全文获取类型
收费全文 | 269篇 |
免费 | 24篇 |
学科分类
工业技术 | 293篇 |
出版年
2024年 | 6篇 |
2023年 | 7篇 |
2022年 | 8篇 |
2021年 | 22篇 |
2020年 | 18篇 |
2019年 | 9篇 |
2018年 | 22篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 12篇 |
2014年 | 20篇 |
2013年 | 27篇 |
2012年 | 11篇 |
2011年 | 14篇 |
2010年 | 18篇 |
2009年 | 7篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有293条查询结果,搜索用时 15 毫秒
81.
Video game goals are important features of video games. Player’s interaction with goals can not only shape the gaming experience by evoking cognitive and affective reactions in players, but also lead to learning outcomes. However, there are few empirical studies on the effects of interacting with game goals, and no previous research has manipulated goal setting. In two experimental studies, participants were randomly assigned to one of the following five conditions: self-set goal repetitive play, assigned goal repetitive play, no-set goal repetitive play, no-set goal single play, and no play. Results show that playing earthquake preparedness video games generates significant learning outcomes; playing repeatedly with self-set goals yields greater learning compared to playing once with no-set goals or not playing; and cognitive reactions mediates the relation between goal interaction and learning. Implications of the results for the design and evaluation of future video games for learning are explored. 相似文献
82.
Thermal Properties, Heat Sealability and Seal Attributes of Whey Protein Isolate/ Lipid Emulsion Edible Films 总被引:1,自引:0,他引:1
ABSTRACT: From 5% w/v whey protein isolate (WPI), whey protein/lipid emulsion edible films were produced that were sorbitol- or glycerol-plasticized, containing butterfat (0.2% w/v) or candelilla wax (0.8% w/v). Thermal properties of the films determined by Differential Scanning Calorimetry (DSC) showed onset temperatures (To) of 126 to 127 °C for sorbitol- and 108 to 122 °C for glycerol-plasticized films. To values were used as the basis for heat sealing temperatures. Temperature (110, 120, 130 °C), pressure (296,445 kPa), and dwell time (1,3 s) affected seal strength. Optimum heat sealing temperature was 130 °C for sorbitol- and 110 °C for glycerol-plasticized films. All films were heat sealable with an impulse heat-sealer. Electron Spectroscopy for Chemical Analysis (ESCA) of the surfaces of both sealed and unsealed films showed increase in hydrogen and covalent bonds involving C-O-H and N-C, which may be the main forces responsible for the sealed joint formation of the films. 相似文献
83.
Haleema Sadia Muhammad Zafar Mushtaq Ahmad Lubna Muhammad P. Z. Khan Ghulam Yaseen Muhammad I. Ali Shazia Sultana Omer Kilic Zeynep ahan Naveed Alam Qamar Abbas Abdul Ghani Saeeda Naz 《Microscopy research and technique》2020,83(3):259-267
The present study is focused on the detailed foliar epidermal anatomy of some selected wild edible fruits (WEFs) from Pakistan using light microscopy (LM) and scanning electron microscopy (SEM). The studied species are Ficus racemosa L., Solanum nigrum L., Capparis spinosa L., Physalis divaricata D.Don, Rosa moschata Herrm. and Ribes orientale Desf. collected from various localities of Pakistan. The objective of the present study is to investigate qualitative and quantitative anatomical characters for the identification and differentiation of collected wild edible fruits. The characters studied are shape and size of epidermal cells, anticlinal wall pattern, trichome type and shape, average number of stomata, length and width of stomata and pore. The detailed microscopic investigation and variations in the characters recorded have a key role in the determination and authentication of wild edible fruits. This study possesses great potential for plant taxonomists to further evaluate the species at molecular and genetic levels. 相似文献
84.
