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71.
High-quality brown factice is produced from meadowfoam and rapeseed oils, while a poorer-quality factice is produced from
soybean oil, a less expensive oil. A one-to-one mixture of soybean and meadowfoam or rapeseed oil produces a factice that
has similar physical characteristics as factice produced from 100% meadowfoam or rapeseed oils. In addition, meadowfoam oil
and rapeseed oil act as accelerators when mixed with castor or jojoba oils. White factice productions from soybean oil can
also be improved when mixed with meadowfoam or rapeseed oils. The difference in cost, obtained by using as much as 50% soybean
oil instead of the higher-costing oil, will translate into significant savings for the factice and rubber industries. 相似文献
72.
Gas chromatography-mass spectrometry of methyl esters of unsaturated oxygenated fatty acids 总被引:5,自引:0,他引:5
Silylation of hydroxyl groups in methyl esters of unsaturated hydroxy acids provides compounds that give mass spectra which
can be readily interpreted, whereas spectra of underivatized esters are extremely difficult to evaluate. The relationship
of the double bond(s) to the trimethylsiloxy (TMS) group results in specific mass spectral patterns. In esters that have the
TMS group separated from the double bond by one methylene group, the ions caused byα-cleavage at the TMS group on the side closest to the olefinic group are much more abundant than those produced fromα-cleavage on the other side of the TMS group. In esters that have the TMS group and the double bond separated by two methylene
groups,α-cleavage ions are approximately equal. When the TMS group and the double bond are allylic, no fragmentation results between
them. Cleavage does occur on either side of this system, and those ions resulting from cleavage alpha to the TMS group are
in greatest abundance. Silylation of esters that have a conjugated diene or ene-yne system adjacent to a hydroxyl group also
gives derivatives amenable to gas chromatographymass spectrometry. In these esters, large peaks are observed that arise fromα-cleavage at the TMS group and at the other end of the olefinic system. No fragmentation between the TMS group and the sites
of unsaturation occurs. Unsaturated epoxy methyl esters produce spectra difficult to interpret. When the epoxide is converted
to methoxy-hydroxy derivatives by BF3-methanol, the spectrum locates the position of the epoxide group. Silylation of the hydroxyl group produces a compound that
gives a less complicated spectrum which also locates the original epoxy group. Mass spectrometry of a series of unsaturated
keto-esters, without derivatization, provides spectra that are easily interpretable.
Presented at the AOCS Meeting, Los Angeles, April 1972.
N. Market. Nutr. Res. Div., ARS, USDA. 相似文献
73.
In the presence of oxygen, a crude soy extract converted 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid into numerous products, from which 9-oxo-trans-12,13-epoxy-trans-10-octadecenoic acid was isolated. Additionally, the soy extract oxidized linoleic acid to the oxo-epoxyoctadecenoic acid,
presumably via a sequential reaction involving lipoxygenase oxidation of linoleic acid followed by degradation of the resultant
linoleic acid hydroperoxide. However, the linoleic acid substrate yielded two isomeric linoleic acid hydroperoxides and because
of this, two isomeric oxoepoxyoctadecenoic acids.
Presented in part at the 13th Congress, International Society for Fat Research, Marseilles, France, August 30–September 4,
1976. 相似文献
74.
Two hydroxy acids, lesquerolic (53 wt%) and auricolic (4%), are present at significant quantities inLesquerella fendleri seed oil. Results reported here indicate the selective release of hydroxy fatty acids during hydrolysis of this oil catalyzed
byRhizopus arrhizus lipase. For example, hydroxy acids composed 85–90 wt% of the free fatty acids released during lipolysis, as compared to 54%
present overall in the oil. In addition, over 80% of the lesquerolic acid is released from the triglycerides. The reason for
this lipase’s success was determined to be its 1,3-positional specificity. The vast majority of lesquerella oil’s hydroxy
acids is at the 1- and 3-positions of its triglycerides, as confirmed by the compositional analysis of partial glycerides
formed during lipolysis. 相似文献
75.
76.
Kenneth D. Carlson Robert Kleiman Marvin O. Bagby 《Journal of the American Oil Chemists' Society》1994,71(2):175-182
Lesquerella gordonii (Gray) Wats andLimnanthes alba Benth. (Meadowfoam) are species being studied as new and alternative crops. Triglyceride oil from lesquerella contains 55–60%
of the uncommon 14-hydroxy-cis-11-eicosenoic acid. Meadowfoam oil has 95% uncommon acids, includingca. 60%cis-5-eicosenoic acid. Both oils are predominantly unsaturated (3% saturated acids), and have similar iodine values (90–91),
from which oxirane values of 5.7% are possible for the fully epoxidized oils. Each oil was epoxidized withm-chloro-peroxybenzoic acid, and oxirane values were 5.0% (lesquerella) and 5.2% (meadowfoam). The epoxy acid composition of
each product was examined by gas chromatography of the methyl esters, which showed that epoxidizedL. gordonii oil contained 55% 11,12-epoxy-14-hydroxyeicosanoic acid, and epoxidized meadowfoam oil contained 63% 5,6-epoxyeicosanoic
acid, as expected for normal complete epoxidation. Mass spectrometry of trimethylsilyloxy derivatives of polyols, prepared
from the epoxidized esters, confirmed the identity of the epoxidation products and the straightforward nature of the epoxidation
process. Synthesis and characterization of these interesting epoxy oils and derivatives are discussed. 相似文献
77.
78.
Selim M. Erhan Robert Kleiman Thomas P. Abbott 《Journal of the American Oil Chemists' Society》1996,73(5):563-567
Estolides were produced from meadowfoam oil fatty acids, oleic, linoleic, petroselinic, andcis-5,cis-13 docosadienoic acids. Estolide reaction mixtures were quantitated by Fourier transform infrared spectroscopy and compared
to the area percentages determined by high-performance liquid chromatography. The absorbance frequency of estolide carbonyl
(1737 cm−1) is different than the lactone carbonyl (1790 cm−1) and the acid carbonyl (1712 cm−1). Estolide standards were obtained by wiped-film molecular-still distillations and column chromatography. 相似文献
79.
80.
Meadowfoam fatty acids (83% monoenoic fatty acid), reacted with 0.01–0.1 mole equivalents of perchloric acid, gave 33–71% yield of estolide, an oligomeric 2° ester, resulting from self condensation. Equimolar amounts of perchloric acid to fatty acid failed to produce estolide but converted the fatty acids to a mixture of lactones, mainly γ-eicosanolactone. Temperature plays a critical role; higher temperatures (75–100°C), at the same acid concentration, provide lactones while lower temperatures (20–65°C) yield estolides. Lower acid levels (<0.1 mole equivalents) gave the best yields (≈70%) at 65°C. The estolide and monomer were characterized by nuclear magnetic resonance, infrared high-pressure liquid chromatography, gas chromatography, gas chromatography/mass spectrometry. The estolide is a mixture of oligomers with an average distribution near 1.65 ester units. The ester linkages are located mainly at the original double bond positions but have some positional isomerization to adjacent sites in accord with carbocation migration along the alkyl chain. The residual double bond of the estolide was extensively isomerized fromcis totrans and positionally along the chain. The distilled monomer is similar in structure to the unsaturated portion of the estolide with geometrical and positional double bond isomerization. In addition, a significant amount of cyclization of the fatty acids to lactone (≈30%) had occurred. 相似文献