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101.
Zoltán Hegedűs Jenő Gubicza Megumi Kawasaki Nguyen Q. Chinh Károly Süvegh Zsolt Fogarassy Terence G. Langdon 《Journal of Materials Science》2013,48(4):1675-1684
The high temperature thermal stability of the ultrafine-grained (UFG) microstructures in low stacking-fault-energy silver was studied by differential scanning calorimetry (DSC). The UFG microstructures in two samples having purity levels of 99.995 and 99.99 at.% were achieved by four passes of equal-channel angular pressing at room temperature. The defect structure was studied by electron microscopy, X-ray line profile analysis, and positron annihilation spectroscopy before and after the exothermic DSC peak related to recovery and recrystallization. The heat released in the DSC peak was correlated to the change of defect structure during annealing. It was found for both compositions that a considerable fraction of stored energy (~15–20 %) was retained in the samples even after the DSC peak due to the remaining UFG regions and a large density of small dislocation loops in the recrystallized volumes. The larger impurity level in Ag yielded a higher temperature of recrystallization and a lower released heat. The latter observation is explained by the much lower vacancy concentration before the DSC peak which is attributed to the segregation of dopants at grain boundaries resulting in a smaller free volume in the interfaces. 相似文献
102.
Tatsuhiko Furuhashi Masao Moroi Nobuhiko Joki Hiroki Hase Megumi Minakawa Hirofumi Masai Taeko Kunimasa Hiroshi Fukuda Kaoru Sugi 《Hemodialysis international. International Symposium on Home Hemodialysis》2013,17(4):568-575
Cardiovascular prognosis in patients under normal stress myocardial perfusion images (MPI) is generally excellent. However, this is not true for patients with chronic kidney disease (CKD) treated by hemodialysis. This study evaluated prognostic factors of adverse cardiovascular events in hemodialysis patients in whom stress MPI was performed. Pharmacological stress MPI was performed in 88 hemodialysis patients, and we retrospectively followed‐up for 26 months. Cardiovascular events included cardiac death, nonfatal myocardial infarction, and unstable angina. Cardiovascular events occurred in 16 patients (18%). Univariate Cox regression analysis revealed that peripheral artery disease (PAD) and parameters of stress MPI were significant predictors of cardiovascular events. Multivariate Cox regression analysis revealed that only PAD (hazard ratio = 6.54; P = 0.002), and abnormal stress MPI (hazard ratio = 8.26; P = 0.008) were independent and significant predictors of cardiovascular events. Kaplan–Meier analysis showed better prognosis in patients with normal stress MPI than in patients with abnormal stress MPI (P < 0.001, log–rank test). However, in patients with normal stress MPI, cardiovascular events occurred in 10 of the 76 patients (13%). Among patients with normal stress MPI, Kaplan–Meier analysis showed that patients with no PAD had better prognosis than patients with PAD (P = 0.001, log–rank test). In hemodialysis patients, both PAD and stress MPI were powerful cardiovascular predictors. Normal stress MPI alone cannot guarantee good prognosis in terms of cardiovascular events. Consideration of PAD may improve the predictive value of stress MPI in some patients. 相似文献
103.
104.
Masaki Okuda Takeshi Akao Masanori Sumihiro Megumi Mizuno Nami Goto‐Yamamoto 《Journal of the Institute of Brewing》2016,122(3):473-479
The potential contamination with radionuclides released by the Fukushima Daiichi Nuclear Power Plant Accident following the great east Japan earthquake and tsunami in March 2011 of agricultural products and processed foods derived from them is a matter of on‐going concern. The stable 133Cs is a useful indicator for predicting the behaviour of radioactive Cs, and potassium (K) is a congener of Cs. In this study, the distribution of 133Cs and K in Ume fruit, and the transfer of 133Cs and K from Ume fruit to Ume liqueur, were investigated. The concentrations of 133Cs and K in Ume fruit were highest in the skin, followed by the kernel or flesh, and then the pit. About 80% of 133Cs and K in all Ume fruits was distributed in the flesh. The transfer ratios of 133Cs and K from Ume fruit to Ume liqueur were similar among all cultivars after 3 months, and they were similar to those of organic acids. The food retention factor (Fr = weight of 133Cs in Ume liqueur/weight of 133Cs in Ume fruit) was ca. 0.8, and the processing factor (Pf = concentration of 133Cs in Ume liqueur/concentration of 133Cs in Ume fruit) was 0.2–0.3. From the present study, the radioactivity of Ume liqueur would be below the legal limit if made using Ume fruits within the legal limit, thereby confirming the safety of Ume liqueur. Copyright © 2016 The Institute of Brewing & Distilling 相似文献
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106.
Experiments were conducted to evaluate the microstructural evolution occurring in the Zn–22% Al eutectoid alloy when processed by high-pressure torsion (HPT) over a range of experimental conditions. Processing by HPT reduces the grain size and at the edges of the disks it produces agglomerates of Zn-rich and Al-rich grains lying in bands delineating the torsional straining. Unlike most metals processed by HPT, the measured hardness values are lower than in the initial annealed condition. This is due to a significant reduction during processing in the distribution of Zn precipitates which are visible within the Al-rich grains in the annealed condition. It is shown that all of the hardness measurements are mutually consistent when plotted against the calculated equivalent strain. 相似文献
107.
