硫酸三(1-甲基)咪唑合钴(II)、硫酸六咪唑合钴(II)的合成和性质研究

合成了硫酸三(1-甲基)咪唑合钴和硫酸六咪唑合钴两种新的配合物。通过元素分析、热重、差热分析、红外光谱、紫外光谱、核磁共振谱、x射线粉末衍射图、磁化率和电导测定等研究了这两配合物的组成和性质,探讨了1-甲基咪唑钴(Ⅱ)配合物中Co(Ⅱ)配位不饱和的原因。     

尾板宽度对高速排水型艇的阻力和耐波性影响

不同尾板宽度的两种艇型的阻力和耐波性试验结果表明，高速排水型艇的尾板相对宽度ＢＴ／Ｂｘ对阻力和耐波性均有影响，ＢＴ／Ｂｘ值过小的艇，其剩余阻力系数明显增加。ＢＴ／Ｂｘ作为影响高速排水型艇航行性能的船型参数较之尾板相对面积ＡＴ／Ａｘ更恰当，综合阻力和耐波性试验结果，ＢＴ／Ｂｘ值取等于或略大于０．７５是适宜的。     

高速排水型艇的初始纵倾对阻力影响的试验研究

根据８条船模在不同初始状态下的试验结果，讨论了初始纵倾对阻力的影响．初始纵倾的选择主要取决于傅汝德数Ｆｒ．只有在较高Ｆｒ时，采用初始纵倾可望得到降阻效果．长度排水体积系数、纵向浮心位置和尾板相对宽度是影响初始纵倾减阻效果的参数．文中归纳不同艇型在初始尾倾为０．５°时的试验资料，给出了用这些参数表示的减阻表达式．     

Cloning and expression of catalytic domain of Abl protein tyrosine kinase gene in E. coli

Protein tyrosine kinases (PTKs) regulate cell proliferation, differentiation and are involved in signal transduction. Uncontrolled signaling from receptor tyrosine kinases to intracellular tyrosine kinases can lead to inflamma tory responses and diseases such as cancer and atherosclerosis. Thus, inhibitors that block the activity of tyrosine kinases or the signaling pathways of PTKs activation could be assumed as the potential candidate for drug development. On this assumption, we cloned and expressed the Abl PTK gene in E. coli, and purified the PTK, which was used to screen the PTK inhibitors from the extracts of Chinese herbs. The catalytic domain sequence of PTK gene was amplified by PCR us ing the cDNA of abl from Abelson murine leukemia virus as template. The amplified fragment was then cloned into the GST-tagged expression vector pGEX2T. The recombinant plasmid was transformed into host cell E. coli DH5α and was induced to express PTK protein. The expression of the protein was detected using SDS-PAGE. The result showed that a specific protein was induced to express after 12 min induction, and reached peak level about 40% of the host total pro tein after 4 h induction. The molecular weight of the fusion protein was about 58 kD. The purified GST-PTK fusion pro tein presented higher activity for tyrosine phosphorylation.     

On the nonexistence of nontrivial small cycles of the µ function in 3x+1 conjecture

This paper studies the property of the recursive sequences in the 3x+ 1 conjecture.The authors introduce the concept ofμfunction,with which the 3x + 1 conjecture can be transformed into two other conjectures:one is eventually periodic conjecture of theμfunction and the other is periodic point conjecture.The authors prove that the 3x + 1 conjecture is equivalent to the two conjectures above.In 2007,J.L.Simons proved the non-existence of nontrivial 2-cycle for the T function.In this paper,the authors prove that theμfunction has no l-periodic points for 2≤l≤12.In 2005, J.L.Simons and B.M.M de Weger proved that there is no nontrivial 2-cycle for the T function for l≤68,and in this paper,the authors prove that there is no nontrivial l-cycle for theμfunction for 2≤l≤102.     

Straightforward Guess and Determine Analysis Based on Genetic Algorithm

With the development of artificial intelligence, the genetic algorithm has been widely used in many fields. In cryptography, the authors find it is natural to code an individual and design its fitness in a genetic algorithm for a straightforward guess and determine analysis(SGDA, in short).Based on this observation, the authors propose an SGDA based on genetic algorithm. Comparing it with the other three SGDAs based on exhaustive search, MILP method and CPP method respectively,the authors illust...     

求解随机互补问题的可微罚方法

【目的】研究随机互补问题的期望值模型。【方法】借鉴罚函数法和样本均值逼近方法求解随机互补问题的期望值模型。【结果】在适当假设下，证明了样本均值逼近问题最优解的收敛性和收敛率。【结论】所得结果为研究随机互补问题提供了新的思路。