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101.
Park DL Coates S Brewer VA Garber EA Abouzied M Johnson K Ritter B McKenzie D 《Journal of AOAC International》2005,88(1):156-160
Performance Tested Method multiple laboratory validations for the detection of peanut protein in 4 different food matrixes were conducted under the auspices of the AOAC Research Institute. In this blind study, 3 commercially available ELISA test kits were validated: Neogen Veratox for Peanut, R-Biopharm RIDASCREEN FAST Peanut, and Tepnel BioKits for Peanut Assay. The food matrixes used were breakfast cereal, cookies, ice cream, and milk chocolate spiked at 0 and 5 ppm peanut. Analyses of the samples were conducted by laboratories representing industry and international and U.S governmental agencies. All 3 commercial test kits successfully identified spiked and peanut-free samples. The validation study required 60 analyses on test samples at the target level 5 microg peanut/g food and 60 analyses at a peanut-free level, which was designed to ensure that the lower 95% confidence limit for the sensitivity and specificity would not be <90%. The probability that a test sample contains an allergen given a prevalence rate of 5% and a positive test result using a single test kit analysis with 95% sensitivity and 95% specificity, which was demonstrated for these test kits, would be 50%. When 2 test kits are run simultaneously on all samples, the probability becomes 95%. It is therefore recommended that all field samples be analyzed with at least 2 of the validated kits. 相似文献
102.
Pretreatment of yellow poplar sawdust by pressure cooking in water 总被引:11,自引:0,他引:11
Joe Weil Ayda Sarikaya Shiang-Lan Rau Joan Goetz Christine M. Ladisch Mark Brewer Rick Hendrickson Michael R. Ladisch 《Applied biochemistry and biotechnology》1997,68(1-2):21-40
The pretreatment of yellow poplar wood sawdust using liquid water at temperatures above 220°C enhances enzyme hydrolysis.
This paper reviews our prior research and describes the laboratory reactor system currently in use for cooking wood sawdust
at temperatures ranging from 220 to 260°C. The wood sawdust at a 6–6.6% solid/liquid slurry was treated in a 2 L, 304 SS,
Parr reactor with three turbine propeller agitators and a proportional integral derivative (PID) controller, which controlled
temperature within ±1°C. Heat-up times to the final temperatures of 220, 240, or 260°C were achieved in 60–70 min. Hold time
at the final temperature was less than 1 min. A serpentine cooling coil, through which tap water was circulated at the completion
of the run, cooled the reactor’s contents within 3 min after the maximum temperature was attained. A bottoms port, as well
as ports in the reactor’s head plate, facilitated sampling of the slurry and measuring the pH, which changes from an initial
value of 5 before cooking to a value of approx 3 after cooking. Enzyme hydrolysis gave 80–90% conversion of cellulose in the
pretreated wood to glucose. Simultaneous saccharification and fermentation of washed, pretreated lignocellulose gave an ethanol
yield that was 55% of theoretical. Untreated wood sawdust gave less than 5% hydrolysis under the same conditions. 相似文献
103.
Brewer C Brewer G Luckett C Marbury GS Viragh C Beatty AM Scheidt WR 《Inorganic chemistry》2004,43(7):2402-2415
Reaction of iron salts with three tripodal imidazole ligands, H(3)(1), H(3)(2), H(3)(3), formed from the condensation of tris(2-aminoethyl)amine (tren) with 3 equiv of an imidazole carboxaldehyde yielded eight new cationic iron(III) and iron(II), [FeH(3)L](3+or2+), and neutral iron(III), FeL, complexes. All complexes were characterized by EA(CHN), IR, UV, M?ssbauer, mass spectral techniques and cyclic voltammetry. Structures of three of the complexes, Fe(2).3H(2)O (C(18)H(27)FeN(10)O(3), a = b = c = 20.2707(5), cubic, I3d, Z = 16), Fe(3).4.5H(2)O (C(18)H(30)FeN(10)O(4.5), a = 20.9986(10), b = 11.7098(5), c = 19.9405(9), beta = 109.141(1), monoclinic, P2(1)/c), Z = 8), and [FeH(3)(3)](ClO(4))(2).H(2)O (C(18)H(26)Cl(2)FeN(10)O(9), a = 9.4848(4), b = 23.2354(9), c = 12.2048(5), beta = 111.147(1) degrees, monoclinic, P2(1)/n, Z = 4) were determined at 100 K. The structures are similar to one another and feature an octahedral iron with facial coordination of imidazoles and imine nitrogen atoms. The iron(III) complexes of the deprotonated ligands, Fe(1), Fe(2), and Fe(3), are low-spin while the protonated iron(III) cationic complexes, [FeH(3)(1)](ClO(4))(3) and [FeH(3)(2)](ClO(4))(3), are high-spin and spin-crossover, respectively. The iron(II) cationic complexes, [FeH(3)(1)]S(4)O(6), [FeH(3)(2)](ClO(4))(2), [FeH(3)(3)](ClO(4))(2), and [FeH(3)(3)][B(C(6)H(5))(4)](2) exhibit spin-crossover behavior. Cyclic voltammetric measurements on the series of complexes show that complete deprotonation of the ligands produces a negative shift in the Fe(III)/Fe(II) reduction potential of 981 mV on average. Deprotonation in air of either cationic iron(II) or iron(III) complexes, [FeH(3)L](3+or2+), yields the neutral iron(III) complex, FeL. The process is reversible for Fe(3), where protonation of Fe(3) yields [FeH(3)(3)](2+). 相似文献
104.
