率为200W的温度,不同处理时间处理离体黄瓜子叶,没有发现促进生根。说明在一定条件下,微波辐射处理离体黄瓜子叶促进生根.主要是微波的辐射效应。 相似文献
6.
J. Siva Kumar K. Vijaya Kumar A. R. Subrahmanyam M. Jaipal Reddy 《Journal of Materials Science》2007,42(14):5752-5755
Ion conducting thin film polymer electrolytes based on polyethylene oxide (PEO) complexed with NaHCO3 salt has been prepared using solution-cast technique. The complexation of NaHCO3 salt with PEO is confirmed by XRD and IR studies. DC conductivity in the temperature range 303–368 K has been evaluated.
The conductivity is found to increase in the PEO complex with the NaHCO3 salt and also with an increase in temperature. Using this polymer electrolyte, an electrochemical cell with the configuration
Na/(PEO + NaHCO3)/(I2 + C + electrolyte) has been fabricated and its discharge characteristics studied. Open Circuit Voltage (OCV) and Short Circuit
Current (SCC) are found to be 2.69 V and 1.28 mA, respectively. Other parameters associated with the cell are evaluated and
presented in this paper. 相似文献
7.
Silicon - In recent times, the study on machining characteristics of combined (hybrid) fiber polymer composites has drawn a remarkable research attention because of its emerging industrial... 相似文献
8.
Tejraj M. Aminabhavi Lakshmi C. Shetty B. Vijaya Kumar Naidu Nadagouda N. Mallikarjuna Vanajakshi M. Hanchinal 《应用聚合物科学杂志》2004,94(3):1139-1150
Sorption, diffusion, and swelling characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) were investigated for water–acetic acid mixtures by using a gravimetric method at 30, 40, and 50°C. The membranes were characterized by X‐ray diffraction and Fourier transform infrared techniques. Concentration‐independent diffusion coefficients were obtained by applying Fick's relationship before completion of equilibrium sorption. Permeation coefficients were calculated from sorption and diffusion coefficients. Concentration profiles of liquids were computed considering the sheet geometry for the membrane by solving Fick's equation under suitable boundary conditions. Arrhenius activation parameters were computed for the transport processes. Experimental results and calculated quantities were discussed to understand membrane–solvent interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1139–1150, 2004 相似文献
9.
This paper presents a new completely hierarchical three dimensional curved shell finite element formulation for linear static analysis of laminated composite plates and shells. The element displacement approximation can be of arbitrary polynomial orders p
, p
and p
in the , , and directions thereby permitting strains of at least (p
–1), (p
–1) and (p
–1) order. The element approximation functions as well as the nodal variables are hierarchical. The element formulation ensures C
0 continuity. The lamina properties are incorporated by numerically integrating the element stiffness matrix for each lamina. The formulation has no restriction on either the number of laminas or the layup pattern of the laminas. The geometry of the laminated shell element is described by the coordinates of the nodes lying on the middle surface of the element and the lamina thicknesses at each node. The element formulation is equally effective for very thin as well as very thick laminated plates and curved shells. The results obtained from the present formulation are compared with those available in the literature as well as available analytical solutions. 相似文献
10.
This paper presents a three node curved three dimensional beam element for linear static analysis where the element displacement approximation in the axial () and transverse directions ( and ) can be of arbitrary polynomial orders p
, p
and p
. This is accomplished by, first constructing one dimensional hierarchical approximation functions and the corresponding nodal variable operators in , and directions using Lagrange interpolating polynomials and then taking the products (also called tensor product) of these hierarchical one dimensional approximation functions and the corresponding nodal variable operators. The resulting approximation functions and the corresponding nodal variables for the three dimensional beam element were hierarchical. The formulation guarantees C
0 continuity. The element properties are established using the principle of virtual work. In formulating the properties of the element all six components of the stress and strain tensor are ratained. The geometry of the beam element is defined by the coordinates of the nodes located at the axis of the beam and node point vectors representing the nodal cross-sections. The results obtained from the present formulation are compared with analytical solutions (when available) and the h-models using isoparametric three dimensional solid elements. The formulation is equally effective for very slender as well as deep beams since no assumptions are made regarding such conditions during the formulation. 相似文献