全文获取类型
收费全文 | 1024篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 69篇 |
金属工艺 | 5篇 |
机械仪表 | 3篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 23篇 |
水利工程 | 1篇 |
无线电 | 40篇 |
一般工业技术 | 14篇 |
冶金工业 | 846篇 |
自动化技术 | 24篇 |
出版年
2019年 | 3篇 |
2018年 | 3篇 |
2016年 | 3篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 6篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 9篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 20篇 |
1998年 | 265篇 |
1997年 | 168篇 |
1996年 | 115篇 |
1995年 | 52篇 |
1994年 | 49篇 |
1993年 | 48篇 |
1992年 | 10篇 |
1991年 | 17篇 |
1990年 | 11篇 |
1989年 | 15篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 17篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 22篇 |
1976年 | 57篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1968年 | 3篇 |
1966年 | 3篇 |
1955年 | 2篇 |
1924年 | 1篇 |
1921年 | 1篇 |
排序方式: 共有1031条查询结果,搜索用时 15 毫秒
991.
PURPOSE: We determined whether early surgical intervention for ischemic penile gangrene in diabetics can be successful and limit morbidity. MATERIALS AND METHODS: A retrospective review was done of 7 diabetic patients with ischemic penile gangrene. RESULTS: Three patients underwent early distal penectomy without complications. All 4 patients initially observed suffered liquefaction and progression from dry to wet gangrene, and 2 underwent surgery (subtotal penectomy in 1 and distal penectomy in 1 who required reoperations for wound complications). CONCLUSIONS: With appropriate patient selection, surgical intervention can be successful and provide a better quality of life for those without terminal disease. Delaying intervention will usually require more extensive surgery and increase the risk of wound complications. However, observation is indicated for moribund hospitalized patients. 相似文献
992.
I Claro CN Leit?o P Oliveira J Correia JD da Costa JM Almeida FC Mira 《Canadian Metallurgical Quarterly》1996,43(12):1653-1655
Tuberculous mesenteric lymphadenitis is a rare clinical entity and non-surgical diagnosis of this condition remains a challenge. A 38-year-old Indian woman presented with a six-week history of epigastric pain, low-grade fever and anorexia. Upper endoscopy showed a gastric ulcer of the posterior wall of the stomach. On CT scan there was a 8 cm abdominal mass involving the pancreatic body and tail and the endoscopic ultrasonography was also compatible with a cystic pancreatic tumor which had eroded into the stomach. An exploratory laparotomy was performed and the diagnosis of tuberculous mesenteric lymphadenitis was confirmed by bacteriological and histological examinations. Medical therapy was started after surgery. At 18 months she is asymptomatic and abdominal CT scan is normal. Tuberculosis of mesenteric lymph nodes usually raises serious diagnostic problems. A high grade of suspicion is necessary in order to perform a pre-operative diagnosis. 相似文献
993.
The health professional multimedia workstation is the natural entry point to health and knowledge networks. It should allow an easy and transparent management of all the data necessary for patient management. Multimedia nature of processed information reflects evolution of medical techniques that involve more and more complex objects such as video sequences or digitized signals. Workstations can be considered from 3 points of view: the professional end-users, the developers and the decision makers. The long term goal for the end-user is to establish an easy access in a working environment, that gives him/her the feeling of a single comprehensive application running on a single computer when the information system relies on a set of heterogeneous and geographically distributed components. Development of a workstation requires the integration into the same environment of tools to localize, access, manipulate and communicate the required information within a health information network. Analysis of the 445 Medline-indexed publications for the January 1991 to December 1994 period, that included the word workstation either in their title or in their abstract, helps in refining objectives and challenges both for the health professionals and the decision makers. 相似文献
994.
995.
