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141.
��This work gives the concept about oil-cut,gas-cut, kick,grave kick,blowout and failure in controlling blowout and summarizes the type of failure in controlling blowout,the objective and man-made reasons causing blowout and the measures to prevent and control well blowout. 相似文献
142.
Objective To study on the role of thymus transplantation for heart allograft in rats. Methods Vascularized heart-thymus combined transplantation was performed with microsurgical technique. Graft survival, histopathology,
level of IL-2, IL-4 and its mRNA expression in serum and cardiac grafts were investigated. Results Heart-thymus combined transplantation achieved effect in the prolongation of cardiac graft survival with short-term administration
of cyclosporine. Conclusions Vascularized thymus transplantation induced immune tolerance in thymectomized rats. 相似文献
143.
The growth time, growth mode and the method of preparing the supported catalysts play an important role in the growth of single-walled nanotubes (SWNTs). Their effects on the chemical vapor deposition (CVD) growth of SWNTs with MgO-supported catalysts were investigated in this study. It is shown that the growth rate of SWNTs was large during the initial few minutes of growth, however the quality of the tubes was low owing to the formation of many defects. Long term growth may favor the formation of tubes with high quality and high yield, but the introduction of other forms of carbon (impurities) is also unavoidable. There was a balance between the increase in yield and quality and sacrifice of the purity during growth of SWNTs. MgO-supported catalysts prepared by the co-precipitation method were found to be more effective for the synthesis of SWNTs than those prepared by the widely used impregnation method. The size and dispersion state of the catalyst were found to be crucial in enhancing the growth of SWNTs. In addition, growth on the surface of SWNTs over nanosized catalyst films was shown to be more favorable for the synthesis of tube products with higher quality, yield and purity. 相似文献
144.
Co-evolution as a computational and cognitive model of design 总被引:6,自引:0,他引:6
Co-evolutionary design has been developed as a computational model that assumes two parallel search spaces: the problem space
and the solution space. The design process iteratively searches each space using the other space as the basis for a fitness
function when evaluating the alternatives. Co-evolutionary design can also be developed as a cognitive model of design by
characterizing the way in which designers iteratively search for a design solution, making revisions to the problem specification.
This paper presents the computational model of co-evolutionary design and then describes a protocol study of human designers
looking for evidence of co-evolution of problem specifications and design solutions. The study shows that co-evolutionary
design is a good cognitive model of design and highlights the similarities and differences between the computational model
and the cognitive model. The results show that the two kinds of co-evolutionary design complement each other, having strengths
in different aspects of the design process.
Electronic Publication 相似文献
145.
146.
山东巨野国家粮食储备库天康面粉公司制粉车间始建于2000年,设计能力为处理小麦100t/d.主要设备有FMFQ10×2/6×2磨粉机8台,FS-FG6×24C高方筛3台,FQFD50×2×3清粉机2台,磨辊总接触长度12000 mm,平筛总筛理面积138.8 m2,单位磨辊接触长度12 mm/(100kg·d),单位平筛筛理面积0.14 m2/(100kg·d).麦间清理工艺(包括初清)为4筛2打2去石3磁选2着水,粉间工艺为488M1S2T4P3Br. 相似文献
147.
To investigate the effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents, macroporous polystyrene (PS) resin and PS‐based adsorbents with different hydrogen‐bond acceptor atoms (PS CH2( OCH2CH2)n OCH3, n = 0, 1, 2, and 3, denoted as PS‐EG0, PS‐EG1, PS‐EG2, and PS‐EG3) were prepared. The phenol adsorption strength order on these adsorbents was PS/PS‐EG0 < PS‐EG1 < PS‐EG2 < PS‐EG3, indicating that the adsorption on PS and PS‐EG0 was driven by hydrophobic and π–π interactions, and the adsorption on PS‐EG1, PS‐EG2, and PS‐EG3 was driven by a hydrogen bond in addition to hydrophobic and π–π interactions. PS‐EG2 may adsorb a second phenol molecule on each binding site and PS‐EG3 may adsorb second and third ones. The adsorption strength of resorcinol increased in the order of PS, PS‐EG1, and PS‐EG2, indicating that the adsorption was driven by 0, 1, and 2 hydrogen bonds in addition to hydrophobic and π–π interactions. Similarly, the adsorption of phloroglucinol on PS, PS‐EG1, PS‐EG2, and PS‐EG3 was driven by 0, 1, 2, and 3 hydrogen bonds in addition to hydrophobic and π–π interactions because the adsorption strength increased in this order. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4652–4658, 2006 相似文献
148.
A shortcut model is developed for predicting the HETP of a structured packed distillation column operating at elevated pressure. The proposed model incorporates the geometrical parameters of the packing, physical properties of the vapor and liquid phases, and the hydrodynamics of the two‐phase flow. The proposed model is tested and validated by comparing the predicted results with the present experimental data and some published HETP data. The results show that the proposed model can predict the experimental data with a deviation smaller than 20 %. 相似文献
149.
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
150.
简要地介绍了氢离子敏场效应晶体管(H~+-ISFET)的基本结构和工作原理,提出了一种新型背面接触式H~+-ISFET。对该结构在版图、工艺设计中的有关问题,进行了探讨。最后指出:它在pH值的测量中有较好的实用价值。 相似文献