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71.
Data is key resource in the modern world. Big data has become a popular term which is used to describe the exponential growth and availability of data. In practice, the growing demand for large-scale data processing and data analysis applications spurred the development of novel solutions from both the industry and academia. For a decade, the MapReduce framework, and its open source realization, Hadoop, has emerged as a highly successful framework that has created a lot of momentum in both the research and industrial communities such that it has become the defacto standard of big data processing platforms. However, in recent years, academia and industry have started to recognize the limitations of the Hadoop framework in several application domains and big data processing scenarios such as large scale processing of structured data, graph data and streaming data. Thus, we have witnessed an unprecedented interest to tackle these challenges with new solutions which constituted a new wave of mostly domain-specific, optimized big data processing platforms. In this article, we refer to this new wave of systems as Big Data 2.0 processing systems. To better understand the latest ongoing developments in the world of big data processing systems, we provide a taxonomy and detailed analysis of the state-of-the-art in this domain. In addition, we identify a set of the current open research challenges and discuss some promising directions for future research.  相似文献   
72.
Water deficit causes substantial yield losses that climate change is going to make even more problematic. Sustainable agricultural practices are increasingly developed to improve plant tolerance to abiotic stresses. One innovative solution amongst others is the integration of plant biostimulants in agriculture. In this work, we investigate for the first time the effects of the biostimulant –Leafamine®–a protein hydrolysate on greenhouse lettuce (Lactuca sativa L.) grown under well-watered and water-deficit conditions. We examined the physiological and metabolomic water deficit responses of lettuce treated with Leafamine® (0.585 g/pot) or not. Root application of Leafamine® increased the shoot fresh biomass of both well-watered (+40%) and deficit-irrigated (+20%) lettuce plants because the projected leaf area increased. Our results also indicate that Leafamine® application could adjust the nitrogen metabolism by enhancing the total nitrogen content, amino acid (proline) contents and the total protein level in lettuce leaves, irrespective of the water condition. Osmolytes such as soluble sugars and polyols, also increased in Leafamine®-treated lettuce. Our findings suggest that the protective effect of Leafamine is a widespread change in plant metabolism and could involve ABA, putrescine and raffinose.  相似文献   
73.
Two novel tetraester- and PAMAM-branched perylene diimides were synthesized and configured as “fluorophore-spacer-receptor” systems based on photoinduced electron transfer. Due to their long alkylester and alkylamine terminal groups the examined compounds were well soluble in organic solvents. Photophysical characteristics of the dyes were investigated in DMF and water/DMF (1:1, v/v) solution. The ability of the synthesized perylene diimides to detect cations was evaluated by the changes in their fluorescence intensity in the presence of metal ions (Zn2+, Co2+, Cu2+, Fe3+, Pb2+, Hg2+, Ag+ and Ni2+) and protons. The dyes under study displayed “off-on” switching in its fluorescence as a function of pH, which is attributed to disallowing photoinduced electron transfer from the receptor moiety to the fluorophore. PAMAM-branched dye displayed a good pH sensor activity (FE = 6.4), however the pH sensing ability of tetraester was substantially higher (FE = 184). In the presence of Cu2+ and Pb2+ ions tetraester quenched its fluorescence intensity (FQ = 22 and 12 respectively), while PAMAM-branched dye enhanced its fluorescence intensity with pronounced selectivity to Cu2+ and Fe3+ (FE = 3.2 and 4.9, respectively). The results obtained indicate the potential of the novel compounds as fluorescent detectors for metal ions with pronounced selectivity towards Cu2+, Pb2+ and Fe3+ ions and highly efficient “off-on” pH switches, especially a tetraester-branched perylene diimide.  相似文献   
74.
An improved classification technique is presented to identify automatically the acute lymphatic leukemia (ALL) subtypes. An adaptive segmentation procedure is performed on peripheral blood smear images to extract the main features (10 geometric features) from the segmented images of white blood cell (WBC), nucleus, and cytoplasm. To show the importance of the different extracted features for the diagnostic accuracy, a comprehensive study is made on all the possible permutation cases of the features using powerful classifiers which are K‐nearest neighbor (KNN) at different metric functions, support vector machine (SVM) with different kernels, and artificial neural network (ANN). This procedure enables us to construct a feature map depending only on least number of features which lead to the highest diagnostic accuracy. It is found that the features map regarding the vacuoles in the cytoplasm and the regularity of the nucleus membrane gives the highest accurate results. The automatic classification for ALL subtypes based only on these two effective features is assessed using the receiver operating characteristic (ROC) curve and F 1 ‐score measures. It is confirmed that the present technique is highly accurate, and saves the effort and time of training.  相似文献   
75.
Cellulose triacetate (CTA) is a polymer which is widely used in a variety of applications in the field of radiation dosimetry. In the present work, CTA samples were irradiated by electron beam in the dose range 10–200 kGy. The modifications in the electron irradiated CTA samples as a function of dose have been studied through different characterization techniques such as thermogravimetric analysis, differential thermal analysis and color-difference studies. The electron irradiation in the dose range 80–200 kGy led to a more compact structure of CTA polymer, which resulted in an improvement in its thermal stability with an increase in activation energy of thermal decomposition.

Also, the variation of melting temperatures with the electron dose has been determined using differential thermal analysis (DTA). The CTA polymer is characterized by the appearance of one endothermic peak due to melting. The results showed that the irradiation in the dose range 10–80 kGy causes defects generation that splits the crystals depressing the melting temperature, while at higher doses (80–200 kGy), the thickness of crystalline structures (lamellae) is increased, thus the melting temperature increased.

