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101.
Urolithiasis is a common diagnostic and therapeutic problem in small-animal veterinary practice. The traditional diagnostic approach usually consists of clinical, radiological and ultrasonographic examination of the patient. The main diagnostic material is still urine sediment, ignoring the fact that presence of crystalluria is not always of pathological significance. In order to establish the most effective therapeutic and preventative strategies, especially in the case of multicomponent stone, it is crucial to define the exact elemental composition of the given stone including crystallization nidus chemical contents. In the course of the research, the usefulness of scanning electron microscopy combined with X-ray-dispersive spectrometry in analysis of canine mixed and compound stones was investigated. The obtained results indicated that the tested method allows one to trace the dynamics of the crystallization process, including crystallization nucleus detection, and concurrently and quantitatively assess the elemental composition of the given urinary concrement. Moreover, the conducted research showed epidemiological data of urolithiasis occurrence in a population of dogs coming from the southern part of Poland.  相似文献   
102.
The content of macroelements P, Mg and Ca and microelements Mn, Fe, Zn and Cu was determined in 10 commercially sold oat products made by different technological processes (dehulling, instantinising, extrusion, flaking). Phosphorus was the most prevalent of the macroelements (from 240.8 ± 2.2 to 845.5 ± 8.1 mg per 100 g), followed by magnesium (from 73.2 ± 0.7 to 271.9 ± 2.7 mg per 100 g) and calcium (from 30.69 ± 0.01 to 112.7 ± 0.3 mg per 100 g). The Ca/P ratio ranged from 1:5.3 in crushed oat to 1:8.2 in oat flakes. Regarding the microelements, manganese was present at the highest concentrations (from 2.62 ± 0.02 to 8.69 ± 0.01 mg per 100 g). The content of iron was similar and that of zinc not much lower, whereas the amount of copper was considerably smaller (from 0.23 ± 0.002 to 0.59 ± 0.002 mg per 100 g). The highest concentrations of mineral elements were found in instant oat bran flakes and the lowest in extruded oat and corn crisps containing 50% corn grouts. Samples of the products analysed were subjected to in vitro enzymatic digestion, simulating the digestive process occurring in the human alimentary tract. The supernatants thus obtained were analysed for their content of the previously determined mineral components; the percentage of minerals released from the products was calculated. The following sequence of mineral components released was observed: Cu (57.2–95.6%) > P (39.7–60.9%) > Ca (18.2–39.5%) > Mg (16.4–39.8%) > Mn (6.4–24.7%) > Fe (6.5–29%) > Zn (11–17.2%). The Ca/P ratio in the supernatant worsened from 1:8.2 in crushed oat to 1:23.3 in extruded oat and corn crisps. Crushed oat released the highest amounts of mineral elements during enzymatic hydrolysis, with oat grouts coming second. As regards the other products, it is difficult to establish their relative sequence in the release of minerals. © 2002 Society of Chemical Industry  相似文献   
103.
Separation and analyses of sound Cox's Orange Pippin apples and those with disorders, after storage for 18 weeks at 3.3°C, revealed that sound apples had the lowest, apples rotted by Gloeosporium spp slightly higher, apples with bitter pit higher, and apples affected by breakdown even higher proportions of calcium in the residue after extraction with distilled water, although total concentrations of calcium in these samples were in the reverse order. Lower proportions of calcium, magnesium and potassium were extracted by 75% ethanol from fruit with breakdown than from sound apples, and similarly lower proportions of magnesium, and magnesium and potassium were extracted by water from apples with bitter pit and breakdown, respectively. Proportions of phosphorus extracted by either solvent were not obviously related to disorders. The high concentration of magnesium in pitted tissue, in relation to that in adjacent sound tissue, was evenly divided between the fractions soluble and insoluble in water, but that of calcium was mainly in the insoluble fraction.  相似文献   
104.
Hyperbranched alkyd-silicone nanoresins (ASiHBRs) with high solid content were synthesized by etherification reaction between a hyperbranched alkyd resin (HABR) and Z-6018 silicone. ASiHBRs were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) and several other techniques. NMR spectra show the presence of aromatic rings, -Si-O and -C-O; grafting was successful. The molar masses of ASiHBRs determined by GPC are higher than that of HABR. The hydroxyl values decrease with increasing silicone content. ASiHBRs have low viscosities what allows easier film formation. Hydrodynamic dimensions, refractive indices, glass transition temperatures, gloss and hardness of ASiHBRs increase with increasing silicone contents. Low contents of volatile organic compounds provide more environmentally friendly coatings.  相似文献   
105.