Rescorla Leslie; Achenbach Thomas M.; Ivanova Masha Y.; Dumenci Levent; Almqvist Fredrik; Bilenberg Niels; Bird Hector; Broberg Anders; Dobrean Anca; D?pfner Manfred; Erol Nese; Forns Maria; Hannesdottir Helga; Kanbayashi Yasuko; Lambert Michael C.; Leung Patrick; Minaei Asghar; Mulatu Mesfin S.; Novik Torunn S.; Oh Kyung-Ja; Roussos Alexandra; Sawyer Michael; Simsek Zeynep; Steinhausen Hans-Christoph; Weintraub Sheila; Metzke Christa Winkler; Wolanczyk Tomasz; Zilber Nelly; Zukauskiene Rita; Verhulst Frank 《Canadian Metallurgical Quarterly》2007,75(2):351
In this study, the authors compared ratings of behavioral and emotional problems and positive qualities on the Youth Self-Report (T. M. Achenbach & L. A. Rescorla, 2001) by adolescents in general population samples from 24 countries (N = 27,206). For problem scales, country effect sizes (ESs) ranged from 3% to 9%, whereas those for gender and age ranged from less than 1% to 2%. Scores were significantly higher for girls than for boys on Internalizing Problems and significantly higher for boys than for girls on Externalizing Problems. Bicountry correlations for mean problem item scores averaged .69. For Total Problems, 17 of 24 countries scored within one standard deviation of the overall mean of 35.3. In the 19 countries for which parent ratings were also available, the mean of 20.5 for parent ratings was far lower than the self-report mean of 34.0 in the same 19 countries (d = 2.5). Results indicate considerable consistency across 24 countries in adolescents' self-reported problems but less consistency for positive qualities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
85.
Influence of Different Unifloral Honeys on Heterocyclic Aromatic Amine Formation and Overall Mutagenicity in Fried Ground-beef Patties 总被引:1,自引:0,他引:1
ABSTRACT The effects of different unifloral honeys (buckwheat, clover, and sage), carbohydrates (fructose, glucose, and sucrose), and antioxidants (vitamin E, BHT), and Trolox® (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) on heterocyclic aromatic amine (HAA) formation and overall mutagenicity in fried ground patties were evaluated. The inhibition of total HAA formation was achieved with buckwheat (55%), clover (52%), and sage (51%); and they also reduced overall mutagenicity 36, 31, and 26%, respectively. The addition of fructose, glucose, or fructose and glucose together, at levels comparable to their occurrence in honey, reduced (p < 0.05) mutagenicity and HAA formation by amounts comparable to that found with honey. 相似文献
86.
ABSTRACT: Edible films were produced using whey protein isolate (WPI) (5%, w/v), glycerol (3.3%, w/v) and candelilla wax (0.8%, w/v). One set of films was heat cured at 90°C for 12 h and another at 80°C for 24 h. WPI-based films, together with collagen films, were put through a meat-processing scheme typical of Polish sausage manufacture. Meat-processing conditions were stage 1: 57°C/60 min/36% RH; stage 2: 65°C/90 min/60% RH; and stage 3: 77°C/30 min/80% RH. Effects of meat-processing conditions on mechanical properties: tensile strength (TS), elongation (%E), and apparent modulus (AM) were determined. All films remained intact throughout the process. TS, %E, and AM of collagen films did not change during the multistage cooking process. The %E of heat-cured WPI films was similar to that of collagen films and also did not change during the cooking stages. The TS and AM of both heat-cured WPI-based films were initially lower than collagen films and continued to decline during the cooking stages. TS and AM of both films at the end of cooking were lower ( P < 0.05) than films that did not go through the multistage cooking process. 相似文献
87.
