全文获取类型
收费全文 | 674篇 |
免费 | 39篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 144篇 |
金属工艺 | 12篇 |
机械仪表 | 33篇 |
建筑科学 | 23篇 |
矿业工程 | 3篇 |
能源动力 | 59篇 |
轻工业 | 38篇 |
水利工程 | 8篇 |
石油天然气 | 3篇 |
无线电 | 55篇 |
一般工业技术 | 121篇 |
冶金工业 | 119篇 |
原子能技术 | 1篇 |
自动化技术 | 93篇 |
出版年
2023年 | 14篇 |
2022年 | 13篇 |
2021年 | 23篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 27篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 20篇 |
2014年 | 33篇 |
2013年 | 48篇 |
2012年 | 35篇 |
2011年 | 66篇 |
2010年 | 40篇 |
2009年 | 36篇 |
2008年 | 40篇 |
2007年 | 36篇 |
2006年 | 23篇 |
2005年 | 18篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有718条查询结果,搜索用时 15 毫秒
91.
Brandon Tonnis Ming Li Wang Xianran Li Jianping Wang Naveen Puppala Shyam Tallury Jianming Yu 《Journal of the American Oil Chemists' Society》2020,97(9):1001-1010
The level of oleic acid is an important parameter in determining seed nutritional quality and oil stability. The level of oleic acid in peanut is genetically controlled by a pair of fatty acid desaturase genes (FAD2A and FAD2B), but the environmental conditions of the production sites can also have a significant effect. To investigate the effect of gene and environment interaction, 45 accessions were grown at three locations for 2 years. Environmental data were collected; individual plants were genotyped with functional SNP markers from FAD2A and FAD2B; and seed level of oleic acid was determined by gas chromatography. Three FAD2A/FAD2B genotypes (448G/no insertion 442A, 448A/no insertion 442A, and 448A/insertion 442A) were identified and designated as G/W, A/W, and A/A, respectively. A/A genotype averaged the highest level of oleic acid (80.0%), followed by A/W (56.0%), and then G/W (40.7%). Analysis of gene and environment interaction revealed that oleic acid phenotype plasticity could be explained by the interaction of FAD2 genotype and photothermal time, which quantified environmental conditions. The A/W genotype was the most sensitive to photothermal time changes. The oleic acid plasticity revealed in this study would be useful for breeders, farmers, and product processors. 相似文献
92.
Individuals in emergencies form spontaneous, emergent groups to respond and recover. With the rise of social media use in crises, academics and professionals must be aware of how groups digitally coordinate emergent response efforts. This paper examines digital emergence through the case of SnowedOut Atlanta, a Facebook group formed during the 2014 ice storms in Atlanta. The posts and actions of the group members are in line with those of traditional emergent groups. For example, group members shared informational, material, and emotional support. The findings also provide implications for practitioners and insight into the communication of such groups. In particular, emergency managers have an opportunity to seek out and partner with these types of groups in future similar events. 相似文献
93.
94.
Ivie L. Conlon Dr. Brandon Drennen Dr. Maryanna E. Lanning Samuel Hughes Rebecca Rothhaas Dr. Paul T. Wilder Dr. Alexander D. MacKerell Jr. Dr. Steven Fletcher 《ChemMedChem》2020,15(18):1691-1698
Protein–protein interactions (PPIs), many of which are dominated by α-helical recognition domains, play key roles in many essential cellular processes, and the dysregulation of these interactions can cause detrimental effects. For instance, aberrant PPIs involving the Bcl-2 protein family can lead to several diseases including cancer, neurodegenerative diseases, and diabetes. Interactions between Bcl-2 pro-life proteins, such as Mcl-1, and pro-death proteins, such as Bim, regulate the intrinsic pathway of apoptosis. p53, a tumor-suppressor protein, also has a pivotal role in apoptosis and is negatively regulated by its E3 ubiquitin ligase HDM2. Both Mcl-1 and HDM2 are upregulated in numerous cancers, and, interestingly, there is crosstalk between both protein pathways. Recently, synergy has been observed between Mcl-1 and HDM2 inhibitors. Towards the development of new anticancer drugs, we herein describe a polypharmacology approach for the dual inhibition of Mcl-1 and HDM2 by employing three densely functionalized isoxazoles, pyrazoles, and thiazoles as mimetics of key α-helical domains of their partner proteins. 相似文献
95.
Bradley J. Smith Brandon S. Harris Tyler J. Harris Lisa A. LaBudde Cari-Ann Hayer 《Journal of Great Lakes research》2018,44(4):798-804
The Asian clam Corbicula fluminea is among the most prolific aquatic invaders in the world; but in colder mid-latitude areas, like the Laurentian Great Lakes, their population expansion has likely been limited by poor overwinter survival. In these areas, Asian clams are typically found in thermal refugia like warmwater discharges from industrial facilities. We sought to identify the current extent of Asian clam populations in Lake Michigan and waters immediately adjacent to it, specifically at locations most likely to harbor overwintering populations – industrial warmwater discharges. During April–May 2017, we surveyed 17 locations around Lake Michigan. Evidence of Asian clam populations was found at four sites, though live specimens (n?=?3) were only found at the Indiana Harbor Ship Canal in East Chicago, IN. Shells or fragments of shells were found at Green Bay, WI, Waukegan, IL, and Port Sheldon, MI. Our findings indicate that although Asian clams are present in Lake Michigan, they are relatively rare, and remain isolated to a few small pockets of over-wintering habitat. 相似文献
96.
