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A Bayesian belief network is adopted to structure and manage an entry decision problem, where a potential entrant has to evaluate the profitability of a given market, depending on an established firm's unknown and unobservable multidimensional type. A multiperiod multisignal model is defined to take account of strategic interaction processes between the incumbent and the potential competitor. Since significant theoretical and computational issues prevent us from finding optimal strategies, a myopic policy is discussed that leads to a reasonable outcome. An application example of the proposed solution procedure is also presented.  相似文献   
3.
The behavior of pectin methylesterase (EC 3.1.1.11) activity as a function of temperature was investigated in Sanguinello orange juice. The thermal inactivation of this enzyme was evaluated in the range of 75–95C and was found to be nonlinear. Due to very low activity content, after the thermal treatment at temperatures above 80C, the active enzyme was concentrated by affinity chromatography. The logarithmic values of decimal reduction times, plotted against temperature, showed a nonlinear pattern featuring a sudden change in slope at temperatures exceeding 85C. The z value determined in the range 85–95C was much higher than that calculated in the range 75–85 C. The decimal reduction times were used to estimate the times of treatment for the enzyme inactivation during a HTST process.  相似文献   
4.
The rheological behavior of liquorice solutions at different concentrations (ranging between 30 and 60 Brix) and temperatures (in the range between 25 and 80C) has been investigated performing both dynamic tests in the linear viscoelastic region and steady shear tests, in 0.1–100 s?1 shear rate range, by using a stress controlled rheometer (DSR 200, Rheometric Scientific, USA) and parallel plate geometry (φ = 40 mm). Small amplitude oscillations has shown the presence of both moduli also at the lowest tested concentration, with G′ greater than G″, except for the 30 Brix sample. It has been found that experimental viscosity data show a good agreement with a power law model, thus allowing the estimation of both the friction factor and the pressure drops in a typical pipeline used for liquorice solution conveying. It has been observed that the assumption of Newtonian behavior can lead to the erroneous design of the apparatuses that have to process liquorice extracts.  相似文献   
5.
An unsteady-state theoretical analysis of the cooling of a large cross-section ice cream brickette is presented, to model the hardening process required for handling and storage purposes. The material physical properties, i.e. heat conductivity and thermal capacity, are considered temperature dependent, according to available experimental data on a vanilla ice cream. The material is assumed to be macroscopically homogeneous, in the sense that the phase change is simulated by adoption of effective physical properties. The bidimensional differential equations governing the process have been solved numerically using the finite element method, which is extremely powerful for defining optimal design criteria and process control strategies. Results are presented and discussed for different external heat transfer conditions.  相似文献   
6.
The existence of an inflammatory process in the heart muscle, related to a progressive worsening of myocardial function, different etiopathogenetic mechanisms concur and often overlap, thus making the diagnosis and the therapeutic approach complex. As the COVID-19 pandemic progresses, the effects of the disease on the organ systems and in particular on the cardiovascular system are becoming more and more profound. Cardiac involvement is a well-known event with a high percentage of findings in the heart’s magnetic field, even in asymptomatic areas. There are numerous uncertainties regarding their evolution, in the long and short term, due not only to a difficult to determine the varied clinical expression and the rarely performed intramyocardial biopsy which additionally presents diagnostic problems but also in part to different clinical prognosis. Today, the new SARS-CoV-2 virus that uses the angiotensin converting enzyme 2 (ACE2) which is present at high levels in myocardial cells as its entrance it can create even severe heart injury. The pathophysiology in all of these cases can involve multiple immune and non-immune mechanisms within organs and vessels and can be occur in the clinical phases. Possible mechanisms of direct and indirect myocardial infarction in patients with COVID-19 include additional lesion and oxygen-rich and generalized inflammation response with myocardial immune hyperactivity (myocarditis). Therefore, these can occur through the excessive release of cytokines, the presence of thrombocytopenia, endocrine damage, heart failure, arrhythmias and more. Patients can show average signs of myocardial damage, and some develop spontaneous cardiac complications, such as heart failure, arrhythmias and, rarely, rare cardiogenic disorders. Pathophysiology in all of these may involve multiple mechanisms within the cytokine cephalic membrane, endocrine damage and thrombogenicity. The diagnosis of this myocardial injuri is mainly based on the myocardial enzyme troponin. This viewpoint paper explains today’s knowledge on viral myocarditis, in particular that from SARS-CoV-2 infection, if there is a connection with other possible biomolecular pathogenetic factors that can influence its natural course. In fact, it is for this reason that the pathogenetic mechanisms are analyzed and described. At the same time, its possible interaction with other parameters that are documented risk factors for cardiovascular disease was examined. Although these biomolecular findings were mainly related to necrotic parts of the myocardium, it is important to recognize that myocardial damage early for a better approach and prognosis.  相似文献   
7.