J Herbergs JW Arends EM Bongers FC Ramaekers AH Hopman 《Canadian Metallurgical Quarterly》1996,16(2):106-112
To examine primary care physician recognition of hypochondriacal patients, we identified a series of such patients in a general medicine clinic using the Whiteley Index. Clinic physicians made blind global ratings of severity of physical disease and unreasonable fear of illness (hypochondriasis) and completed a checklist of somatizing characteristics. Patient records were audited for diagnoses, laboratory tests, consultations, and medications prescribed. Twenty-nine (14%) of 210 patients scored above an established cutoff on the Whiteley Index. These hypochondriacal patients were rated by clinic physicians as more hypochondriacal and were more often given psychiatric diagnoses. Also, clinic physicians identified more somatizing features among hypochondriacal patients including their own reaction to them. This recognition of hypochondriac characteristics may have contributed to better management but may need to be raised to the diagnostic level for maximum benefit. 相似文献
996.
SE Clarke NE Austin JC Bloomer RE Haddock FC Higham FJ Hollis M Nash PC Shardlow TC Tasker FR Woods 《Canadian Metallurgical Quarterly》1994,24(11):1119-1131
1. The disposition and metabolic fate of 14C-granisetron, a novel 5-HT3 antagonist, was studied in rat, dog, and male human volunteers after intravenous and oral administration. 2. Complete absorption occurred from the gastrointestinal tract following oral dosing, but bioavailability was reduced by first-pass metabolism in all three species. 3. There were no sex-specific differences observed in radiometabolite patterns in rat or dog and there was no appreciable change in disposition with dose between 0.25 and 5 mg/kg in rat and 0.25 and 10 mg/kg in dog. Additionally, there were no large differences in disposition associated with route of administration in rat, dog and man. 4. In rat and dog, 35-41% of the dose was excreted in urine and 52-62% in faeces, via the bile. Metabolites were largely present as glucuronide and sulphate conjugates, together with numerous minor polar metabolites. In man, about 60% of dosed radioactivity was excreted in urine and 36% in faeces after both intravenous and oral dosing. Unchanged granisetron was only excreted in urine (5-25% of dose). 5. The major metabolites were isolated and identified by MS spectroscopy and nmr. In rat, the dominant routes of biotransformation after both intravenous and oral dosing were 5-hydroxylation and N1-demethylation, followed by the formation of conjugates which were the major metabolites in urine, bile and plasma. In dog and man the major metabolite was 7-hydroxy-granisetron, with lesser quantities of the 6,7-dihydrodiol and/or their conjugates. 相似文献
997.
FC Rector NW Carter DW Seldin 《Canadian Metallurgical Quarterly》1998,9(6):1134-45; discussion 1134-9
The mechanism of HCO3- reabsorption in proximal and distal tubules was examined in rats undergoing NaHCO3 diuresis. The steady-state intratubular pH was measured with pH-sensitive glass microelectrodes and compared with the equilibrium pH calculated from the HCO3- concentration of the tubular fluid (measured with quinhydrone electrodes) and plasma Pco2. In the proximal tubule the intratubular pH and the equilibrium pH were identical, indicating no accumulation of excess H2CO3. After inhibition of carbonic anhydrase, however, intratubular pH was significantly lower (0.85 pH U) than the equilibrium pH. It was concluded that HCO3- reabsorption in the proximal tubule was mediated by H+ secretion, but that carbonic anhydrase located in the luminal membrane of the cell prevented H2CO3 from accumulating in the tubular fluid. In the distal tubule the intratubular pH was 0.85 U lower than the equilibrium pH. This difference could be obliterated by an intravenous injection of carbonic anhydrase. It was concluded that HCO3- reabsorption in this segment was also accomplished by H+ secretion. The accumulation of excess H2CO3 in the tubular fluid indicated that, in contrast to the proximal tubule, carbonic anhydrase was not located in the luminal membrane of distal tubular cells. 相似文献
998.
