全文获取类型
收费全文 | 72篇 |
免费 | 0篇 |
专业分类
化学 | 52篇 |
力学 | 4篇 |
数学 | 6篇 |
物理学 | 10篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 5篇 |
1974年 | 1篇 |
排序方式: 共有72条查询结果,搜索用时 15 毫秒
51.
Steven A. Anderson Thatcher W. Root 《Journal of molecular catalysis. A, Chemical》2004,220(2):247-255
Direct synthesis of dimethyl carbonate offers prospects for a “green chemistry” replacement to eliminate use of phosgene for polymer production and other processes. The carbonylation of methanol to produce dimethyl carbonate over Cu+X and Cu+ZSM-5 zeolites prepared by solid-state ion exchange has been investigated, focusing on the interaction of carbon monoxide with the Cu+ zeolites. The methanol carbonylation mechanism reported previously has been extended to account for carbon monoxide adsorption at high pressure. The comparison of the results obtained from Cu+X and Cu+ZSM-5 show that strong CO adsorption on the catalyst is not related to increased rate of dimethyl carbonate production. The rate limiting step for DMC production is best described as the Eley-Rideal reaction of gas-phase CO with surface methoxide. 相似文献
52.
K. B. Kalmykov N. E. Dmitrieva O. K. Lebedeva N. V. Root D. Yu. Kultin L. M. Kustov 《Russian Chemical Bulletin》2016,65(12):2801-2804
The surfaces of the alloy based on Zr2Ni doped by silicon (3 at.%) in the amorphous and crystalline states and of the Zr and Ni foils were electrochemically modified for the first time. The modification was carried out in the ionic liquid in the galvanostatic regime. The much more uniform distribution of the nanosized fragments can be obtained and stability of their geometric shapes can be retained in the absence of intergrain boundaries and texture in the amorphous materials. 相似文献
53.
Daniel A. Nelson Brandon L. Thompson An-Chi Scott Renna Nouwairi Christopher Birch Jacquelyn A. DuVall Delphine Le Roux Jingyi Li Brian E. Root James P. Landers 《Electrophoresis》2022,43(16-17):1746-1754
The laser print, cut, and laminate (PCL) method for microfluidic device fabrication can be leveraged for rapid and inexpensive prototyping of electrophoretic microchips useful for optimizing separation conditions. The rapid prototyping capability allows the evaluation of fluidic architecture, applied fields, reagent concentrations, and sieving matrix, all within the context of using fluorescence-compatible substrates. Cyclic olefin copolymer and toner-coated polyethylene terephthalate (tPeT) were utilized with the PCL technique and bonding methods optimized to improve device durability during electrophoresis. A series of separation channel designs and centrifugation conditions that provided successful loading of sieving polymer in less than 3 min was described. Separation of a 400-base DNA sizing ladder provided calculated base resolution between 3 and 4 bases, a greater than 18-fold improvement over separations on similar substrates. Finally, the accuracy and precision capabilities of these devices were demonstrated by separating and sizing DNA fragments of 147 and 167 bases as 148.62 ± 2 and 166.48 ± 3 bases, respectively. 相似文献
54.
Lebedeva O. K. Root N. V. Kultin D. Yu. Kalmykov K. B. Kustov L. M. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(5):965-967
Russian Journal of Physical Chemistry A - The formation of nanostructures in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide on the surface of a nickel electrode during anodizing was... 相似文献
55.
56.
C. Root F. J. Lederer T. E. Schrader T. T. Herzog T. Cordes P. Gilch M. Braun 《Applied Physics A: Materials Science & Processing》2009,96(1):99-106
The photodynamics of single crystals of 4-(diisopropylamino)benzonitrile (DIABN) have been studied by femtosecond UV/Vis and
mid-IR absorption spectroscopy. The observed spectroscopic response, especially in the UV/Vis, strongly depends on the optical
excitation conditions. For the excitation light in resonance with the absorption of DIABN, broad and structureless transient
spectra are observed, which decay non-exponentially within pico- to nanoseconds. For off-resonance excitation in the very
red wing of the absorption band a stimulated emission signal is detected, which decays in ∼10 ps matching the known behavior
of the non-interacting chromophore in solution. The 10 ps decay is due to an intramolecular charge transfer process which
is supported by femtosecond IR spectroscopy. The observed dependence on the excitation wavelength is assigned to a change
in the density of excited chromophores and therefore bears relevance for time resolved X-ray diffraction experiments. 相似文献
57.
O. K. Lebedeva D. Yu. Kultin N. V. Root L. M. Kustov S. F. Dunaev V. B. Kazansky 《Doklady Chemistry》2018,479(2):41-44
The anodic oxidation of a titanium metal electrode in two ionic liquids was studied of amorphous titania nanostructures were obtained. The nanostructures are formed only in the case where a hydrophilic ionic liquid (1-butyl-3-methylimidazolium chloride) with addition of some water is used as the electrolyte. The role of water is to provide a sort of construction material (source of oxygen) for titania nanostructures. In the hydrophobic ionic liquid (1-butyl-3-methylimidazolium), the thickness of the anodic oxide increases and no nanostructures are formed. 相似文献
58.
Teeters MA Conrardy SE Thomas BL Root TW Lightfoot EN 《Journal of chromatography. A》2003,989(1):165-173
Adsorptive membranes were investigated for the downstream processing of plasmid DNA by quantifying both separation efficiencies and adsorption uptake with the anion-exchange membranes. Separation efficiencies of the 10-ml Mustang-Q were measured using pulses of 6.1-kilo base pair plasmid DNA and lysozyme tracers, and comparing the responses for both conventional and reverse-flow operation. The plasmid exhibited nearly 200 plates/cm, almost as high efficiency as the protein despite the large difference in size. This behavior contrasts strongly with typical behavior for spherical porous particle packings, which predicted large decreases in efficiency with increases in tracer size. Batch adsorption isotherms for the 6.1-kilo base pair plasmid on small sheets of anion-exchange membranes at various ionic strengths showed high capacities for very large biomolecules. The maximum binding capacity for the membrane unit was calculated as 10 mg plasmid/ml, an order of magnitude greater than typical values reported for porous beads. 相似文献
59.
Cylindrical Wiener processes in real separable Banach spaces are defined, and an approximation theorem involving scalar Wiener processes is given for such processes. A weak stochastic integral for Banach spaces involving a cylindrical Wiener process as integrator and an operator-valued stochastic process as integrand is defined. Basic properties of this integral are stated and proved.A class of linear, time-invariant, stochastic differential equations in real, separable, reflexive Banach spaces is formulated in such fashion that a solution of the equation is a cylindrical process. An existence and uniqueness theorem is proved. A stochastic version of the problem of heat conduction in a ring provides an example.Research supported by National Science Foundation under Grant No. ECS-8005960. 相似文献
60.