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101.
102.
Mohamed H. Hekal Fatma S. M. Abu El‐Azm Hanan A. Sallam 《Journal of heterocyclic chemistry》2019,56(3):795-803
A series of new N‐substituted isoquinolin‐1,3‐dione derivatives were prepared, starting from reaction of (Z)‐4‐((E)‐3‐phenylallylidene)isochromane‐1,3‐dione 4 with different nitrogen nucleophiles. The assigned structures of the prepared compounds were elucidated by spectral methods (IR, 1H NMR, 13C NMR, and mass spectroscopy). Some of the newly prepared compounds were tested in vitro against a panel of three human tumor cell lines, namely, hepatocellular carcinoma (liver) HepG2, colon cancer HCT‐116, and mammary gland breast MCF‐7. Also, they were tested as antioxidants. Some of the tested compounds showed very strong cytotoxic activity with respect to the standard. 相似文献
103.
In this article, we presented a novel, efficient and facile approach for using strontium titanate supported catalyst in organic synthesis. Bis and tetrakis of coumarin, indole and xanthene derivatives can effortlessly have prepared using V2O5/perovskite nanoparticles (NPs) under solvent‐free condition. V2O5/perovskite in (NPs) was prepared and identified using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and scanning electron microscope supported with energy dispersive X‐ray (SEM/EDAX). Calculated crystal size was from the intense XRD peaks was found to range between 50–60 nm in agreement with that obtained from the transmission electron microscopic investigation. EDAX analysis and mapping images reveal a homogenous distribution of all constituents with their calculated ratios in the synthesized catalyst. 相似文献
104.
Ahmed B.M. Ibrahim Amna S.A. Zidan Aref A.M. Aly Hanan K. Mosbah Ghada Abd-Elmonsef Mahmoud 《应用有机金属化学》2020,34(2):e5391
A cadmium complex of the general formula Cd(C13H9O2NCl)2(H2O)2 {C13H9O2NCl = 2-(4-chlorophenylamino)benzoate} was synthesized and characterized regarding its CHN data, solution molar conductivity and spectroscopic (UV–Vis. and IR) properties. Cadmium sulfide nanoparticles (CdS NPs) were grown form the microcrystalline complex and thiourea via a hydrothermal route. The as-prepared NPs were assigned based on X-ray powder diffraction (PXRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and Brunauer – Emmett – Teller (BET) surface area measurements. The CdS absorption and emission spectra were also recorded that revealed an energy gap of 2.47 eV and large Stokes shift of 130 nm. For the as-prepared NPs, the measurements have also indicated a mesoporous structure and an average particle size of 20–28 nm associated with an average pore diameter of 11.21 nm. The as-synthesized CdS NPs acted as antifungal controlling agent against human and plant pathogenic fungi of serious environmental and health concerns. The NPs at concentration of 200 ppm inhibited several fungi with inhibition efficiency of 100% against Aspergillus ustus Au-28. The nanoparticles induced morphological abnormalities in fungal mycelia, conidia and vesicle. Additionally, they inhibited the conidia septum formation, accelerated the chlamydospores generation and enlarged the yeast cells. 相似文献
105.
106.
Electron spin relaxation times and rapid scan EPR imaging of pH‐sensitive amino‐substituted trityl radicals 下载免费PDF全文
Hanan B. Elajaili Joshua R. Biller Mark Tseitlin Ilirian Dhimitruka Valery V. Khramtsov Sandra S. Eaton Gareth R. Eaton 《Magnetic resonance in chemistry : MRC》2015,53(4):280-284
Carboxy‐substituted trityl (triarylmethyl) radicals are valuable in vivo probes because of their stability, narrow lines, and sensitivity of their spectroscopic properties to oxygen. Amino‐substituted trityl radicals have the potential to monitor pH in vivo, and the suitability for this application depends on spectral properties. Electron spin relaxation times T1 and T2 were measured at X‐band for the protonated and deprotonated forms of two amino‐substituted triarylmethyl radicals. Comparison with relaxation times for carboxy‐substituted triarylmethyl radicals shows that T1 exhibits little dependence on protonation or the nature of the substituent, which makes it useful for measuring O2 concentration, independent of pH. Insensitivity of T1 to changes in substituents is consistent with the assignment of the dominant contribution to spin lattice relaxation as a local mode that involves primarily atoms in the carbon and sulfur core. Values of T2 vary substantially with pH and the nature of the aryl group substituent, reflecting a range of dynamic processes. The narrow spectral widths for the amino‐substituted triarylmethyl radicals facilitate spectral‐spatial rapid scan electron paramagnetic resonance imaging, which was demonstrated with a phantom. The dependence of hyperfine splittings patterns on pH is revealed in spectral slices through the image. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
107.
