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671.
Anja M. Waetjen Dominik A. Polsakiewicz Ingo Kuhl Rainer Telle Horst Fischer 《Journal of the European Ceramic Society》2009,29(1):1-6
To obtain ceramic components of high density by means of laser sintering, a high density of the green-compact is necessary. This is a problematic aspect when using ceramic granulates. We present a new procedure based on an airbrush spraying technique using slurries of high solid content. Alumina as well as zirconia slurries were developed and optimized for the process. After the layer-wise airbrush deposition of slurry, the microstructure of green, sintered and laser sintered samples were analyzed using SEM. On the basis of the high density of the green-compact achieved the described technique could be used for individual production of laser sintered structural ceramic components. 相似文献
672.
673.
Antje Müller Bettina Krause Anja Kerstein-Sthle Sara Comdühr Sebastian Klapa Sebastian Ullrich Konstanze Holl-Ulrich Peter Lamprecht 《International journal of molecular sciences》2021,22(12)
ANCA-associated vasculitis (AAV) comprises granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). While systemic vasculitis is a hallmark of all AAV, GPA is characterized by extravascular granulomatous inflammation, preferentially affecting the respiratory tract. The mechanisms underlying the emergence of neutrophilic microabscesses; the appearance of multinucleated giant cells; and subsequent granuloma formation, finally leading to scarred or destroyed tissue in GPA, are still incompletely understood. This review summarizes findings describing the presence and function of molecules and cells contributing to granulomatous inflammation in the respiratory tract and to renal inflammation observed in GPA. In addition, factors affecting or promoting the development of granulomatous inflammation such as microbial infections, the nasal microbiome, and the release of damage-associated molecular patterns (DAMP) are discussed. Further, on the basis of numerous results, we argue that, in situ, various ways of exposure linked with a high number of infiltrating proteinase 3 (PR3)- and myeloperoxidase (MPO)-expressing leukocytes lower the threshold for the presentation of an altered PR3 and possibly also of MPO, provoking the local development of ANCA autoimmune responses, aided by the formation of ectopic lymphoid structures. Although extravascular granulomatous inflammation is unique to GPA, similar molecular and cellular patterns can be found in both the respiratory tract and kidney tissue of GPA and MPA patients; for example, the antimicrobial peptide LL37, CD163+ macrophages, or regulatory T cells. Therefore, we postulate that granulomatous inflammation in GPA or PR3-AAV is intertwined with autoimmune and destructive mechanisms also seen at other sites. 相似文献
674.
In this paper new comparison parameters are defined for assessing statistical similarity between two data sets. The new parameters are based on the commonly used Kolmogorov-Smirnov test. They allow quantifying differences between the cumulative distribution functions of each data series. These parameters are applied to global horizontal daily irradiation values from pyranometric measurements and satellite data. The test data from 38 stations distributed throughout Germany cover the time from 1995 until 2003. The results affirm that the new parameters contribute valuable information to the comparison of data sets complementing those that are found with the mean bias and root mean squared differences. 相似文献
675.
Impacts of membrane flux enhancers on activated sludge respiration and nutrient removal in MBRs 总被引:1,自引:0,他引:1
This paper presents the findings of experimental investigations regarding the influence of 13 different flux enhancing chemicals (FeCl3, polyaluminium chloride, 2 chitosans, 5 synthetic polymers, 2 starches and 2 activated carbons) on respirometric characteristics and nitrification/denitrification performance of membrane bioreactor (MBR) mixed liquor. Flux enhancing chemicals are a promising method to reduce the detrimental effects of fouling phenomena via the modification of mixed liquor characteristics. However, potentially inhibiting effects of these chemicals on mixed liquor biological activity triggered the biokinetic studies (in jar tests) conducted in this work. The tested polyaluminium chloride (PACl) strongly impacted on nitrification (−16%) and denitrification rate (−43%). The biodegradable nature of chitosan was striking in endogenous and exogenous tests. Considering the relatively high costs of this chemical, an application for wastewater treatment does thus not seem to be advisable. Also, addition of one of the tested activated carbons strongly impacted on the oxygen uptake rate (−28%), nitrification (−90%) and denitrification rate (−43%), due to a decrease of pH. Results show that the changes in kLa values were mostly not significant, however, a decrease of 13% in oxygen transfer was found for sludge treated with PACl. 相似文献
676.
Anja M. Maier Claudia M. Eckert P. John Clarkson 《Expert systems with applications》2006,31(4):663-672
Communication is a critical success factor in design. It can be seen as the social and cognitive process by which information is selected, messages are exchanged between interacting partners, and meaning is created. How communication processes can best be captured, analysed and assessed, as a preliminary step toward suggestions for improvement of communication practices, remains a challenge for researchers and practitioners. To this end, a maturity grid-inspired approach to audit communication practices has been developed. This paper employs a maturity grid approach and reflects critically on the construction and application of the approach in a structured group workshop in software design. Such an approach yields dual benefits: (a) as a research method to gather insight into communication and (b) as a guide to plan improvements in practice. Conclusions are drawn for the process of auditing communication in design. 相似文献
677.
