全文获取类型
收费全文 | 609篇 |
免费 | 12篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 6篇 |
综合类 | 1篇 |
化学工业 | 30篇 |
金属工艺 | 7篇 |
机械仪表 | 17篇 |
建筑科学 | 8篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 89篇 |
无线电 | 40篇 |
一般工业技术 | 51篇 |
冶金工业 | 326篇 |
原子能技术 | 4篇 |
自动化技术 | 41篇 |
出版年
2022年 | 2篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 10篇 |
2013年 | 14篇 |
2012年 | 16篇 |
2011年 | 19篇 |
2010年 | 8篇 |
2009年 | 10篇 |
2008年 | 14篇 |
2007年 | 17篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 18篇 |
2002年 | 19篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 18篇 |
1998年 | 91篇 |
1997年 | 64篇 |
1996年 | 33篇 |
1995年 | 24篇 |
1994年 | 19篇 |
1993年 | 16篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 10篇 |
1976年 | 23篇 |
1968年 | 3篇 |
1965年 | 4篇 |
1960年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有623条查询结果,搜索用时 15 毫秒
141.
WM Sy IS Seo CJ Homs R Gulrajani P Sze KF Smith J McBride 《Canadian Metallurgical Quarterly》1998,12(2):77-82
OBJECTIVE: The aim of this study was to assess the capability of high-resolution images obtained with a commercially available pelvic phased-array surface coil to demonstrate normal hip anatomy. DESIGN: We retrospectively analyzed the oblique coronal magnetic resonance (MR) images of hips of 36 consecutive patients acquired on a 1.5-T clinical imager using a pelvic phased-array coil as a receiver, a 16-20 cm field of view, and 5 mm slice thickness. PATIENTS: Thirty-six patients were studied, age 15-81 years. There were 20 males and 16 females. RESULTS AND CONCLUSIONS: The articular cartilage, cortex, superior labrum, and iliofemoral ligament were well visualized on proton density weighted fat saturation (PDF) images. The femoral and obturator vessels, obturator nerve, and various muscles were easily seen on T1-weighted images. High-resolution imaging of the hip is achievable in a reasonable amount of time using newer phased-array surface coils and may play an increasing role in the future evaluation of hip disorders. 相似文献
142.
Brody Gene H.; Murry Velma McBride; Kogan Steven M.; Gerrard Meg; Gibbons Frederick X.; Molgaard Virginia; Brown Anita C.; Anderson Tracy; Chen Yi-fu; Luo Zupei; Wills Thomas Ashby 《Canadian Metallurgical Quarterly》2006,74(2):356
The Strong African American Families Program, a universal preventive intervention to deter alcohol use among rural African American adolescents, was evaluated in a cluster-randomized prevention trial. This 7-week family skills training program is based on a contextual model in which intervention effects on youth protective factors lead to changes in alcohol use. African American 11-year-olds and their primary caregivers from 9 rural communities (N = 332 families) were randomly selected for study participation. Communities were randomized to prevention and control conditions. Intent-to-treat analyses indicated that fewer prevention than control adolescents initiated alcohol use; those who did evinced slower increases in use over time. Intervention-induced changes in youth protective factors mediated the effect of group assignment on long-term changes in use. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
143.
Gerrard Meg; Gibbons Frederick X.; Brody Gene H.; Murry Velma McBride; Cleveland Michael J.; Wills Thomas A. 《Canadian Metallurgical Quarterly》2006,20(2):185
This study examined mediators of the Strong African American Families Program, a randomized, dual-focus prevention trial intended to delay the onset of alcohol use and reduce alcohol consumption among rural African American youths. More specifically, it demonstrated that changes in consumption 2 yrs after the intervention were mediated through 2 different paths, a social reaction path and a reasoned/intention path. The social reaction path provided evidence that relative to the control condition, the intervention decreased children's willingness to drink by making their images of drinkers less favorable. The reasoned/intention path provided evidence that the intervention influenced the children's intentions to drink by increasing targeted parenting behaviors related to alcohol. Furthermore, the data demonstrate that these changes in willingness and intentions were independently associated with alcohol consumption at the follow-up, and they suggest that a dual-process model approach that targets both intentions and willingness can be more successful than either approach alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
144.
