全文获取类型
收费全文 | 3157篇 |
免费 | 15篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 48篇 |
机械仪表 | 5篇 |
建筑科学 | 10篇 |
矿业工程 | 1篇 |
能源动力 | 17篇 |
轻工业 | 53篇 |
水利工程 | 1篇 |
无线电 | 53篇 |
一般工业技术 | 56篇 |
冶金工业 | 2839篇 |
自动化技术 | 82篇 |
出版年
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 15篇 |
2009年 | 13篇 |
2008年 | 20篇 |
2007年 | 13篇 |
2006年 | 23篇 |
2005年 | 18篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 18篇 |
2001年 | 9篇 |
2000年 | 15篇 |
1999年 | 99篇 |
1998年 | 923篇 |
1997年 | 529篇 |
1996年 | 279篇 |
1995年 | 185篇 |
1994年 | 169篇 |
1993年 | 180篇 |
1992年 | 19篇 |
1991年 | 29篇 |
1990年 | 26篇 |
1989年 | 43篇 |
1988年 | 43篇 |
1987年 | 29篇 |
1986年 | 33篇 |
1985年 | 29篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 15篇 |
1981年 | 18篇 |
1980年 | 26篇 |
1978年 | 4篇 |
1977年 | 60篇 |
1976年 | 143篇 |
1975年 | 7篇 |
1972年 | 2篇 |
1955年 | 2篇 |
1939年 | 2篇 |
1938年 | 2篇 |
排序方式: 共有3173条查询结果,搜索用时 15 毫秒
31.
32.
A Region Ensemble for 3-D Face Recognition 总被引:1,自引:0,他引:1
Faltemier T.C. Bowyer K.W. Flynn P.J. 《Information Forensics and Security, IEEE Transactions on》2008,3(1):62-73
In this paper, we introduce a new system for 3D face recognition based on the fusion of results from a committee of regions that have been independently matched. Experimental results demonstrate that using 28 small regions on the face allow for the highest level of 3D face recognition. Score-based fusion is performed on the individual region match scores and experimental results show that the Borda count and consensus voting methods yield higher performance than the standard sum, product, and min fusion rules. In addition, results are reported that demonstrate the robustness of our algorithm by simulating large holes and artifacts in images. To our knowledge, no other work has been published that uses a large number of 3D face regions for high-performance face matching. Rank one recognition rates of 97.2% and verification rates of 93.2% at a 0.1% false accept rate are reported and compared to other methods published on the face recognition grand challenge v2 data set. 相似文献
33.
T Rinne AM Bronstein P Rudge MA Gresty LM Luxon 《Canadian Metallurgical Quarterly》1998,245(6-7):314-321
The clinical presentations and aetiologies of a series of 53 cases of bilateral vestibular failure (BVF) seen by the authors over a decade were evaluated by retrospective review of the medical records. Thirty-nine per cent of patients had associated neurological disease; 13% had a progressive cerebellar syndrome with disabling gait ataxia, abnormal eye movements and cerebellar atrophy on neuro-imaging. BVF was usually unsuspected. Nine per cent had cranial or peripheral neuropathies and in this group there was no abnormality of brain stem/cerebellar oculomotor function, but hearing loss was common. Eleven per cent revealed BVF and hearing loss secondary to meningitis, and 6% had other neurological disorders. Idiopathic BVF was found in 21% of cases, characterised by paroxysmal vertigo and/or oscillopsia, but no abnormal clinical signs. Gentamicin ototoxicity accounted for a further 17%, while autoimmune disease was present in 9% of patients. Otological or neoplastic disease was diagnosed in the remaining 13% of patients. It was concluded that neurological, audiological and ocular motor assessments allow the probable cause of BVF to be defined in approximately 80% of cases. A group of BVF related to autoimmune pathologies is reported for the first time, indicating the need for immunological screening. Idiopathic BVF may present with only minor visual or vestibular symptoms, while in patients with cerebellar degeneration, BVF may be unsuspected and, thus, underdiagnosed. 相似文献
34.
35.
