首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   178篇
  免费   12篇
电工技术   10篇
化学工业   58篇
金属工艺   3篇
机械仪表   1篇
建筑科学   2篇
能源动力   11篇
轻工业   24篇
水利工程   2篇
无线电   12篇
一般工业技术   25篇
冶金工业   21篇
原子能技术   3篇
自动化技术   18篇
  2024年   1篇
  2023年   3篇
  2022年   6篇
  2021年   8篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   4篇
  2016年   10篇
  2015年   4篇
  2014年   8篇
  2013年   13篇
  2012年   6篇
  2011年   3篇
  2010年   7篇
  2009年   8篇
  2008年   6篇
  2007年   7篇
  2006年   8篇
  2005年   2篇
  2004年   8篇
  2003年   5篇
  2002年   5篇
  2001年   5篇
  2000年   3篇
  1999年   5篇
  1998年   10篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1993年   5篇
  1992年   3篇
  1991年   3篇
  1990年   2篇
  1989年   5篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   1篇
  1983年   3篇
  1981年   1篇
  1978年   1篇
  1977年   2篇
  1967年   1篇
排序方式: 共有190条查询结果,搜索用时 15 毫秒
101.
Combination chemotherapy with CDDP and 5-FU is one of the effective regimens for head and neck cancer. We studied the difference in the effects and adverse effects between two kinds of schedules of CDDP administration for CDDP-5-FU combination chemotherapy. For 13 patients, CDDP was administered on 5 consecutive days from day 1 to day 5 at a daily dose of 16 mg/m2 (Regimen A). For 14 patients CDDP was administered 80 mg on day 1 (Regimen B). 5-FU was administered 700 mg/m2/ day as a continuous drip infusion for 120 hours from day 1 to day 5. For regimen A, the response rate was 77%; for regimen B, it was 64%. The pattern of adverse effects showed a difference. Regimen B was more toxic for renal function than regimen A. But regimen A showed toxicity for bone marrow function. Acute phase nausea and vomit appeared more frequently in regimen B. The difference in the adverse effect pattern, which depends on the schedule of CDDP administration, seems important in order to apply this regimen for head and neck cancer patients safely. The schedule of CDDP administration should be changes depending on the renal and bone marrow function of patients. In order to evaluate the efficacy of UFT as adjuvant chemotherapy, UFT was administered p.o. to patients with maxillary sinus carcinoma for more than one year after definitive treatment with surgery or radiotherapy. Fifteen patients with UFT adjuvant chemotherapy showed significantly better survival rates than patients without adjuvant chemotherapy. We also studied adjuvant chemotherapy with CBDCA and FT for patients with advanced head and neck cancer. Administration with UFT (600 mg/day) from day 1 to day 14 with CBDCA 350 mg/m2 at day 7 was repeated more than twice. This regimen showed low toxicity and better survival for nasopharyngeal cancer patients. More clinical trials with this regimen for adjuvant chemotherapy are needed.  相似文献   
102.
Although adult sycamore lace bugs Corythucha ciliata (Say) show no sign of aggregation, nymphs at all developing stages are gregarious. When an individual nymph in the center of a colony was squashed with a needlepoint, proximate nymphs showed evasive behavior. The same evasive reaction was produced by exposing aggregated nymphs to nymph hexane extract. The active component, E-3,7-dimethyl-2,6-octadien-1-ol, geraniol, was responsible for the evasive behavior, and identified as the alarm pheromone. One nanogram of the alarm pheromone elicited activity similar to that in a third instar nymph. Presence of 2-acylcyclohexane-1,3-diones and their 4-hydroxy analogues are reconfirmed as nymph-specific components, though their biological significance remains unknown.  相似文献   
103.
We conducted an experimental investigation of natural convection in an enclosure containing horizontal parallel heated plates. Our experimental setup was as follows: Two heated plates were arranged vertically in an enclosure. The temperature of the ceiling was maintained at a constant low temperature, while the other sides satisfied thermal insulation boundary conditions. We examined flow characteristics in the enclosure and heat transfer around the horizontal heated plates. In the region between the cooled ceiling and the upper heated surface, vortex motion occurred when the accompanying flow from the lower region interfered with the ascending flow. Heat transfer around the heated surface was enhanced by this vortex motion. In other regions, the flow circulated along the heated surfaces in all cases. Generally speaking, for each flow pattern, the Nusselt number was proportional to some power of the modified Rayleigh number.  相似文献   
104.
We introduce advanced servo techniques for optical disk drives. High speed and precise optcal beam-positioning and following controls are required archival memories such as high density and high data transfer rate optical disk drives for recording many data and high quality moving pictures toward next generation systems. The zero phase error tracking-feed-forward (ZPET-FF) control method is effective for the next generation systems, which have high disk rotation speed beyond the limit of 10,000 rpm of optical disk drives such as current CDs, DVDs or Blu-ray discs. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.  相似文献   
105.
