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101.
Efficient Bulk Operations on Dynamic R-Trees 总被引:8,自引:0,他引:8
In recent years there has been an upsurge of interest in spatial databases. A major issue is how to manipulate efficiently
massive amounts of spatial data stored on disk in multidimensional spatial indexes (data structures). Construction of spatial indexes (bulk loading ) has been studied intensively in the database community. The continuous arrival of massive amounts of new data makes it
important to update existing indexes (bulk updating ) efficiently.
In this paper we present a simple, yet efficient, technique for performing bulk update and query operations on multidimensional
indexes. We present our technique in terms of the so-called R-tree and its variants, as they have emerged as practically efficient
indexing methods for spatial data. Our method uses ideas from the buffer tree lazy buffering technique and fully utilizes the available internal memory and the page size of the operating system. We
give a theoretical analysis of our technique, showing that it is efficient both in terms of I/ O communication, disk storage, and internal computation time. We also present the results of an extensive set of experiments
showing that in practice our approach performs better than the previously best known bulk update methods with respect to update
time, and that it produces a better quality index in terms of query performance. One important novel feature of our technique
is that in most cases it allows us to perform a batch of updates and queries simultaneously. To be able to do so is essential
in environments where queries have to be answered even while the index is being updated and reorganized.
Received November 15, 1998; revised May 3, 2001. 相似文献
102.
In dairy cattle breeding, there is a clear trend toward the use of only a few high-yielding breeds. One main reason is that efficient breeding programs require a certain population size. Since some numerically small breeds are well known for their functional traits, they might be an interesting crossing partner for high-yielding breeds with the aim to utilize heterosis. This simulation study investigated the transition period of a small cattle population for the implementation of genomic selection and rotational crossbreeding with a high-yielding breed. Real SNP chip genotype data from the numerically small red dairy breed Angler and the high-yielding breed Holstein Friesian were used to simulate the base generations, from which rotational crossbreeding was conducted for 10 generations. A polygenic trait with many quantitative trait loci with additive and directional dominance effects was simulated. Different selection methods for Angler sires (purebred performance, crossbred performance, and weighted purebred-crossbred performance) and different sizes and structures of the reference population (Angler, crossbred animals, and Angler plus crossbred animals) were considered. The results showed that the implementation of a genomic rotational crossbreeding scheme is an appealing option to promote the numerically small Angler breed. The growing reference population consisting of Angler and crossbred individuals maximized the genetic gain for Angler and the performance level for the crossbred individuals. Selection for purebred performance, crossbred performance, or a weighted combination of both hardly affected the results, and differences between selection scenarios were observed only in the long term with decreasing purebred-crossbred correlations. 相似文献
103.
Anisa J. Heck Johannes Schäfer Stefan Nöbel Jörg Hinrichs 《Comprehensive Reviews in Food Science and Food Safety》2021,20(6):6057-6088
The popularity of fat-free fermented concentrated milk products, such as fresh cheeses and high-protein yogurt, has increased over the recent years, attributed to greater availability and improvements in taste and texture. These improvements have been achieved through modifications and new developments in processing technologies, for example, higher heat treatment intensities and incorporating different membrane filtration technologies. Though numerous processing parameters are discussed in the literature, as well as reasons behind the developments, detailed examinations of how process modifications affect the final textural attributes of these products are lacking. To draw links between processing parameters and texture, we review the literature on fat-free fermented concentrated milk products from the perspective of fermented milk protein-based microgel particles as the basic structural unit. At each main processing step, relationships between process parameters, micro- and macrostructural and sensory (textural) properties are discussed.An overview of particle characteristics that drive structural changes at each processing step is developed in relation to textural characteristics. Using this approach of assessing relationships between structural characteristics of concentrated dispersions of fat-free fermented milk protein-based microgel particles and processing parameters provides a basic context for the selection of optimal parameters to achieve a desired texture. 相似文献
104.
105.
