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61.
Citrin is the hepatic mitochondrial aspartate–glutamate carrier that is encoded by the gene SLC25A13. Citrin deficiency often leads to hyperammonemia, for which the current treatment concept is different from that for primary
hyperammonemias. Metabolite level diagnosis, often referred to as chemical diagnosis, is not always successful in identifying
citrin deficiency immediately or in a timely fashion. We previously made the chemical diagnosis of citrin deficiency in ten
patients from nine families. In order to devise a more rapid and more accurate chemical diagnosis of this disorder than is
currently available, we reinvestigated the gas chromatography/mass spectrometry-based urine metabolome in these patients.
In patients aged 2 to 5 months, prominent biomarkers detected included one or more of the following metabolites: tyrosine,
p-hydroxyphenyllactate, p-hydroxyphenylpyruvate, and N-acetyltyrosine, galactose, galactitol and galactonate, glucose, glucitol, and cystathionine. These biomarkers are less prominent
in older patients, but are not increased in argininosuccinate synthetase deficiency or other hyperammonemias. α-Ketoglutaramate
(KGM), a recently recognized urinary biomarker of primary hyperammonemias associated with defects of the urea cycle, was increased
in most patients with citrin deficiency studied here in spite of normal urinary levels of glutamine (the immediate precursor
of KGM), 5-oxoproline, glutamate, aspartate, and asparagine. Other important urinary biomarkers that should be measured for
differential diagnosis of hyperammonemias, including orotate, uracil, and β-ureidopropionate, were not increased. The presence
of citrulline and citrulline-derived metabolites was noted in all cases. The present study shows that noninvasive urine metabolomics,
together with an analysis of selected metabolites or groups of metabolites, provides a more reliable and rapid chemical diagnosis
of citrin deficiency than was previously available and more readily differentiates this disorder from other hyperammonemic
syndromes. 相似文献
62.
Ito S Tanaka Y Yoshikawa H Ishibashi Y Miyasaka H Masuhara H 《Journal of the American Chemical Society》2011,133(37):14472-14475
Controlling chemical reactions within a small space is a significant issue in chemistry, and methods to induce reactions within a desired position have various potential applications. Here we demonstrate localized, efficient photopolymerization by radiation pressure. We induced a one-photon UV polymerization of liquid acrylate solutions in the optical-trapping potential of a focused near-IR (NIR) laser beam, leading to the confinement of solidification to a minute space with dimensions smaller or equal to one-fifth of the wavelength of the NIR laser. Our approach can produce solidification volumes smaller than those achievable with conventional one-photon polymerization, thus enabling the production of tiny polymeric structures that are smaller than the diffraction limit of the trapping light. This is the first demonstration of a radiation pressure effect on a photochemical reaction. 相似文献
63.
Kidera M Seto Y Takahashi K Enomoto S Kishi S Makita M Nagamatsu T Tanaka T Toda M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,78(3):1215-1219
We developed a detection technology for vapor forms of chemical warfare agents (CWAs) with an element analysis system using an electron cyclotron resonance ion source. After the vapor sample was introduced directly into the ion source, the molecular material was decomposed into elements using electron cyclotron resonance plasma and ionized. The following CWAs and stimulants were examined: diisopropyl fluorophosphonate (DFP), 2-chloroethylethylsulfide (2CEES), cyanogen chloride (CNCl), and hydrogen cyanide (HCN). The type of chemical warfare agents, specifically, whether it was a nerve agent, blister agent, blood agent, or choking agent, could be determined by measuring the quantities of the monatomic ions or CN(+) using mass spectrometry. It was possible to detect gaseous CWAs that could not be detected by a conventional mass spectrometer. The distribution of electron temperature in the plasma could be closely controlled by adjusting the input power of the microwaves used to generate the electron cyclotron resonance plasma, and the target compounds could be detected as molecular ions or fragment ions, enabling identification of the target agents. 相似文献
64.
A germacalix‐crown, 25,27‐bis[1‐(3‐trimethylgermylpropyl)oxy]calix[4]arene‐crown‐6, 1,3‐alternate ( 1a ), and its carbon analog, 25,27‐bis‐[1‐(4,4‐dimethylpentyl)oxy]calix[4]arene‐crown‐6, 1,3‐alternate ( 1b ), were prepared and their structures were confirmed by elemental analysis and 1H and 13C NMR spectroscopy. A cation transport test indicated that both compounds exhibited much the same cation transport ability, so that the role of the germanium moiety in capturing and transporting counteranions is not yet clear. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
65.
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68.
Geoffrey B Edwards Kaoru Yamanouchi Kozo Kuchitsu Masaaki Sugie Harutoshi Takeo Chi Matsumura Keiichiro Ogawa Yoshito Takeuchi 《Journal of Molecular Spectroscopy》1985,111(2):301-319
The microwave spectrum of 1-pyrroline has been measured from 8 to 48 GHz. The transitions have been assigned to those of the ground state and the four lowest excited states of the ring-puckering vibration of monomer, which is a five-membered ring molecule with one CN double bond. The trimer, which exists in the liquid phase, has not been detected in the gas phase. The geometrical structure of the monomer has been estimated by an ab initio calculation and the trimer by a molecular mechanics calculation. The former is consistent with the experimental rotational constants. A gas-phase infrared spectrum has also been measured, and the ring-puckering potential has been determined by an analysis of the combination bands of the ring-puckering mode and the ring-stretching modes. The potential is described using a puckering coordinate, z, as V(z) = az2 + bz4, where and ; these values are intermediate of the corresponding values for cyclopentene and 1-pyrazoline. The nuclear quadrupole coupling constants, χaa = ?4.39(10), χbb = 1.04(10), and χcc = 3.35(10) MHz, have been determined by an analysis of well-resolved hyperfine splittings. These constants have been reproduced by an ab initio calculation with a 4-31G(N1) basis set. 相似文献
69.
70.
Determination of reduced and total ubiquinones in biological materials by liquid chromatography with electrochemical detection 总被引:2,自引:0,他引:2
A convenient and reliable liquid chromatographic (LC) method with electrochemical detection (ED) was developed for the determination of reduced (ubiquinol) and total ubiquinones in biological materials. After extraction of samples with n-hexane, ubiquinol was separated on a reversed-phase column and assayed directly by ED. In order to determine the total amount of a ubiquinone in biological samples, the unbiquinone was converted into the corresponding reduced form by treatment with sodium borohydride. No significant interfering peak (plastoquinol-9, ubichromenol-9, etc.) was observed in the elution areas of ubiquinol-7 to -11. This LC-ED method was about 70 times more sensitive than the previous LC-UV method and was able to detect 150 pg of ubiquinol-10. The method was applied satisfactorily to the determination of the contents of ubiquinol homologues in biological materials. The content of ubiquinols is a major component of the total ubiquinones in human plasma and urine and rat plasma and liver, but a minor component in rat heart and kidney. 相似文献