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1.
We studied 722 reexcision scars of benign and malignant lesions (except melanocytic lesions) excised over a 24-month period. The formalin-fixed, paraffin-embedded tissue sections were examined histologically and immunohistochemically. The histological features of melanocytic hyperplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most common sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). Basal cell carcinoma was the most frequent original lesion in both sexes (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen this reaction pattern following reexcision of melanocytic lesions as well. Thus, interpreting reexcision margins when lentigo maligna or similar lesions are reexcised may be fraught with difficulty. It is important for pathologists and dermatopathologists to recognize this phenomenon because histologically the presence of increased numbers of large melanocytes could be misinterpreted as melanoma in situ.  相似文献   
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Meckel's diverticulum is one of the primary concerns in the differential diagnosis of the pediatric patient with massive, acute gastrointestinal bleeding, intussusception, or abdominal pain of uncertain cause. The hospital course of two children with Meckel's diverticulum, successfully treated by laparoscopic excision, is presented, along with details of the operative procedure. Both patients recovered from the procedure without incident and were discharged at 24 and 48 hours after surgery. The authors believe a laparoscopic approach is safe and effective in the diagnosis and treatment of Meckel's diverticulum.  相似文献   
4.
We report 40-Gb/s capability of 50-mum core plastic optical fiber using differential modal delay measurements and power penalty due to intersymbol interference computations. The results are explained via a comprehensive multimode fiber model that includes mode coupling (MC) and differential modal attenuation (DMA). We show that strong MC can enable 40-Gb/s transmission for reach in excess of 100 m even in the presence of irregularities in the refractive index profile that prevent 10-Gb/s performance without MC. Furthermore, we show that DMA effects are negligible and that the mode power distributions are not a good indicator of bandwidth.  相似文献   
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This study explored influences of story structure properties on recall of story events by children with and without attention deficit hyperactivity disorder (ADHD). Participants listened to and retold 2 stories. Two properties of the stories' causal structure were derived: the number of causal connections an event has to other events and whether an event is on the causal chain linking events from beginning to end. The extent to which causal properties and the more subjective property of perceived importance predicted recall in the 2 groups of children was examined. Each property predicted recall, but there were group differences in sensitivity to causal structure that were moderated by intelligence level and gender. Variations in amount and allocation of cognitive resources applied to comprehension contributed to performance of children with ADHD. There are implications for understanding academic and social difficulties common in children with ADHD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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X-band performance, high temperature D.C. operation and uniformity have been evaluated for 1 μm gate AlGaN/GaN HEMTs grown by RF atomic nitrogen plasma MBE. Deposition and fabrication were performed on 2-inch (0001) sapphire substrates to determine process uniformity. HEMTs with 300 μm total gate width and dual gate finger geometry have been fabricated with 650–700 cm2 V−1×s mobility. Maximum frequency cut-offs on the order of 8–10 GHz were achieved. D.C. performance at room temperature was >500 mA mm−1, and external transconductance was >70 mS mm−1. The transistors operated at test temperatures of 425°C in air.  相似文献   
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Four experiments were conducted to assess infants' ability to solve isomorphic problems and to explore the nature of early representations. Ten- and 13-month-olds attempted to solve problems that required combining 2 subgoals to bring a toy (goal object) within reach. A problem-series paradigm was used in which 3 tasks differing in surface features but sharing common goal structures and similar solutions were presented. The results indicate that 13-month-olds transferred a modeled solution strategy across isomorphic problems, whereas 10-month-olds did so only after experiencing either multiple source problems or high perceptual similarity between problems. Comprehension of the relations between solution actions and outcome, and between tools and target object, appeared critical to transfer. The results suggest that 1-year-olds can construct relatively abstract and