This article presents the results from research related to graphene functionality based on the production of spatial structures provided for the reversible storage of hydrogen. The functionality process was conducted during graphene synthesis onto a liquid metallic support, on a single level, using SiC nanoparticles. Within the scope of research it was proved that heterogenic growth of the domains of polycrystalline graphene onto the SiC nanoparticles is possible. These nanoparticles are in-built into the graphene structure constituting the pillars of the spatial structure. Material produced in such a way constitutes the foundation for creating a spatial 3D structure (through the rolling operation), called GraphRoll, for the reversible storage of hydrogen in order to conduct its sorption and de-sorption. So, independently of the theoretical configuration, deviations or a possible exception from the 2D configuration on the silicon carbide/graphene were discussed. These differences resulted from the difference between the crystallographic structures of the analyzed forms as well as the structure determined to decrease tensions within the structure.  相似文献   
106.
Bond strength, physical, and mechanical properties of lightweight PC were investigated with inclusion of pumice lightweight aggregate in maximum size of 12 mm. As binder material, epoxy resin‐based polymer was used with its hardener. The binder to aggregate ratio was 30% by weight. In addition, steel fibers were added to lightweight PC mixtures in ratio of 0, 0.5, and 1%. After lightweight PC mixture was prepared, it was poured in the molds with different type of steel‐bars in size of 100 × 100 × 100 mm3. The steel‐bars centered in the cubic molds, and they were in size of Ø12, Ø14, and Ø16. The specimens were cured at 60°C for 2 h. On the hardened polymer lightweight concrete (PLC), pull‐out test for bond strength and compressive strength tests were performed. Moreover, ultrasonic pulse velocity, water absorption by weight, specific porosity, and density experiments were carried out. The relation between physical and mechanical properties showed that PLCs become more durable when using ratio of steel fibers. POLYM. COMPOS., 34:2125–2132, 2013. © 2013 Society of Plastics Engineers  相似文献   
107.
Transparent glass-ceramics were successfully prepared during controlled heat treatment of lead borate glasses. The PbF2 particles were dispersed into a borate glass matrix which was evidenced by X-ray diffraction analysis. The phase identification revealed that crystalline peaks can be related to the orthorhombic PbF2 phase. Green up-conversion luminescence due to the 4S3/24I15/2 transition of Er3+ ions was registered. In comparison to the precursor glass the luminescence intensity was considerably higher, whereas the luminescence linewidth slightly decreased in the studied oxyfluoride transparent glass-ceramics. It indicated that a part of the trivalent erbium was incorporated into the PbF2 crystalline phase.  相似文献   
108.
Tests were performed on two different four‐ball testers. The first was used to determine antiwear (AW) and extreme pressure (EP) properties at sliding friction. The second was used to assess the surface fatigue (pitting) life at rolling movement. Lubricating oils of various chemical compositions were tested. A base mineral oil was blended with two different commercial packages of lubricating additives of AW and EP types. The AW additives contained ZDDP and were blended with the base oil at 0.2 and 3wt %. The EP additives were organic compounds of sulphur and phosphorus, blended with the base oil at 1 and 10wt %. It is shown that AW additives not only improve AW and EP properties but also — at 0.2% — are beneficial for the fatigue life. An increase in the concentration of AW additives leads to an improvement of AW and EP properties but — for one of the packages — reduces the fatigue life. EP additives — at 1% concentration — significantly improve EP properties, and to a lesser extent AW properties. Such a concentration of EP additives has no influence on the fatigue life. An increase in the concentration of EP additives leads to a further improvement of EP and AW properties. However, this is accompanied by a considerable decrease in the fatigue life. By using a scanning electron microscope and energy dispersive spectrometer for analysis of the worn surface, mechanisms of action of various lubricating additives under different friction conditions were identified. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
109.
The Eu3+:KGdF4 powders with average crystallite size of 20 and 25 nm have been obtained from solution by co-precipitation method. Morphology of the as-received powders was examined by XRD and TEM methods. Behaviour of these two powdered batches, characterised by different size of nanocrystallites, versus thermal treatment has been studied by X-ray powder diffraction, thermogravimetric, infrared spectroscopy and emission spectroscopy methods. The phase transitions between low-temperature cubic, orthorhombic, trigonal and high-temperature cubic modifications of KGdF4 were detected for both samples heated in 300–790 °C temperature range. Abundance of the particular polymorphic form observed at given temperature differs considerably for samples of different initial crystallite size. Besides, significant differences in number of lattice defects, water contents and emission properties were observed for these two samples. The properties of material precipitated from solution are also compared with structural and optical properties of the Eu3+:KGdF4 fluoride synthesised by a solid-state reaction.  相似文献   
110.
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