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181.
Enrico Lorencini 《Journal of Engineering Physics and Thermophysics》1970,19(6):1548-1554
A variational method is employed to solve stationary and nonstationary heat conduction problems when the thermal conductivity coefficient is temperature-dependent and the heat generation function of the medium is arbitrary.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 19, No. 6, pp. 1070–1078, December, 1970. 相似文献
182.
Nine commercial potato cultivars have been analyzed in order to detect differences in nutritional quality, considering the balance between nutrients and anti-nutrient compounds present in each. The most important nutrients studied in this paper were: water, starch, free sugars, such as glucose, fructose and sucrose, malic acid, citric acid, ascorbic acid and chlorogenic acid. The anti-nutrients measured included α-solanine, α-chaconine and asparagine. This last compound was added to the anti-nutrient compounds because it is involved in the formation of acrylamide during thermal food processes. From this study, by considering the nutritional quality of each cultivar, we can divide the potato cultivars into three groups, each being suitable for a different technological processes. 相似文献
183.
184.
Sulfur-bridged polyaniline coatings are obtained onto Fe anodes by electrolyzing a basic solution of one aniline and ammonium sulfide. Their sulfur content ranges from 7% to 17%, depending on the substituents on aniline. Variously substituted anilines may be polymerized in this way and coating pollution by azobenzene formed in a side reaction is almost completely avoided. Sulfur probably enters the polymer chains through a free radical mechanism. HS? intermediates being formed by both homogeneous and anodic oxidation of HS? anions. Coatings from N-allylaniline, being thermally curable, show satisfactory physical properties. 相似文献
185.
Amorphous poly(ethylene terephthalate) has been isothermally annealed in a wide range of temperatures from Tg to Tm. The effects of temperature and time of thermal treatment on density, melting curve and WAXS have been systematically explored. The results showed that densification and crystal perfection take place through a step mechanism involving partial melting and diffusion. The evaluation of the activation energies suggests that diffusion is the rate determining step in the low temperature range. 相似文献
186.
Bigi Sabrina; De Acetis Luigi; De Simone Roberta; Aloe Luigi; Alleva Enrico 《Canadian Metallurgical Quarterly》1993,107(2):363
Subcutaneous (sc) administration of capsaicin (50 mg/kg) at Postnatal Days 2 and 5 exerted long-term effects on isolation-induced aggressive behavior of adult mice of the CD-1 strain. Isolated capsaicin-treated mice (scored during a 10-min session) showed the highest frequency and the longest duration of total attacks, attacks, rattling, and offensive upright posture when compared with nonisolated capsaicin-treated Ss and both isolated and nonisolated vehicle control animals. Hypothalamic substance P (SP) was assessed by radioimmunoassay. Capsaicin treatment significantly lowered hypothalamic SP content in both isolated and nonisolated mice. Moreover, individual scores of isolated capsaicin-treated Ss showed a significant correlation between SP depletion and expression of offensive upright posture. Isolation per se was revealed to play an important role in depleting SP from the hypothalamus. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
187.
Formation of 7α-hydroxycholesterol by rat liver microsomes was quantitated using a gas chromatograph-mass spectrometer (GC/MS)
operated in selected ion monitoring (SIM) mode. Microsomes from normal rat livers incubated for different periods were found
to yield increased 7α-hydroxycholesterol with time. This was also true when incubations contained Tween-80, but in this instance,
the rate of 7α-hydroxycholesterol production was lower and dependent on the concentration of Tween used. Similarly, Triton
X-100, Renex-30, Kyro EOB, Cutscum, and Emulgen 911 all lowered the formation of 7α-hydroxycholesterol by rat liver microsomes,
whereas Triton WR-1339 stimulated its production. Analysis of data obtained from following the enzyme reaction over an extended
period using an integrated Michaelis-Menten equation indicated the enzyme possesses a very significant affinity for the product
(Ks>Kp). Similar analysis shows that Tween-80 is a noncompetitive inhibitor of the enzyme. 相似文献
188.
Agosteo S Cammi A Garlati L Lombardi C Padovani E 《Radiation protection dosimetry》2005,115(1-4):86-91
The International Reactor Innovative and Secure is a modular pressurised water reactor with an integral design. This means that all the primary system components, such as the steam generators, pumps, pressuriser and control rod drive mechanisms, are located inside the reactor vessel, which requires a large diameter. For the sake of better reliability and safety, it is desirable to achieve the reduction of vessel embrittlement as well as the lowering of the dose beyond the vessel. The former can be easily accomplished by the presence of a wide downcomer, filled with water, which surrounds the core region, while the latter needs the presence of additional internal shields. An optimal shielding configuration is under investigation, for reducing the ex-vessel dose due to activated internals and for limiting the amount of the biological shielding. MCNP 4C calculations were performed to evaluate the neutron and the gamma dose during operation and the 60Co activation of various shields configurations. The gamma dose beyond the vessel from activation of its structural components was estimated in a shutdown condition, with the Monte Carlo code FLUKA 2002 and the MicroShield software. The results of the two codes are in agreement and show that the dose is sufficiently low, even without an additional shield. 相似文献
189.
A method is described which permits rapid evaluation of reliability functions and some probabilistic parameters related to the operation of systems. The method is based on the concept of system states and on the observation that, in terms of such states, the probabilistic behavior of systems is well described by the Markov process in infinitesimal dt, whenever subsystems behave independently of each other and randomly in time. Out of many methods useful to determine the probability that a system is in state Sj at time t, i. e., to solve the set of system state differential equations, the algorithm of the signal flow diagram has been emphasized here. Actually, such an algorithm gives us a Laplace transform of the reliability function rapidly and easily, from which one can evaluate some probabilistic parameters related to the reliability of systems (as the well-known mean time between failures) without passing through time-domain. Several applications have been examined, some of which can be resolved with intuitive methods, while some others cannot. 相似文献
190.
The stress-softening effect, which comes out when SBS three block copolymers are stretched, is taken into consideration and the conclusion is reached that it is due to a disruption of the polystyrene continuous phase, according to the hypothesis of other authors. This conclusion is supported by two kinds of experiments performed on samples having a well known and simple morphology. First of all by stress-strain measurements on specimens previously swollen: it can be seen that the stress-softening effect disappears as soon as the structure of the material is completely modified by the treatment. Secondly by the direct observation at the electron microscope of the structure after the deformation. This shows how the original continuous and regular polystyrene rods of the “single crystal” assume a string of pearl structure which finally is irreversibly disrupted. 相似文献