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101.
报道了以茈为荧光探针,探讨小剂量~(60)Co γ射线照射后小鼠胸腺细胞膜流动性的变化。结果表明,剂量在0.25-1.00Gy范围,胸腺细胞膜流动性降低与剂量之间呈明显线性关系。从0.50Gy起,辐照组荧光强度比值I_1/I_2与I_3/I_2与对照组的比较存有显著差异(P<0.05)。提示淋巴细胞膜流动性的变化可作为小剂量辐照早期效应的敏感指标。 相似文献
102.
This paper discussed the application of the method of the simplex-lattice design for predicting the properties of cement-based composites. On the basis of the compressive strength, its use was demonstrated on ternary paste systems composed of cement, silica fume and fly ash with constant water to binder ratio and a mass fraction of mineral admixtures not exceeding 30%. The regression model between compressive strength of paste and binder proportion was built up. The F-test method was utilized for validation of the regression model. The nonlinear programming system with upper and lower bound was solved. This allowed assessment of optimum mixture proportions and corresponding maximum compressive strength. It was shown that: (1) the 3rd-order regression model constructed by using the simplex-lattice design method could accurately predict the compressive strength in ternary paste system made of cement, silica fume and fly ash (the total mass fraction of all mineral admixtures was up to 30%); (2) to solve the nonlinear programming with the constraints of upper and lower bound played an important role in getting the optimum compressive strength and its corresponding mixture proportion at different ages; (3) the combination of the simplex-lattice design method and the optimization theory could be valuable tool for optimization of cement-based composites' properties. 相似文献
103.
In CFD simulation of diesel combustion, the predictive capabilities of the spray model play the most important role. Consequently, under the strict guidelines of the V&V, a method to adjust parameters of diesel spray model WAVE to accompany with the in-cylinder physical progress has been investigated in this paper. Moreover, the simulation of the spray has been validated by high-speed photography experiments and verified by the equation proposed by Hiroyasu. Finally, a modified setup for the WAVE spray model has been proposed and applied in the spray and combustion simulation for Deutz1013 diesel in different engine speed. 相似文献
104.
105.
A novel fully conjugated polymer containing 1,10‐phenanthroline (DAPcDOD) was first synthesized by the polycondensation of 2,7‐dimethyl‐2,4,6‐octatriene‐1,8‐dial with 5,6‐diamine‐1,10‐phenanthroline. Three polymeric complexes were first prepared by the reaction of DAPcDOD with NiSO4, CoCl2, and FeSO4, respectively. The structures of the polymer and the complexes were characterized by IR, 1H‐NMR, and elemental analysis. The magnetic behaviors of these complexes were measured as a function of magnetic field strength (0–50 kOe) at 5 K and as a function of temperature (5–300 K) at a magnetic field strength of 30 kOe. The results show that DAPcDOD–Ni2+ and DAPcDOD–Co2+ were soft ferromagnets, whereas DAPcDOD–Fe2+ exhibited the features of an antiferromagnet. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
106.
通过对铸造湿型小件产品缺陷典型实例的原因分析,从型砂的选择及配制、造型工艺、浇注工艺等方面提出控制缺陷产生的工艺方法。 相似文献
107.
Hongfang Sun Zewen Liu Jiahao Zhao Li Wang Jing Zhu 《IEEE transactions on magnetics》2007,43(8):3457-3461
A low-temperature annealing process in vacuum is proposed to enhance the inductance of RF inductors with FeNi-SiO2 magnetic granular films. Due to the great improvement of soft magnetic property in the 200degC and 350degC annealed film, the inductance is enhanced by 9.6% (200degC) and 8.3% (350degC), respectively, compared with the case of as-deposited film inductor. The peak value of quality factor, which is 9.18 for the as-deposited film inductor, is also increased to 9.27 (200degC ) and 12.27 (350degC), respectively. 相似文献
108.
A globally convergent algorithm for transportation continuous network design problem 总被引:2,自引:0,他引:2
The continuous network design problem (CNDP) is characterized by a bilevel programming model, in which the upper level problem
is generally to minimize the total system cost under limited expenditure, while at the lower level the network users make
choices with regard to route conditions following the user equilibrium principle. In this paper, the bilevel programming model
for CNDP is transformed into a single level convex programming problem by virtue of an optimal-value function tool and the
relationship between System Optimum (SO) and User Equilibrium (UE). By exploring the inherent nature of the CNDP, the optimal-value
function for the lower level user equilibrium problem is proved to be continuously differentiable and its derivative in link
capacity enhancement can be obtained efficiently by implementing user equilibrium assignment subroutine. However, the reaction
(or response) function between the upper and lower level problem is implicit and its gradient is difficult to obtain. Although,
here we approximately express the gradient with the difference concept at each iteration, based on the method of successive
averages (MSA), we propose a globally convergent algorithm to solve the single level convex programming problem. Comparing
with widely used heuristic algorithms, such as sensitivity analysis based (SAB) method, the proposed algorithm needs not strong
hypothesis conditions and complex computation for the inverse matrix. Finally, a numerical example is presented to compare
the proposed method with some existing algorithms. 相似文献
109.
110.
Conventional cancer therapies, the second leading cause of death worldwide, result in serious side effects and, at best, merely extend the patient''s lifespan by a few years. Searching for effective prevention is of high priority in both basic and clinical sciences. In recent decades natural products have been considered to be an important source of cancer chemopreventive agents. Red wine polyphenols, which consisted of various powerful antioxidants such as flavonoids and stilbenes, have been implicated in cancer prevention and that promote human health without recognizable side effects. Since resveratrol, a major component of red wine polyphenols, has been studied and reviewed extensively for its chemopreventive activity to interfere with the multi-stage carcinogenesis, this review focuses on recent progress in studies on cancer chemopreventive activities of red wine polyphenol extracts and fractions as well as other red wine polyphenols, like procyanidin B5 analogues and myricetin. 相似文献