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11.
The pure dye content of FD&C yellow lake #5 and FD&C red lake #40 was found to be inversely related to the point of zero charge. The effect of the adsorbed anionic dye on the zeta potential of aqueous suspensions of FD&C yellow lake #5 at pH 5 was demonstrated.  相似文献   
12.
The effect of pH on the bleeding of FD&C yellow No. 5 aluminum lake and FD&C red No. 40 aluminum lake was investigated. The pH-bleeding profiles corresponded to the pH-solubility profile of aluminum hydroxide. The similarity of the bleeding profiles of both lake dyes and the pH-solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydroxide substrate. This dissolution is related to the properties of the substrate rather than to the structure of adsorbed dye.  相似文献   
13.
14.
A pyrometallurgical method for partial separation of hafnium from zirconium has been investigated. The method involves continuous reaction between a flowing gas mixture of zirconium tetrachloride and hafnium tetrachloride with solid sodium chloride in a packed bed reactor. The solid-vapour reaction enriches the vapour phase with respect to zirconium tetrachloride. This may be attributed to a more favourable reaction for hafnium tetrachloride. The influence of a number of parameters, e.g. temperature, gas flow rate, particle size and bed length, has been studied. Decreases in flow rate and particle size and increase in bed length are found to favour separation, while temperature has little effect. A simple equation has been derived to explain the experimental observations.  相似文献   
15.
Reductive iodonio-Claisen rearrangement (RICR) involving λ3-iodanes and allyl or substituted-allyl silanes in fluoroalcohols, such as 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and 2,2,2-trifluoroethanol (TFE), was studied for the synthesis of complex ortho-allyl or substituted-allyl iodoarenes. In comparison to the previously reported condition involving boron trifluoride diethyl etherate, the RICR mediated by fluoroalcohols was found to proceed more effectively. The resulting complex ortho-allyl iodoarenes are useful synthetic intermediates and can be readily converted to various heterocyclic compounds.  相似文献   
16.
Highly porous Poly (ε-caprolactone; PCL) microfibers were successfully fabricated by collecting the fibers into a water bath during electrospinning. The morphology of the fibers collected with and without the water bath was investigated. We observed that altering the pH of the water bath affected both the fiber diameter and the size of pores on the fibers. Acidic or basic condition was found to be more favorable than neutral conditions for the formation of well-porous fibers. The morphology and pore size of the microfibers were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The average diameter of the fibers and the pore size on the surface of the microfibers were found to be 12–14.5 and 0.3–0.7 μm, respectively. The crystallinity and thermal properties of the PCL mats were investigated by DSC. This highly porous nature of the microfibers makes PCL less crystalline and increases the surface to volume ratio of the mat. Therefore, the PCL mat obtained by water bath electrospinning may be more effective for tissue scaffolds and drug delivery than the mat obtained without water bath.  相似文献   
17.
There is a known negative correlation between soybean [Glycine max [L.] Merr.] seed protein and oil and between protein and yield. This challenges breeders to increase protein concentration while maintaining oil concentration and yield. The objective of this study was to determine if marker-assisted selection for the Danbaekkong (Dan) protein allele on chromosome 20 influences seed yield and quality traits in near isogenic genetic backgrounds. A population of 24 F7-derived near isogenic lines (NIL) of soybean was created by crossing G03-3101 × LD00-2817P. The 24 NIL consisted of 12 wild type (WT) and 12 mutant Dan type lines. These NIL were grown in 2016 and 2017 field seasons in replicated field trials in nine environments, with six in Tennessee and one each in Arkansas, Missouri, and North Carolina. There were significant (P < 0.05) differences in yield, protein, and oil concentrations between the two experimental groups. The Dan group had significantly (P < 0.05) more protein (421 g kg−1), less oil (192 g kg−1), and lower yield (3143 kg ha−1) than the WT group (390 g kg−1 protein, 210 g kg−1 oil, and 3281 kg ha−1 yield). These results support previous research and corroborate the overall negative genetic correlations. Nevertheless, seed yield of several higher-protein Dan lines MC-13, MC-16, MC-19, and MC-24 exceeded seed yield of lower protein WT lines MC-2, MC-3, MC-6, and MC-10. The higher-protein lines represent genetic resources for reducing the negative correlation between protein and yield.  相似文献   
18.
