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111.
Simultaneous NO and CO(2) measurement in human breath with a single IV-VI mid-infrared laser 总被引:1,自引:0,他引:1
A tunable diode laser absorption spectroscopy (TDLAS) system equipped with a IV-VI mid-IR laser operating near 5.2>mu;m was used to measure exhaled nitric oxide (eNO) and carbon dioxide (CO(2)) simultaneously in human breath over a single exhalation. Breath was sampled in real time, and eNO levels were measured from seven volunteers, two steroid-naive asthmatics and five nonasthmatics. Measured CO(2) levels were used as an internal standard to verify correct breath collection and calculate eNO values. Calculated eNO concentrations agreed well with reported values for asthmatic and nonasthmatic individuals. 相似文献
112.
Rex A. Palmer Brian S. Potter Michael J. Leach Babur Z. Chowdhry 《Journal of chemical crystallography》2007,37(11):771-777
Abstract Drugs based on 5-phenyl-2,4 diamino pyrimidine and 6-phenyl-1,2,4 triazine derivatives are well known for their effects on
the central nervous system. The study presented here provides detailed crystal structures of two pyrimidine derivatives which
have neuroprotective properties in models of both grey and white matter ischemia. Recently published studies suggest that
the compounds lamotrigine (a triazine derivative), and the two pyrimidines BW1003C87 (I) and sipatrigine (II) mediate their primary in vivo mode of action by inhibiting voltage-gated Na+ channels. The X-ray crystal structures will contribute valuable data for applications involving binding and modelling studies
of the biological actions of these drugs.
Graphical Abstract
X-ray crystallographic structures of neuroprotective pyrimidine derivatives: (I) the mesylate salt of BW1003C87 and (II) sipatrigine
base
Rex A. Palmer*, Brian S. Potter, Michael J. Leach and Babur Z. Chowdhry
Surface representations, [20] are a useful tool with respect to considerations employed for the purposes of drug design. Shown here are the neuroprotective
drug molecules (a) BW1003C87 and (b) Sipatrigine Base (BW619C89) derived from their solid state structures reported in this
paper. The molecules are viewed edge on to ring B with the two adjacent Cl atoms uppermost on the left.
相似文献
113.
Kinkini Bhattacharyya Tanusree Kar Rex A. Palmer Brian S. Potter Akira Inada 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):979-980
In the title compound, C30H50O3, the three six‐membered rings adopt chair, twist and twist‐boat conformations. The five‐membered ring is in a slightly distorted envelope conformation. The substituent on the five‐membered ring is in an extended conformation, with its two hydroxyl O atoms forming an intramolecular hydrogen bond. One of these O atoms also forms an intermolecular hydrogen bond with the oxygen of the carbonyl group in a neighbouring molecule. 相似文献
114.
Summary The fluidity model ofHildebrand has been applied to dilute aqueous polymer solutions exhibiting non-Newtonian behaviour. As for Newtonian fluids, it is found that the temperature dependence of apparent viscosity of non-Newtonian fluids is determined entirely by the temperature dependence of fluid density. However, whereas the parameters ofHildebrand's equation are constants, independent of the conditions of shear for Newtonian fluids, these parameters become shear-rate dependent for non-Newtonian fluids. The magnitude of the parameters and their variation with shear rate can be explained qualitatively in terms of interactions of polymer molecules and their behaviour in a shear field.
Notation B Parameter inHildebrand's fluidity equation, eq. [1] (N–1 m2 s–1) - K Consistency parameter in the power-law (Nm–2 s n ) - n Flow behaviour index in the power-law (–) - T Temperature (K) - V Molar volume (m3 mol–1) - V 0 Intrinsic molar volume; parameter inHildebrand's fluidity equation, eq. [1] (m3 mol–1) - Shear rate (s–1) - Viscosity or apparent viscosity (Nm–2 s) - Density (kg m–3) - 0 Intrinsic density; modified parameter inHildebrand's fluidity equation; eq. [5] (kg m–3) - Shear stress (Nm–2) With 4 figures and 1 table 相似文献
Zusammenfassung Das Fließmodell vonHildebrand wird auf verdünnte wäßrige Polymerlösungen mit nicht-newtonschem Verhalten angewandt. Wie bei newtonschen Flüssigkeiten findet man hierfür, daß die Temperaturabhängigkeit der schergeschwindigkeitsabhängigen Viskosität ausschließlich durch die Temperaturabhängigkeit der Flüssigkeitsdichte bestimmt ist. Während jedoch die Parameter derHildebrandschen Gleichung für newtonsche Flüssigkeiten von den Scherbedingungen unabhängige Konstanten darstellen, werden diese bei nichtnewtonschen Flüssigkeiten schergeschwindigkeitsabhängig. Die Größe dieser Parameter und ihrer Variation mit der Schergeschwindigkeit kann qualitativ als eine Folge der Wechselwirkung der Polymermoleküle und ihres Verhaltens im Scherfeld gedeutet werden.