Hanan Luss 《The Journal of the Operational Research Society》1977,28(2):275-284
In this paper we describe a model for systems in which the customers usually reserve the required facilities in advance. The model has been developed for a communication network which provides visual conferencing services. We concentrate upon a network with a single pair of cities. Each customer calls the reservation office and specifies the desired day, starting time and holding time for his conference. A scheduler either satisfies the customer's request or offers him up to two alternatives which he may or may not accept. Various performance indices of the system, such as the proportion of lost customers, the proportion of rescheduled customers and the facilities' occupancy rate, are derived. Numerical examples and applications are discussed. 相似文献
108.
We consider minimax optimization problems where each term in the objective function is a continuous, strictly decreasing function of a single variable and the constraints are linear. We develop relaxation-based algorithms to solve such problems. At each iteration, a relaxed minimax problem is solved, providing either an optimal solution or a better lower bound. We develop a general methodology for such relaxation schemes for the minimax optimization problem. The feasibility tests and formulation of subsequent relaxed problems can be done by using Phase I of the Simplex method and the Farkas multipliers provided by the final Simplex tableau when the corresponding problem is infeasible. Such relaxation-based algorithms are particularly attractive when the minimax optimization problem exhibits additional structure. We explore special structures for which the relaxed problem is formulated as a minimax problem with knapsack type constraints; efficient algorithms exist to solve such problems. The relaxation schemes are also adapted to solve certain resource allocation problems with substitutable resources. There, instead of Phase I of the Simplex method, a max-flow algorithm is used to test feasibility and formulate new relaxed problems.Corresponding author.Work was partially done while visiting AT&T Bell Laboratories. 相似文献
109.
Montanet L Gieselmann K Technical Associate Barnett RM Groom DE Trippe TG Wohl CG Armstrong B Technical Associate Wagman GS Technical Associate Murayama H Stone J Hernandez JJ Porter FC Morrison RJ Manohar A Aguilar-Benitez M Caso C Lantero P Technical Associate Crawford RL Roos M Törnqvist NA Hayes KG Höhler G Kawabata S Manley DM Olive K Shrock RE Eidelman S Schindler RH Gurtu A Hikasa K Conforto G Workman RL Grab C 《Physical review D: Particles and fields》1994,50(3):1173-1826
110.
Ahmed A. Mohamed Hanan E. Abdou Michael D. Irwin José M. López-de-Luzuriaga John P. Fackler Jr. 《Journal of Cluster Science》2003,14(3):253-266
The structures of the tetragold(I) formamidinate cluster complexes, [Au4(ArNC(H)NAr)4], Ar=C6H4-4-OMe (1), C6H3-3,5-Cl (2), C6H4-4-Me (3), have been characterized by x-ray crystallography. The range of AuAu distances is 2.8–3.0 Å. The angles at AuAuAu are acute and obtuse 70 and 109°, 88 and 91°, and 63 and 116° in 1, 2, and 3, respectively. The four gold atoms are located at the corner of a rhomboid with the formamidinate ligands bridged above and below the near plane of the four Au(I) atoms. The tetranuclear gold(I) complexes show a bright blue-green luminescence under UV light, with an emission at 490 nm and a weak emission at 530 nm in the solid state, at room temp and 77 K. The oxidation of the formamidinate cluster, 1, has been studied electrochemically in 0.1 M Bu4NPF6/CH2Cl2 at a Pt working electrode with different scan rates. Three waves were obtained, 0.75, 0.95, and 1.09V vs. Ag/AgCl at a scan rate of 500 mV/s, the three waves are reversible. The potentials are independent of the scan rate in the range 50 mV/s to 3 V/s. The current at the third wave is larger than those at the first two. 相似文献