基于可持续发展的IS—LM—SD模型

可持续发展是经济、社会和环境三者和谐发展的统一,不仅与一个国家的自然资源禀赋有关,而且与国家的财政、货币政策等制度安排有着内在的联系,表现为产品市场、货币市场和与社会、环境相关的特殊服务市场的均衡,因此,国家可以通过财政政策、货币政策的合理应用,实现社会、经济、生态环境的协调发展。通过把社会可持续发展曲线和环境可持续发展SE曲线合并成可持续发展SD曲线,纳入到IS—LM模型中去,得出了国家可以通过财政、货币政策调整SH影响经济发展,影响产品市场、货币市场和特殊服务品市场的均衡,实现经济、社会、生态环境的可持续发展的结论。     

考虑入流角的水平井筒混合损失模型

对水平井的孔眼入流处的微元段进行了流动分析,根据气、液两相的连续性方程、动量方程和能量方程,在相间不存在传质和等温稳态流动等条件下,得到了气、液两相的混合损失计算模型。根据得到的模型,计算了不同入流角条件下水平井筒混合损失的值,结果表明:入流角对混合损失的影响较大,在不影响产量等条件下,应尽量采用小于90°的入流角,有利于减小井筒的压降。本模型对改变传统的射孔方式、鱼刺型分支井和压裂水平井的研究具有一定的指导意义。     

知识经济环境下加强无形资产财务管理的思考

为了满足知识经济环境下对财务管理的要求,针对目前无形资产在财务管理中弱化的表现,提出了相应对策,以完善财务管理的内容。     

深井离心泵的回归分析与数值模拟

选择了叶轮叶片出口安放角、叶片进口冲角、叶轮出口宽度及导叶进口宽度这4个几何因素,按中心组合试验方法,设计了30组方案．通过FLUENT软件,对冲压井泵的全流场进行数值模拟,获得了额定工况下30组方案的效率．采用四元二次回归方程拟合四因素与效率值之间的函数关系,通过求解回归方程以寻求最优几何参数组合．利用DesignExpert6．0．5软件对回归模型进行分析,得到二次回归响应面图．由图中发现：在给定的范围内,叶轮出口宽度对效率的影响最为显著,表现为等值线最密;导叶进口宽度与叶轮叶片出口安放角次之;叶轮叶片进口冲角对效率的影响最小,表现不显著．通过样机试制及试验,发现在设计工况下采用两级全流场的数值模拟值与试验值相当接近,误差在2％以内,验证了数值模计算的可行性．     

并列建筑物周围风场的数值模拟

研究单体建筑物高度及并列建筑物高差及并列建筑物间距等因素对并列建筑物周围风场的影响．建立了10组不同的并列建筑群布局,计算采用标准k-ε湍流模型．数值计算得到各种布局下建筑群周围风场,并对它们进行了对比分析．结果表明,单体建筑物高度与并列建筑物高差、并列建筑物间距与单体建筑物高度差共同对并列建筑物周围风场产生影响．     

Approximation methods of mixed l_1/H_2 optimization problems for MIMO discrete-time systems

The mixed l1/H2 optimization problem for MIMO (multiple input-multiple output) discrete-time systems is considered. This problem is formulated as minimizing the l1-norm of a closed-loop transfer matrix while maintaining the H2-norm of another closed-loop transfer matrix at prescribed level. The continuity property of the optimal value in respect to changes in the H2-norm constraint is studied. The existence of the optimal solutions of mixed l1/H2 problem is proved. Because the solution of the mixed l1/H2 problem is based on the scaled-Q method, it avoids the zero interpolation difficulties. The convergent upper and lower bounds can be obtained by solving a sequence of finite dimensional nonlinear programming for which many efficient numerical optimization algorithms exist.     

Control of the cardiovascular system ofAplysia by identified neurons

The neural network that controls the cardiovascular system of<i>Aplysia</i> adapts cardiovascular function to a variety of different physiological and behavioral situations. It (1) coordinates the cardiovascular system with the renal and respiratory systems; (2) modifies both systemic and regional blood flow during food-elicited arousal and feeding; and (3) changes the tension of longitudinal vascular muscle to adapt the arterial tree to changes in body shape. Indirect evidence suggests that the cardiovascular control circuit may also play a role in maintaining homeostasis during egg laying. Several putative neurotransmitters, including acetylcholine, serotonin, R15<img src="/content/n688g2qr6422185l/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">1 and R15<img src="/content/n688g2qr6422185l/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">2 peptides, have been localized to identified neurons in this circuit.     

Evidence for the extranuclear localization of thymosins in thymus

A new radioimmunoassay has been developed for thymosin <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"><sub>4</sub> by generating rabbit polyclonal antibodies against the synthetic N-terminal peptide fragment 1–15 coupled to KLH. The synthetic analogue [Tyr<sup>12</sup>]-thymosin <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"><sub>4</sub> (1–15) was used as tracer. This radioimmunoassay, with a useful range of 10–1000 pmoles, showed cross-reactivity with the second homologous <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-thymosin of man and rat (thymosin <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"><sub>10</sub>) but not of calf (thymosin <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"><sub>9</sub>). This radioimmunoassay, together with an improved radioimmunoassay for the N-terminus of parathymosin <img src="/content/u060l2vp75368616/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">, was employed for the measurement of the levels of thymosin <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"><sub>4</sub> and parathymosin <img src="/content/u060l2vp75368616/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0"> in nuclear and extranuclear extracts of calf thymus. The bulk of these polypeptides was found in the extranuclear material whereas only traces were observed in the nuclear environment, which indicates the extranuclear localisation of <img src="/content/u060l2vp75368616/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">- and <img src="/content/u060l2vp75368616/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-thymosins.     

Oviposition stimulants of aCitrus-feeding swallowtail butterfly,Papilio xuthus L

Summary A methanolic extract of<i>Citrus unshiu</i> induces oviposition by females of a<i>Citrus</i>-feeding swallowtail butterfly,<i>Papilio xuthus</i> L. The chemical factors responsible for stimulating oviposition were isolated and characterized as 5-hydroxy-<i>N</i><img src="/content/l1601064866243kr/xxlarge969.gif" alt="ohgr" align="BASELINE" BORDER="0">-methyltryptamine, adenosine, vicenin-2, narirutin, hesperidin and rutin. An artificial blend of these six components elicited significant oviposition behavior, apparently identical to that induced by contact with intact<i>Citrus</i> leaves.     

基于有限元方法的CF/PTFE复合材料界面应力

经表面改性和未经改性的碳纤维（CF）增强聚四氟乙烯（PTFE）复合材料的弹性强度均随着碳纤维含量的增加而增强．以碳纤维增强聚四氟乙烯（CF／PTFE）复合材料弯曲强度试验结果作为依据,开展CF／PTFE复合材料界面应力的研究工作．采用各向异性等参单元,推导出在平面载荷作用下多层纤维增强复合板的层间应力分布．进一步利用有限元方法对CF／PT—FE复合材料的界面进行应力分析,并得到与试验结果相一致的结论．