全文获取类型
收费全文 | 151篇 |
免费 | 6篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 44篇 |
金属工艺 | 3篇 |
机械仪表 | 2篇 |
建筑科学 | 4篇 |
能源动力 | 7篇 |
轻工业 | 5篇 |
无线电 | 16篇 |
一般工业技术 | 24篇 |
冶金工业 | 11篇 |
自动化技术 | 36篇 |
出版年
2022年 | 11篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 14篇 |
2007年 | 5篇 |
2006年 | 9篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 15 毫秒
1.
C Matache M Stefanescu A Onu G Szegli M Barel S Tanaseanu I Matei S Bouillie R Frade 《Canadian Metallurgical Quarterly》1996,24(4):217-228
A comparative study of tyrosine phosphorylation was performed on peripheral blood lymphocytes from systemic lupus erythematosus (SLE) patients and from healthy donors. Freshly isolated SLE lymphocytes presented an elevated tyrosine phosphorylation level when compared to healthy donors lymphocytes (p = 0.005). Among all phosphorylated proteins, those called p120, p110, p80 and p55-p60 were more phosphorylated. The level of tyrosine phosphorylation of p120 and p110 proteins discriminated significantly (p = 0.0048, respectively, p = 0.02) between SLE patients and healthy donors. Lymphocytes form SLE patients and healthy donors were then stimulated by cross-linking T cell antigens (CD3, CD4, CD8) to further distinguish the signal transduction between normal and pathologic lymphocytes. No statistical differences in the tyrosine phosphorylation pattern, following CD4 or CD8 cross-linking, were observed between SLE patients and healthy donors lymphocytes. CD3 cross-linking induced an effect on tyrosine phosphorylation different in SLE patients versus healthy donors lymphocytes. Thus, the lymphocytes of SLE patients were refractile in anti-CD3 stimulation in comparison with the healthy donors lymphocytes. Chi-square analysis demonstrated that a significantly larger number of healthy donors responded to anti-CD3 stimulation compared to SLE patients (p = 0.03). The high frequency of tyrosine phosphorylation of p110 and p80 proteins, following CD3 stimulation, in normal versus SLE lymphocytes, suggested that these proteins could be involved in abnormal signal transduction in SLE cells. 相似文献
2.
Camelia Betianu Florentina A Caliman Maria Gavrilescu Igor Cretescu Corneliu Cojocaru Ioannis Poulios 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(11):1454-1465
BACKGROUND: Heterogeneous photocatalysis is influenced by a number of parameters involving synergistic effects; hence, an experimental strategy design that considers interactions between the main variables is needed. The response surface methodology was applied for the investigation of photodegradation of 20 mg L?1 Orange II in aqueous solutions and for optimization of color removal efficiency. Preliminary studies were performed to identify the parameters to be selected for optimization. RESULTS: The input variables considered for experimental design were: solution initial pH, oxidizing agent (H2O2) initial concentration and UV‐A irradiation time. The multivariate experimental design allowed the development of a quadratic response surface model to be used for the prediction of color removal efficiency over the full range of the experimental region. Under the optimum conditions established in the region of experimentation (pH = 6.9, [H2O2]0 = 183 mg L?1 and t = 32 min), a 100% color removal efficiency was obtained in experiments. CONCLUSIONS: It was found that the variables considered have important effects on color removal efficiency. The results demonstrate that the use of experimental design strategy is indispensable for successful investigation and adequate modeling of the process because the interdependence of the reaction parameters cannot be neglected. Copyright © 2008 Society of Chemical Industry 相似文献
3.
DV Matei F Pascale A Clemente F Della Corte D Pucello F Grassetti 《Canadian Metallurgical Quarterly》1996,20(3):302-306
Since in vitro experiments had excluded interactions between Fe-gluconate (Fe-gluc) and magnesium-L-aspartate hydrochloride (MAH) in aqueous solutions the present in vivo studies seemed to be justified. Animal studies: Rats were kept on magnesium-(Mg)- and iron-(Fe)- sufficient and deficient diets. The intragastral administration of Fe-gluc significantly increased plasma Fe after 3 h, either given alone, or in combination with MAH (inducing hypermagnesemia). Same results were obtained when fortified diets were offered to Fe/Mg-deficient animals. Human studies: The combination of Fe-gluc (2 x 50 mg Fe per day, per os) plus MAH (2 x 7.5 mmol Mg per day, p.o.) was well tolerated by healthy volunteers. Single dose experiments revealed that Fe-gluc alone and in combination with MAH increased plasma Fe levels during 3 h to the same extent. Two groups of pregnant women with moderately reduced hemoglobin levels either received Fe-gluc (out-patients) or its combination with MAH (at least temporarily hospitalised because of preterm labor). Treatments were well tolerated. Hemoglobin levels did not further decrease, as expected without Fe supplements, during the course of pregnancy, thus indicating the therapeutic availability of the electrolytes in both study groups. Progesterone-induced constipation is frequently observed during pregnancy; hence stool softening reported by 50% of the women receiving Fe-gluc plus MAH (versus 33% in the Fe-gluc group) can be regarded as desirable effect. It is concluded that MAH does not interfere with the enteral absorption of Fe-gluc when both electrolytes are orally administered together. Taking both electrolytes together instead of 2 to 3 h apart from each other, as actually recommended, means a less complicated dosage regimen and probably improves compliance. 相似文献
4.
