全文获取类型
收费全文 | 78篇 |
免费 | 1篇 |
专业分类
化学工业 | 13篇 |
金属工艺 | 9篇 |
建筑科学 | 2篇 |
能源动力 | 6篇 |
轻工业 | 6篇 |
水利工程 | 2篇 |
无线电 | 1篇 |
一般工业技术 | 17篇 |
冶金工业 | 18篇 |
原子能技术 | 3篇 |
自动化技术 | 2篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 3篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 4篇 |
排序方式: 共有79条查询结果,搜索用时 15 毫秒
1.
Shape memory properties of Ni-Ti based melt-spun ribbons 总被引:1,自引:0,他引:1
R. Santamarta E. Cesari J. Pons T. Goryczka 《Metallurgical and Materials Transactions A》2004,35(3):761-770
Shape-memory properties of equiatomic NiTi, Ni45Ti50Cu5, and Ni25Ti50Cu25 ribbons made by melt spinning have been studied by temperature inducing the martensitic transformation under constant tensile
loads. Recoverable strains above 4 pct can be obtained under ∼100 MPa loads for the NiTi and Ni45Ti50Cu5 ribbons, transforming to B19’ martensite. The B19 martensite is formed in the Ni25Ti50Cu25 ribbon after crystallization, and according to the lowering in transformation strain as Cu content increases, the recoverable
strain is close to 2.5 pct for ∼150 MPa load. The transformation temperatures exhibit a linear dependence on the applied stress,
which can be quantitatively described by means of a Clausius-Clapeyron type equation. The NiTi and Ni45Ti50Cu5 ribbons exhibited some degree of two-way shape-memory effect (TWSME) after thermomechanical cycling. Texture analyses performed
on the different ribbons allow us to better understand the transformation strains obtained in each ribbon. The amounts of
shape-memory effect (SME) and nonrecoverable strain shown by the studied ribbons are of the same order as those already observed
in bulk materials, which makes melt spinning an ideal substitute to complicated manufacturing processes if really thin samples
are needed. However, applicable stresses in melt-spun ribbons are limited by a relatively “premature” brittle fracture caused
by irregularities in ribbon thickness. 相似文献
2.
3.
Cesari V Colautti P Magrin G De Nardo L Baek WY Grosswendt B Alkaa A Khamphan C Ségur P Tornielli G 《Radiation protection dosimetry》2002,99(1-4):337-342
This paper illustrates a tissue-equivalent proportional counter designed to have high gas gain and good energy resolution at nanometric simulated site sizes. Microdosimetric neutron and gamma spectra were measured in dimethyl ether and in propane-based tissue-equivalent gas mixture down to 35 nm. The comparison of experimental data with the results of Monte Carlo calculations shows a satisfactory agreement. 相似文献
4.
Regioregular azobenzene-substituted polythiophenic copolymers were prepared by a regiospecific organometallic polycondensation procedure based on a Grignard metathesis reaction. Copolymers with a high content of chromophoric groups in the side chains and a high degree of configurational order of the backbones were obtained. A sample was also functionalized with hydroxyalkyl chains capable of setting up ordered supramolecular structures through hydrogen bonds. The final materials were fully characterized via NMR, IR, elemental analysis, GPC, DSC and X-ray diffraction. Moreover, measurements of NLO activity on polymer films showed the synthetic strategies adopted and monomers used to be correct. Values obtained by the in situ deprotection of the interacting functional groups after the alignment of the chromophorized side chains were very promising, proving the procedure to be suitable for industrial and commercial applications. 相似文献
5.
Kireeva I. V. Pobedennaya Z. V. Chumlyakov Yu. I. Pons J. Cesari E. Karaman I. 《Technical Physics Letters》2009,35(2):186-189
The temperature interval ΔT
SE of superelasticity in [001]-, [$
\bar 1
$
\bar 1
23]-, and [$
\bar 1
$
\bar 1
24]-oriented Co40Ni21Ga30 (at. %) single crystals strained at compression has been studied. It is established that ΔT
SE in the [001]-oriented single crystal amounts to 441 K and the reversible B2-L10 martensite transformations in loaded samples take place at T
2 = 698 K. In [$
\bar 1
$
\bar 1
23]- and [$
\bar 1
$
\bar 1
24]-oriented samples, ΔT
SE decreases to 233 K and the superelasticity is observed up to T
2 = 523 K. 相似文献
6.
7.
D. Contini A. DonateoD. Cesari A.G. Robins 《Journal of Wind Engineering & Industrial Aerodynamics》2011,99(5):539-553
The evaluation of the trajectories of plumes rising into a crossflow is relevant for the correct modelling of pollutant dispersal in the atmosphere. Plume rise models are therefore an important part of several dispersion models. There is a general consensus on the formulation of plume rise through solution of equations describing the conservation of energy and momentum in the plume closed with an empirical formulation of the entrainment rate of fresh air into the developing plume. However, there are differences in the entrainment coefficients found in different studies. In this work the trajectories of sixty plumes, simulated at small scale in a towing water tank, have been analysed in order to test the performance of widely used dispersion codes and to find statistically the best entrainment coefficients for the different models. The plumes simulated cover a wide range of scenarios from pure jets to buoyant plumes developing in both neutral and linearly stable stratified crossflows. A new analytical model for stable crossflows, representing an extension of an existing model, has been presented and tested. Results show that the entrainment coefficients are different for neutral and stable crossflows, especially for approximate analytical codes. In contrast, the coefficients of the integral model seem to be less sensitive to the stability of the crossflow. The entrainment coefficients found by the fitting of the analytical models are significantly lower than the measured spread rate of the plumes. In neutral crossflows the generalised Briggs model and the integral model give statistically similar performances. In stable crossflows the new analytical model as well as the integral model are able to predict the oscillation of the plumes around their equilibrium height; however, there is an underestimation of both the oscillation frequency and the downwind position of the maximum height. The use of an added mass coefficient allows, with almost the same entrainment coefficients, improved prediction of the oscillation frequency and of the maximum rise position. Measured plume height oscillations are more strongly damped than predicted ones. 相似文献
8.
9.
10.
The problem of a centre-cracked plate of finite crack length to plate width ratio when subjected to a quadratic thermal gradient is studied. Stress intensity factors are derived from elastic analysis using an analytical approach and the finite element method. The analytical approach is exact only for an infinitely wide plate so that the finite element results enable the evaluation of finite width correction factors. Various techniques for evaluating the stress intensity factor under thermal loading are reviewed, and the preferred ones are applied to the present problem. The resulting finite width correction factors are compared to those derived for the tensile Mode I loading case. 相似文献