半潜平台运动计算的单体合成法

本文用单体合成法计算了一个半潜平台的运动以及作用在乎台上的水动力和波浪扰动力,利用平台水下部分透浪性能良好的物理假设,在数学上论证了这种方法。     

近海圆柱形贮液罐的振动特性

本文主要研究近海圆柱形贮液罐振动特性,这是个典型液-壳相互作用体系的研究课题.文中提出的解析法,将液、壳轴向模态位移用同一完备正交级数表示,使液、壳振型解耦合.同时将液、壳振型函数分解为一个一致收敛级数和另一线性多项式,解决了振型级数的收敛性和可微性.这样就得到对应于不同液深、任意边界条件、受约束的近海贮液罐的耦合固有频率的精确值和相应振型分布.     

聚丙烯酸钠溶液的粘性行为研究

本文利用恒定外加盐浓度稀释法研究了聚丙烯酸钠溶液的粘性行为。     

固相萃取-超高效液相色谱-串联质谱法同时测定保健食品中21种非法添加化合物

建立了固相萃取-超高效液相色谱-串联质谱同时测定保健食品中21种非法添加化合物的方法。样品用乙腈超声提取后，采用HLB固相萃取小柱净化，经Waters BEH C18色谱柱（100 mm×2.1 mm，1.7 μm）分离，以10 mmol/L乙酸铵和甲醇为流动相进行梯度洗脱，采用电喷雾电离（ESI）源，在多反应监测模式下检测。结果表明，21种非法添加化合物均呈良好的线性关系，相关系数均≥0.995，不同基质的检出限为3~160 μg/kg，回收率为61.8%~109.3%，相对标准偏差为1.6%~14.7%。该方法可用于减肥类、降脂类、降糖类、降压类保健食品中21种非法添加药物的同时测定。     

Role of added Lewis base and alkylaluminum halide on living cationic polymerization of vinyl ether

In the living cationic polymerization of isobutyl vinyl ether (IBVE) by the CH₃CH (OiBu) OCOCH₃ ( 1 )/EtAlCl₂ initiating system in the presence of the added base in hexane at +40°C, the stability of the initiating system 1 /EtAlCl₂, which form initiating species CH₃CH^⊕ (OiBu) derived from 1 , was investigated. In the presence of the Lewis base such as ethyl acetate or 1,4-dioxane, the active species was stable for 300 min even at +40°C in the absence of IBVE, and the living polymers were quantitatively obtained by adding IBVE. However, the active species was partly consumed by side reactions during the standing time for 60 min in the presence of a less basic additive such as ethyl benzoate, and about 50% of the active species was deactivated in the presence of methyl chloroacetate. Consequently, in the case of a less basic additive such as methyl chloroacetate (which was effective for the fast living polymerization), it can be seen that the careful selection of polymerization conditions was required. The living polymerization rate was dependent on the second order of EtAlCl₂ concentration. EtAlCl₂ induced the cleavage of 1 into CH₃CH^⊕ (OiBu) and EtAl^?Cl₂(OCOCH₃), and the reactivity of CH₃CH^⊕ (OiBu) and propagating carbocation may be controlled by EtAl^?Cl₂(OCOCH₃) with the aid of other EtAlCl₂. Et_1.5AlCl_1.5 exists as a bimetallic complex of EtAlCl₂ and Et₂AlCl, and it is expected that the polymers having a bimodal molecular weight distribution will be obtained due to two kinds of counteranions coming from EtAlCl₂ and Et₂AlCl. However, in the cationic polymerization of IBVE by 1 /Et_1.5AlCl_1.5 in the presence of ethyl acetate, the living polymer exhibiting a unimodal and very narrow molecular weight distribution was obtained. Thereby, it was suggested that the counteranions, EtAl^?Cl₂(OCOCH₃) and Et₂Al^?Cl(OCOCH₃), exchange rapidly with each other. © 1994 John Wiley & Sons, Inc.     

SIMPLIFIED CALCULATION METHOD FOR DEALING WITH ADDED WATER MASS FOR IMMERSED CANTILEVER CYLINDER 1)

采用解析方法研究了部分浸入水中的圆形悬臂柱的附连水质量分布,给出了无量纲的质量分布系数,通过对质量分布系数的数值拟合分析,附连水质量效应可最终表达为结构的等效质量密度,在振动计算中只需将浸入水中的悬臂柱密度用等效密度替代即可。采用试验方法测量了部分浸入水中的悬臂柱湿频率,简化附连水质量方法计算的湿频率结果与试验测量值吻合很好,表明本文的附连水质量简化公式可很好地描述附连水的质量效应。     

空投鱼雷倾斜姿态落水冲击研究

利用轴长体假设和Ｔａｙｌｏｒ关于圆柱在不同浸深时的附加质量表达式，运用切片理论建立了空投鱼雷在其纵向平面内以倾斜姿态落水时的运动微分方程组，通过实例计算得到了空投鱼雷入水冲击时作用在其上的弯矩和剪力分布的规律，为理论预测空投鱼雷入水冲击时的强度破坏建立了基础。     

银行责任延伸信贷资金循环系统的运转与传导利率作用机制研究

履行延伸责任是银行承担社会责任的一个重要表现,是解决地区信贷资金支持不足的关键性问题。本文在信贷资金循环系统中分析了银行是否履行延伸责任对系统收益的影响。构建了集成化决策和分散化决策的六种不同的决策环境模型,给出了最优决策,评价了六种模型产生的社会效益和经济效益。引入了利率传导机制,讨论了信贷资金循环系统中集成化决策和分散化决策中利率在引导参与方履行延伸责任的作用,分析了信贷资金循环系统利益的协调实现条件。研究结果表明:在信贷资金循环系统六种决策环境下,履行延伸责任的社会效益和经济效益优于不履行延伸责任的;银行履行延伸责任的优于非银行贷款投放人履行延伸责任;集成化决策环境履行延伸责任的系统收益最好。同时,通过传导利率实现博弈各方利益协调和参与人经济效益的帕累托改进。     

Coupled vibrations and frequency shift of compound system consisting of quartz crystal resonator in thickness-shear motions and micro-beam array immersed in liquid

The dynamic characteristics of a quartz crystal resonator(QCR) in thicknessshear modes(TSM) with the upper surface covered by an array of micro-beams immersed in liquid are studied. The liquid is assumed to be inviscid and incompressible for simplicity. Dynamic equations of the coupled system are established. The added mass effect of liquid on micro-beams is discussed in detail. Characteristics of frequency shift are clarified for different liquid depths. Modal analysis shows that a drag effect of liquid has resulted in the change of phase of interaction(surface shear force), thus changing the system resonant frequency. The obtained results are useful in resonator design and applications.