Yazan Boshmaf Ildar Muslukhov Konstantin Beznosov Matei Ripeanu 《Computer Networks》2013,57(2):556-578
Online Social Networks (OSNs) have attracted millions of active users and have become an integral part of today’s web ecosystem. Unfortunately, in the wrong hands, OSNs can be used to harvest private user data, distribute malware, control botnets, perform surveillance, spread misinformation, and even influence algorithmic trading. Usually, an adversary starts off by running an infiltration campaign using hijacked or adversary-owned OSN accounts, with an objective to connect with a large number of users in the targeted OSN. In this article, we evaluate how vulnerable OSNs are to a large-scale infiltration campaign run by socialbots: bots that control OSN accounts and mimic the actions of real users. We adopted the design of a traditional web-based botnet and built a prototype of a Socialbot Network (SbN): a group of coordinated programmable socialbots. We operated our prototype on Facebook for 8 weeks, and collected data about user behavior in response to a large-scale infiltration campaign. Our results show that (1) by exploiting known social behaviors of users, OSNs such as Facebook can be infiltrated with a success rate of up to 80%, (2) subject to user profile privacy settings, a successful infiltration can result in privacy breaches where even more private user data are exposed, (3) given the economics of today’s underground markets, running a large-scale infiltration campaign might be profitable but is still not particularly attractive as a sustainable and independent business, (4) the security of socially-aware systems that use or integrate OSN platforms can be at risk, given the infiltration capability of an adversary in OSNs, and (5) defending against malicious socialbots raises a set of challenges that relate to web automation, online-offline identity binding, and usable security. 相似文献
5.
When forecasts are assessed by a general loss (cost-of-error) function, the optimal point forecast is, in general, not the conditional mean, and depends on the conditional volatility—which, for stock returns, is time-varying. In order to provide forecasts of daily returns of 30 DJIA stocks under a general multivariate loss function, the following issues are addressed. We discuss what conditions define a multivariate loss function, and a simple class of such functions is proposed. Based on suitable combinations of univariate losses, the suggested multivariate functions are convenient for practical applications with many variables. To keep the computational aspect tractable, a flexible multivariate GARCH model is employed in estimating the conditional forecast distributions. The model easily copes with large number of series while allowing for skewness, fat tails, non-ellipticity, and tail dependence. Based on Engle’s DCC GARCH, it uses multivariate affine generalized hyperbolic distributions as conditional probability law, and the number of parameters to be estimated simultaneously does not depend on the number of series. The model is fitted using daily data from 2002 to 2007 (keeping data from 2008 for out-of-sample forecasts), and a bootstrap procedure is used to derive point forecasts under several multivariate loss functions of the proposed type. 相似文献
6.
In this paper we present new edge detection algorithms which are motivated by recent developments on edge-adapted reconstruction techniques [F. Aràndiga, A. Cohen, R. Donat, N. Dyn, B. Matei, Approximation of piecewise smooth functions and images by edge-adapted (ENO-EA) nonlinear multiresolution techniques, Appl. Comput. Harmon. Anal. 24 (2) (2008) 225–250]. They are based on comparing local quantities rather than on filtering and thresholding. This comparison process is invariant under certain transformations that model light changes in the image, hence we obtain edge detection algorithms which are insensitive to changes in illumination. 相似文献
7.
Stroila M Eisemann E Hart J 《IEEE transactions on visualization and computer graphics》2008,14(1):135-145
Clip art is a simplified illustration form consisting of layered filled polygons or closed curves used to convey 3D shape information in a 2D vector graphics format. This paper focuses on the problem of direct conversion of smooth surfaces, ranging from the free-form shapes of art and design to the mathematical structures of geometry and topology, into a clip art form suitable for illustration use in books, papers and presentations.We show how to represent silhouette, shadow, gleam and other surface feature curves as the intersection of implicit surfaces, and derive equations for their efficient interrogation via particle chains. We further describe how to sort, orient, identify and fill the closed regions that overlay to form clip art. We demonstrate the results with numerous renderings used to illustrate the paper itself. 相似文献
8.
