全文获取类型
收费全文 | 869篇 |
免费 | 24篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 29篇 |
综合类 | 2篇 |
化学工业 | 203篇 |
金属工艺 | 14篇 |
机械仪表 | 10篇 |
建筑科学 | 20篇 |
能源动力 | 45篇 |
轻工业 | 85篇 |
水利工程 | 2篇 |
石油天然气 | 14篇 |
无线电 | 72篇 |
一般工业技术 | 139篇 |
冶金工业 | 170篇 |
原子能技术 | 23篇 |
自动化技术 | 70篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 17篇 |
2017年 | 16篇 |
2016年 | 37篇 |
2015年 | 13篇 |
2014年 | 30篇 |
2013年 | 49篇 |
2012年 | 39篇 |
2011年 | 62篇 |
2010年 | 37篇 |
2009年 | 23篇 |
2008年 | 35篇 |
2007年 | 29篇 |
2006年 | 30篇 |
2005年 | 26篇 |
2004年 | 20篇 |
2003年 | 20篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 17篇 |
1998年 | 76篇 |
1997年 | 33篇 |
1996年 | 33篇 |
1995年 | 23篇 |
1994年 | 24篇 |
1993年 | 24篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1972年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有898条查询结果,搜索用时 109 毫秒
891.
Development of aroma-active compounds during fermentation in the preparation of fermented fish-meat paste product (fish miso) from horse mackerel meat was quantitatively determined and characterized by olfactometric and organoleptic assessments. The critical ripening time was estimated by quantitative and/or qualitative analyses of volatile compounds, peptides, amino acids, product color, and total phenolics of the fish miso matrix throughout fermentation. The results confirmed that the application of koji for the fermentation of horse mackerel meat to produce fish miso significantly reduced the fishy off odor and promoted the development of highly acceptable fish miso with a nutty, cheesy, and fruity aroma. Ethyl acetate, ethyl heptanoate, ethyl decanoate, 2-methylpropanal, 3-methylbutanal, 2,3-butanedione, dimethyl trisulfide, and 3-(methylthio) propanal were identified as key odor-active compounds in fish miso prepared from horse mackerel meat. Among the volatiles, 2-methylpropanal, 3-methylbutanal, and 2,3-butanedione were identified to serve as potential indicators of the maturation of fish miso. Amino acid content could also be a potential indicator of maturation of protein-rich, fermented products such as fish miso. In addition, surface color analysis of fish miso revealed a high correlation between sensory attributes and color components. Specifically, r and b values were considered potential indicators of maturation. Practical Application: Variability is a major drawback in fermented products such as fish miso and it requires establishing the optimum ripening time, defined as that providing the aroma attributes qualitatively and quantitatively mostly appreciated by consumers. We have carried out this work for comprehensive determination of the critical ripening time by applying several instrumental and sensory tools including quantitative and/or qualitative analysis of volatile compounds, peptides, amino acids, product color, and total phenolics of the fish miso matrix throughout the fermentation period. The outcome of the present study can be efficiently applied for detection of maturation in similar types of fermented product for large-scale production. 相似文献
892.
893.
Masayuki Taniguchi Yohei Ishiyama Takeomi Takata Toshihiro Nakanishi Mitsuoki Kaneoke Ken-ichi Watanabe Fujitoshi Yanagida Yi-sheng Chen Tomoaki Kouya Takaaki Tanaka 《Journal of Bioscience and Bioengineering》2010,109(6):570-575
The bacteriocins produced by Lactococcus lactis subsp. lactis C101910 (C101910) and NBRC 12007 (NBRC 12007) were used to prevent the growth of sake spoiling hiochi bacteria (Lactobacillus hilgardii, Lactobacillus fructivorans, and Lactobacillus paracasei) in namazake, which is raw (unpasteurized) sake. The bacteriocin concentrations required for decreasing the viable cell concentrations of L. hilgardii and L. fructivorans below the detection limit (1.0 × 102 cells/ml) in 24 h from the initial concentration of 4.0–9.5 × 105 cells/ml in the namazake at pH 4.5 and at 4°C, were 18–35 U/ml and 5.6 U/ml for the bacteriocin from C101910 and NBRC 12007, respectively. To decrease the viable cell concentration of L. paracasei from the initial concentration of 7.5 × 105 cells/ml to below the detection limit (1.0 × 102 cells/ml) in 24 h, 350 U/ml bacteriocin from C101910 and 140 U/ml bacteriocin from NBRC 12007 were required. In experiments using McIlvaine buffer (pH 4.5) with 15% ethanol instead of namazake as the medium, the viable cell concentrations of L. hilgardii and L. paracasei decreased to less than 1.0 × 102 cells/ml, whereas those of L. fructivorans decreased to less than 1.0 × 103 cells/ml, when bacteriocins were added at the concentrations that had proven effective in namazake. The membrane depolarization assay using a fluorescent probe showed that the presence of ethanol stimulated the collapse of the membrane potential induced by bacteriocins. The ethanol induced collapse of the membrane potential suggests that the application of bacteriocins at the storage stage of namazake is more beneficial than when used in other stages of the sake brewing process. 相似文献
894.