Manuel Krewinkel Claudia Baur Bertolt Kranz Mario von Neubeck Mareike Wenning Siegfried Scherer Marina Stoeckel Jörg Hinrichs Lutz Fischer 《Food Analytical Methods》2016,9(3):646-655
Microbial lipases may be produced during milk storage and processing. This can lead to organoleptic changes in the corresponding dairy products. Thus, monitoring of lipase activity in milk is desirable. Turbidity of milk prevents a direct photometric measurement of lipase activity using chromophore- or fluorophore-based assays. Laborious pretreatments or alternative analytical methods normally have to be used. With the method for the determination of lipolytic activity (MeDeLi) proposed here, it is possible to measure lipase activity directly in the natural milk utilizing tailored fluorometric substrates. Only a defatting step is carried out initially for the MeDeLi. Then, the conversion of added lipase substrate is carried out in the unmodified milk without addition of any solutions or any enzyme extraction procedure which may influence the enzyme activity. Thereafter, the milk sample is treated with two solutions to remove the turbidity of milk by dissolution. A valid and sensitive fluorometric measurement is then possible. The applicability of the MeDeLi was demonstrated in comparison with tests published previously: The limit of detection for lipolytic activity measured by MeDeLi was the lowest, with 41 pkat/mL. Raw milk, milk products, and spoiled milk samples were also investigated with the MeDeLi. 相似文献
106.
Srinarong P Pham BT Holen M van der Plas A Schellekens RC Hinrichs WL Frijlink HW 《Drug development and industrial pharmacy》2012,38(4):490-500
The aim of this study was to develop a new fast-disintegrating tablet formulation containing 1?mg tacrolimus for sublingual application. First, solid dispersions containing tacrolimus (2.5%, 5% and 10% w/w) incorporated in Ac-Di-Sol(?) and carriers (inulin 1.8?kDa and 4?kDa, and polyvinylpyrrolidone (PVP) K30) were prepared by freeze drying. Subsequently, a tablet formulation composed of a mixture of the solid dispersions, Ac-Di-Sol(?), mannitol, Avicel(?) PH-101 and sodium stearyl fumarate was optimized concerning drug load in the solid dispersions and the type of carrier. Tablet weight was kept constant at 75?mg by adjusting the amount of Avicel(?) PH-101. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) results indicated the absence of the drug in the crystalline state, which was confirmed by the scanning electron microscopy (SEM). These results suggest that tacrolimus incorporated in all of the solid dispersions was fully amorphous. Dissolution of the tablets containing solid dispersions with a low drug load highly depends on the type of carrier and increased in the order: PVP K30 < inulin 4?kDa < inulin 1.8?kDa. Solid dispersions with a drug load of 10% w/w incorporated in the carriers yielded optimal formulations. In addition, the physicochemical characteristics and the dissolution behavior of the tablet formulation containing inulin 1.8 kDa-based solid dispersions with a drug load of 10% w/w did not change after storage at 20°C/45%RH for 6 months indicating excellent storage stability. 相似文献
107.
For mozzarella production the curd is plasticised and kneaded. To characterise the process rheologically, mozzarella cheese curd was investigated using a capillary rheometer at different temperatures. Measurements with the capillary rheometer regularly revealed pressure oscillations and product distortion, starting at 55 °C, 21/s and at 60 °C, 36/s which leads to the conclusion that there is melt fracture of the stick‐slip type above a critical shear rate. Additionally, at 60 °C and 65 °C phase separation of water and fat was observed, which limits the optimal range of the cooker–stretcher machines. 相似文献
108.
