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41.
A.F. Kertz T.M. Hill J.D. Quigley A.J. Heinrichs J.G. Linn J.K. Drackley 《Journal of dairy science》2017,100(12):10151-10172
The first calf paper, published in the May 1919 issue of the Journal of Dairy Science (JDS), described factors affecting birth body weight of different breeds of calves. Other studies were done on nonmilk ingredients, growth charts were developed, and early weaning was followed to conserve milk fed to calves. Calf papers did not report use of statistics to control or record variation or to determine whether treatment means were different. Many experiments were more observational than comparative. Typically fewer than 5 calves, and sometimes 1 or 2 calves, were used per treatment. During the next 20 yr, calf studies increased and included colostrum feeding, milk and milk replacer feeding, minerals and vitamins, and fats and oils. Many concepts fundamental to current knowledge and understanding of digestion, rumen development, and milk replacer formulation were developed during this period. In addition, the concept of using antibiotic growth promoters in dairy calf diets was first evaluated and developed during the 1950s. During the 20-yr period of January 1957 through December 1976, a large number of universities in the United States and 1 in Canada contributed almost 150 papers on a variety of calf-related topics. These topics included genetics, physiology of the calf, review of calf immunity, antibiotic feeding, and milk replacer ingredients. This became the golden era of calf rumen development studies, which also engendered studies of calf starter rations and ingredients. A classic review of management, feeding, and housing studies summarized research related to calf feeding and management systems up to that point with an emphasis on maintaining calf growth and health while reducing labor and feed costs. It was also during this period that metric measurements replaced English units. In the 20-yr period from 1977 to 1996, more than 400 articles on calf nutrition and management were published in JDS. With the growing research interest in calves, a paper outlining standardized procedures for conducting and reporting data from calf experiments was first published. A very active area of calf nutrition research from the late 1970s to the mid 1980s was colostrum quality, feeding, and preservation; more than 60 such research articles were published in the journal during this time. Various nonmilk protein sources were evaluated. Extensive studies were done evaluating trace and major mineral requirements in calves along with some vitamin studies. Throughout the 1970s, 1980s, and 1990s, the primary objective of most calf research was how to wean healthy, adequately grown calves at an early age—generally less than 30 d of age. This program was reviewed in a 1979 publication. Research on calf starter ingredients, nutrient composition, and additives was minimal in the 1980s and 1990s given the importance of starter intake to the success of early weaning, but the role of water intake in starter intake and growth was established. Research on issues with calves continued to increase during the last 20-yr period as evidenced by publication of more than 580 articles in JDS as well as many more in other refereed journals. In addition to papers contributed by several universities in the United States and Canada, the number of papers authored by scientists at universities and institutes in other countries increased dramatically during this period. Factors influencing colostral antibody absorption, heat treatment of colostrum, and efficacy of colostrum supplements and replacers were reported. Most studies in this period related to nutrition. Studies were published supporting greater neonatal growth rates from feeding more milk replacer but with a higher crude protein content than traditional. Protein energy effects on growth and body composition were evaluated in concert with greater growth rates. Milk and nonmilk protein sources in milk replacers along with AA supplementation were evaluated. Limited studies were done with fat sources and fatty acid supplementation along with trace minerals and fat-soluble vitamins. Waste milk feeding and heat treatment became more prevalent. Studies established starter ingredient palatability and use of forage when fed with pelleted starters. With the advent of automatic milk and milk replacer feeders, factors influencing how and when to wean were established. Research programs established factors affecting calf behavior and welfare. Several databases were evaluated along with various published studies, and established calf growth during the first 2 mo was subsequently reflected in first- and later-lactation milk production of those calves. A new area of calf research that emerged from 1997 on was the effects of maternal environment and nutrition on calf health, growth, and future productivity. From a mechanistic standpoint, the field of epigenetics seems likely to explain many of these phenomena. Some possibilities for future calf nutrition and management were elaborated. 相似文献
42.
Heikki M. Salo Nga Nguyen Emmi Alakärppä Linards Klavins Anne Linn Hykkerud Katja Karppinen Laura Jaakola Maris Klavins Hely Häggman 《Comprehensive Reviews in Food Science and Food Safety》2021,20(5):5197-5225
Berries represent one of the most important and high-valued group of modern-day health-beneficial “superfoods” whose dietary consumption has been recognized to be beneficial for human health for a long time. In addition to being delicious, berries are rich in nutrients, vitamins, and several bioactive compounds, including carotenoids, flavonoids, phenolic acids, and hydrolysable tannins. However, due to their high value, berries and berry-based products are often subject to fraudulent adulteration, commonly for economical gain, but also unintentionally due to misidentification of species. Deliberate adulteration often comprises the substitution of high-value berries with lower value counterparts and mislabeling of product contents. As adulteration is deceptive toward customers and presents a risk for public health, food authentication through different methods is applied as a countermeasure. Although many authentication methods have been developed in terms of fast, sensitive, reliable, and low-cost analysis and have been applied in the authentication of a myriad of food products and species, their application on berries and berry-based products is still limited. The present review provides an overview of the development and application of analytical chemistry methods, such as isotope ratio analysis, liquid and gas chromatography, spectroscopy, as well as DNA-based methods and electronic sensors, for the authentication of berries and berry-based food products. We provide an overview of the earlier use and recent advances of these methods, as well as discuss the advances and drawbacks related to their application. 相似文献
43.
