全文获取类型
收费全文 | 44篇 |
免费 | 1篇 |
专业分类
化学工业 | 7篇 |
能源动力 | 1篇 |
轻工业 | 1篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 19篇 |
一般工业技术 | 3篇 |
冶金工业 | 5篇 |
自动化技术 | 7篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1983年 | 2篇 |
排序方式: 共有45条查询结果,搜索用时 937 毫秒
31.
MJ Canto MA Vives F Carmona C Agusti V Cararach X Iglesias 《Canadian Metallurgical Quarterly》1995,63(2):191-193
In this report we describe a case of a successful pregnancy in a 19-year-old patient suffering from the familial form of pulmonary alveolar proteinosis, a very rare pulmonary disorder. The pregnancy course was complicated by preterm labour. The outcome and management are discussed. 相似文献
32.
This paper presents the performance of a pseudoerror monitoring technique for a 16 QAM 140 Mbit/s digital radio in presence of multipath dispersive fading. The so-called pseudoerrors, generated by means of a threshold modification of two, namely, secondary receivers are entered into an extrapolating function to obtain a fast bit error ratio (BER) calculation. A counting time of 10 ms was retained in order to follow fading depth changes up to 100 dB/s and fading notch speeds up to 300 MHz/s approximately. We have considered three structures for the receiver: without equalization, with IF amplitude equalization, and decision feedback equalization (DFE). The results obtained show the estimated and real BER within a margin that includes the two recommended CCIR values: 10-3and10-6. In particular, the estimated signature obtained in the case of using IF equalization reveals that this fast BER calculation could be an effective choice to control a frequency diversity switch, even in the presence of a fading activity with rapid variations. 相似文献
33.
Isaias Hernndez-Verdin Karim Labreche Marion Benazra Karima Mokhtari Khê Hoang-Xuan Agusti Alentorn 《International journal of molecular sciences》2021,22(1)
B-cell non-Hodgkin’s lymphoma (NHL) risk associations had been mainly attributed to family history of the disease, inflammation, and immune components including human leukocyte antigen (HLA) genetic variations. Nevertheless, a broad range of genome-wide association studies (GWAS) have shed light into the identification of several genetic variants presumptively associated with B-cell NHL etiologies, survival or shared genetic risk with other diseases. The present review aims to overview HLA structure and diversity and summarize the evidence of genetic variations, by GWAS, on five NHL subtypes (diffuse large B-cell lymphoma DLBCL, follicular lymphoma FL, chronic lymphocytic leukemia CLL, marginal zone lymphoma MZL, and primary central nervous system lymphoma PCNSL). Evidence indicates that the HLA zygosity status in B-cell NHL might promote immune escape and that genome-wide significance variants can give biological insight but also potential therapeutic markers such as WEE1 in DLBCL. However, additional studies are needed, especially for non-DLBCL, to replicate the associations found to date. 相似文献
34.
35.
Perez-Romero J. Agusti R. Sallent O. 《Vehicular Technology, IEEE Transactions on》2001,50(6):1354-1365
An inhibit sense multiple access-direct sequence/code division multiple access (ISMA-DS/CDMA) medium access control protocol for a packet transmission mobile radio network is presented. The main feature of this protocol is its ability to retain the inherent flexibility of random access protocols while at the same time reducing to some extent the randomness in the access in order to increase the system capacity. In this framework, the protocol is presented together with some adaptive mechanisms that improve the protocol performance by means of regulating the access and varying the transmission bit rate according to the channel load that is broadcast by the base station. As a result, an adaptive bit rate algorithm is presented that reaches a throughput value close to the theoretical maximum 相似文献
36.
37.
A type II hybrid automatic repeat request scheme is considered as a retransmission strategy in a direct-sequence code-division multiple-access packet mobile radio network. An analysis based on equilibrium point analysis is presented to model the behavior of the system in a message-based traffic generation model. A simulation approach is introduced to validate the proposed analytical model, obtaining results that closely match those derived theoretically. 相似文献
38.
Future third-generation mobile communication systems will need multi-access control (MAC) protocols suitable for multimedia code division multiple access (CDMA) radio communications. Distributed queueing random access protocol (DQRAP)/CDMA is a general purpose MAC protocol oriented to the CDMA environment. Analytical model expressions and computer simulations have shown its capacity to achieve near-optimum performance under heterogeneous traffic scenarios in a unicellular environment. A cellular environment has been designed to verify that DQPAP/CDMA maintains its near-optimum performance in a packet switched mobile communication system. A new handover technique based on the protocol is proposed to further improve the system performance 相似文献
39.
This paper analyzes the performance of a MAC scheme for wireless local area networks (WLANs) that makes use of distributed queues to improve radio channel utilization. Analytical values for the maximum throughput performance are derived as a function of the system parameters. The obtained results show that the proposed scheme outperforms the legacy 802.11 MAC protocol in terms of maximum stable throughput. This benefit is obtained from eliminating back-off periods and collisions in data packet transmissions while minimizing the needed control overhead. The proposal also makes performance to be independent of the number of nodes transmitting in the system and provides stability for high load conditions. 相似文献
40.
KL Woods D Ketley A Agusti C Hagn R Kala NB Karatzas A Leizorowicz A Reikvam J Schilling R Seabra-Gomes D Vasiliauskas L Wilhelmsen 《Canadian Metallurgical Quarterly》1998,19(9):1348-1354
AIMS: There is little evidence to inform routine practice in the use of coronary angiography and revascularization procedures after acute myocardial infarction. Large differences in the uptake of these procedures have been reported but representative data are scarce. Outcome studies have produced opposing conclusions concerning the impact of the high rate of these cardiac procedures. METHODS AND RESULTS: A population-based patient sampling approach was utilized to identify routine practice in representative samples from 11 European countries. Data were collected retrospectively on treatment in the 6 months following acute myocardial infarction (n=2807). There was wide variation in utilization of coronary angiography and revascularization procedures. Even after restricting the analysis to patients <65 years (n=1262), there remained a 6 13 fold variation in the use of these procedures. A decreased likelihood of undergoing these procedures was associated with older age. In addition, there was an independent and negative association between female sex and utilization of coronary angiography and coronary artery bypass grafting (CABG). CONCLUSION: The effect on patient outcome of the observed variation in use of these procedures is not known but has important cost and resource implications for the health services. Outcome research is needed to define patient selection criteria and to measure the cost-utility of different angiography and revascularization rates. 相似文献