FC Luft 《Canadian Metallurgical Quarterly》1997,75(6):387-388
To improve management of risk factors in patients diagnosed with significant coronary artery disease after day case angiography, we gave patients a discharge information sheet emphasising the importance of prognostic therapy, risk factors and follow-up. The sheet was evaluated in 40 patients. A nurse talked through the information sheet with the patients after their angiogram and helped to complete relevant sections. One group of patients was given a copy of the sheet to take home, while the second group remained a 'verbal information only' group. Providing written information resulted in improvements in follow-up regarding blood pressure and drug therapy checks, but there was no significant difference between the groups in the follow-up management of cholesterol or in patient awareness of their cholesterol level. Patients were not likely to remember the sheet, even though a nurse had talked them through it, unless it was backed up with a written copy which could be taken away. It became apparent that the vast majority of patients remembered a pictorial representation of the extent of their disease (routinely provided) in contrast to the relatively disappointing numbers (43%) who remembered the information sheet. To evaluate further the importance of content and style in effective information delivery, we are evaluating the combination of written information with a visual representation of the heart. 相似文献
999.
L Zamorano FC Vinas R Buciuc Z Jiang OH Li FG Diaz 《Canadian Metallurgical Quarterly》1997,40(3):79-82
We describe an open ring as a new design to the Zamorano-Dujovny (Z-D) stereotactic unit. The titanium base ring has an opening of 45 degrees that can be located in any chosen position. Imaging studies such as computed tomography, X-ray, positron emission tomography, digital angiography, and digital substraction angiography can be performed with the open stereotactic ring for multimodality image localization. Preoperatively and intraoperatively, this open design provides the anesthesiologist with an unobstructed pathway for airway management. During the surgical procedure, it facilitates approach to any intracranial lesion, including orbitozygomatic, combined supra-infratentorial, and others. During awake craniotomies it not only allows for easy airway management, but also provides good access to the patient's face for intraoperative evaluation of speech and visual functions. Accuracy and reliability of this unit were similar to results obtained with the original circular ring. This system can be used in conventional stereotaxis with the Z-D arc, as well as a reference for intraoperative registration with any digitizer system. The open stereotactic unit is a relatively inexpensive, reliable, and easy-to-use solution for resections using conventional stereotaxis or interactive image guidance in any intracranial site. 相似文献
1000.
J van Bavel SR Findlay FC Hampel BG Martin P Ratner E Field 《Canadian Metallurgical Quarterly》1994,154(23):2699-2704
BACKGROUND: We compared the efficacy and tolerability of the intranasal corticosteroid fluticasone propionate with that of the antihistamine terfenadine in patients with seasonal allergic rhinitis. METHODS: Two hundred thirty-two adults and adolescents with seasonal allergic rhinitis received intranasal fluticasone propionate (200 micrograms once daily), terfenadine tablets (60 mg twice daily), or placebo for 2 weeks in a double-blind, randomized, parallel-group study. Main outcome measures were clinician- and patient-rated individual and total nasal symptom scores (based on ratings of nasal obstruction, sneezing, nasal itching, and rhinorrhea); clinician-rated overall response to therapy; changes in nasal inflammatory cell counts; adverse events; and morning plasma cortisol concentrations. RESULTS: Both clinician- and patient-rated total and individual nasal symptom scores were significantly lower in the fluticasone group than in either the terfenadine group or the placebo group at nearly every measured time point throughout the treatment period. After 2 weeks of therapy, clinician-rated total nasal symptom scores decreased by 49% in the fluticasone group compared with 27% in the terfenadine group and 19% in the placebo group. In general, therapy with terfenadine was not statistically distinguishable from that with placebo based on patient-rated total or individual nasal symptom scores. According to clinician ratings, 64% of fluticasone-treated patients compared with 49% and 44% of patients treated with terfenadine and placebo, respectively, experienced significant or moderate improvement. A greater percentage of fluticasone-treated patients compared with either terfenadine- or placebo-treated patients experienced reductions in intranasal eosinophil and basophil counts after 2 weeks of therapy. No unusual or serious drug-related adverse events were reported. Morning plasma cortisol concentrations after 2 weeks of therapy did not differ among groups. CONCLUSION: Fluticasone aqueous nasal spray, a well-tolerated corticosteroid preparation that can be administered once daily, is more effective than terfenadine tablets or placebo in controlling symptoms of seasonal allergic rhinitis. 相似文献