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41.
The authors confirm the fundamental role of the pulse-echo technique in the study of pelvic masses; they outline the usefulness of the ultrasonography in the early presumptive diagnosis of the possible neoplastic alterations of such masses. The authors present five clinical cases in which the use of the pulse-echo technique has allowed to locate, in spite of a scanty clinical symptomatology, the presence of pathologies requiring a rapid surgical resolution.  相似文献   
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43.
Iron, calcium, zinc and phytic acid contents in vegetable blends from wheat, corn and soy were determined. Wheat and corn substitution with soy in compound products, gave an important amount of iron and calcium to the blends, while the initial content of phytic acid in wheat and corn was not significantly modified. Dehulling and enzymatic inactivation technological processes denoted a rather low influence on soy mineral content. In a similar way, the extrusion-cooking process did not affect appreciably the soluble iron content in blends. Soy incorporation greatly decreased in vitro iron availability in vegetable blends, while fortification with mineral blends slightly interfered, decreasing iron availability with regard to iron-fortified vegetable blends.  相似文献   
44.
Since dye-sensitized solar cells (DSSCs) appeared as a promising inexpensive alternative to the traditional silicon-based solar cells, DSSCs have attracted a considerable amount of experimental and theoretical interest. In contrast with silicon-based solar cells, DSSCs use different components for the light-harvesting and transport functions, which allow researchers to fine-tune each material and, under ideal conditions, to optimize their overall performance in assembled devices. Because of the variety of elementary components present in these cells and their multiple possible combinations, this task presents experimental challenges. The photoconversion efficiencies obtained up to this point are still low, despite the significant experimental efforts spent in their optimization. The development of a low-cost and efficient computational protocol that could qualitatively (or even quantitatively) identify the promising semiconductors, dyes, and electrolytes, as well as their assembly, could save substantial experimental time and resources. In this Account, we describe our computational approach that allows us to understand and predict the different elementary mechanisms involved in DSSC working principles. We use this computational framework to propose an in silico route for the ab initio design of these materials. Our approach relies on a unique density functional theory (DFT) based model, which allows for an accurate and balanced treatment of electronic and spectroscopic properties in different phases (such as gas, solution, or interfaces) and avoids or minimizes spurious computational effects. Using this tool, we reproduced and predicted the properties of the isolated components of the DSSC assemblies. We accessed the microscopic measurable characteristics of the cells such as the short circuit current (J(sc)) or the open circuit voltage (V(oc)), which define the overall photoconversion efficiency of the cell. The absence of empirical or material-related parameters in our approach should allow for its wide application to the optimization of existing devices or the design of new ones.  相似文献   
45.
Aryl α‐diimine derivatives have been used, for the first time, as efficient new ligands for the palladium‐catalyzed oxidative bis‐alkoxycarbonylation reaction of olefins. The most active catalyst was formed in situ from bis(9‐anthryl)‐2,3‐dimethyl‐1,4‐diazabutadiene and palladium(II) trifluoroacetate [Pd(TFA)2]. This catalytic system was able to selectively convert olefins into succinic diesters in good yields (up to 97%) and low catalyst loading (up to 0.5 mol%) under mild reaction conditions [4 bar of carbon monoxide (CO) at 20 °C in the presence of p‐toluenesulphonic acid as additive and p‐benzoquinone as oxidant]. The optimized conditions could be successfully applied to both aromatic and aliphatic olefins, by using methanol, benzyl alcohol or isopropyl alcohol as nucleophiles.

  相似文献   

46.
A new conduit made with a bioabsorbable copolymer, poly (L-lactide-co-6-caprolactone), was evaluated in an animal model as a guide for nerve regeneration. The conduit had an inner diameter of 1.3 mm and a wall thickness of 175 microns. Segments of length 1.2 cm were interposed between the proximal and distal stumps of transected ischiatic nerves in Wistar rats, bridging a nerve gap of 1 cm. All of the procedure was performed under general anaesthesia using microsurgical techniques. Controls were performed at 1, 3 and 6 months and it was demonstrated that the conduit was still undamaged after 30 d. Progressive signs of degradation appeared at 90 and 180 d. Nerve regeneration in the lumen was effective as confirmed by histological and electron microscopical investigations. These preliminary results emphasize the interesting properties of the conduit with regard to the achievement of a neural prosthesis.  相似文献   
47.
In 971 patients with squamous cell carcinoma of supraglottic larynx several clinical and physical prognostic factors were evaluated. There were 55% of patients with advanced primary tumours and 71% of patients with no regional neck metastases. All patients were irradiated radically using external megavoltage beam. The total dose was in range 60-70 Gy for 95% of patients. The 3-year local control rate and 3-year overall in whole group were 41% and 50% respectively. Clinical stage, haemoglobin level at the end of treatment, overall treatment time, sex and total dose were estimated as an independent and important prognostic factors for the outcome in radiotherapy of supraglottic larynx cancer.  相似文献   
48.
Osteosarcoma (OS) is the most common primary bone tumor mainly occurring in young adults and derived from primitive bone-forming mesenchyme. OS develops in an intricate tumor microenvironment (TME) where cellular function regulated by microRNAs (miRNAs) may affect communication between OS cells and the surrounding TME. Therefore, miRNAs are considered potential therapeutic targets in cancer and one of the goals of research is to accurately define a specific signature of a miRNAs, which could reflect the phenotype of a particular tumor, such as OS. Through NGS approach, we previously found a specific molecular profile of miRNAs in OS and discovered 8 novel miRNAs. Among these, we deepen our knowledge on the fifth candidate renamed now miR-CT3. MiR-CT3 expression was low in OS cells when compared with human primary osteoblasts and healthy bone. Through TargetScan, VEGF-A was predicted as a potential biological target of miR-CT3 and luciferase assay confirmed it. We showed that enforced expression of miR-CT3 in two OS cell lines, SAOS-2 and MG-63, reduced expression of VEGF-A mRNA and protein, inhibiting tumor angiogenesis. Enforced expression of miR-CT3 also reduced OS cell migration and invasion as confirmed by soft agar colony formation assay. Interestingly, we found that miR-CT3 behaves inducing the activation of p38 MAP kinase pathway and modulating the epithelial-mesenchymal transition (EMT) proteins, in particular reducing Vimentin expression. Overall, our study highlights the novel role of miR-CT3 in regulating tumor angiogenesis and progression in OS cells, linking also to the modulation of EMT proteins.  相似文献   
49.
An exception handling system for a language defined as a CSP/OCCAM-based extension of C++ is presented. This language is part of a project we are developing which aims at constructing a high level programming environment for transputer-based multiprocessors. In this proposal, the replacement model of Yemini and Berry (1985) is considered, parallelism and exception handling are closely combined, making process pre-emption available but raising problems of atomicity and non-determinism. These problems are discussed, a solution is suggested and an efficient implementation we have carried out is presented.  相似文献   
50.
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