全文获取类型
收费全文 | 2038篇 |
免费 | 17篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 107篇 |
金属工艺 | 11篇 |
机械仪表 | 18篇 |
建筑科学 | 60篇 |
矿业工程 | 1篇 |
能源动力 | 15篇 |
轻工业 | 104篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 73篇 |
一般工业技术 | 64篇 |
冶金工业 | 1493篇 |
原子能技术 | 6篇 |
自动化技术 | 84篇 |
出版年
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 31篇 |
2012年 | 22篇 |
2011年 | 29篇 |
2010年 | 26篇 |
2009年 | 24篇 |
2008年 | 30篇 |
2007年 | 30篇 |
2006年 | 32篇 |
2005年 | 18篇 |
2004年 | 21篇 |
2003年 | 20篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 16篇 |
1999年 | 68篇 |
1998年 | 480篇 |
1997年 | 254篇 |
1996年 | 175篇 |
1995年 | 114篇 |
1994年 | 79篇 |
1993年 | 118篇 |
1992年 | 21篇 |
1991年 | 31篇 |
1990年 | 24篇 |
1989年 | 17篇 |
1988年 | 31篇 |
1987年 | 23篇 |
1986年 | 21篇 |
1985年 | 12篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 18篇 |
1980年 | 20篇 |
1979年 | 4篇 |
1978年 | 11篇 |
1977年 | 34篇 |
1976年 | 75篇 |
1975年 | 5篇 |
1974年 | 8篇 |
1968年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有2056条查询结果,搜索用时 15 毫秒
101.
TR Kirkpatrick 《Canadian Metallurgical Quarterly》1985,31(9):5746-5755
102.
103.
K. Pfeilsticker und H. Rasmussen 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1969,139(6):365-369
Zusammenfassung Die Begasung von Weizen mit radioaktiv markiertem Äthylenoxid-1,2-C14 in der üblichen Konzentration und eine Konzentrationsbestimmung des Äthylenoxids durch Radioaktivmessung zeigt, daß eine statistisch gesicherte lineare Regression mit sehr enger Korrelation (r = 0,866) zwischen dem Aschegehalt von Mehlfraktionen und dem Äthylenoxidgehalt besteht. Kleie enthält beispielsweise 54,0 mg ÄO/kg, Weißmehl 6,8 mg ÄO/kg und der Keimling 62,0 mg ÄO/kg, während der Rückstand im Mittel (Gesamtweizen) bei 12–15 mg ÄO/kg liegt. Frühere Bilanzversuche wurden bestätigt durch Werte zwischen 22,8 und 28% metabolisierten Äthylenoxids (Weizen-Wassergehalt 8,8%). 相似文献
104.
Forty subjects were administered the portable rod-and-frame test (RFT) before and after operant autonomic conditioning training or control experiences. Ten subjects were assigned to each of four groups: a heart rate conditioning group; a false heart rate feedback group; a galvanic skin-response conditioning group; and a control group. Half of the subjects in the three experimental groups were informed of the response-reinforcement contingencies, and half were not informed. Informed subjects in the conditioning groups exhibited significantly lower portable RFT scores after conditioning. The results suggest that awareness of and control over autonomic functioning may be an important determinant of RFT performance. 相似文献
105.
106.
107.
The Doppler technique has been used to evaluate venous reflux in the spermatic cord. Valsalva-induced reflux occurred on the left side in 83% and on the right side in 59% of 118 patients without clinical varicoceles and there was no difference in incidence between fertile and infertile men. The significance of Valsalva-induced reflux should be questioned. Greater importance should be attributed to the spontaneous venous reflux that occurred during quiet respiration in the majority of patients with varicoceles. Seven velocity waveform patterns are described and these are thought to represent increasing degrees of internal spermatic vein reflux and provide a basis on which it is possible to grade varicoceles. The Doppler grades correlated with the size of the varicocele, and with the internal spermatic vein diameter and testosterone concentrations. 相似文献
108.
Reversal of pretreatment hypotension and control of hemorrhage in trauma patients by a simple device
JM Civetta ST Nussenfeld EL Nagel BH Kaplan TR Rowe F Pettijohn 《Canadian Metallurgical Quarterly》1977,43(1):20-29
The injection of a suspension of Walker 256 carcinoma cells into the carotid artery of rats produced a model of hematogenously spread cerebral metastases. Most animals died from massive extracerebral tumors of the head and jaw; brain tumors were present in only one-quarter. External carotid artery ligation prior to tumor inoculation did not increase the incidence of fatal brain tumor. When cyclophosphamide, 15 mg/kg, was injected as a single dose on the fourteenth day after tumor inoculation, most of the extracerebral tumor disappeared. Fifty percent of the animals so treated were cured of tumor, but 90% of the remainder died of large intracerebral tumors. Severe cytopathic changes resulting from cyclophosphamide were present in extracerebral or choroid plexus tumors but were mild or nonexistent in intracerebral tumors. These selective effects of cyclophosphamide suggest that water-soluble agents are less effective against tumor in the brain than against extracerebral tumors despite the fact that metastatic tumor breaks down the blood-brain barrier. 相似文献
109.
Reduction of immunoreactivity of bovine beta-lactoglobulin upon combined physical and proteolytic treatment 总被引:3,自引:0,他引:3
Bonomi F Fiocchi A Frøkiaer H Gaiaschi A Iametti S Poiesi C Rasmussen P Restani P Rovere P 《The Journal of dairy research》2003,70(1):51-59
Bovine beta-lactoglobulin was hydrolyzed with trypsin or chymotrypsin before, during and after treatment at 600 MPa and pH 6.8 for 10 min at 30, 37 and 44 degrees C. The extent of beta-lactoglobulin hydrolysis under pressure was noticeably higher than at atmospheric pressure, particularly when chymotrypsin was used. Addition of proteases at ambient pressure to previously pressure-treated beta-lactoglobulin gave only a modest increase in proteolysis with respect to the untreated protein. Products of enzyme hydrolysis under pressure were separated by reverse-phase HPLC, and were found to be different from those obtained at atmospheric pressure when chymotrypsin was used. The residual immunochemical reactivity of the products of combined pressure-enzyme treatment was assessed on the unresolved hydrolysates by ELISA tests using polyclonal and monoclonal antibodies, and on individual hydrolytic fractions by Western Blotting using sera of paediatric patients allergic to whey proteins in cow milk. The immunoreactivity of the whole hydrolysates was related to their content of residual intact beta-lactoglobulin, and no immunochemical reactivity was found for all the products of chymotrypsin hydrolysis under pressure. The results indicate that chymotrypsin effectively hydrolysed hydrophobic regions of beta-lactoglobulin that were transiently exposed during the pressure treatments and that were not accessible in the native protein or in the protein that had been previously pressure treated. 相似文献
110.
Shermis MD Rasmussen JL Rajecki DW Olson J Marsiglio C 《Journal of applied measurement》2001,2(2):154-170
Scores assigned to college placement essays by a computer program (PEG) showed high agreement with the evaluations of human readers (r =.82). Further, both types of graders tended to assign higher or lower scores to essays written about particular topics. Content analyses by a second program (MCCA) indicated that themes in essays varied in terms of emphasis on "analytic," "emotional," or "practical" dimensions. Human and machine readers tended to give higher scores for analytic and practical themes, and lower scores for those involving emotion. The ranks of mean prompt-related grades were concordant with the ranks of mean analytic and practical content across topics. Such findings call for the refined standardization of prompts for future testing, and the need for care in the evaluation of existing essays. 相似文献