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1.
Polymers containing intact lactone groups are a new class of macromolecules with reactive groups, which are relatively easy to obtain by polymerization, polycondensation and polyaddition, as well as by reactions on existing macromolecules. Polymers with β-lactone Groups in particular can enter into numerous addition reactions, which can be used, for example, to obtain macromolecules containing hydroxy acid or amino acid groupings. The reactions proceed under mild conditions, and can even be carried out in aqueous media, frequently giving water-soluble polymers. The polymers can be cross-linked at low temperatures, even from the aqueous phase, by the addition of bifunctional or oligofunctional reagents. Polymers containing β-lactone groups can also be used as a basis for graft co-polymers; polyester or polyether branches can be grafted on, depending on whether monomeric lactones or monomeric epoxides are used. 相似文献
2.
Morimasa Saito 《Analytical and bioanalytical chemistry》1995,351(2-3):148-153
Relative sensitivity factors (RSF) (Fe=1) were determined for steel, aluminium and copper standard samples by direct current glow discharge mass spectrometry using Kr and Xe as discharge gas. In general, the RSF values in Kr and Xe were higher than in Ar; however for S and P in Kr gas and P, As and Se in Xe gas they were considerably lower. This decrease is related to the relative importance of the Penning ionization process in overall ionization of the sputtered species. The results showed the percentage of Penning ionization to account for 75.6–82.0% for Se, As and P and 64.2% for S. 相似文献
3.
Morimasa Saito 《Analytical and bioanalytical chemistry》1997,357(1):18-21
In dc glow discharge mass spectrometry, the addition of small amounts of H2 to pure Ar as discharge gas has greatly increased the ion intensities of elements compared with the conventional method using
pure Ar. This phenomenon was also observed for the addition of H2 to pure Kr. The reason for the increase of the ion intensities of elements was studied by using a Kr gas mixture containing
0.2% (v/v) H2. The ion intensities of the elements P, Se and As (whose first ionization potentials are higher than the energy levels of
the excited state of Kr) did not increase even if the Kr/H2 gas mixture was used. The results show that the addition of H2 significantly contributed to increasing the number of metastable argon or krypton atoms (Penning ionization).
Received: 4 November 1995/Revised: 5 January 1996/Accepted: 10 January 1996 相似文献
4.
Morimasa Saito 《Fresenius' Journal of Analytical Chemistry》1997,357(1):18-21
In dc glow discharge mass spectrometry, the addition of small amounts of H2 to pure Ar as discharge gas has greatly increased the ion intensities of elements compared with the conventional method using
pure Ar. This phenomenon was also observed for the addition of H2 to pure Kr. The reason for the increase of the ion intensities of elements was studied by using a Kr gas mixture containing
0.2% (v/v) H2. The ion intensities of the elements P, Se and As (whose first ionization potentials are higher than the energy levels of
the excited state of Kr) did not increase even if the Kr/H2 gas mixture was used. The results show that the addition of H2 significantly contributed to increasing the number of metastable argon or krypton atoms (Penning ionization).
Received: 4 November 1995/Revised: 5 January 1996/Accepted: 10 January 1996 相似文献
5.
Yuki Hirayama Morimasa Nakamura Takashi Matsuoka 《Surface and interface analysis : SIA》2020,52(12):850-854
Polyoxymethylene (POM, polyacetal) is one of the most popular plastics for machine elements, especially in Japan. However, it is difficult to use it under severe operating conditions such as high speed and high contact pressure. Diamond-like carbon (DLC) coatings were well known to be tribological and functional coatings. However, both POM and DLC coatings are difficult to adhere them each other. In the present paper, DLC coatings are deposited by plasma-based ion implantation and deposition (PBIID) method on POM substrate, and validity of DLC coatings on POM was investigated through friction and mechanical tests. When gas pressure was 0.2 and 0.8 Pa, hardness and adhesion properties of DLC coating deposited under gas pressure of 0.5 Pa were lower compared with under 0.2 and 0.8 Pa. For preparing DLC coatings having hard and good adhesion properties, relatively thin substrate was suitable. A correlation between relative humidity in the laboratory and friction coefficient was confirmed while DLC coatings remain on the substrate. 相似文献
6.
7.
J. Wilhelm M. Grötschel E. Mezgolits E. Strohmeier E. Unsinn K. Brockhoff D. Ohse 《Mathematical Methods of Operations Research》1979,23(4):B126-B130
Ohne Zusammenfassung 相似文献
8.
We study relations between induced subgraphs and (n,m)-subposets. Using properties of (n,m)-subposets, we consider a characterization of chordal double bound graphs in terms of forbidden subposets. Furthermore, we deal with properties of a poset whose double bound graph is isomorphic to its upper bound graph or its comparability graph, etc. 相似文献
9.
10.
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