全文获取类型
收费全文 | 396篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 113篇 |
金属工艺 | 13篇 |
机械仪表 | 5篇 |
建筑科学 | 12篇 |
能源动力 | 19篇 |
轻工业 | 16篇 |
无线电 | 38篇 |
一般工业技术 | 65篇 |
冶金工业 | 61篇 |
原子能技术 | 3篇 |
自动化技术 | 65篇 |
出版年
2023年 | 24篇 |
2022年 | 31篇 |
2021年 | 23篇 |
2020年 | 10篇 |
2019年 | 14篇 |
2018年 | 16篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 16篇 |
2012年 | 18篇 |
2011年 | 18篇 |
2010年 | 16篇 |
2009年 | 16篇 |
2008年 | 17篇 |
2007年 | 17篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1943年 | 1篇 |
排序方式: 共有412条查询结果,搜索用时 15 毫秒
91.
Niklas Lavesson Martin Boldt Paul Davidsson Andreas Jacobsson 《Knowledge and Information Systems》2011,26(2):285-307
The amount of software that hosts spyware has increased dramatically. To avoid legal repercussions, the vendors need to inform
users about inclusion of spyware via end user license agreements (EULAs) during the installation of an application. However,
this information is intentionally written in a way that is hard for users to comprehend. We investigate how to automatically
discriminate between legitimate software and spyware associated software by mining EULAs. For this purpose, we compile a data
set consisting of 996 EULAs out of which 9.6% are associated to spyware. We compare the performance of 17 learning algorithms
with that of a baseline algorithm on two data sets based on a bag-of-words and a meta data model. The majority of learning
algorithms significantly outperform the baseline regardless of which data representation is used. However, a non-parametric
test indicates that bag-of-words is more suitable than the meta model. Our conclusion is that automatic EULA classification
can be applied to assist users in making informed decisions about whether to install an application without having read the
EULA. We therefore outline the design of a spyware prevention tool and suggest how to select suitable learning algorithms
for the tool by using a multi-criteria evaluation approach. 相似文献
92.
We use a data set covering 13,471 Swedish limited liability firms in the Swedish wholesale industries during 2000–2004 to ascertain the determinants of new start-ups and of in-migration of firms. Access to a large harbor, international airport or large railroad classification yard in the municipality nearly triples the number of start-ups and increases the expected number of in-migrating firms with 53 %. The presence of a university, many educated workers and low local taxes are also associated with more start-ups and firm in-migration. 相似文献
93.
94.
To meet the future environmental challenges, hydrogen direct reduced iron (H-DRI) is expected to constitute the principal material for virgin steel production. For an efficient value chain, knowledge of the melting mechanism and dephosphorization mechanism of H-DRI is needed. The in situ melting behavior, the melting mechanism, and the dephosphorization mechanism during heating of H-DRI are investigated experimentally at 1773 and 1873 K. It is found that the melting rate of H-DRI varies with the reduction degree (91–99.5%), increasing with decreasing reduction degree. An autogenous slag forms during heating and flows through the pores of the H-DRI, thus increasing its effective thermal conductivity. The fraction of filled pores varies with reduction degree explaining the difference in melting rate. At this stage, the dissolution of apatite is initiated and completed upon melting of the metal phase. A gradual reversion of phosphorus from the autogenous slag to the liquid metal is observed after complete melting. The rate of reversion is discussed based on the properties of the H-DRI, for example, reduction degree and carbon addition. 相似文献
95.
Niklas Tenhaef Alina Hermann Moritz Fabian Müller Jonas Görtz Jan Marienhagen Marco Oldiges Wolfgang Wiechert Michael Bott Andreas Jupke Laura Hartmann Sonja Herres-Pawlis Stephan Noack 《化学,工程师,技术》2023,95(4):587-595
A simplified and scalable one-pot process for the anaerobic production of succinic acid using a metabolically engineered Corynebacterium glutamicum strain is demonstrated. With targeted bioprocess optimization, succinic acid titer of 78 g L−1 and yield of 1.41 molSAmolGLC−1 were achieved. Succinic acid was recovered from the neutral fermentation broth by electrochemically induced crystallization and applied for polybutylene bio-succinate synthesis using a biocompatible zinc catalyst. Except for a slight color change, the final biopolymer was comparable to the polymer from commercial precursors. 相似文献
96.
Chou Chia-Ying Karlsson Dennis Pettersson Niklas Holländer Helander Thomas Harlin Peter Sahlberg Martin Jansson Ulf Odqvist Joakim Lindwall Greta 《Metallurgical and Materials Transactions A》2022,53(8):3073-3082
Metallurgical and Materials Transactions A - The microstructure response of laser-powder bed fusion (L-PBF)-processed ferritic stainless steel (AISI 441) during post-heat treatments is studied in... 相似文献
97.