Emission of inorganic particulate matter (PM) from the incineration of dewatered sewage sludge has been investigated in a novel ash melting furnace. The sludge containing 79 wt% water was incinerated in an oxygen-enriched atmosphere at the primary temperature of 1400 °C, and its unburned volatile was combusted at 1100 °C in a secondary combustion chamber. A 13-stage low-pressure-impactor and the conventional impinger methods were employed for PM sampling at the outlet of the secondary combustion chamber. The results indicate that, PM is dominated by volatile and semi-volatile elements including Br, Cl, P, S, Na, K, Zn, As, Cu, Mn and Ni. Less refractory elements were found. PM has two major fractions: <0.22 and ?0.22 μm. Their chemical forms as well as water solubility are different between two fractions. The majority of Br, nearly half of Cl, and 40% of S and P are present in the small fraction. They are mostly water-soluble due to the association with alkali elements and heavy metals. The water-insoluble calcium sulfate and calcium/iron phosphate were, however, found in the large fraction of PM. Regarding the cations, the water solubilities of Na, K, Mn and Ni are close to their proportions partitioned into the small fraction of PM, since their water-soluble species were preferentially formed in this fraction. A relatively weak correlation for Al, Ca and As, while no such a correlation were found for Cu, Zn and Fe, due to the complex compounds formed for them. 相似文献
108.
Methyltrimethoxysilane (MTMS)-coupled mica substrate is reportedly suitable for fixing and straightening of DNA, but 3-aminopropyltriethoxysilane (APTES)-coupled mica substrate has been found less suitable. On MTMS-coupled mica substrate, the straightness of fixed DNA was sufficient, and the adsorption of contaminants was not observed using fluorescence microscopy and atomic force microscopy. For the APTES-coupled mica substrate, however, aggregated or curved DNA and adsorption of contaminants were observed. To clarify the surface factors that are responsible for this suitability, we analyzed the surface free energies of these substrates using the extended Fowkes theory. In each of the surface free energy components, the dispersion force component in the MTMS-coupled mica substrate was lower than that in the APTES-coupled mica substrate. The ratio of the polar force component on the MTMS-coupled mica substrate was about one order of magnitude on the APTES-coupled mica substrate. In addition, the ratio of the hydrogen-bonding force component for the MTMS-coupled mica substrate was about two times larger than that of the APTES-coupled mica substrate. These results suggest that the polar force and hydrogen-bonding force components are important factors for the fixation and straightening of DNA and that the dispersion force components influence the production and adsorption of contaminants. 相似文献
109.
Evolution of microhardness and microstructure in a cast Al–7 % Si alloy during high-pressure torsion
Tarang Mungole Naresh Nadammal Kunal Dawra Praveen Kumar Megumi Kawasaki Terence G. Langdon 《Journal of Materials Science》2013,48(13):4671-4680
Disks of a cast Al–7 % Si alloy were processed through high-pressure torsion (HPT) for 1/4, 1/2, 1, 5, and 10 revolutions under a pressure of 6.0 GPa and at temperatures of 298 and 445 K. The hardness of the samples after processing was significantly higher than in the cast sample, and the hardness profiles across the samples became more uniform with increasing numbers of turns. Processing at higher temperature gave lower hardness values. Experiments were conducted to examine the effects of HPT processing on various microstructural aspects of the cast Al–7 % Si alloy such as the grain size, the Taylor factor, and the fraction of high-angle grain boundaries. The results demonstrate that there is a correlation between trends in the microhardness values and the observed microstructures. 相似文献
110.
Nakao M Maeda K Haraguchi R Kurosaki K Kagisaki K Shiraishi I Nakazawa K Minato K 《IEEE transactions on information technology in biomedicine》2012,16(1):70-79
This paper proposes a 3-D cardiovascular modeling system based on neonatal echocardiographic images. With the system, medical doctors can interactively construct patient-specific cardiovascular models, and share the complex topology and the shape information. For the construction of cardiovascular models with a variety of congenital heart diseases, we propose a set of algorithms and interface that enable editing of the topology and shape of the 3-D models. In order to facilitate interactivity, the centerline and radius of the vessels are used to edit the surface of the heart vessels. This forms a skeleton where the centerlines of blood vessel serve as the nodes and edges, while the radius of the blood vessel is given as an attribute value to each node. Moreover, parent-child relationships are given to each skeleton. They are expressed as the directed acyclic graph, where the skeletons are viewed as graph nodes and the connecting points are graph edges. The cardiovascular models generated from some patient data confirmed that the developed technique is capable of constructing cardiovascular disease models in a tolerable timeframe. It is successful in representing the important structures of the patient-specific heart vessels for better understanding in preoperative planning and electric medical recording of the congenital heart disease. 相似文献