Fresh‐cut potato strips were dipped in 1% N‐acetyl‐L‐cysteine (NALC), 1% diethylenetriamine pentaacetic acid (DTPA) and 5% erythorbic acid ‐ 1% citric acid (EACA) prior to storage under modified atmosphere at 1 and 6C. Color changes over a 21 day storage period were assessed by tristimulus colorimetry; microbial changes (total aerobic populations, lactic acid bacteria, yeast and mold) by standard microbiological methods; and color, texture, exudation, off odor and integrated quality assessment by a six‐member sensory panel. All chemical treatments delayed color changes, microbial growth and sensory alterations in the stored potatoes. However, dipping in EACA was the only treatment that yielded product that compared favorably with freshly prepared potatoes after 14 days at 1C or 7 days at 6C. The effectiveness of all the treatments was strongly affected by storage temperature.  相似文献   
8.
Water-in-oil-in-water (W/O/W) double emulsions are systems where a water-in-oil emulsion (W/O) is dispersed in a second aqueous phase. The W/O emulsion exists in the suspending aqueous medium as oil globules containing smaller water droplets.
In this work, a selection of both materials and procedures has been made in order to obtain an optimal formulation of a W/O/W food emulsion for both yield and rheologica] properties.
The rheological properties of W/O/W emulsions have been studied by means of both steady-shear and oscillatory measurements, and appeared to be similar to those of a simple O/W emulsion having the same volume fraction of dispersed phase, but lower oil content.
This is of great interest to the food industry, since producing double emulsions with the same texture as simple ones, but a lower oil content, helps to formulate reduced-calorie foods.  相似文献   
9.
In this paper, we study the behavior of the aerodynamic fan-shaped scheme of cable-stayed bridges under wind load. A numerical analysis is developed, based upon time integration of the motion equations of the discretized structure. The main structural nonlinearity arising from the stress–strain stay's constitutive equation is taken into account together with the nonlinear effects that arise assuming a nonstationary model for aerodynamic loads. A Newmark's type algorithm is used to discuss first the problem of free oscillations in still air, and to determine next the critical wind speeds, both in the case of A-shaped and of H-shaped towers. For the latter case, the overall discrete model is validated by comparison with analytical results obtained by a continuous model, already developed [5, 7]. The performance improvement of the structural behavior obtained by using A-shaped towers is numerically investigated by using the discrete model proposed here.  相似文献   
10.
Three isozymes of pectin methylesterase (EC 3.1.1.11) have been purified to homogeneity from tomato (var. S. marzano). The isozymes were separated by affinity chromatography on Heparin-Sepharose column. They exhibited a molecular mass of 31 kDa when analyzed in sodium dodecyl sulfate gel electrophoresis and of 35 kDa in gel-filtration chromatography in native conditions. The isoelectric points of all three isozymes were found to be higher than 9.3. The Kms calculated for the three isozymes were different toward citrus pectin used as substrate; one had a Km of 9.7 mM (by expressing the pectin concentration as mmoles/L of methoxy groups) and the other two had similar Kms of 3.0 and 2.6 mM, respectively. The isozyme having the higher Km for substrate was inhibited by citrus pectin (which had a degree of methylation of 70%) at concentrations higher than 5 mM, but no inhibition was found using a pectin with a degree of methylation of 30% at concentrations up to 13 mM (i.e. 9 mg/ml) with a Km of 14.7 mM. Furthermore, this isozyme showed a more broad range of activity in a pH range 5–10 with respect to that exhibited by the other two isozymes. All three isozymes were found to be glycosylated, although to different extents.  相似文献   
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