Børge N. Fredriksen Linn Benjaminsen Hølvold Jarl Bøgwald Roy A. Dalmo 《Polymer-Plastics Technology and Engineering》2013,52(14):1468-1473
Efficient antigen entrapment is a key factor in preparation of poly (lactide-co-glycolide) acid (PLGA) vaccine formulations when the antigen is of short supply. This study presents a systematic approach in the testing of formulation variables with the objective to increase antigen entrapment in particles when the antigen stock concentration was low. Some of the experimental variables tested were poly (vinyl) alcohol (PVA) concentration in the inner (W1) and outer (W2) aqueous phase, W1/oil (O) phase ratio and choice of organic solvent. The double emulsion solvent evaporation technique was applied to prepare PLGA particles with sonication as the emulsifying force. To measure antigen entrapment efficiency, the antigen (bovine serum albumin, BSA) was isotope labeled with 125iodine (125I). Our results demonstrated that a low PVA concentration in the inner aqueous (W1) phase was beneficial to achieve a high encapsulation efficiency of antigen. On the contrary, in the outer aqueous (W2) phase, a high PVA concentration favored antigen entrapment. We also demonstrated that decreasing the W1 to O/polymer ratio contributed to increased entrapment efficiency. Testing different organic solvents (ethyl acetate, dichloromethane and chloroform), either alone or in combination, revealed that using chloroform as solvent resulted in the highest encapsulation of antigen and the highest production yield. Some of the results presented in this work are in disagreement with well-established formulation variables from previous studies. 相似文献
44.
Attachment, separation, and women's vocational development: A longitudinal analysis. 总被引:1,自引:0,他引:1
O'Brien Karen M.; Friedman Suzanne Miller; Tipton Linda C.; Linn Sonja Geschmay 《Canadian Metallurgical Quarterly》2000,47(3):301
This study tested a proposed model investigating the relations among attachment to and separation from parents, career self-efficacy, and career aspiration over a 5-year period with a sample of 207 young women. Results suggested that being attached to parents may lead to the development of confidence in pursuing career-related tasks, which in turn influences career aspiration. Separation from parents did not have direct effects on career self-efficacy. Results also indicated that women's career plans changed over a 5-year period with young women selecting more traditional and less prestigious careers than those to which they aspired in their senior year of high school. In addition, these women chose careers that underutilized their abilities. Finally, this sample of young women intended to have both careers and families, and the majority of these women ranked family as more important than career. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
45.
Newcombe Nora S.; Ambady Nalini; Eccles Jacquelynne; Gomez Louis; Klahr David; Linn Marcia; Miller Kevin; Mix Kelly 《Canadian Metallurgical Quarterly》2009,64(6):538
Improving mathematics and science education in the United States has been a matter of national concern for over half a century. Psychology has a vital role to play in this enterprise. In this article, the authors review the kinds of contributions that psychology can make in four areas: (a) early understanding of mathematics, (b) understanding of science, (c) social and motivational aspects of involvement in mathematics and science, and (d) assessment of learning in mathematics and science. They also examine challenges to psychology’s playing a central and constructive role and make recommendations for overcoming those challenges. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
46.
基于有机聚合物乳液的吸附及络合作用,采用丙烯酸乳液(AE)对氯氧镁水泥(MOC)进行改性,对改性后的MOC工作性能、力学性能、耐水性能及微观结构进行研究,揭示AE对MOC的改性机理. 结果表明:AE在MOC中的分散作用可增大MOC的流动度;AE在水泥颗粒及水化产物表面形成的膜结构在抑制5·1·8相晶体生长的同时,还改变了晶体形态,对MOC的凝结时间及强度产生了影响;AE不仅降低了MOC内部有害孔的体积分数,还在MOC内部形成了膜结构,在这两者共同作用下,5·1·8相晶体的水解得以延缓,Mg(OH)2晶体的生成量减少,从而改善了MOC的耐水性能. 相似文献
47.
48.
目的 综合应用传统分离培养、内部转录间隔区(ITS)测序和高通量基因组学测序技术,建立分析市售普洱茶中真菌群落构成和物种多样性的新方法.方法 按照GB 4789.15-2016《食品安全国家标准食品微生物学检验霉菌和酵母计数》对普洱茶样本进行可培养真菌检测和分离纯化,对分离到的菌株进行ITS测序并在NCBI数据库中进行... 相似文献
49.
50.
B Guillaume D E Otterby J G Linn M D Stern D G Johnson 《Journal of dairy science》1987,70(11):2339-2348
Data were from 45 Holstein cows (23 multiparous, 22 primiparous) assigned by calving date and parity within groups to one of two isonitrogenous (16% crude protein) diets. The diets were 50% forages (corn silage, alfalfa silage) and 50% concentrate, dry basis. In diet A, soybean meal supplied 34.2% of total crude protein; in diet B, ground sweet white lupin seeds provided 37.9% of total crude protein. Cows were fed once daily during the experimental period (d 4 to 116 postpartum). Cows fed lupins consumed significantly less dry matter, produced 1.8 kg/d less milk (but not significantly different), and had lower milk protein percent. Milk fat and total solids percents were similar. Reasons for reduced intake of cows fed lupins were not evident. Traces of alkaloids (.005% dry basis) were present in diet B. Combined results of in vitro continuous culture fermentation and in situ degradation measurements indicated that crude protein from lupins was more degradable than that of soybean meal. Poor performances of cows fed lupins could be partly due to a reduced true protein supply to the small intestine. 相似文献