145.
D Rosen A Wirtschafter VM Rao TO Wilcox 《Canadian Metallurgical Quarterly》1998,77(2):125, 129-125, 132
Dermoid cysts of the lateral neck are rare, with the majority of head and neck dermoids occurring in the midline. The demonstration of a fat-fluid level on MRI or CT is diagnostic for a cervical dermoid cyst. The treatment of choice remains surgical excision. 相似文献
146.
JC Bornstein JB Furness HF Kelly RA Bywater TO Neild PP Bertrand 《Canadian Metallurgical Quarterly》1997,64(2-3):143-157
Recent electrophysiological studies of the properties of intestinal reflexes and the neurons that mediate them indicate that the intrinsic sensory neurons may transmit to second order neurons via either fast (30-50 ms duration) or slow (10-60 s duration) excitatory synaptic potentials or both. Which of these possible modes of transmission is involved in the initiation of motility reflexes has not been determined and it is not clear and what the consequences of the different forms of synaptic transmission would be for the properties of the reflex pathways. In the present study, this question has been addressed by the use off a suite of computer programs, Plexus, which was written to simulate the activity of the neurons of the enteric nervous system during intestinal reflexes. The programs construct a simulated enteric nerve circuit based on anatomical and physiological data about the number, functions and interconnections of neurons involved in the control of motility. The membrane potentials of neurons are calculated individually from physiological data about the reversal potentials and membrane conductances for Na+, K+ and Cl-. Synaptic potentials are simulated by changes in specific conductances based on physiological data. The results of each simulation are monitored by recording the membrane potentials of up to 16 separate defined neurons and by recording the summed activity of whole classes of neurons as a function of time and location in the stimulated network. The present series of experiments simulated the behaviour of a network consisting of 18,898 sensory neurons and 3708 ascending interneurons after 75% of the sensory neurons lying in the anal 10 mm of a 30 mm long segment of small intestine were stimulated once. The results were compared with electrophysiological data recorded from myenteric neurons during ascending reflexes evoked either by distension or mechanical stimulation of the mucosa. When transmission from sensory neurons to ascending interneurons was via fast excitatory synaptic potentials, the latencies and durations of the simulated responses were too brief to match the electrophysiologically recorded responses. When transmission from sensory neurons was via slow excitatory synaptic potentials, the latencies were very similar to those recorded physiologically, but the durations of the stimulated responses were much longer than seen in physiological experiments. The latencies and durations of simulated and physiologically recorded responses matched only when the firing of ascending interneurons was limited to the beginning of a slow excitatory synaptic (in this study by limiting the duration of the decrease in K+ conductance). The simulation provided several physiologically testable predictions, indicating that Plexus is an important tool for the investigation of the properties and behaviour of the enteric nervous system. 相似文献
147.
148.
Kramer SM McBride SL Mair HD Hutchins DA 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1988,35(2):253-263
The transient pressure fields of ideal planar ultrasonic transducers may be described in terms of plane and edge wave contributions. Based on this concept, a technique is developed which allows characterization of wideband unfocused transducers by a single measurement close to the transducer face. This method is examined experimentally for both polyvinylidene difluoride and commercial PZT transducers. Also investigated is the effective radiated frequency of these devices. 相似文献
149.
McBride JS 《Computers in healthcare》1993,14(13):38, 40
The world's largest cancer center, New York's Memorial Sloan-Kettering, is finding concrete efficiencies--and real savings--by implementing "OSCAR" the Optical System Controlling Administrative Records. The system now handles more than 2.7 million documents, including patient accounts and medical records. 相似文献
150.