发射药床冲击破碎过程的数值模拟

发射装药挤压破碎是导致膛炸的根本因素,发射药床的破碎动力学是发射安全性理论研究的基础之一.以离散元法为基础,模拟了发射药床的自然堆积过程,获得了发射药床的密实堆积构型;将密实构型下的发射药床离散成弹簧-球单元系统,应用Mohr-Coulomb型破坏准则,对发射药床动态压缩模拟试验装置中的发射药粒在动态载荷下的挤压破碎过程进行数值仿真,并对数值计算结果进行后处理,实现了模拟药室中发射药粒挤压破碎过程数值计算的动画显示,再现了发射药床冲击破碎动力学过程,仿真结果与试验结果吻合较好,验证了论文理论与模型的正确性,为进一步研究发射药床的破碎规律提供了重要的理论基础和计算手段.     

氧氟沙星镍配合物的合成、红外光谱、热分析与抗肿瘤活性

合成了以氧氟沙星为配体的镍(Ⅱ)配合物Ni(ofo)2*4H2O,通过红外光谱和热分析等方法对配合物的结构进行了表征,推测了配合物的可能结构,并利用液体稀释法测定了药物配体和配合物对两种革兰氏阳性菌和两种革兰氏阴性菌的体外抑制活性.结果表明配合物与药物配体的抗菌活性和抗菌谱相同.采用MTT比色法测定了配体及配合物对HL-60(人急性早幼粒白血病)细胞的抑制作用,采用SRB蛋白染色法测定了配体及配合物对BEL-7402(人肝细胞性肝癌)细胞的抑制作用.结果表明Ni(ofo)2*4H2O对BEL-7402细胞没有抑制作用,对HL-60细胞在较高浓度时有一定的抑制作用.     

函数最值问题中的设参消参技巧

应用均值不等式或柯西不等式求函数最值,使和(或积)为定值或者凑出所需要的式子是关键的一步,而设参数可使这一棘手的问题得到圆满解决.下面举例说明设参、定参的技巧,供参考.例1已知a>b>0,求a2+16/b(a-b)的最小值(高中数学第二册(上)复习参考题).     

模糊集对分析用于脱硫除尘器的综合评价

提出了锅炉脱硫除尘器综合评价的模糊集对分析方法.评述了方法的基本原理和计算步骤,通过实例介绍了方法的应用.评价实例结果表明模糊集对分析用于脱硫除尘器综合评价是可行的.与密切值法相比,所得评价结果相同.该法具有计算简便和实用的特点.     

一种声、波同步显示的“拍”现象演示仪

本装置通过扬声器可分别发出两个单频音和合成后的拍音，同时利用激光将波形投影在墙上；可见（闻）度极高，还可单独利用激光演示光的干涉、衍射、偏振等现象。     

一类生态模型的数学分析

本文用上下解方法解决了一类生态系统的数学模型非负平衡解的分支结构及平凡解，既非平凡解又非正解的全局稳定性及正解的逼留区域。     

双核铜(Ⅱ)-氟喹诺酮-邻菲咯啉混配配合物的合成、晶体结构和抗肿瘤活性

A new binuclear copper (Ⅱ) complex with 1,10-phen and fluoroquinolone ligands, [Cu₂(cfc)₂(phen)₂(pip)](NO₃)₂(CO)₂,was synthesized and its crystal structure was solved.The formula of the complex is C₂₈H₂₄ClCuFN₅O₇, and the crystallography data are as follows, triclinic, space group P1, a=0.80372(6)nm, b=0.94712 (7)nm, c=1.67826(13)nm, α=88.5650(10)°, β=80.9920(10)°, γ=70.2780(10)°, V=1.18722(6)nm³, Z=2, D=1.848g· cm^-3, F(000)=676. R₁=0.0627 and wR₂=0.1684 (I>2σ(I)). The copper atom is five- coordinate with square-based pyramidal geometry and involves two nitrogen atoms from phen, two oxygen atoms from cfc and one nitrogen atom from pip anion. The stacking effect between cfc and phen ligands from two neighboring molecules was observed. FT-IR spectrum of the complex was also discussed. Both ligand and complex were assayed against gram-positive and gram-negative bacteria by doubling dilutions method； the complex shows the same mini-mal inhibitory concentration (MIC) as the corresponding ligand against S. Aureus, E. Coli and M. Lutens bac-teria. The inhibitory effect of the ligand and complex on leukemia HL-60 cell line and liver cancer BEL-7402 cell line have been measured by using MTT (Methyl-Thiazol- Tetrozolium) and SRB (Sulphurhodamin B) assay meth-ods, respectively. The results indicated that the complex has strong inhibitory effect on HL-60 and BEL-7402 cell line. CCDC: 203964.     

Homocoupling of Polyfluorovinylstannanes Mediated by a Novel Combination of CuCl/2,2''''-Dipyridyl. Stereospecific Syn-thesis of Polyfluorinated Alka-2,4-dienes

Introduction Stille reaction, which is known as the cross-coupling reaction between organostannanes and organic electro-philes, has become a widely employed synthetic tool in organic synthesis for the construction of carbon-carbon single bond,1 particularly in the synthesis of naturally occurring compounds.2 But the homocoupling reaction of vinylstannanes is still limited. Intramolecular CuCl mediated oxidative coupling of alkenyltrimethylstan-nane has been reported3 and applied to the synthe…     

阴离子交换色谱-电感耦合等离子体质谱法测定长期汞暴露人群硒干预后血清中的小分子硒形态

建立了阴离子交换高效液相色谱-电感耦合等离子体质谱联用测定不同形态硒的在线分离检测方法,并将其应用于长期汞暴露人群血清中小分子硒的形态研究.流动相A为0.5 mmol/L柠檬酸铵-2%(V/V)甲醇(pH 3.7),流动相B为100 mmol/L柠檬酸铵-2%(V/V)甲醇(pH 8.0);采用93%A-7%B时,硒代...