Kentaro Yamada Tomoaki Takata Takuji Iyama Shintaro Hamada Yukari Mae Takaaki Sugihara Hajime Isomoto 《International journal of molecular sciences》2022,23(15)
A clear identification of the etiology of glomerular disease is essential in patients with diabetes. Renal biopsy is the gold standard for assessing the underlying nephrotic pathology; however, it has the risk for potential complications. Here, we aimed to investigate the feasibility of urinary fluorescence imaging using an enzyme-activatable probe for differentiating diabetic kidney disease and the other glomerular diseases. Hydroxymethyl rhodamine green (HMRG)-based fluorescent probes targeting gamma-glutamyl transpeptidase (GGT) and dipeptidyl-peptidase (DPP) were used. Urinary fluorescence was compared between groups which were classified by their histopathological diagnoses (diabetic kidney disease, glomerulonephritis, and nephrosclerosis) as obtained by ultrasound-guided renal biopsy. Urinary fluorescence was significantly stronger in patients with diabetic kidney disease compared to those with glomerulonephritis/nephrosclerosis after DPP-HMRG, whereas it was stronger in patients with nephrosclerosis than in patients with glomerulonephritis after GGT-HMRG. Subgroup analyses of the fluorescence performed for patients with diabetes showed consistent results. Urinary fluorescence imaging using enzyme-activatable fluorescence probes thus represents a potential noninvasive assessment technique for kidney diseases in patients with diabetes. 相似文献
895.
Colonial mentality, or internalized colonialism, has been discussed by scholars and by Filipino American community members as a significant factor in the experiences of contemporary Filipino Americans, yet this construct has not received empirical attention in psychology. The authors of the current study addressed this gap in the Asian American psychological literature by developing the Colonial Mentality Scale for Filipino Americans, a theoretically derived and psychometrically tested multidimensional measure of colonial mentality. Exploratory (n = 292) and confirmatory (n = 311) factor analyses on Internet-obtained data suggest that colonial mentality among Filipino Americans is best conceptualized and measured as composed of 5 related factors, each of which represents unique manifestations of the construct. Results also suggest that colonial mentality is associated with the psychological well-being and mental health of modern day Filipino Americans. Research and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
896.
897.
Yuriko Okazaki Shinichiro Okazaki Shingo Asamoto Toru Yamaji Minoru Ishige 《Computer-Aided Civil and Infrastructure Engineering》2023,38(15):2145-2162
The data acquired in civil engineering tasks often involve high acquisition costs, and the available datasets tend to have a limited number of samples and are highly biased. To estimate the performance of machine learning models, k-fold cross-validation (k-CV) is widely used. However, if only limited data are available and the data distribution is biased, k-CV tends to overestimate the performance for practical applications. This study proposed a new estimator, leave one reference out and k-CV (LORO-k-CV), to determine the practical performance of machine learning models, that is, the generalization performance for population data in the target task, in case data are collected by multiple references resulting in biased data. LORO-k-CV is a combination of a new concept, LORO-CV, that estimates the performance in the extrapolation region of the training data without human intervention and k-CV, considering the ratio of the interpolation and extrapolation regions. The efficacy of LORO-k-CV was validated with its application to the regression task for the chloride-ion concentration of concrete structures. To more specifically demonstrate the advantages of LORO-k-CV in model construction, the feature selections were conducted using both k-CV and LORO-k-CV methods. These results revealed that LORO-k-CV can effectively construct a model with improved generalization performance even from the same data in cases where data are collected by multiple references, resulting in biased data. 相似文献
898.
Shinya Sekizaki Teruyuki Kato Ichiro Nishizaki Tomohiro Hayashida Kazuhisa Hikoyama Tomoaki Nonoyama 《Electrical Engineering in Japan》2023,216(3):e23442
The service restoration to sound sections within a short period as much as possible, performed after the permanent fault occurs in a distribution system, is significant for maintaining power supply reliability. This paper proposes an efficient method to find service restoration procedures based on fault searching and the optimal work scheduling of crews, considering the power supply priorities of loads and the probability of occurrence of faults. The proposed method is composed of two-stage problems to reduce the outage sections efficiently: (i) the problem to find a series of searching procedures for unknown fault locations in the first stage and (ii) the optimization problem of work schedules of crews in the second stage. In the first stage, the order of operation of switches opened for searching for the fault direction is determined, constituting the searching tree. After that, the proposed optimization method can efficiently solve the work scheduling problem by formulating it as a mixed-integer linear programming problem in the second stage. The computational experiments using a large-scale distribution system model with many remote and manual switches show that the proposed method can provide efficient service restoration procedures within a reasonable computational time. 相似文献