flexible mental representations and that analogical problem solving may be 1 of the major accomplishments during the 1st year of life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Historically, science of science (Sci2) studies have been performed by single investigators or small teams. As the size and complexity of data sets and analyses scales up, a “Big Science” approach (Price, Little science, big science, 1963) is required that exploits the expertise and resources of interdisciplinary teams spanning academic, government, and industry boundaries. Big Sci2 studies utilize “big data”, i.e., large, complex, diverse, longitudinal, and/or distributed datasets that might be owned by different stakeholders. They apply a systems science approach to uncover hidden patterns, bursts of activity, correlations, and laws. They make available open data and open code in support of replication of results, iterative refinement of approaches and tools, and education. This paper introduces a database-tool infrastructure that was designed to support big Sci2 studies. The open access Scholarly Database (http://sdb.cns.iu.edu) provides easy access to 26 million paper, patent, grant, and clinical trial records. The open source Sci2 tool (http://sci2.cns.iu.edu) supports temporal, geospatial, topical, and network studies. The scalability of the infrastructure is examined. Results show that temporal analyses scale linearly with the number of records and file size, while the geospatial algorithm showed quadratic growth. The number of edges rather than nodes determined performance for network based algorithms.  相似文献   
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OBJECTIVE: To study the effects of monopolar diathermy on the bile ducts in pigs. DESIGN: Experimental study. SETTING: University hospital, Norway. MATERIAL: 18 pigs. INTERVENTIONS: Laparotomy, application of diathermy at standard sites along the cystic duct, the bile ducts, and a cystic duct containing a metal clip, 3 to 12 times of 5 seconds' duration at each site. Temperature was subsequently recorded at standard measurement points on the bile ducts. Twelve pigs were killed after three weeks for assessment of the bile ducts at necropsy. MAIN OUTCOME MEASUREMENTS: Increase in temperature in the bile duct walls and late changes in the bile ducts. RESULTS: Temperature increased by 4-6 degrees C during 6 of 330 diathermy applications along the cystic duct, by 4-18 degrees C in 8 of 126 applications along the common bile duct, and by 4-11 degrees C at the clip in 9 of 54 applications. There were no macroscopic or microscopic changes in the bile ducts. CONCLUSION: Monopolar diathermy induced unexpected distant increases in the temperature of the bile duct walls and at a clip on the cystic duct probably because diathermy current energy was distributed along channels of high current conductivity.  相似文献   
10.
JW Polley  FT Charbel  D Kim  MF MaFee 《Canadian Metallurgical Quarterly》1998,102(3):619-28; discussion 629-32
This paper presents a prospective longitudinal outcome study on patients with nonsyndromal craniosynostosis who were treated with the contemporary craniofacial surgical techniques of suture release, cranial decompression, and cranial and orbital reconstruction and reshaping in infancy. Diagnosis, surgical treatment, and long-term results and complications are reviewed. Preoperative and long-term postoperative intracranial volumes in these patients were evaluated and compared with age and gender match controls throughout the period of the study. From July 1, 1990, to July 1, 1994, 25 patients with isolated nonsyndromal craniosynostosis underwent surgery of the deformity. Eight patients were excluded from the study based on incomplete postoperative computed tomography (CT) records. Of the 17 patients with long-term computerized records, 11 were boys and 6 were girls. The nonsyndromal craniosynostosis patients in this study include six with bilateral coronal craniosynostosis, six with unilateral coronal craniosynostosis, four with sagittal craniosynostosis, and one with metopic craniosynostosis. The average age at the time of surgery for all patients was 9 months, and the average age at the time of the latest follow-up CT scan for all patients in the study was 3.5 years. There were no perioperative complications in this series of patients including no bleeding, no infection, no wound healing complications, and no mortality. Bony fixation included a combination of wire osteosynthesis and rigid microfixation. All patients had only one surgical procedure for the correction of their deformity. Evaluation of both preoperative and long-term postoperative intracranial volume measurements in this series of patients revealed that these volume measurements were comparable with the gender match control groups at all ages throughout the study. The significance of these findings for this longitudinal outcome study is discussed.  相似文献   
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