A series of DNA-linked RNases H, in which the 15-mer DNA iscross-linked to the Thermus thermophilus RNase HI (TRNH) variantsat positions 135, 136, 137 and 138, were constructed and analyzedfor their abilities to cleave the complementary 15-mer RNA.Of these, that with the DNA adduct at position 135 most efficientlycleaved the RNA substrate, indicating that position 135 is themost appropriate cross-linking site among those examined. Toexamine whether DNA-linked RNase H also site-specifically cleavesa highly structured natural RNA, DNA-linked TRNHs with a seriesof DNA adducts varying in size at position 135 were constructedand analyzed for their abilities to cleave MS2 RNA. These DNAadducts were designed such that DNA-linked enzymes cleave MS2RNA at a loop around residue 2790. Of the four DNA-linked TRNHswith the 8-, 12-, 16- and 20-mer DNA adducts, only that withthe 16-mer DNA adduct efficiently and site-specifically cleavedMS2 RNA. Primer extension revealed that this DNA-linked TRNHcleaved MS2 RNA within the target sequence.  相似文献   
106.
Implementation of the TX1 VLSI microprocessor is described. Particular emphasis is placed on the design method, which meets the requirements of short design time with reasonable chip size. A one-phase clock system, which is a better solution for high-speed operation but requires careful design for evading the skew problem, is discussed. Design for testability is embedded in the chip. The TX1 is fabricated with a 1.0 μm two-layer metal CMOS process. The chip contains 450 K transistors in a 10.89×10.27 mm2 die  相似文献   
107.
The chemotactic activity of the culture supernatants from 14 strains of Lactobacillus acidophilus and L. gasseri was examined for murine macrophages. Significant macrophage chemotactic activity was observed in three strains of L. acidophilus and all strains of L. gasseri. The highest activity was observed in the supernatant (1131-sup) from 24-h cultures of L. gasseri JCM1131T. The chemotactic factor from 1131-sup, designated as "Gasserokine", was purified by the C18 reverse phase and ion-exchange chromatography. The purity of Gasserokine was checked by HPLC with the reverse-phase mode. The chemotactic activity of Gasserokine was also observed for human monocytes. The macrophage chemotaxis induced by L. gasseri JCM1131T culture supernatants was discovered to be a new biological function exerted by probiotic lactic acid bacteria. Therefore, the activity is expected to be used for one of the functional parameters in the immunomodulating properties of probiotic lactic acid bacteria.  相似文献   
108.
A knowledge-based software tool for developing interactive robot applications, called SPAK, has been developed. The “world” of interest is represented in a SPAK knowledge base by using a frame knowledge technique. This technique is chosen because it can represent the world meaningfully and naturally. Relationships among frames, which represent things in the world, and actions to be taken when certain things occur can be specified. In action, SPAK perceives changes in the environment, updates the knowledge base if needed, and generates output actions according to the knowledge contents. To support robotic applications, extensions to the conventional frame model are proposed. Various robotic applications can run cooperatively on top of SPAK. Each can easily make use of the knowledge available, and share its knowledge with others. A SPAK knowledge editor allows simple and intuitive development and modification of robot applications. To demonstrate these benefits, a prototype system and a sample robot application are developed. A multiagent technique is employed to combine various robotic components, both hardware and software, together. A sample dialogue manager for managing interactions with humans runs as an application on SPAK.  相似文献   
109.
Polycrystalline thin films of La-substituted bismuth titanate (BLT) were formed directly on p-type Si(100) substrates by using sol-gel and spin coat methods. The BLT film and interfacial layer between BLT and Si were quantitatively investigated by the X-ray reflectivity method. Also, crystal orientations of sub-100-nm-thick BLT thin films were confirmed by X-ray diffraction using a synchrotron radiation source. The preferred c-axis orientation normal to the surface depended on the crystallization temperature. The difference in the preferred c-axis orientations of the BLT films caused the difference in the hysteresis voltage width in the capacitance-voltage characteristics of Au/BLT/p-Si structures. Furthermore, the c-axis of the Bilayered structure was preferentially oriented and aligned in the in-plane direction.  相似文献   
110.
Two extremely thermophilic alkane-degrading bacterial strains, B23 and H41, were respectively isolated from deep subterranean petroleum reservoirs in the Minami-aga (Niigata) and Yabase (Akita) oil fields. Both strains were able to grow at temperatures ranging from 50 to 80 degrees C, with optimal growth at 70 degrees C for B23 and 65 degrees C for H41. From 16S rRNA gene sequence analysis and physiological characterization, both strains were identified as Bacillus thermoleovorans (identities of 99.5% and 99.6% to strain DSM 5366, and 98.3% and 98.7% to the type strain LEH-1(TS), respectively). Strains B23 and H41 effectively (60%) degraded n-alkanes longer than C12 and C15, respectively, at 70 degrees C, while strain LEH-1(TS) degraded undecane (C11) most effectively. When B23 and H41 were cultivated in the presence of heptadecane, heptadecanoate and pentadecanoate were specifically accumulated in the cells. These results strongly suggest that the two strains degraded n-alkanes by a terminal oxidation pathway, followed by a beta-oxidation pathway.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号