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91.
Crude palm oil contains about 1% of minor components including carotenoids, tocopherols, sterols, triterpene alcohols, phospholipids,
glycolipids and terpenic and paraffinic hydrocarbons. The nutritionally important components such as carotenes and tocopherols
also improve stability of the oil. Although a highly valued product, carotene unfortunately is bleached or destroyed in refining
because suitable recovery technology is not available. Thermal degradation of carotene, previously suspected of giving rise
to undesirable chemicals, now is known to furnish mainly harmless hydrocarbons, most of which are removed by the deodorization
step in refining. Tocopherols, being natural antioxidants, need to be carefully preserved during milling, refining, fractionation
and modification of palm oils. The accumulation of tocopherols in the palm fatty acid distillate promises to provide a new
source for the recovery of this valuable substance. The role played by phospholipids is frequently misunderstood because they
can act in two ways, i.e. as an antioxidant synergist and a surface active agent to disperse impurities in oil. In crude palm
oil the phospholipid content is small, because most of it is removed during milling; the phosphorus content is due mainly
to inorganic phosphorus. Among the sterols, cholesterol constitutes too small a percentage to be of much concern. Sterols,
triterpenoids and terpenoid hydrocarbons are also potentially useful side products should recovery technology become available.
Other newly characterized minor and trace components also are discussed. 相似文献
92.
Published field experimental data [11, 15, 19] were used to compare measured NH3(g) losses following applications of urine or aqueous urea to pasture soils with values predicted by a simplified ammonia volatilization model [16]. Total measured losses were generally in close agreement with predictions. For example, predicted losses following applications of urine to a ryegrass-white clover pasture in Canterbury, New Zealand were 20.7% in summer and 22.4% in autumn and were highly correlated with measured losses of 21.5% and 24.4% respectively (r = 0.998).The model was also tested for instantaneous rate of ammonia gas loss at 33 discrete sampling times for the summer experiment. Correlations were again highly significant (r = 0.951 for urine and r = 0.885 for urea).The interception of urine solution by herbage and litter on the pasture surface is discussed and was shown to account for some of the discrepancies between measurements and predictions. Soil surface pH was confirmed as an important factor in determining the extent of ammonia gas loss, and the practicalities of measuring this parameter under field conditions are presented. It was concluded that the model offers the potential for predicting ammonia volatilization losses following urine or aqueous urea applications to short pasture in non-leaching, non-nitrifying environments. 相似文献
93.
94.
Interaction between non-histone protein HMG1 or HMG2 and DNA has been studied by using thermal denaturation and circular dichroism (CD) spectroscopy. We have made the following observations. 1. The binding of each of these two proteins to DNA stabilizes the latter, as shown by an increase in melting temperature of 20 degrees C (from 45 degrees C to about 65 degrees C). 2. There are 6.0 amino acids/nucleotide in HMG1-bound DNA and 5.0 in HMGI-bound DNA which suggests that each HMB1 moleculae would cover about 20 base pairs of DNA and each HMG2 molecule would cover about 25 base pairs. 3. The alpha-helical content of these two non-histone proteins in the complexes, estimated from the CD value at 220 nm, is about one third to one half that of total proteins in calf thymus chromatin. 4. DNA conformation is distorted only slightly by the binding of protein HMG1 or HMG2. 5. Neither the melting nor the CD properties of HMG1-DNA or HMG2-DNA complexes differ substantially whether they are prepared by NaCl-gradient dialysis in urea or by direct mixing of protein and DNA at 0.15 M NaCl, followed by dialysis against the same buffer i.e. 0.25 mM EDTA (pH 8.0). 相似文献
95.
The desipramine-sensitive uptake (neuronal uptake) of 14C-bretylium and 14C-bethanidine into the rabbit aortic adventitial layer from 3 X 10(-6) M solutions increased with time during a 20 min incubation. For both compounds a neuronal uptake of 50 pmol/50 mg wet weight adventitia was associated with 10% block of the contractile response to field stimulation at 16 Hz and 150 pmol/50 mg with 60% block. The concentration of blocking agents inside the neuron at 50% blockade was calculated to be 260 X 10(-6) M, an 87-fold increase over the medium. The bretylium in the neuron decreased by 50% during 20 min washout, and bethanidine by 29%. Desipramine when added to the bath 20 min following the addition of the blocking agents led to a loss of bretylium but not of bethanidine from the adventitia. Desipramine had little or no effect on the uptake, washout or disposition of either blocking agent in the media-intimal layers. The data indicate that bretylium has a greater propensity than bethanidine to be lost from the neurons; however, it appears to be recycled back through the membrane via the amine pump more readily than bethanidine. The fact that conservative calculations indicate that the neuronal membrane slowly established a concentration of the blocking agents within the neuron that is known to produce rapid local anesthesia when topically applied to adrenergic nerve trunks and which approaches a concentration needed to inhibit sensory endings suggests that local anesthesia may play a role in the mechanism of neuron blockade. 相似文献
96.