Kecheng Quan Zexin Zhang Hong Chen Xiaoxiang Ren Yijin Ren Brandon W. Peterson Henny C. van der Mei Henk J. Busscher 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(39)
The poor penetrability of many biofilms contributes to the recalcitrance of infectious biofilms to antimicrobial treatment. Here, a new application for the use of magnetic nanoparticles in nanomedicine to create artificial channels in infectious biofilms to enhance antimicrobial penetration and bacterial killing is proposed. Staphylococcus aureus biofilms are exposed to magnetic‐iron‐oxide nanoparticles (MIONPs), while magnetically forcing MIONP movement through the biofilm. Confocal laser scanning microscopy demonstrates artificial channel digging perpendicular to the substratum surface. Artificial channel digging significantly (4–6‐fold) enhances biofilm penetration and bacterial killing efficacy by gentamicin in two S. aureus strains with and without the ability to produce extracellular polymeric substances. Herewith, this work provides a simple, new, and easy way to enhance the eradication of infectious biofilms using MIONPs combined with clinically applied antibiotic therapies. 相似文献
97.
Mahesh Mani Brandon M. Lane M. Alkan Donmez Shaw C. Feng Shawn P. Moylan 《国际生产研究杂志》2017,55(5):1400-1418
Additive manufacturing technologies are increasingly used in the development of new products. However, variations in part quality in terms of material properties, dimensional tolerances, surface roughness and defects limit its broader acceptance. Process control today based on heuristics and experimental data yields limited improvement in part quality. In an effort to identify the needed measurement science for real-time closed-loop control of additive manufacturing (AM) processes, this paper presents a literature review on the current AM control schemes, process measurements and modelling and simulation methods as it applies to the powder bed fusion process, though results from other processes are reviewed where applicable. We present our research findings to identify the correlations between process parameters, process signatures and product quality. We also present research recommendations on the key control issues to serve as a technical basis for standards development in this area. Complimentary details to this paper with summary tables, range of values, preliminary correlations and correlation figures can be accessed from a National Institute of Standards and Technology Report (http://nvlpubs.nist.gov/nistpubs/ir/2015/NIST.IR.8036.pdf). This paper is developed based on the report. 相似文献
98.
Brandon S. Gerig Dominic T. Chaloner Sean A. Cullen Roger Greil Kevin Kapucinski Ashley H. Moerke Gary A. Lamberti 《Journal of Great Lakes research》2019,45(1):160-166
Pacific salmon were introduced to the Great Lakes in the 1960s and now support major recreational fishery. Population declines resulting from invasive species have prompted agencies to consider diversifying sport fisheries through stocking. Atlantic salmon are native to Lake Ontario, but a small fishery has developed in northern Lake Huron since the 1990s that appears suited to the Lake Huron food web leading to requests for increased stocking by anglers and consideration by agencies. However, no study has evaluated the trophic ecology of Atlantic salmon in relation to other salmonine predators in northern Lake Huron. In this study, we used stable isotopes of carbon (δ13C) and nitrogen (δ15N), along with mercury (Hg) concentrations to assess resource use, niche overlap, and contaminant accumulation in Atlantic salmon compared to select Lake Huron predators. Atlantic salmon exhibited considerable niche overlap with Chinook and coho salmon but were strongly differentiated from lake trout. In addition, we observed that Atlantic salmon had similar Hg concentrations as coho but were lower than both Chinook salmon and lake trout. Based upon the relationship between fish size, δ15N, and Hg, Atlantic salmon bioaccumulate Hg similarly to Pacific salmon but likely have lower consumptive demands than Chinook salmon. Continued attention should be placed on understanding how Atlantic salmon fit into the current Lake Huron food web in order to evaluate the long-term efficacy of the Atlantic salmon stocking program. 相似文献
99.
Adversarial search, or game‐tree search, is a technique for analyzing an adversarial game to determine what moves a player should make in order to win a game. Until recently, lookahead pathology (in which deeper game‐tree search results in worse play) has been thought to be quite rare. We provide an analysis that shows that every game should have some sections that are locally pathological, assuming that both players can potentially win the game. We also modify the minimax algorithm to recognize local pathologies in arbitrary games and cut off search accordingly (shallower search is more effective than deeper search when local pathologies occur). We show experimentally that our modified search procedure avoids local pathologies and consequently provides improved performance, in terms of decision accuracy, when compared with the minimax algorithm. In addition, we provide an experimental evaluation on the African game of Kalah, which shows the improved performances of our suggested error‐minimizing minimax algorithm when there is a large degree of pathology. 相似文献
100.