Shear Behavior of Compacted Rubber Fiber-Clay Composite in Drained and Undrained Loading 总被引:1,自引:0,他引:1
The ductility, toughness, and resistance to tensile cracking of clays can be improved with the inclusion of short fibers. Tire buffings are derived from the tire retread process and because of their elongated shape, may be used as fiber inclusions. The objective of this study was to evaluate the drained and undrained shear strength of mixtures of clay and tire buffings. Mixtures of silty low plasticity kaolinitic clay and 10% by dry weight of tire buffings were compacted at both Standard and Modified compaction energy. Consolidated-drained and consolidated-undrained triaxial tests were run at confining stresses ranging from 50?to?300?kPa. Preshear and postshear permeability tests were conducted. Results showed that the peak strength of the composite is comparable to or greater than that of clay alone when tested at confining stresses below 200–300?kPa. Above this threshold, the presence of inclusions tends to degrade the strength of the clay. Changes in permeability were not significant. 相似文献
88.
Inactivation of Bacillus spores in batch vs continuous heating systems at sterilisation temperatures
Marina Stoeckel Setya B M Abduh Zeynep Atamer Jörg Hinrichs 《International Journal of Dairy Technology》2014,67(3):334-341
This study was performed to assess the heat resistance of spores of Bacillus species in batch and continuous heating systems under commercial sterilisation conditions. Spores of thermophilic Bacillus smithii and mesophilic Bacillus amyloliquefaciens were found to be highly heat resistant in the batch system. They were able to withstand typical sterilisation temperatures. B. amyloliquefaciens showed tailing in the batch system and, before the onset of the tailing, a higher inactivation rate than in the continuous system at low temperatures. The reason for the tailing might be the presence of spore aggregates which are disrupted in the continuous system. 相似文献
89.
Zeynep Koksal Ramazan Kalin Ilhami Gulcin Hasan Ozdemir 《International Journal of Food Properties》2018,21(1):385-394
The objective of this study was to determine the in vitro inhibition effects of seven commonly used pesticides including 2,4-d-acid dimethylamine, fenoxaprop-p-ethyl, glyphosate isopropylamine, haloxyfop-p-methyl, cypermethrin, λ-cyhalothrin, and dichlorvos on the peroxidase purified from turnip (Brassica rapa L.) and black radish (Raphanus sativus L.) using 4-amino benzohydrazide affinity column chromatography. The purification factors for the turnip and black radish peroxidases were found to be 263.29-fold (with a yield of 12.89%) and 36.20-fold (with a yield of 6.90%), respectively. Among these compounds, λ-cyhalothrin showed the strongest inhibitory effect against turnip peroxidase (Ki: 1.23 × 10?2 ± 0.21 × 10?2 mM) as noncompetitive inhibition. On the other hand, cypermethrin demonstrated the highest inhibition effect against black radish peroxidase (Ki: 2.14 × 10?2 ± 0.08 × 10?2 mM) as competitive inhibition. 相似文献
90.
Effects of Temperature,Time, and pH on the Stability of Anthocyanin Extracts: Prediction of Total Anthocyanin Content Using Nonlinear Models 总被引:1,自引:0,他引:1
Lutfiye Ekici Zeynep Simsek Ismet Ozturk Osman Sagdic Hasan Yetim 《Food Analytical Methods》2014,7(6):1328-1336
In this study, different anthocyanin sources including grape skin, black carrot, and red cabbage were used to determine the effect of thermal treatment, different acidity levels, and time on the anthocyanin content and degradation. The total anthocyanin contents were modeled by neuro fuzzy inference system (ANFIS) and artificial neural network (ANN) models. The red cabbage anthocyanin stabilities were higher than others. The anthocyanins degraded more rapidly at higher temperatures. The anthocyanin contents of samples decreased with the increase of pH from 3 to 7. Comparison of the models showed that the ANFIS model performed better than the ANN model for the estimation of total anthocyanin content in all samples. The lowest root mean square error (0.0457) and highest R 2 (0.9942) values were obtained for red cabbage and grape skin in the validation period with the ANFIS model, respectively. This study showed that both models can be utilized efficiently for the prediction of total anthocyanin content affected by temperature, time, and pH. 相似文献