Collagen metabolism in osteoarthritic human articular cartilage was compared to that in normal cartilage and was also correlated with the degree of severity of the osteoarthritic lesion as determined by a histological-histochemical grading system. No correlation was apparent between the concentrations of DNA, hydroxyproline, and hydroxylysine and the degree of severity of the osteoarthritic lesion (except in far-advanced lesions). Similarly, there was no correlation in levels of these components in tissues from the normal vs. osteoarthritic group. The similarity of the values of the ratio hydroxylysine/hydroxyproline in osteoarthritic tissue compared with normal, and the lack of variation in these with increasing severity of the disease process argues against the possibility that osteoarthritis is associated with a major shift in the synthesis of type II collagen to type I. [3H]Proline incorporation into osteoarthritic cartilage was increased fourfold as compared to normal cartilage and varied with advancing histological-histochemical grade. Measurement of the specific activity of insolubilized hydroxyproline-containing material of the cartilage matrix, as an index of the turnover of collagen, showed a sixfold increase in osteoarthritic cartilage which also varied with grade. These data suggest that collagen synthesis in these tissues is substantially greater than in nonosteoarthritic tissues and varies directly with the severity of the disease process up to a point and then varies inversely as the lesion becomes more severe. 相似文献
97.
Resection of a large postinfarctional ventricular aneurysm led to termination of intractable angina pectoris in one patient. The patient has been followed for 5 years and remains angina-free, even though aorto-coronary bypass surgery was not performed in this patient. The patient presented no evidence of congestive heart failure, arterial emboli, or cardiac arrhythmia before or after the surgery. Intractable angina alone in the absence of congestive heart failure, systemic embolism, and refractory ventricular tachyarrhythmia may constitute another indication for ventricular aneurysmectomy with or without concomitant aorto-coronary bypass surgery. 相似文献
98.
D Fink-Bennett GF Conway RJ Reiner HJ Dworkin AA Cacciarelli 《Canadian Metallurgical Quarterly》1977,118(5):888-889
An abnormal accumulation of radionuclide was identified within the right juxtadiaphragmatic and juxtahepatic spaces during gallium-67 citrate scintigraphy in a post-pyeloplasty patient. Its mode of presentation, the recent pyeloplasty and the known biologic distribution of gallium suggested that it represented gallium-67 concentration within a postoperatively created urinoma. Diagnosis was confirmed by excretory urography and laparotomy. 相似文献
99.
HJ Maurer 《Canadian Metallurgical Quarterly》1977,87(3):257-267
The preparation of 125I-labelled tracer for digoxin radioimmunoassay (125I monoiodinated 3-succinyl digoxigenin-1-tyrosine) is described, and its performance in radioimmunoassay of plasma samples is compared with that obtained with tritiated digoxin. The accuracy levels were assessed through the evaluation of different potential sources of systematic errors, such as interference from digoxin-related molecules and plasma proteins and methodological artefacts possibly associated with the immunocomplex instability, and through a series of checks including the recovery and parallelism tests and the correspondence of results obtained with the two tracers. The slope and the repeatability with time of the calibration curves and the spread of replicate estimates were taken into consideration to assess the assay precision. An essential equivalence in terms of reliability of measurement was proved for the two methodological variants, so that practical aspects and economic factors remain the main criteria to evaluate the relative merits: from this point of view, the advantages of using 125I-labelled tracer, as an alternative to tritiated digoxin, are discussed. 相似文献
100.
Kok Ming Goh Soo San Low Kar Lin Nyam 《International Journal of Food Science & Technology》2021,56(12):6649-6655
Roselle seed oil (RSO) is an underutilised seed oil, which is having beneficial properties to humans. Microencapsulation of vegetables and seed oil is an alternative to preserve these properties and deliver them to the human diet. In this study, microencapsulation of RSO was performed using co-extrusion technology and 1.5% w/w sodium alginate solution with 1.5% w/w high methoxyl pectin as the wall materials. Results showed that the microencapsulation efficiency was high (95.68 ± 1.95%) and the microencapsulation indeed preserved the content of unsaturated fatty acids, phytosterols, and tocopherols. During an accelerated storage condition at 65 °C for 24 days, most of these properties remained high for the first six storage days, including tocopherol which preserved high γ-tocopherol. Worth noting that the microencapsulated RSO (MRSO) was particularly effective in preserving the total unsaturated fatty acids (especially C18:1 and C18:2), even during the 24th day of storage. The total unsaturated fatty acids retained by MRSO were significantly (P < 0.05) higher (70 ± 0.4%) than the RSO (65.6 ± 1.6%). In short, microencapsulation was effective in preserving the RSO properties. 相似文献