全文获取类型
收费全文 | 80篇 |
免费 | 0篇 |
专业分类
化学工业 | 3篇 |
机械仪表 | 1篇 |
能源动力 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 6篇 |
冶金工业 | 55篇 |
自动化技术 | 3篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2016年 | 3篇 |
2012年 | 1篇 |
2010年 | 1篇 |
2007年 | 1篇 |
2006年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1986年 | 4篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1976年 | 9篇 |
1975年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 15 毫秒
1.
I Dalsgaard BK Gudmundsdóttir S Helgason S H?ie OF Thoresen UP Wichardt T Wiklund 《Canadian Metallurgical Quarterly》1998,84(6):999-1006
Estrogen therapy increases plasma HDL levels, which may reduce cardiovascular risk in postmenopausal women. The mechanism of action of estrogen in influencing various steps in hepatic HDL and apolipoprotein (apo) A-I synthesis and secretion are not fully understood. In this study, we have used the human hepatoblastoma cell line (Hep G2) as an in vitro model system to delineate the effect of estradiol on multiple regulatory steps involved in hepatic HDL metabolism. Incubation of Hep G2 cells with estradiol resulted in the following statistically significant findings: (1) increased accumulation of apoA-I in the medium without affecting uptake/removal of radiolabeled HDL-protein; (2) accelerated incorporation of [3H]leucine into apoA-I; (3) selective increase in [3H]leucine incorporation into lipoprotein (LP) A-I but not LP A-I+A-II HDL particles (HDL particles without and with apoA-II, respectively); (4) increased ability of apoA-I-containing particles to efflux cholesterol from fibroblasts; (5) stimulated steady state apoA-I but not apoA-II mRNA expression; and (6) increased newly transcribed apoA-I mRNA message without effect on apoA-I mRNA half-life. The data indicate that estradiol stimulates newly transcribed hepatic apoA-I mRNA, resulting in a selective increase in LP A-I, a subfraction of HDL that is associated with decreased atherosclerotic cardiovascular disease, especially in premenopausal women. 相似文献
2.
3.
4.
5.
6.
V. P. Shibaev H. J. Deussen A. Yu. Bobrovsky P. V. Shibaev N. I. Boiko T. Bjrnholm K. Schaumburg K. Bechgaard 《Polymer Engineering and Science》1997,37(6):945-951
Novel comb-shaped liquid crystalline acrylic copolymers consisting of nematogenic methoxy-phenylbenzoate acrylic monomers (A) together with novel chiral binaphthol (BN) methacrylic monomers (MB-m) were synthesized in this study. The prepared copolymers differ in spacer lengths of MB-m (m = 3, 5, 11) and in their compositions. The homopolymers of the three new chiral BN monomers MB-m were also prepared. Copolymers with a low concentration of BN monomeric units (less than 16 mol %) display a cholesteric mesophase. The induced chirality in the polymers is due to atropisomerism (chirality due to hindered rotation around single bonds) of the BN molecules. The helical twisting power β (HTP) caused by the atropisomeric units in the synthesized copolymers was shown to decrease significantly on heating. The unusually high negative temperature coefficient of HTP observed above the glass transition temperature (Tg) could be explained in terms of conformational changes of the BN molecules in the copolymers. 相似文献
7.
J von Kempis P Kalden J Gutfleisch B Grimbacher T Krause M Uhl UP Ketelsen B Volk E R?ther P Vaith HH Peter 《Canadian Metallurgical Quarterly》1998,17(5):207-213
The widespread use and dramatic success of prosthetic joint implant surgery (arthroplasty) has greatly improved the quality of life for many individuals suffering from degenerative, arthritic, or injured joints. However, in a number of cases, recipients experience discomfort at the arthroplasty site that can signal biomechanical failure, or periprosthetic infection of the joint, or both. In fact, infection remains a devastating obstacle, preventing arthroplasty from being an almost perfect medical procedure. Existing tests for the diagnosis of infection in orthopedics are disappointing because of the relatively high frequency of false negative results. To overcome this shortcoming, and to reduce the number of infected revision arthroplasties, a methodology based on molecular biology has been established. The method allows the rapid, sensitive and accurate diagnosis of orthopedic infections, and should aid the clinician with treatment regimens, surgical decisions, and overall patient management in the growing arthroplasty population. 相似文献
8.
BACKGROUND: Normovolemic hemodilution is a well-accepted method for intraoperative blood salvage. However, some controversy exists concerning the possible risk of myocardial fiber injury as consequence of the reduced oxygen content. Laboratory diagnosis of perioperative myocardial fiber injury is difficult, since biochemical markers are elevated postoperatively due to the surgical trauma. Cardiac troponin I (cTnI) is a new, highly sensitive and specific marker for the detection of myocardial injury. The aim of our study was to investigate whether normovolemic hemodilution in patients with major orthopedic surgery (13 hemodiluted patients, 15 control) induces a release of cTnI. METHODS: cTnI as a highly specific and sensitive cardiac parameter, as well as total creatine kinase (CK), creatine kinase isoenzyme MB mass (CKMB mass) and myoglobin were measured after induction of anesthesia, after normovolemic hemodilution, prior to retransfusion of blood components, 3 h after surgery, and on the first and third postoperative days. RESULTS: Prior to retransfusion of blood components the hematocrit was decreased to 25.4 +/- 1.2% (mean +/- SEM; range: 18%-34%) in the control group and to 20.2 +/- 0.8% (mean +/- SEM; range: 17%-24%) in the hemodilution group. Total CK, CKMB mass as well as myoglobin concentration increased significantly in both groups, reaching their maxima within the first day of surgery. In contrast, cTnI was below the detection limit of assay (< 0.5 micrograms/L) at any time. CONCLUSIONS: We suggest that pre- and intraoperative hemodilution to a hematocrit of approximately 20% by maintaining normovolemia does not induce myocardial fiber injury in patients without preexisting cardiac diseases. 相似文献
9.
UP Schmiedl C Yuan HV Nghiem TC Winter PC Freeny 《Canadian Metallurgical Quarterly》1996,17(4):404-411
MR angiography (MRA) for the evaluation of peripheral arterial occlusive disease is a rapidly evolving technique. Recent prospective clinical trials have indicated that MRA may play an important role in the evaluation of patients with peripheral arterial disease. This article discusses the pertinent technical aspects and limitations of peripheral MRA as well as some of the clinical data available. 相似文献
10.
D. Yachil J. Davidson B. Bobrovsky 《International Journal of Satellite Communications and Networking》2006,24(1):1-22
In satellite communications, the space segment is a large slice of the operating costs. Therefore every effort should be made to increase the spectral efficiency, thereby reducing the space segment costs. In order to optimize spectral efficiency, channel spacing (CS) should be reduced. Unfortunately, this introduces spectrally overlapping transmissions, thereby creating adjacent channel interference (ACI), which impairs the performance of satellite communication systems. To overcome this problem, intelligent interference mitigation schemes should be considered. This paper considers the problem of multi‐channel synchronization of several spectrally overlapping transmissions in a satellite TDMA/frequency division multiple access burst system. The synchronization aims to estimate carrier frequency, carrier phase and symbol timing in the presence of ACI. The potential performance gain of multi‐channel processing over conventional single channel processing is shown. Two types of low‐complexity algorithms are proposed: ‘channelized’ expectation maximization and ‘channelized’ interference cancellation. Both of these algorithms attain this performance gain. Computer simulations show a 78% improvement in spectral efficiency for a wide range of carrier‐imbalance values. This translates into a large potential saving in space segment costs compared to conventional CS. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献