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61.
FLT3 (fms-related tyrosine kinase 3) is a receptor tyrosine kinase class III that is expressed on by early hematopoietic progenitor cells and plays an important role in hematopoietic stem cell proliferation, differentiation and survival. FLT3 is also expressed on leukemia blasts in most cases of acute myeloid leukemia (AML). In order to determine the frequency of FLT3 oncogene mutations, we analyzed genomic DNA of adult de novo acute myeloid leukemia (AML). Polymerase chain reaction (PCR) and conformation-sensitive gel electrophoresis (CSGE) were used for FLT3 exons 11, 14, and 15, followed by direct DNA sequencing. Two different types of functionally important FLT 3 mutations have been identified. Those mutations were unique to patients with inv(16), t(15:17) or t(8;21) and comprised fifteen cases with internal tandem duplication (ITD) mutation in the juxtamembrane domain and eleven cases with point mutation (exon 20, Asp835Tyr). The high frequency of the flt3 proto-oncogene mutations in acute myeloid leukemia AML suggests a key role for the receptor function. The association of FLT3 mutations with chromosomal abnormalities invites speculation as to the link between these two changes in the pathogenesis of acute myeloid leukemiaAML. Furthermore, CSGE method has shown to be a rapid and sensitive screening method for detection of nucleotide alteration in FLT3 gene. Finally, this study reports, for the first time in Saudi Arabia, mutations in the human FLT3 gene in acute myeloid leukemia AML patients.  相似文献   
62.
The effect of RN(-) allele on minimally processed hams as manufactured in France is now well established. In the present study, meat from 35 rn(+) and 51 RN(-) pigs on the basis of their glycolytic potential (GP) was used to assess the effect of the RN(-) allele on a model system and on yields and quality of cooked hams cured with a 40% brine addition containing the most common meat processing ingredients. Quality parameters were also measured on the fresh loins and a glucose assay was carried out on meat juice from both hams and longissimus dorsi (LD) muscles. With respect to GP, glucose content of LD juice gave the best prediction of RN status with 10% misclassified samples in comparison with 20% as determined from ham juice. Lower pH and higher drip loss and L* values were measured on the LD from RN(-) pigs (p?0.001). Technological yields obtained on the model system and on extended cooked cured hams were lower in meat from RN(-) pigs (p?0.001). However, pH value was more influential on the yield of the model system while protein content and particularly the amount of extractable sarcoplasmic proteins were more determinative on cured hams probably due to the effect of tumbling. All other quality traits were lower in hams from RN(-) pigs (p?0.001). Meat from RN(-) pigs can be used for the manufacture of extended cured products, but under similar processing technologies, quality and yield will remain inferior to what would provide pork of normal quality.  相似文献   
63.
Present work was aimed to develop an artificial neural networks (ANN) model to predict the polysaccharide-based biopolymer (Hylon VII starch) nanofiber diameter and classification of its quality (good, fair, and poor) as a function of polymer concentration, spinning distance, feed rate, and applied voltage during the electrospinning process. The relationship between diameter and its quality with process parameters is complex and nonlinear. The backpropagation algorithm was used to train the ANN model and achieved the classification accuracy, precision, and recall of 93.9%, 95.2%, and 95.2%, respectively. The average errors of the predicted fiber diameter for training and unseen testing data were found to be 0.05% and 2.6%, respectively. A stand-alone ANN software was designed to extract information on the electrospinning system from a small experimental database. It was successful in establishing the relationship between electrospinning process parameters and fiber quality and diameter. The yield of smaller diameter with good quality was favored by lower feed rate, lower polymer solution concentration, and higher applied voltage.  相似文献   
64.
Heat transfer inside wall-joint-fins systems is analyzed. The coupled two-dimensional energy equations of the wall and the joint-fin are solved numerically using an iterative high order scheme finite volume method. Advanced fine analytical solution is proposed and various closed form equations for different heat transfer augmentation indicators are obtained. Excellent agreement is noticed between the numerical and the analytical results. Wall-joint-fins systems are more effective in transferring thermal energy when the joint-fin is made of a highly conductive material. Moreover, varying the joint-fin lengths ratio may increase the system effectiveness by a factor of 1.2. In addition, the maximum reported system effectiveness is 925% above that when both wall and joint-fin have same thermal conductivity. The maximum system effectiveness which occurs at specific geometrical aspect factors increases as convective heat transfer coefficients increase. Furthermore, the effectiveness and efficiency of the wall-joint-fins system increase as the relative joint-fins to wall volume ratio increases. The wall-joint-fins efficiency is least affected by the joint-fin lengths ratio. Eventually, the heat transfer coefficient between the joint-fin and the wall is identified. Finally, wall-joint-fin systems are recommended as heat transfer enhancing elements.  相似文献   
65.