This report describes five cases of osteofibrous dysplasia-like adamantinoma of the tibia in young patients ranging from ages 4 1/2 to 14 years. Radiologically and histologically, these cases were indistinguishable from osteofibrous dysplasia of bone, and no epithelial cells were recognized on routine staining. However, epithelial differentiation was seen in the form of scattered keratin-positive cells in all five cases, and tonofilaments in four cases. The patients were treated by curettage, and three had recurrences. Follow-up showed no progression to classic adamantinoma. Osteofibrous dysplasia-like adamantinoma is a special histological type of adamantinoma that affects children and adolescents. It differs from classic adamantinoma in that it lacks conspicuous nests and masses of epithelial cells, and the prognosis after conservative treatment is generally good. Recent publications suggest that osteofibrous dysplasia-like adamantinoma is a precursor of classic adamantinoma. In a comparative study of three cases of classic adamantinoma, we found, in the fibroblastic stroma of the tumors, spindle epithelial cells that were indistinguishable from the epithelial cells of osteofibrous dysplasia-like adamantinoma. This finding suggests that there is an overlap between these conditions. Four additional cases of osteofibrous dysplasia of the tibia from our files lacked epithelial differentiation. It is most likely that osteofibrous dysplasia is part of the morphologic spectrum of adamantinoma.  相似文献   
19.
Structure of an antioxidant from fermented soybeans (tempeh)   总被引:7,自引:0,他引:7  
In an exhaustive investigation of the antioxidative properties of tempeh constituents, the substance at R f 0.58 (cyclohexane/ethyl ether, 9:1) was isolated and purified. Until now, only the ultraviolet and fluorescence data of the substance were known, and the presence of an OH group was indicated. In the present paper, the structure of the substance at R f 0.58 was elucidated by the application of spectroscopic methods and found to be 5-(δ-tocopheroxy)-δ-tocopherol. That previous researchers did not confirm antioxidant activity in tempeh oil has been related to the way the tempeh oil was prepared. Previous suggestions regarding the substance at R f 0.58 as being one of the main tempeh antioxidants could not be proved. The antioxidative effect of tempeh oil seems to be the result of a synergistic effect of tocopherols (present in the soybeans) and amino acids (liberated during the fermentation process with Rhizopus oligosporus).  相似文献   
20.
Biodiesel, defined as mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats, is an attractive renewable fuel alternative to conventional petroleum diesel fuel. Biodiesel produced from oils such as cottonseed oil and poultry fats suffer from extremely poor cold flow properties because of their high saturated fatty acid content. In the current study, Ethyl Levulinate (ethyl 4-oxopentanoate) was investigated as a novel, bio-based cold flow improver for use in biodiesel fuels. The cloud (CP), pour (PP), and cold filter plugging points (CFPP) of biodiesel fuels prepared from cottonseed oil and poultry fat were improved upon addition of ethyl levulinate at 2.5, 5.0, 10.0, and 20.0% (vol). Reductions of 4-5 °C in CP, 3-4 °C in PP and 3 °C in CFPP were observed at 20 vol % ethyl levulinate. The influence of ethyl levulinate on acid value, induction period, kinematic viscosity and flash point was determined. The kinematic viscosities and flash points decreased with increasing content of ethyl levulinate. All samples (≤15 vol % ethyl levulinate) satisfied the ASTM D6751 limit with respect to flash point, but none of the 20 vol % blends were acceptable when compared to the higher EN 14214 specification. Acid value and oxidative stability were essentially unchanged upon addition of ethyl levulinate. In summary, ethyl levulinate appears acceptable as a diluent for biodiesel fuels with high saturated fatty acid content.  相似文献   
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