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91.
采用通用蒙特卡罗粒子输运程序MCNP/38计算低环径比Tokamak(紧凑环或球形环)聚变堆第一壁及中心导体上的中子壁负荷分布和核热沉积分布,并与常规Tokamak堆第一壁上中子壁负荷分布和核热沉积分布进行比较、分析。结果表明,在中子壁负荷归一化为1MW/m2时,与常规Tokamak相比,在低环径比Tokamak堆第一壁及中心柱表面上中子壁负荷分布峰值并不比常规Tokamak堆第一壁上的峰值高,而且低于低环径比Tokamak堆整个第一壁上的平均值,而中心柱上的核热沉积峰值稍高于常规Tokamak堆第一壁上的核热沉积峰值,但对较高中子壁负荷情况,中心导体柱上的核热沉积和辐照损伤仍可能是比较严重和值得特别研究的问题。 相似文献
92.
大红山铜矿岩体结构调查分析 总被引:2,自引:1,他引:1
大量工程实践已证明岩体结构是控制岩体稳定性的重要影响因素。为此,以大红山铜矿为研究背景,在选定有代表性调查地段的基础上,引入详细观测线法对其岩体结构进行了详细调查与统计。分析结果表明:调查区域内巷道岩体节理裂隙比较密集和发育,主要发育有倾向N53E、走向N37W、倾角53°,倾向W26S、走向N36W、倾角68°;倾向E1S、走向NIE、倾角89°的三组优势结构面,其中优势结构面第二组和第三组构成不稳定块体,并且断层及软弱夹层比较发育,加剧了巷道的破碎程度,对巷道围岩的稳定性有控制作用。最后提出了在巷道施工中密切注意围岩稳定性变化,避免工程事故的发生的建议。 相似文献
93.
94.
文章通过对夏热冬冷地区建筑节能应考虑的因素及相关技术指标,及高舒适的低能耗技术构成等方面的论述,从理论和实践中加以分析了目前建筑节能面临的问题和误区,从技术角度分析入手,提出了相应的解决措施和方法,以达到舒适和节能的要求为目的.同时还从另一个方面提醒购房者在购房时要增强节能意识,警惕假节能. 相似文献
95.
阮芙英 《纺织高校基础科学学报》1995,8(1):91-95
现代光学和通讯理论由于引入了傅里叶变换的方法,使计算光学系统和通讯系统的物像的对应关系简洁、清晰。该文用傅氏变换计算长为2a、照度为A的均匀缝光源在观察面上的光强分布为I(x)=│E(x)│^2=AA^2a^2(sin2πfa/2πfa)此方法也可运用于矩形孔、圆孔等。 相似文献
96.
The mechanisms governing the solubilizing interactions between zwitterionic/anionic mixed surfactant systems at different
molar fractions of the zwitterionic surfactant (Xzwitter) and neutral or electrically charged unilamellar liposomes were investigated. The mixed systems were formed by N-dodecyl-N,N-dimethylbetaine
and sodium dodecyl sulfate in the presence of piperazine-1,4-bis-(2-ethanesulfonic acid) buffer at pH 7.20. Unilamellar liposomes formed by egg phosphatidylcholine, in some cases together
with stearylamine or phosphatidic acid, were used. Solubilization was detected as a decrease in static light-scattering of
liposomes. Two parameters were regarded as corresponding to the effective surfactant/lipid molar ratios (Re) at which the
surfactant system (i) saturated the liposomes, Resat, and (ii) led to a total solubilization of liposomes, Resol. From these parameters the bilayer/aqueous medium surfactant partition coefficients for the saturation (Ksat) and complete bilayer solubilization (Ksol) were determined. When Xzwitter was 0.40, The Re and K parameters showed a maximum, whereas the critical micellar concentration (CMC) of these systems exhibited
a minimum, regardless of the electrical charge of bilayers. Given that the ability of the surfactant systems to saturate or
solubilize liposomes is inversely related to the Resat and Resol parameters, these capacities appear to be directly correlated with the CMC of the mixed systems. The similarity of both Ksat and Ksol (particularly for Xzwitter=0.2–0.8) suggests that a similar partition equilibrium governs both the saturation and the complete solubilization of bilayers,
the free surfactant concentration (Sa,Sb), remaining almost constant with similar values to the CMC for each mixed system studied. 相似文献
97.
The static and dynamic properties of solutions of a side chain polysiloxane liquid crystal polymer have been studied in a cyanobiphenyl nematic host as a function of concentration and temperature. Refractive index measurements were carried out on aligned samples and the data used to determine the macroscopic order parameter, S, using Haller's method. Photon correlation spectroscopy has been used to measure () for the pure nematic solvent and the solutions. From these measurements it appears that the static properties vary slowly and linearly with increasing polymer concentration whilst the dynamic or viscoelastic properties change markedly. This change has been attributed to γ1, the twist viscosity, and the results have been discussed in terms of the function of the siloxane polymer backbone. 相似文献
98.
高速公路水毁成因及防治措施 总被引:1,自引:0,他引:1
从高速公路水泥混凝土路面裂缝,挖方地段护面墙开裂、拦水带与路面衔接部位裂缝,急流槽水泥砂浆勾缝脱落等方面分析了高速公路水毁的成因,并提出了切实可行的防治措施,保证了高速公路的正常运营。 相似文献
99.
100.
David C. Whitehead Katherine M. Goulden Roy D. Hartley 《Journal of the science of food and agriculture》1985,36(5):311-318
The distribution of 10 nutrient elements was assessed in three fractions of herbage samples of perennial ryegrass, tall fescue, white clover and lucerne. The cell wall fraction, prepared by mechanical disintegration of undried material, contained the following proportions of the total herbage content of the major elements: N, 2.9–16.4%; P, 3.0–6.9%; S, 3.6–17.2%; Ca, 11.3–51.8%; Mg. 6.4–27.6% and K, 0.1–1.7%. Substantial though more variable proportions of the trace element cations, Fe, Mn, Zn and Cu were also present in the cell wall fraction. The extent to which the elements were soluble in water was assessed by analysis of the water-insoluble fraction prepared from freeze-dried samples of each herbage. The proportions of the total herbage content of the major elements soluble in water were: N, 30–57%; P, 80–92%; S, 35–71%; Ca, 48–69%; Mg. 65–83% and K, 90–96%. With the trace element cations the proportions soluble in water were more variable, though they were generally less than 70% of the total. The extent to which the various elements were soluble in 80% aqueous ethanol was assessed by analysis of the insoluble fraction prepared from freeze-dried materials. With each of the major elements, smaller proportions of the total herbage content were soluble in 80% ethanol than in water, which may reflect in part the lower solubility of proteins and pectin. With the trace element cations, the differences in solubility between 80% ethanol and water were generally small and inconsistent. 相似文献