Anja Schwiebs Farha Faqar-Uz-Zaman Martina Herrero San Juan Heinfried H. Radeke 《International journal of molecular sciences》2021,22(11)
Background: Reduction of the Sphingosine-1-phosphate (S1P) degrading enzyme S1P lyase 1 (SGPL1) initiates colorectal cancer progression with parallel loss of colon function in mice. We aimed to investigate the effect of SGPL1 knockout on the stem cell niche in these mice. Methods: We performed immunohistochemical and multi-fluorescence imaging on tissue sections of wildtype and SGPL1 knockout colons under disease conditions. Furthermore, we generated SGPL1 knockout DLD-1 cells (SGPL1−/−M.Ex1) using CRISPR/Cas9 and characterized cell cycle and AKT signaling pathway via Western blot, immunofluorescence, and FACS analysis. Results: SGPL1 knockout mice were absent of anti-Ki-67 staining in the stem cell niche under disease conditions. This was accompanied by an increase of the negative cell cycle regulator FOXO3 and attenuation of CDK2 activity. SGPL1−/−M.Ex1 cells show a similar FOXO3 increase but no arrest of proliferation, although we found a suppression of the PDK1/AKT signaling pathway, a prolonged G1-phase, and reduced stem cell markers. Conclusions: While already established colon cancer cells find escape mechanisms from cell cycle arrest, in vivo SGPL1 knockout in the colon stem cell niche during progression of colorectal cancer can contribute to cell cycle quiescence. Thus, we propose a new function of the S1P lyase 1 in stemness. 相似文献
678.
The use of synthetic pipes for drinking water distribution has increased. High desnity polyethylene (HPDE) is preferred because of its favorable mechanical properties, ease of handling during manufacturing, and low permeability to external contaminants. Off-flavor drinking water is a problem with plastic pipes. The compounds causing off-flavors are mainly carbonyl compounds. A combined zeolite called Abscents is used to eliminate odors and to remove odor-causing compounds. In this study, four different amounts of Abscents were added to raw HDPE pellets, and the influence on the off-flavor properties were analyzed. When the maximum amount of Abscents was added, almost all the carbonyl compounds disappeared, and the intensities of odors also decreased. The use of Abscents notably increased the acceptability of HDPE pipes. The system used for analysis of volatile organic compounds was a gas chromatographic/mass spectrometric/sniffing system. Purge and trap techniques were used to introduce the volatile, off-flavor components into the gas chromatograph. 相似文献
679.
Hannes J. König Frieder Graef Jana Schindler Anja Fasse Khamaldin Daud Mutabazi Christine Lambert Pamela Ngwenya Götz Uckert Henry Mahoo Fred F. Hattermann Stefan Sieber 《Food Security》2017,9(6):1309-1321
An impact assessment of food-securing upgrading strategies (UPS) can be performed to assess actual and potential UPS effects at the local level. We developed an assessment framework that integrates the main components of the food value chain (FVC), including natural resources, food production, processing, marketing, and consumption. The framework provides a generic template in which different impact assessment approaches can be complementarily integrated and was tested for a case study in Tanzania. The framework employs a structured sequence of steps: (1) context analysis and the development of UPS, (2) the selection and application of assessment approaches and (3) the establishment of food security criteria and UPS effects. To illustrate the flexibility and use of the framework, the inputs of three different impact assessment approaches were considered. First, data from a household survey was applied to provide baseline information at the local level. Second, scientific knowledge was employed to systematically assess the selected UPS. Third, local stakeholder knowledge was considered to identify the local food security constraints and preferences and provide assessments of potential UPS effects. The Framework for Participatory Impact Assessment (FoPIA) approach was utilized to conduct local focus group discussions, and the Scaling Up Assessment Tool for Food Security (ScalA-FS) was employed to gather scientific knowledge about specific UPS impacts. Based on the preliminary results from the framework testing, diverse stakeholder participation was found to be essential for considering local preferences and to engage stakeholders in the assessment process, whereas scientific knowledge and monitoring data were needed to complement the “local picture” with more quantifiable results. The strengths and shortcomings of the framework are discussed. 相似文献
680.
Katrin Reincke Elisa Vilvert Anja Fasse Frieder Graef Stefan Sieber Marcos A. Lana 《Food Security》2018,10(4):911-924
Due to beneficial characteristics of cassava such as robustness and versatility for multiple uses, it can have a major role in contributing to local food security. The objective of this study was to find out whether and how the cultivation of cassava benefits smallholder farmers in the regions of Dodoma and Morogoro, Tanzania. In addition, the study assessed the main factors that support or threaten food security of smallholder farmer households in the survey region and analysed whether cassava cultivation could counteract them. We applied a mixed methods approach. Quantitative data were provided by a comprehensive household survey of the Trans-SEC project, and qualitative data were collected by conducting semi-structured interviews. To approach the complexity of our chosen food security definition, three approaches for household food security measurement were applied. These covered the components of food availability, food access, and food utilization. Additionally, dependent variables for regression models were constructed and a multivariate analysis was run. The results show that cassava contributes to food security in the households, but achieving food security through cassava cultivation was constrained by several factors, including pests, missing markets, poor processing, social perception and lack of knowledge. Besides these, other factors affecting food security in the study area were found, uncovering some roots of local food insecurity and serving as a basis for further research and action on how to enhance food security. 相似文献