Jakob Hofmann Kai Borcherding Karsten Thiel Thomas Lingner Ulrike Sommer Uwe Haberkorn Tim Niklas Bewersdorf Gerhard Schmidmaier Tobias Grossner 《International journal of molecular sciences》2022,23(24)
99-Metastabil Technetium (99mTc) is a radiopharmaceutical widely used in skeletal scintigraphy. Recent publications show it can also be used to determine the osteogenic potential of human mesenchymal stem cells (hMSCs) by binding to hydroxyapatite formed during bone tissue engineering. This field lacks non-destructive methods to track live osteogenic differentiation of hMSCs. However, no data about the uptake kinetics of 99mTc and its effect on osteogenesis of hMSCs have been published yet. We therefore evaluated the saturation time of 99mTc by incubating hMSC cultures for different periods, and the saturation concentration by using different amounts of 99mTc activity for incubation. The influence of 99mTc on osteogenic potential of hMSCs was then evaluated by labeling a continuous hMSC culture three times over the course of 3 weeks, and comparing the findings to cultures labeled once. Our findings show that 99mTc saturation time is less than 0.25 h, and saturation concentration is between 750 and 1000 MBq. Repeated exposure to γ-radiation emitted by 99mTc had no negative effects on hMSC cultures. These new insights can be used to make this highly promising method broadly available to support researchers in the field of bone tissue engineering using this method to track and evaluate, in real-time, the osteogenic differentiation of hMSC, without any negative influence on the cell viability, or their osteogenic differentiation potential. 相似文献
98.
Niklas Blum Piotr Jacak Florian Schreiner Dragos Vingarzan Peter Weik 《Journal of Network and Systems Management》2008,16(1):63-91
The IP Multimedia Subsystem (IMS), already widely recognized as a fundamental core component of Next Generation Networks (NGNs),
enables proliferation of a huge variety of value added services. Simultaneous to the emergence of triple play services there
is a strong need for establishing standardized methodologies for service fulfillment and assurance, maintaining service execution
parameters at advertised levels. Traditional Operations Support Systems (OSS) are not adequate for managing NGNs. This work
shows experiences gained from implementing OSS for NGNs. It describes a solution that combines extensive NGN development expertise
with a new generation, of policy-based, service oriented OSS solutions in order to provide enhanced levels of automation and
reliability to the NGN service delivery and session control environment. Primary focus of this approach is put on service
assurance and service fulfillment mechanisms for remote monitoring, automated control and configuration of standard compliant
IMS infrastructures, such as the Open Source IMS Core (OSIMS) based Open IMS Playground. This work describes state of the
art NGN OSS design principles and knowledge attained by integration of standardized fault management as well as service and
subscriber provisioning procedures showing how the full cycle from service deployment to service advertisement to service
execution can be delivered in an automated way.
相似文献
Peter WeikEmail: |
99.
Niklas Paul Matthias Kraume Sebastian Schön Regine von Klitzing 《American Institute of Chemical Engineers》2015,61(3):1092-1104
In many industrial applications, the knowledge of the occurring transport processes in liquid/liquid systems is of great interest to design a multiphase reactor or an extraction column, for instance. All transport processes in liquid/liquid systems are governed by the interface. In some processes surfactants are needed. Surfactants change many interfacial properties which affect the transport processes. In this work, the influence of high surfactant concentrations (micellar systems) on transport processes is regarded. To understand, the occurring reduction of the drop rise velocity and of mass transfer rates experimental investigations of the occurring interfacial phenomena are carried out. Therefore, interfacial tension measurements as well as colloidal probe atomic force measurements of liquid/liquid systems were conducted. It was proved that for high nonionic surfactant concentrations a change of the phase behavior must be taken into consideration to describe transport processes in micellar liquid/liquid systems. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1092–1104, 2015 相似文献
100.
Kirsten Tracht Ann-Kathrin Onken Phil Gralla Joel Haji Emad Niklas Kipry Peter Maaß 《CIRP Annals》2018,67(1):9-12
In micro production, small tolerances, as well as size effects increase the requirement for a fast, precise, and reliable methodology that enhances the output of assemblies. In contrast to conventional approaches, a widening of the tolerance field enables an overall improvement of the output of a process chain while assuring functionality of parts. Therefore, the consideration of trends for building sections is essential for increasing the outcome by identifying sections that can be matched. This paper presents the Linked Parts Clustering Algorithm for the identification of trend-specific clusters in linked parts and demonstrates the area of application. 相似文献