铸造起重机桥架结构分析与局部改进

铸造起重机载荷谱系数大、使用频繁、工作级别高,其桥架在作业时承受繁重的载荷作用。对于薄板焊接的桥架结构而言,构造复杂的部位会存在应力集中问题。针对传统计算很难周全考虑和准确评价桥架结构复杂部位应力分布规律的情况。采用有限元分析方法,在建立逼近真实的离散化模型的基础上,通过有限元分析软件,对现有的铸造起重机的桥架进行了力学性能分析,并和传统计算结果加以对比研究。在此基础上,对桥架结构局部构造的合理性进行评价与改进,使设计方案得到优化,保证铸造起重机桥架结构的工作安全性。     

塔台管制中NNI注视指数与情境意识的相关性研究

为挖掘测量塔台管制员情境意识（SA）的可用眼动指标,搭建模拟塔台管制眼动试验平台,设计3组难度试验。用NASA-TLX量表评估被试的任务负荷,对其进行方差分析,验证了试验设计的合理性;利用NNI算法量化被试的注视模式,用3D-SART量表评估被试的SA,利用SPSS软件对被试的NNI注视指数与SA进行以任务负荷为控制变量的偏相关分析和无控制变量的皮尔逊相关性分析。结果表明,被试的NNI注视指数与SA有显著中度正相关,且相关程度不受试验难度影响;NNI注视指数可以作为测量塔台管制员SA的一项眼动指标。     

综合阳离子钻井液体系在JZ25-1SA区块的研究及应用

针对JZ25-1SA区块难点,先后尝试了PEC、PEM钻井液体系,后期引进阳离子体系,经过不断的细化和优化,形成了综合阳离子体系及针对JZ25-1SA区块的操作工艺。综合阳离子体系具有优良的携砂、防塌、封堵性能和合适的抑制性能。     

Kuhnian theory-choice and virtue convergence: Facing the base rate fallacy

Perhaps the strongest argument for scientific realism, the no-miracles-argument, has been said to commit the so-called base rate fallacy. The apparent elusiveness of the base rate of true theories has even been said to undermine the rationality of the entire realism debate. On the basis of the Kuhnian picture of theory choice, I confront this challenge by arguing that a theory is likely to be true if it possesses multiple theoretical virtues and is embraced by numerous scientists–even when the base rate converges to zero.     

金融危机后主要发达国家科技发展战略走向

简要介绍了主要发达国家在金融危机爆发后推出的科技发展与产业振兴战略；通过对这些战略的分析，归纳出共性特征与值得借鉴之处；并指出在此背景下我国科技发展与自主创新面临的机遇与挑战。     

Preparation,thermal stability and biocompatibility studies of gelatin-induced hydroxyapatite co-substituted with essential physiological trace elements

Gelatin-induced hydroxyapatite with combined substitution of essential physiological trace elements(G-FAP)was prepared by a precipitation method.Pure hydroxyapatite(HAP)and ion-substituted hydroxyapatite(FAP)were also prepared for comparison.The characteristics of the precipitated powders were determined using X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FT-IR),specific surface area measurement(SSA),X-ray fluorescence spectroscopy(XRF),and thermogravimetric(TG)analysis.The biocompatibility was also determined by an in vitro investigation with MC3T3-E1 cells.SEM and TEM results showed that the G-FAP powders were composed of dense aggregates of agglomerated whisker-like crystals of200–300 nm in length and 10–20 nm in width.XRD and FT-IR analyses indicated the formation of pure apatite phase,and the substituted ions and gelatin did not change the diffraction pattern of the precipitated powders.The SSAs of the precipitated powder were 64.741,72.492,and107.745 m2/g,for HAP,FAP,and G-FAP,respectively.XRF analysis showed that Na+,Mg2+,and F-were substituted into the crystal lattice.TG results showed a reduced thermal stability of the precipitated G-FAP powders,with an advanced phase transformation beginning at800°C and a serious phase transformation from hexagonal apatite phase to rhombohedral b-TCP phase at 1,200°C in comparison with HAP and FAP.In vitro biological tests showed non-cytotoxic effects for all powders.However,G-FAP stimulated the proliferation of MC3T3-E1 cells earlier than HAP and FAP.The present G-FAP will therefore be a promising primary biomaterial for bone regeneration,tooth filling,or as a coating for metal artificial limbs.     

Roles for interleukin-2 (IL-2) and IL-4 in the generation of allocytotoxic T cells in the primary and secondary responses in vitro

Roles for interleukin-2(IL-2) and IL-4 in the generation of murine allocytotoxine T lymphocytes (allo-CTL) in the primary and secondary responses were studied in vitro. The generation of allo-CTL in the primary response was inhibited by anti-IL-2 monoclonal antibody (mAb), but was not inhibited by anti-IL-4 mAb. On the other hand, the generation of allo-CTL in the secondary response was partially inhibited by either anti-IL-2 or anti-IL-4 mAb, and it was almost completely inhibited by the combination of two mAbs. CD8⁺ cell-depleted splenocytes produced IL-2, but not IL-4, in response to alloantigens in the primary response, and these cells produced both IL-2 and IL-4 in the secondary response. Both exogenous IL-2 and IL-4 induced functionally active allo-CTL in the primary response from CD4⁺ cell-depleted splenocytes when these cells were stimulated with T cell-depleted allogeneic cells. These results suggest that the allo-CTL induction in the primary response is IL:-2-dependent and secondary allo-CTL induction is both IL-2 and IL-4-dependent, because unprimed CD4⁺ T cells produce IL-2, but not IL-4, whereas primed cells produce both IL-2 and IL-4 in response to alloantigens.     

仿金氮化钛薄膜的磁控反应溅射法研究

本文利用磁控反应溅射法研究制备氮化钛薄膜,结果表明,氮气分气压P_(N_2)直接影响膜中的氮、钛原子比,适当的衬底负偏电压可以消除膜中氧原子的存在。薄膜变与膜中原子组份、微观结构有关。     

西安市科技进步现状分析与对策

本文首先对西安的科技优势和科技水平与态势进行了分析,应用中性技术进步的生产函数模型,对西安市“七五”以来的科技水平、科技进步速度以及贡献率进行了定量分析研究。然后分析了西安市科技进步及成果转化中存在的问题和造成的原因,在此基础上,从技术的选择、加速科技体制改革、建立风险投资机制,以及如何把发挥科技优势同发挥存量优势相结合,加速向乡镇企业注入科学技术,调动科技人员的积极性等方面,探讨了加速科技成果转化和科技进步的对策与途径。