全文获取类型
收费全文 | 353篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
化学 | 128篇 |
晶体学 | 1篇 |
力学 | 17篇 |
数学 | 119篇 |
物理学 | 91篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2019年 | 7篇 |
2018年 | 5篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 6篇 |
2013年 | 19篇 |
2012年 | 24篇 |
2011年 | 19篇 |
2010年 | 12篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 19篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 17篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1917年 | 1篇 |
1906年 | 3篇 |
1905年 | 1篇 |
1893年 | 1篇 |
1891年 | 1篇 |
排序方式: 共有356条查询结果,搜索用时 31 毫秒
1.
2.
F. Aliotta M. E. Fontanella M. Pieruccini G. Salvato S. Trusso C. Vasi R. E. Lechner 《Colloid and polymer science》2002,280(2):193-202
The role played by the solvation water molecules on the macroscopically observed sol–gel transition in lecithin/cyclohexane/water
reverse micelles is investigated by quasielastic neutron scattering, dielectric relaxation and conductivity measurements.
The experimental results are juxtaposed to those from spherical Aerosol OT reverse micelles. It is shown how the results from
lecithin-based system can be interpreted only assuming that, in contrast to Aerosol OT systems, the water molecules are entrapped
at the interfaces without coalescing into an inner water pool. It is suggested that, in the case of lecithin, the solvation
water can induce a change in the surface curvature, in such a way promoting the formation of branch points. Such a hypothesis
is supported by the temperature dependence of the conductivity which agrees with the hypothesis of an intermicellar bond percolation.
The investigation of the structures imposed by an external electric field is also studied. The observed electrorheological
behaviour seems to confirm the existence of a percolated transient network in the gel phase.
Received: 21 March 2001 Accepted: 24 August 2001 相似文献
3.
Akchurin N Langland J Onel Y Bonner BE Corcoran MD Cranshaw J Nessi-Tedaldi F Nessi M Nguyen C Roberts JB Skeens J White JL Bravar A Giacomich R Penzo A Schiavon P Zanetti A Bystricky J Lehar F de Lesquen A van Rossum L Cossairt JD Read AL Derevschikov AA Matulenko YA Meschanin AP Nurushev SB Patalakha DI Rykov VL Solovyanov VL Vasiliev AN Grosnick DP Hill DA Laghai M Lopiano D Ohashi Y Shima T Spinka H Stanek RW Underwood DG Yokosawa A Funahashi H Goto Y Imai K Itow Y Makino S Masaike A 《Physical review D: Particles and fields》1993,48(7):3026-3036
4.
Natalini B Marinozzi M Sardella R Macchiarulo A Pellicciari R 《Journal of chromatography. A》2004,1033(2):363-367
The chromatographic resolution of enantiomeric amino acids is accomplished on a reversed phase column using aqueous mobile phase containing the chiral reagent N,N-dimethyl-S-phenylalanine-Cu(II). The separation is a result of the whole interaction between the diastereomeric complex surface and the mixed stationary phase realized by the dynamic coating of the RP-18 carbon chains layer. The elution order seems to be related to the different water coordination capability on copper ion in the formation of the mixed ternary complexes. 相似文献
5.
Gino Bontempelli Franco Magno Benedetto Corain Gilberto Schiavon 《Transition Metal Chemistry》1985,10(1):8-11
Summary The reduction of nickel perchlorate in the presence of carbon monoxide and substituted phosphines or diphosphines has been studied in acetonitrile by cyclic voltammetry. The results show that only mono- and bis-carbonylphosphinenickel(O) complexes are formed, while no evidence for the formation of carbonyl-nickel(I) and -nickel(II) species was obtained. Although the oxidation processes are not reversible, a good correlation between the anodic peak potentials relative to nickel(O) complexes and the -donor--acceptor abilities of the phosphines employed was observed. 相似文献
6.
G. E. De Benedetto F. Catalano L. Sabbatini P. G. Zambonin 《Analytical and bioanalytical chemistry》1998,362(1):170-175
This paper is part of a systematic archaeometric investigation aimed at the characterisation of the pigments and related materials (ligand, colour substrate) used in decoration of pottery excavated in the archaeological zone of Canosa (Puglia, Italy). Shards found in thirteen different tombs have been analysed; in this paper samples exhibiting a white colouration have been selected. Both surface (XPS) and bulk (FT-IR) spectroscopies were used which gave complementary information and enabled white pigments to be divided into two groups. Moreover, X-ray diffraction was used in some cases to further support some spectral assignments. The molecular specificity of FT-IR, when applied to the analysis of both pigments and ceramic body, allowed the identification of the various constituents and, hence, provided indirect information on the end-use of the original wares. The potential of the combined use of different spectroscopies to obtain valuable information on both painting materials and technical aspects is shown. 相似文献
7.
This paper presents pragmatic particulars pertaining to plume protection problems with special emphasis on the health care environment. Practical approaches to optimizing protection are discussed with an eye toward facilitating the safety of personnel and the general health care environment from particulates, parasites, viruses and other undesirable entities, elements and compounds. 相似文献
8.
DNA sequencing is performed in a multiplexed capillary electrophoresis system by UV absorption detection. Four individual electropherograms are obtained by simultaneously running the unlabeled DNA products of the four ddNTP-terminated reactions in the capillary array. The sequence of the template used in the cycle-sequencing reaction can be determined by overlaying the four electropherograms. Two internal standards are employed to adjust for the variance in migration times among the capillaries. After applying the correction algorithm, base calling can be done at a high level of confidence. 相似文献
9.
10.
Nancy C. Forero-Martinez Robinson Cortes-Huerto Antonio Benedetto Pietro Ballone 《Molecules (Basel, Switzerland)》2022,27(5)
The thermodynamics, structures, and applications of thermoresponsive systems, consisting primarily of water solutions of organic salts, are reviewed. The focus is on organic salts of low melting temperatures, belonging to the ionic liquid (IL) family. The thermo-responsiveness is represented by a temperature driven transition between a homogeneous liquid state and a biphasic state, comprising an IL-rich phase and a solvent-rich phase, divided by a relatively sharp interface. Demixing occurs either with decreasing temperatures, developing from an upper critical solution temperature (UCST), or, less often, with increasing temperatures, arising from a lower critical solution temperature (LCST). In the former case, the enthalpy and entropy of mixing are both positive, and enthalpy prevails at low T. In the latter case, the enthalpy and entropy of mixing are both negative, and entropy drives the demixing with increasing T. Experiments and computer simulations highlight the contiguity of these phase separations with the nanoscale inhomogeneity (nanostructuring), displayed by several ILs and IL solutions. Current applications in extraction, separation, and catalysis are briefly reviewed. Moreover, future applications in forward osmosis desalination, low-enthalpy thermal storage, and water harvesting from the atmosphere are discussed in more detail. 相似文献