OPTICAL PHASE CONJUGATION RESPONSE OF PHOTOINDUCED POLYMER FILMS CONTAINING AZOBENZENE MOIETIES WITH CHIRAL GROUP

An optically active monomer containing azobenzene moieties with chiral group (s-2-methyl-butyl), 4-[2-(methacryloyloxy)ethyloxy]-4'-(s-2-methyl-1-butyloxycarbonyl) azobenzene(Ml) was synthesized. Polymer (PMl)possessing optical phase conjugated response was obtained by homopolymerzation of the optically active monomer (Ml)using free radical polymerization. The polymer was very soluble in common solvents and good optical quality films could beeasily fabricated by spin coating. The optical phase conjugated responses of the polymer PM1 were measured by degeneratefour-wave mixing (DFWM). In comparison with polymer containing no chiral group, it was found from the preliminarymeasurement of photoisomeric change that optical phase conjugated response of the PM1 in the long-range order hexagonalsymmetry microstructure could be easily controlled by choosing the appropriate polarization direction of the irradiatingbeams (514.5 nm) and the irradiating number, presumably due to the chiral group in the PM1 molecular structure. For thecase of the polymer investigated here, a chiral group side chain was introduced to increase optical phase conjugated responseintensity with different polarization directions of the irradiating beams, which aims originally at searching for a new photo-ative material.     

多羰基甾体化合物的区域和立体选择性还原

在对多羰基甾体化合物雄甾-4-烯-3,6,17-三酮及可的松的还原研究中发现,在不同金属离子如Ce3+、Mn2+、Co2+ 及Ni2+存在下,以甲醇为溶剂,NaBH4为还原剂对上述这两个多羰基甾体化合物进行还原,可以得到不同的区域和立体选择性还原产物.     

怎样有效地使用挂式酒精喷灯

酒精喷灯是实验室中常用的高温热源之一,其温度可达1000～1200℃,可用于熔融分解矿物试样,或熔融去掉坩埚中残渣之用.使用过程中,怎样才能快速有效地发挥其功效呢?首先向酒精储存罐内注入工业酒精400ml以上,把盖拧紧,再将储存罐挂于2m以上的钉子上,拧开储存罐节门,同时打开调火旋钮,排出皮管中空气,直至有酒精喷出,关上调火旋钮.若喷嘴堵塞时,可将喷座在桌子上倒过来敲几下,直到有酒精喷出.关上调火旋钮.然后向引火碗内注入少量酒精(作引     

Synthesis and crystal structure of β-hexanitrohexaazaisowurtzitane

A polycyclic caged compound with high strain——hexanitrohexaazaisowurtzitane (HNIW)——has been synthesized via a three-step reaction: condensation, hydrogenolysis debenzylation and nitrolysis, starting with benzylmine and glyoxal. HNIW is the most powerful high energy density compound (HEDC) ever tested. β-HNIW possesses a caged structure consisting of two five-membered rings and one six-membered ring with a nitro group attached to each of the six bridging nitrogens. The nitro group lies basically within a plane. The lengths of C--C bonds of β-HNIW range from 0.156 nm to 0.159 nm, 0.002--0.005 nm longer than the sp~3 C-C bond. The β-HNIW's crystal belongs to orthorhombic system and space group Pca2_1 with parameters: a=0.9670 (2), b=1.1616 (2), c=1.3032 (3) nm; V=1.4638(5) nm~3, Z=4; D_c=1.989 g/cm~3 and D_m=1.982 g/cm~3.     

低功耗便携式温度自动记录仪的设计

综合应用计算机技术、通信技术、数理统计和控制论的有关知识设计了能自动检测并记忆温度的仪器,该仪器具有掉电自动保护、低功耗、便携的特点,并具有智能性,能预测温度变化趋势,有超前警示和及时报警两种报警功能。     

含金属Y型沸石的合成,表征及其催化性能研究

在水热合成体系中制备了系列含金属的Y型沸石(金属=铁、铬、钴),并采用XRD、SEM、ICP、FTIR和UV-vis技术对其进行了表征。FTIR和UV-vis测试结果表明Fe(Ⅲ)、Co(Ⅱ)和Mn(Ⅱ)离子进入沸石骨架,而Cr(Ⅲ)则没有。金属离子对所制备产物晶化及组成有很大的影响。此外,还对含金属的Y型沸石在环己烷氧化反应中的催化性能进行了考察。     

基于神经网络的混沌系统鲁棒自适应同步

基于神经网络,研究了两个混沌系统都存在扰动情况下的同步问题.该方法能有效地克服不确定性对同步所造成的破坏,实现了良好的同步效果.针对Lorenz系统进行了数值计算.数值计算结果证明了所给方法的有效性. 关键词： 混沌系统 同步 神经网络     

SRXRF在浙江越窑古瓷元素谱分析中的应用研究

用同步辐射X荧光(SRXRF)分析了浙江越窑晚唐至南宋早期古瓷中的元素谱,对实验数据进行了聚类统计分析,研究了多个元素在越窑古瓷中的分布.结果表明:越窑古瓷样品釉中Ca,Mn等元素含量相对比胎中的高,而K,Ti,Fe等低于胎中的含量;大部分古瓷样品具有明显的年代特征,不同窑址和各文化期烧制的古瓷具有产地特征.     

Fe-25Al铝化物的电子结构及其本质脆性

铁铝金属间化合物是一类具有良好应用前景的新型材料,但室温脆性影响了其进一步应用.本文基于Fe-25Al各种物相的晶体结构和实际原子占位,运用固体与分子经验电子理论(EET)建立起Fe-25Al各相的价电子结构.通过比较不同相结构的价电子结构参数,对Fe3Al的室温脆性进行了阐述.认为较少的晶格电子、键络分布不均匀使Fe3Al具有本质脆性,添加固溶组元可以改变价电子结构参数从而改善强度和韧性.