Describes the general characteristics of a newly developed nonconstant-flow generator for automatic ventilation of the lungs. It is known that the application of very high pressure to high internal resistance leads to a very stable flow, in that the flow itself is unaffected by external load (patient) variations. The stability of the flow means that the inspiratory process can be controlled by means of the ventilated volume, thus extending DIGIT utilization to high resistance patients. The modulation of the flow is implemented via a digital electromechanical system, which allows the ventilator functions to be accurately programmed. The desired flow waveform is obtained by means of a series of pneumatic valves, the apertures of which are digitally controlled. The design is innovative in that it allows the flow waveform in each of the ten digitalized time steps into which each inspiratory phase is divided to be both programmed and controlled. Other ventilators commercially available and currently in use do not have this functional capability, as they are all designed to model the integral flow of the inspiratory waveform without being able to modify the subunit time steps of a single inspiratory phase. The authors also discuss the results of fundamental tests concerning the performance characteristics of the ventilator  相似文献   
66.
A corrected prism-mirror-prism electron energy filter with curved entrance and exit faces was designed and incorporated into a Zeiss EM902 transmission electron microscope. The installation of the new filter required little modification to the existing microscope geometry and electronics. The filter had an energy resolution of 1.1 eV over the full image plane (acceptance half angle 10 mradian). The improved energy resolution was applied in studies of the low electron energy loss region that includes molecular orbital excitations or chromophore energy absorptions. Chromophore signal behaviour under electron irradiation was characterized using embedded crystals of hematin and of the dye mercury orange. Images of these crystals confirmed the expected decrease in signal intensity on shifting the selected energy loss from the region of molecular orbital excitations (less than approximately 5 eV) to higher energy losses. Electron irradiation-induced fading of the chromophore signal from hematin and mercury orange yielded similar 1/e dose values of 1.1 x 10(5) e(-) nm(-2) and 1.4 x 10(5) e(-) nm(-2) respectively. In a cellular context, chromophore signals were obtained from energy-filtered images of RIF-1 cell sections containing the photosensitizer chlorin e6 and from sections of BS-C-1 cells with cytoskeletal labelling via FITC-conjugated antibodies. The respective signals were extracted using a dose-dependent method or a shift in selected energy. Chromophore signal distributions were in agreement with fluorescence light microscopic images, but provided detail at higher spatial resolution.  相似文献   
67.
Three hundred and forty (340) Duroc×(Landrace×Yorkshire) crossbred piglets were allotted to a 2×2×3 factorial design experiment. The independent variables were the growth rate (fast: around -10 days at 100kg and slow: around +2 days at 100kg), based on two different EBV's (estimated breeding value) of the sire-line for age, the sex (barrows and gilts) and the live weight at slaughter (107, 115 and 125kg). A sub-population of 119 pigs (10 carcasses per treatment) was selected for the carcass and meat quality evaluation trials. As live weight increased there were significant increases in hot carcass weight and dressing percentage (P<0.05). Lean, fat and bone proportions were not affected by weight. Gilts had higher lean proportion (P<0.05) than barrows. Furthermore, carcasses of fast growing pigs were fatter (P<0.05) than those of slower growing ones. Loin muscle pH, drip loss and reflectance values did not vary significantly with any of the treatments. Intramuscular fat was higher in barrows (P<0.05) than in gilts and soluble collagen content decreased with increasing weight (P<0.05). Muscle protein (%) increased (P<0.05) from 107 to 115kg and gilts had a higher (P<0.05) content than castrates. No evidence was found that increasing slaughter weight detracts from carcass characteristics or meat quality.  相似文献   
68.
69.
A lab model vacuum-assisted solar dryer was developed to study the drying kinetics of tomato slices (4, 6, and 8 mm thicknesses) compared with open sun drying under the weather conditions of Montreal, Canada. The drying study showed that the time taken for drying of tomato slices of 4, 6, and 8 mm thicknesses from the initial moisture content of 94.0% to the final moisture content of around 11.5 ± 0.5% (w.b.) was 360, 480, and 600 min in vacuum-assisted solar dryer and 450, 600, and 750 min in open sun drying, respectively. During drying, it was observed that the temperature inside the vacuum chamber was increased to 48°C when the maximum ambient temperature was only 30°C. The quality of tomato slices dried under vacuum-assisted solar dryer was of superior quality in terms of color retention and rehydration ratio. The drying kinetics using thin-layer drying models and the influence of weather parameters such as ambient air temperature, relative humidity, solar insolation, and wind velocity on drying of tomato slices were evaluated.  相似文献   
70.
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