LM East CJ Savage JL Traub-Dargatz CE Dickinson RP Ellis 《Canadian Metallurgical Quarterly》1998,212(11):1751-1756
OBJECTIVE: To identify clinical signs, physical examination findings, results of diagnostic tests, treatments administered, and clinical outcome of neonatal foals with enterocolitis associated with Clostridium perfringens infection. DESIGN: Retrospective study. ANIMALS: 54 neonatal foals. RESULTS: Most foals had acute onset of obtunded mentation, colic, or diarrhea and developed leukopenia, neutropenia, an abnormally high number of band neutrophils, toxic WBC, and hypoproteinemia within 24 hours after admission, despite high serum IgG concentrations (> 800 mg/dl). Abdominocentesis and abdominal radiography of some foals revealed exudative peritonitis and gaseous distention of the small and large intestine, respectively. Cytologic examination of feces revealed spores or gram-positive rods in 8 of 10 foals. The most common genotypes of C perfringens isolates were type A and C, alone or in combination. Treatment did not alter mortality rate for most foals that had a positive culture for C perfringens type C. Of 54 foals, 29 (54%) that had C perfringens-associated enterocolitis died. Foals that had a culture that yielded C perfringens had higher sepsis scores, IgG concentrations, and mortality rates, compared with the overall hospital population of neonatal foals. CLINICAL IMPLICATIONS: Foals less than 7 days old that have enterocolitis associated with C perfringens infections, especially type C, have a guarded prognosis. Cytologic examination of feces to determine spore counts and detect rods may be a means for early identification of C perfringens infections. Polymerase chain reaction assays to determine genotype are important for designing preventive treatment regimens. 相似文献
36.
37.
LM Budel R Delwel C van Buitenen H Hoogerbrugge B L?wenberg 《Canadian Metallurgical Quarterly》1993,7(3):426-434
We have investigated the stimulative effects of mast cell growth factor (MGF) in primary acute myeloid leukemia (AML) in vitro. MGF stimulated DNA synthesis of purified leukemic blasts in eight out of 10 cases and colony formation in four cases in serum-free (SF) culture. MGF synergized with interleukin-3 (IL-3; four out of 10 cases), granulocyte-macrophage colony-stimulating factor (GM-CSF; three out of 10 cases), granulocyte colony-stimulating factor (G-CSF; six out of 10 cases), macrophage colony-stimulating factor (M-CSF; one out of 10 cases) and erythropoietin (EPO; one out of 10 cases) when added to culture in combination. Synergistic effects of MGF in combination with other CSFs were also seen in the colony assay. Antibodies against GM-CSF, M-CSF, G-CSF, and IL-6 did not inhibit the MGF response, suggesting that the stimulative effect of MGF was not mediated through autocrine release of those cytokines. Cell recovery data in liquid cultures that contained MGF, IL-3, or MGF + IL-3, indicated that both MGF and IL-3 augmented the maintenance of clonogenic cells as compared to nonsupplemented cultures, but the effect of the combination of IL-3 + MGF did not show synergy. In contrast, activation of DNA synthesis by MGF was abrogated in the presence of tumor necrosis factor (TNF; four out of 10 cases) and interleukin-4 (IL-4; two out of 10 cases). Fluorescence-activated cell sorting (FACS) analysis with anti c-kit antibodies revealed MGF receptor expression in eight out of nine cases, often in a subpopulation of the cells. Scatchard analysis of MGF receptors in two cases indicated the presence of 1460 and 41,500 (mean) binding sites, respectively, of high affinity (Kd 40-160 pmol/l). The MGF dose-response curve in the presence of IL-3 or GM-CSF resulted in a higher plateau of DNA synthesis, however no shift in the dose response was apparent. The respective reciprocal dose response relations to GM-CSF, IL-3, or G-CSF were similarly elevated when MGF was added. MGF did not alter IL-3 and GM-CSF receptor expression, nor did IL-3, GM-CSF, G-CSF, TNF, or IL-4 influence MGF binding to AML cells.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
38.
LM Harewood 《Canadian Metallurgical Quarterly》1993,7(4):319-322
Twenty patients with relapsed or refractory non-Hodgkin's lymphoma were treated with high-dose chlorambucil (14 mg/m2 every 6 hours for 6 doses) and dexamethasone (40 mg/day for 5 days). There was a 45% response rate with 17% complete responses. The median duration of complete response was 7 months. The regimen was well tolerated and had minimal toxicity. 相似文献
39.
40.