Sharon M. Molnar Glen E. Jensen Lisa M. Vogler Sumner W. Jones Leroy Laverman Jon S. Bridgewater Mark M. Richter Karen J. Brewer 《Journal of photochemistry and photobiology. A, Chemistry》1994,80(1-3):315-322
We have prepared a series of mixed-metal trimetallic complexes of the form {[(bpy)2Ru(BL)]2MCl2}n+(bpy 2,2′-bipyridine; BL 2,3-bis(2-pyridyl)pyrazine (dpp), 2,3-bis(2-pyridyl)quinoxaline (dpq) or 2,3-bis(2-pyridyl)-benzoquinozaline (dpb); M Ir(III), Rh(III) or Os(II). This new class of trimetallic complexes can be prepared with a good yield, often as high as 95%, using our building block strategy. The central rhodium and iridium fragments of these trimetallic, namely [M(BL)2Cl2]+, have been shown in our laboratory to be capable of delivering multiple electrons, “stored” on the bridging ligand π* orbitals, to a substrate as they functioned as electrocatalysts for the reduction of carbon dioxide to formate. The two terminal ruthenium metals are good light absorbers designed to give rise to photochemical activity. These bichromophoric systems should be capable of absorbing two photons of light, each giving rise to a desired photochemical reaction, namely excited-state electron transfer. Thus these systems form the basis of a molecular device for photoinitiated electron collection. The properties of these supramolecular complexes have been tuned by variation in the central metal and bridging ligand. Comparison of this array of nine complexes is described herein. 相似文献
105.
The reactions of a wide range of transition-metal carbonyls with anhydrous HF are described. In particular, Ru3(CO)12, Os3(CO)12 and Ir4(CO)12 give the solution stable [Ru3(CO)12H]+, [Ru(CO)5H]+, [Os3(CO)12H]+, [Os(CO)5H]+ and [Ir4(CO)12H2]2+ respectively, which have been characterised by a combination of 1H and 13C NMR spectroscopy. 相似文献
106.
107.
108.
Tim M. Brewer Christopher Szakal Greg Gillen 《Rapid communications in mass spectrometry : RCM》2010,24(5):593-598
A method to increase useful yields of organic molecules is investigated by cluster secondary ion mass spectrometry (SIMS). Glycerol drops were deposited onto various inkjet‐printed arrays and the organic molecules in the film were rapidly incorporated into the drop. The resulting glycerol/analyte drops were then probed with fullerene primary ions under dynamic SIMS conditions. High primary ion beam currents were shown to aid in the mixing of the glycerol drop, thus replenishing the probed area and sustaining high secondary ion yields. Integrated secondary ion signals for tetrabutylammonium iodide and cocaine in the glycerol drops were enhanced by more than a factor of 100 compared with an analogous area on the surface, and a factor of 1000 over the lifetime of the glycerol drop. Once the analyte of interest is incorporated into the glycerol microdrop, the solution chemistry can be tailored for enhanced secondary ion yields, with examples shown for cyclotrimethylenetrinitramine (RDX) chloride adduct formation. In addition, depositing localized glycerol drops may enhance analyte secondary ion count rates to high enough levels to allow for site‐specific chemical maps of molecules in complex matrices such as biological tissues. Published in 2010 by John Wiley & Sons, Ltd. 相似文献
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