In addition, the transmission of these samples in the wavelength range 200–2500 nm, as well as any color changes, was studied. The color intensity ΔE* was greatly increased with increasing the electron beam dose, and accompanied with a significant increase in the blue color component.  相似文献   

76.
In this new information era, the transfer of data and information has become a very important matter. Transferred data must be kept secured from unauthorized persons using cryptography. The science of cryptography depends not only on complex mathematical models but also on encryption keys. Amino acid encryption is a promising model for data security. In this paper, we propose an amino acid encryption model with two encryption keys. The first key is generated randomly using the genetic algorithm. The second key is called the protein key which is generated from converting DNA to a protein message. Then, the protein message and the first key are used in the modified Playfair matrix to generate the cypher message. The experimental results show that the proposed model survives against known attacks such as the Brute-force attack and the Ciphertext-only attack. In addition, the proposed model has been tested over different types of characters including white spaces and special characters, as all the data is encoded to 8-bit binary. The performance of the proposed model is compared with other models using encryption time and decryption time. The model also balances all three principles in the CIA triad.  相似文献   
77.
OBJECTIVES: Several investigators have reported that African-American men with clinically localized prostate cancer have poorer survival than do white men. In addition, prostate cancer in African-American men is commonly diagnosed at a more advanced stage of disease. Is race or ethnicity predictive of outcome of clinically localized prostate cancer? It has been reported that the presence of positive surgical margins significantly influences time to progression independently of other prognostic factors. Therefore, we have elected to conduct a multivariate analysis of clinical factors including race as potential predictors of positive surgical margin outcome. METHODS: We studied 369 consecutive men (120 African-American and 249 white) who had radical prostatectomies at a single institution. Comparisons by race of Gleason score, stage, presence of positive surgical margins, and mean preoperative prostate-specific antigen (PSA) level were carried out. RESULTS: Our data demonstrate that African-American men have more pathologically locally advanced prostate cancer than do white American men: 69% among blacks compared with 57% among whites. However, the difference in rate of positive surgical margins between blacks and whites is statistically significant: 58% among blacks versus 40% among whites (P = 0.002). Four factors were predictive of positive surgical margins: preoperative PSA level, race, clinical stage, and Gleason score. CONCLUSIONS: We have demonstrated that race is an independent predictor of positive surgical margins among patients with clinically localized prostate cancer and should be included in treatment decisions. In addition, the risk of positive surgical margins increases noticeably when PSA is greater than 10 ng/mL.  相似文献   
78.
PURPOSE: The Southwest Oncology Group (SWOG) coordinated an Intergroup study with the participation of Radiation Therapy Oncology Group (RTOG), and Eastern Cooperative Oncology Group (ECOG). This randomized phase III trial compared chemoradiotherapy versus radiotherapy alone in patients with nasopharyngeal cancers. MATERIALS AND METHODS: Radiotherapy was administered in both arms: 1.8- to 2.0-Gy/d fractions Monday to Friday for 35 to 39 fractions for a total dose of 70 Gy. The investigational arm received chemotherapy with cisplatin 100 mg/m2 on days 1, 22, and 43 during radiotherapy; postradiotherapy, chemotherapy with cisplatin 80 mg/m2 on day 1 and fluorouracil 1,000 mg/m2/d on days 1 to 4 was administered every 4 weeks for three courses. Patients were stratified by tumor stage, nodal stage, performance status, and histology. RESULTS: Of 193 patients registered, 147 (69 radiotherapy and 78 chemoradiotherapy) were eligible for primary analysis for survival and toxicity. The median progression-free survival (PFS) time was 15 months for eligible patients on the radiotherapy arm and was not reached for the chemo-radiotherapy group. The 3-year PFS rate was 24% versus 69%, respectively (P < .001). The median survival time was 34 months for the radiotherapy group and not reached for the chemo-radiotherapy group, and the 3-year survival rate was 47% versus 78%, respectively (P = .005). One hundred eighty-five patients were included in a secondary analysis for survival. The 3-year survival rate for patients randomized to radiotherapy was 46%, and for the chemoradiotherapy group was 76% (P < .001). CONCLUSION: We conclude that chemoradiotherapy is superior to radiotherapy alone for patients with advanced nasopharyngeal cancers with respect to PFS and overall survival.  相似文献   
79.
Host genetic factors including major histocompatibility complex (MHC) polymorphisms influence both susceptibility to leprosy per se and also to leprosy type. Non-MHC genes may play an important role, but such genes remain undefined. The influence of two non-MHC candidate genes was assessed in a case-control study of Bengali leprosy patients from Calcutta. Recent studies have implicated variation in the vitamin D receptor (VDR) gene in susceptibility to several diseases, including osteoporosis and pulmonary tuberculosis. In this population, homozygotes for the alternate alleles of the VDR polymorphism are associated, respectively, with lepromatous and tuberculoid leprosy. The NRAMP1 (natural resistance associated macrophage protein 1) gene may influence human mycobacterial disease susceptibility based on studies with the murine homologue Nramp1. However, no significant association was found between NRAMP1 and leprosy susceptibility. This study suggests that the VDR polymorphism may influence susceptibility to some diseases by affecting the type and the strength of the host immune response.  相似文献   
80.
Enzymuria observed in PCM, especially in severe cases, does not seem to be a simple reflection of the increased serum values and suggests renal involvements. A number of factors among which are :- lowered clearance threshold for certain enzymes as well as rapid wear and tear or renal cells seem to participate in the causation of such enzymuria. Urine enzyme analysis may reflect the extent and state of renal pathology among different forms of PCM.  相似文献   
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