全文获取类型
收费全文 | 1379篇 |
免费 | 8篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 99篇 |
金属工艺 | 19篇 |
机械仪表 | 16篇 |
建筑科学 | 29篇 |
能源动力 | 7篇 |
轻工业 | 84篇 |
水利工程 | 8篇 |
石油天然气 | 1篇 |
无线电 | 58篇 |
一般工业技术 | 115篇 |
冶金工业 | 887篇 |
原子能技术 | 2篇 |
自动化技术 | 58篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2014年 | 7篇 |
2013年 | 54篇 |
2012年 | 17篇 |
2011年 | 35篇 |
2010年 | 18篇 |
2009年 | 19篇 |
2008年 | 13篇 |
2007年 | 18篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 28篇 |
1998年 | 252篇 |
1997年 | 166篇 |
1996年 | 95篇 |
1995年 | 55篇 |
1994年 | 47篇 |
1993年 | 55篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 22篇 |
1989年 | 31篇 |
1988年 | 20篇 |
1987年 | 23篇 |
1986年 | 12篇 |
1985年 | 14篇 |
1983年 | 11篇 |
1982年 | 16篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1978年 | 7篇 |
1977年 | 36篇 |
1976年 | 51篇 |
1975年 | 7篇 |
1974年 | 5篇 |
1972年 | 4篇 |
1970年 | 7篇 |
1955年 | 6篇 |
1937年 | 5篇 |
排序方式: 共有1387条查询结果,搜索用时 31 毫秒
1.
Zachary Zander Deirdre Newton Heather Scaglione Averie Reiber Parminder Agarwal 《Polymer Engineering and Science》2021,61(12):3029-3036
The incursion of microbial growth on polymeric products can deteriorate their performance and lead to the development of undesirable staining and odors. A growing trend in the industry has aimed to reduce microbial populations on high-touch surfaces via the use of antimicrobials to protect material aesthetics and durability or to prevent the spread of pathogenic microorganisms. In this study, a variety of plastic substrates (30 unique polymer compounds), including poly(acrylonitrile-co-butadiene-co-styrene), poly(butylene terephthalate), poly(etherimide), various thermoplastic elastomers (TPEs), poly(carbonates), and poly(amides), were screened for susceptibility to microbial attack using American Society for Testing and Materials (ASTM) G21 (fungi susceptibility), Japanese Industrial Standard (JIS) Z2801, and modified ASTM E1428-15a (bacterial susceptibility) test standards. TPEs were determined to be most susceptible to microbial attack under the appropriate environmental conditions. Subsequent studies assessed the use of an antimicrobial additive, zinc pyrithione (ZPT), for potential efficacy in a variety of TPE blends for diverse target market applications. ZPT proved to be very effective in protecting TPEs, reducing Staphylococcus aureus and Escherichia coli populations by 99.9% or more in JIS Z2801 testing and inhibiting fungal growth (rating = 0) according to the ASTM G21 standard. 相似文献
2.
WR Volger RS Weiner JO Moore GA Omura AA Bartolucci M Stagg 《Canadian Metallurgical Quarterly》1995,9(9):1456-1460
A phase III clinical trial was designed to determine if more intensive induction and consolidation therapy for acute myeloblastic leukemia increases the remission rate and prolongs survival. A minor objective was to determine if the use of non-cross resistant drugs was more effective than the same drugs used for induction. Patients with untreated leukemia between the ages of 15 and 50 were given daunorubicin 45 mg/m2 for the first 3 days of a 10-day continuous infusion of cytosine arabinoside, initially at a dose of 2000 mg/m2 but reduced to 100 mg/m2 because of toxicity. Those under 36 achieving a complete remission and with an histocompatible donor were assigned to a transplant arm. The rest were randomized to receive one of three consolidation arms: A, cytosine arabinoside, 200 mg/m2 daily for 7 days and daunorubicin 45 mg/m2 daily for 3 days for three courses; B, one course as in Arm A followed by amsacrine, 120 mg/m2 daily for 5 days followed by a 5-day continuous infusion of azacytidine, 150 mg/m2/day; C, thioguanine and cytosine arabinoside, 100 mg/m2 every 12 h and daunorubicin 10 mg/m2 daily for 5 days for three courses followed by four maintenance courses of cytosine arabinoside, 100 mg/m2 daily for 5 days and daunorubicin, 45 mg/m2 for 2 days every 13 weeks. From 1981 to 1986, 398 eligible patients were enrolled and 219 achieved a complete remission. The initial induction dose of cytosine arabinoside was reduced after five of 29 patients exhibited fatal gastrointestinal toxicity. Only 11 patients were assigned to the transplant arm. There were no significant differences in the consolidation arms. The 5 year disease-free survivals were 38, 31 and 27% in arms A, B, and C respectively. Intensive consolidation therapy with the same or different drugs used in induction was as effective as lower dose consolidation followed by maintenance therapy. 相似文献
3.