Notation B Parameter inHildebrand's fluidity equation, eq. [1] (N–1 m2 s–1) - K Consistency parameter in the power-law (Nm–2 s n ) - n Flow behaviour index in the power-law (–) - T Temperature (K) - V Molar volume (m3 mol–1) - V 0 Intrinsic molar volume; parameter inHildebrand's fluidity equation, eq. [1] (m3 mol–1) - Shear rate (s–1) - Viscosity or apparent viscosity (Nm–2 s) - Density (kg m–3) - 0 Intrinsic density; modified parameter inHildebrand's fluidity equation; eq. [5] (kg m–3) - Shear stress (Nm–2) With 4 figures and 1 table 相似文献
115.
Novel Product Chemistry from Mechanistic Analysis of ent‐Copalyl Diphosphate Synthases from Plant Hormone Biosynthesis 下载免费PDF全文
Kevin Potter Jared Criswell Dr. Jiachen Zi Alisha Stubbs Prof. Dr. Reuben J. Peters 《Angewandte Chemie (International ed. in English)》2014,53(28):7198-7202
An active‐site water molecule coordinated by conserved histidine and asparagine residues seems to serve as the catalytic base in all ent‐copalyl diphosphate synthases (CPSs). When these residues are substituted by alanine, the mutant CPSs produce stereochemically novel ent‐8‐hydroxy‐CPP. Given the requisite presence of CPSs in all land plants for gibberellin phytohormone biosynthesis, such plasticity presumably underlies the observed extensive diversification of the resulting labdane‐related diterpenoids. 相似文献
116.
One of the effects of using Photofrin II as a sensitizer in clinical photodynamic therapy is skin photosensitivity. Avoiding the harmful effect of this photosensitivity typically requires the patient to remain indoors during daylight hours for 4 weeks post injection. Photosensitivity can last up to 8 weeks. A possible method of quickly eliminating skin photosensitivity is the use of photobleaching to eliminate the DHE (dihematoporphyrin ether, the active agent in Photofrin II) from the skin. The Photofrin II was used as supplied (Photomedica, Raritan, NJ) and will be referred to as DHE. We report a series of experiments using Swiss mice which demonstrate the ability to reduce the period of photosensitivity to 1 week. The Swiss mice received 5 mg kg-1 DHE intraperitoneal. Beginning at 24 h post injection they were given daily increasing light doses starting with 18 J cm-2 (at 630 nm). Only the left hind feet were treated with light. At 7 days post injection both hind feet were treated with 135 J cm-2. The pretreated left foot showed no reaction to this treatment whereas the right foot reacted as strongly as control mice which had received no pretreatment with light. The control mice were also injected 7 days prior to treatment. As a check for tolerance animals received a second injection of 5 mg kg-1 DHE intraperitoneally 96 h after the conclusion of the bleaching protocol. Twenty-four h later the left hind foot (previously desensitized by light) reacted to 135 J cm-2 as strongly as controls which had received the 5 mg kg-1 of DHE but no pretreatment. 相似文献
117.
118.
Cho Jeong-Guk Potter William T. Sublette Kerry L. 《Applied biochemistry and biotechnology》1994,45(1):861-870
Applied Biochemistry and Biotechnology - Porphyrins are tetrapyrrole ring structures which are metal chelating and often found in the active sites of enzymes involved in redox reactions. We have... 相似文献
119.
Rapid, accurate methods for the determination of neodymium and boron in iron-neodymium-boron alloys are presented. The procedure involves dissolution of the alloy with nitric acid and measurement of the elemental concentrations by direct-current plasma atomic-emission spectrometry. Lithium is added in the determination of neodymium, to control interferences. The relative standard deviations are approximately 1%, and the accuracies comparable to those obtained by classical chemical methods. 相似文献
120.
Gary D. Fullerton Ph.D. Janet L. Potter M.D. N.Carol Dornbluth M.D. 《Magnetic resonance imaging》1982,1(4):209-226
Nuclear magnetic resonance (NMR) longitudinal (T1) and transverse (T2) relaxation parameters have been evaluated for protein solutions, cellular suspensions and tissues using both data from our laboratory and the extensive literature. It is found that this data can be generalized and explained in terms of three water phases: free water, hydration water, and crystalline water. The proposed model which we refer to as the FPD model differs from similar models in that it assumes that free and hydration water are two phases with distinct relaxation times but that T1 = T2 in each phase. In addition there is a single correlation time for each rather than a distribution as assumed in most other models. Longitudinal decay is predicted to be single exponent in character resulting from a fast exchange between the free and hydration compartments. Transverse decay is predicted to be multiphasic with crystalline (T2 10 μsec), hydration (T2 10 sec) and free (T2 100 sec) water normally visible. The observed or effective transverse relaxation times for both the hydration and free water phases are greatly affected by the crystalline phase and are much shorter than the inherent relaxation times. 相似文献