Laurent Bédouet Florentina Pascale Michel Bonneau Alexandre Laurent 《Drug development and industrial pharmacy》2015,41(1):85-94
Intra-articular drug delivery systems (DDSs) are envisaged as interesting alternative to locally release non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen to reduce pain in patients with osteoarthritis. The present study examines the efficacy of S-(+)-ibuprofen on cartilage degradation as drug candidate for DDS loading. Humeral cartilage and joint capsule explants were collected from healthy sheep shoulder joints and they were cultured in mono- or in co-culture for 13?days with LPS in combination with S-(+)-ibuprofen at 50?µM and 1?mM. S-(+)-ibuprofen (50?µM) blocked prostaglandins production in LPS-activated explants but did not reduce cartilage degradation. By contrast, 1?mM S-(+)-ibuprofen treatment of cartilage explants reduced nitric oxide synthesis by 51% (p?=?0.0072), proteoglycans degradation by 35% (p?=?0.0114) and expression of serum amyloid protein – the main protein induced upon LPS challenge – by 44% (p?0.0001). On contrary, in presence of synovial membrane, the protective effects of S-(+)-ibuprofen on cartilage damages were significantly diminished. At 1mM, S-(+)-ibuprofen reduced the cell lysis during culture of cartilage and joint capsule either in mono- or in co-culture. This study performed on sheep explants shows that 1?mM S-(+)-ibuprofen inhibited cartilage degradation via a mechanism independent of cyclooxygenase inhibition. Reduction of prostaglandins synthesis at 50?µM in all treatment groups and reduction of cartilage degradation observed at 1?mM suggest that S-(+)-ibuprofen could be considered as a promising drug candidate for the loading of intra-articular DDS. 相似文献
9.
Gelu Onose Aurelian Anghelescu Dan Blendea Vlad Ciobanu Cristina Daia Florentina Carmen Firan Mihaela Oprea Aura Spinu Cristina Popescu Anca Ionescu tefan Busnatu Constantin Munteanu 《International journal of molecular sciences》2022,23(2)
BACKGROUND: Cerebral circulation delivers the blood flow to the brain through a dedicated network of sanguine vessels. A healthy human brain can regulate cerebral blood flow (CBF) according to any physiological or pathological challenges. The brain is protected by its self-regulatory mechanisms, which are dependent on neuronal and support cellular populations, including endothelial ones, as well as metabolic, and even myogenic factors. OBJECTIVES: Accumulating data suggest that “non-pharmacological” approaches might provide new opportunities for stroke therapy, such as electro-/acupuncture, hyperbaric oxygen therapy, hypothermia/cooling, photobiomodulation, therapeutic gases, transcranial direct current stimulations, or transcranial magnetic stimulations. We reviewed the recent data on the mechanisms and clinical implications of these non-pharmaceutical treatments. METHODS: To present the state-of-the-art for currently available non-invasive, non-pharmacological-related interventions in acute ischemic stroke, we accomplished this synthetic and systematic literature review based on the Preferred Reporting Items for Systematic Principles Reviews and Meta-Analyses (PRISMA). RESULTS: The initial number of obtained articles was 313. After fulfilling the five steps in the filtering/selection methodology, 54 fully eligible papers were selected for synthetic review. We enhanced our documentation with other bibliographic resources connected to our subject, identified in the literature within a non-standardized search, to fill the knowledge gaps. Fifteen clinical trials were also identified. DISCUSSION: Non-invasive, non-pharmacological therapeutic/rehabilitative interventions for acute ischemic stroke are mainly holistic therapies. Therefore, most of them are not yet routinely used in clinical practice, despite some possible beneficial effects, which have yet to be supplementarily proven in more related studies. Moreover, few of the identified clinical trials are already completed and most do not have final results. CONCLUSIONS: This review synthesizes the current findings on acute ischemic stroke therapeutic/rehabilitative interventions, described as non-invasive and non-pharmacological. 相似文献
10.
Kaktcham Pierre Marie Zambou Ngoufack François Foko Kouam Edith Marius Oana Ciobotaru Florentina Matei Calina Petruta Cornea 《Food Biotechnology》2013,27(4):237-256
This study aims to evaluate the antifungal activity of lactic acid bacteria (LAB) from some Cameroonian food commodities against mycotoxigenic and spoilage molds. Following LAB isolation, the antifungal activity of the isolates was assessed. The organic acids were quantified using high-performance liquid chromatography and the ability of the LAB to reduce mold biomass and aflatoxin production was evaluated. The LAB were identified and the biopreservative potential of strain LO3 was evaluated on tomato paste. Nine percent of the strains isolated showed broad antifungal activity. The activity was due to the effect of organic acids comprising lactic, acetic, 4-hydroxy-3-phenyllactic and 3-phenyllactic acids. Lactobacillus plantarum LO3 exhibiting the highest and broadest antifungal activity was selected and showed the capacity to inhibit fungal growth and aflatoxin production in vitro. Moreover, this strain and its cell-free supernatant showed the ability to prevent aflatoxigenic mold growth in tomato paste without altering its physico-chemical and organoleptic properties. 相似文献