4.
5.
This study examined the role of marital conflict structure--who desires and requests change versus who responds to the change request--in spouses' cardiovascular responses to marital interactions. Forty-one couples discussed 2 marital topics: one in which the wife desired change in the husband, and one in which the husband desired change in the wife. Cardiovascular responses were assessed at 2-min intervals. Results indicated that marital conflict structure moderates cardiovascular reactivity during negative marital interactions: Husbands and wives whose interactions were characterized by high levels of negative behavior showed the most pronounced diastolic blood pressure reactivity, but only when they were in the role of desiring change in their spouses. Implications for gender differences in marital conflict physiology are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
H Nakamine AS Masih WC Chan WG Sanger JO Armitage DD Weisenburger 《Canadian Metallurgical Quarterly》1993,10(1-2):79-88
Southern blot analysis was performed with a panel of DNA probes to detect rearrangements of c-myc, bcl-1, bcl-2 and bcl-3 in 14 cases of B-cell non-Hodgkin's lymphoma (NHL) with a clonal cytogenetic rearrangement involving the chromosome 14q32 locus and no known donor chromosome [t(14;?)(q32;?)]. In our experience, 21% of all chromosomal abnormalities involving the 14q32 locus in B-cell NHL are of this type. We found oncogene rearrangements in five of the 14 cases: bcl-1 rearrangement on one mantle zone lymphoma, bcl-2 rearrangements in two follicular lymphomas, and c-myc rearrangements in two small noncleaved cell lymphomas. We conclude that a 14q32+ abnormality of unknown origin is a relatively frequent karyotypic finding in B-cell NHL. In one third of the cases, known oncogenes that have been previously described in reciprocal translocations involving the immunoglobulin heavy chain locus were shown to be involved in the 14q32+ abnormality. The translocations in the other cases are likely to have involved one of the above oncogenes with breakpoints not revealed by the probes employed, other known oncogenes, or oncogenes that have not yet been identified. 相似文献
7.
8.
9.
CM Newton 《Canadian Metallurgical Quarterly》1993,26(4):327-343
GRIFFIN (graphics investigation of familial information), an interactive graphics system for exploratory investigation of data on individuals associated by familial relationships, was designed to provide genetic epidemiologists a flexible, rapidly responsive tool for viewing and guiding exploration of complex databases in the context of familiar pedigree structures. It graphically portrays both categorical and multivariate scalar data on individuals in those structures. The display can be inverted to show all ancestors and descendants of any individual the user designates. It provides cues to censored information when bushy pedigrees cannot be fully displayed without sacrificing legibility. These guide users on where to next invert the system. Investigators may translate/zoom the display, vary the mode of representing data, point to individuals to obtain displays of alphameric information about them, etc. Developed in Fortran using IBM's GDDM graphics subroutines for an IBM 3090 mainframe, GRIFFIN's design anticipates porting to smaller systems. 相似文献
10.
DL Newton S Walbridge SM Mikulski W Ardelt K Shogen SJ Ackerman SM Rybak RJ Youle 《Canadian Metallurgical Quarterly》1994,14(2):538-544
Purkinje cell toxicity is one of the characteristic features of the Gordon phenomenon, a syndrome manifested by ataxia, muscular rigidity, paralysis, and tremor that may lead to death (Gordon, 1933). Two members of the RNase superfamily found in humans, EDN (eosinophil-derived neurotoxin) and ECP (eosinophil cationic protein), cause the Gordon phenomenon when injected intraventricularly into guinea pigs or rabbits. We have found that another member of the RNase superfamily, an antitumor protein called onconase, isolated from Rana pipiens oocytes and early embryos, will also cause the Gordon phenomenon when injected into the cerebrospinal fluid of guinea pigs at a dose similar to that of EDN (LD50, 3-4 micrograms). Neurologic abnormalities of onconase-treated animals were indistinguishable from those of EDN-treated animals, and histology showed dramatic Purkinje cell loss in the brains of onconase-treated animals. The neurotoxic activity of onconase correlates with ribonuclease activity. Onconase modified by iodoacetic acid to eliminate 70% and 98% of the ribonuclease activity of the native enzyme displays a similar decrease in ability to cause the Gordon phenomenon. In contrast, the homologous bovine pancreatic RNase A injected intraventricularly at a dose 5000 times greater than the LD50 dose of EDN or onconase is not toxic and does not cause the Gordon phenomenon. A comparison of the RNase activities of EDN, onconase, and bovine pancreatic RNase A using three pancreatic RNA substrates demonstrates that onconase is orders of magnitude less active enzymatically than EDN and RNase A. Thus, another member of the RNase superfamily in addition to EDN and ECP can cause the Gordon phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献