Estimation of the nutritional parameters of various types of wheat flours using fluorescence spectroscopy and chemometrics
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M. Haseeb Ahmad Marius Nache Jörg Hinrichs Bernd Hitzmann 《International Journal of Food Science & Technology》2016,51(5):1186-1194
The purpose of this study is to evaluate the potential of fluorescence spectroscopy to predict the nutritional parameters of twenty‐six commercially available wheat flours from different vendors. Principal component analysis (PCA) was used to clearly identify the correlations among different types of flours. A partial least square regression (PLSR) model gives a good prediction for moisture, fat and carbohydrates using cross‐validation, with a R2 of 0.86, 0.88 and 0.89 respectively. However, the protein, sucrose and salt contents showed little correlation in PLSR. Locally weighted regression (LWR) provides a significant improvement in the prediction of all of the nutritional parameters. The error decreases with an increasing R2 to 0.96, 0.93, 0.99, 0.98, 0.99, 0.88, 0.95 and 0.99 for the energetic value, protein, fat, moisture, carbohydrate, sucrose, salt and saturated fatty acid contents respectively, for different wheat flours. Hence, fluorescence, which is a non‐invasive and rapid method, can be used to evaluate the nutritional parameters of different types of wheat flours. 相似文献
109.
In the present study, 6 different mastitis data sets of 3 dairy herds with an overall herd size of 3200 German Holstein cows were analyzed. Data collection periods included the first 50, 100, or 300 d of lactation. The 3 data collection periods were analyzed with a lactation model and a test-day model. All models were animal threshold models. Mastitis frequencies in the lactation model data sets varied between 29 and 45%, and varied between 3 and 6% in the test-day model data sets. Depending on the period of data collection, heritabilities of liability to mastitis in the lactation models were 0.05 (50 d), 0.06 (100 d), and 0.07 (300 d). In the test-day models, heritabilities were slightly higher with values of 0.09 (50 and 100 d), and 0.06 (300 d). Between lactation models, the rank correlations between the relative breeding values were high and varied between 0.86 and 0.94. Rank correlations between the relative breeding values of the test-day models ranged from 0.68 to 0.87. The rank correlations between the relative breeding values of lactation models and test-day models varied from 0.51 and 0.80. Genetic correlations between mastitis and milk production traits were estimated with a linear animal test-day model. The correlations with mastitis were 0.29 (milk yield), 0.30 (fat yield), 0.20 (fat content), 0.34 (protein yield), and 0.20 (protein content). The estimated genetic correlation between mastitis and somatic cell score was 0.84. 相似文献
110.
Genetic analysis of mastitis data with different models 总被引:1,自引:0,他引:1
Hinrichs D Bennewitz J Stamer E Junge W Kalm E Thaller G 《Journal of dairy science》2011,94(1):471-478
The aim of this study was to analyze different mastitis data sets with different statistical models and compare results. Data recording took place on 3 commercial milk farms with an average herd size of 3,200 German Holstein cows. Recording started in February 1998 and was completed in December 2005. During this period, 63,540 treatments for clinical mastitis were recorded. Five different data sets were analyzed and the number of cows varied between 12,972 and 13,618, depending on the data set. Data collection periods contained either the first 50 or the first 300 d of lactation. When the data-recording period ended after 50 d of lactation, data sets were analyzed with a lactation threshold model (LTM), a multiple threshold lactation model (MTLM), and a test-day threshold model (TDTM). In the LTM analysis, mastitis was treated as a binary trait coded as 0 (no mastitis) or 1 (mastitis), whereas in MTLM mastitis, codes were between 0 and 4, depending on the number of estimated days with mastitis. The TDTM treated each day as a single observation coded similarly to that of the LTM. When the data collection period included the first 300 d of lactation, data sets were analyzed with the LTM or MTLM only, because the TDTM was computationally infeasible. Mastitis frequencies in LTM data sets were 25.8 and 39.2%, and 26.9 and 39.2% in MTLM data sets, when data recording ended after 50 and 300 d of lactation, respectively. The mastitis frequency in the TDTM data set was 5.2%. Respective heritability estimates of liability to clinical mastitis were 0.08 and 0.09 using the LTM, and 0.08 and 0.11 using the MTLM. When the TDTM was used, the estimated heritability was 0.15. Rank correlation between breeding values of the different data sets ranged between 0.40 and 0.97. Rank correlation between the LTM and MTLM were higher (0.78 to 0.97) than those between these 2 models and the TDTM (0.40 to 0.59).The MTLM combined the positive effects of both the LTM, with respect to the size of the data sets, and the TDTM, with respect to the lack of information. 相似文献