市场角

透明聚丙烯包装渐成市场主流 透明聚丙烯是一种多用途的聚合物,用于生产透明热成型包装,成本较低,且温度范围很大,此外,与其他常用的热成型材料相比,透明聚丙烯的柔性更好,热成型的浅盘不会破裂,具有极好的密封性。     

凝胶型聚苯乙烯强碱阴树脂去除天然水中有机物的机理与废弃树脂的利用Ⅰ.强碱阴树脂与有机物的作用机理

当今国内外水处理工作者认为,天然水中的有机物对凝胶型聚苯乙烯强碱阴树脂的污染,是离子交换与范德华吸附共同作用的结果。本研究通过大量试验研究。论证了该树脂与有机物之间主要是范德华吸附。     

上海旧城区的生态环境与改善对策

上海旧城区住区,以不太高的建筑容量和很高的居住密度为形态特征。反映居住密度的指标也是一项生态指标,而生态质量又以物质环境优劣表达。作者在分析上海旧住区的具体表现后,认为如此低下的物质环境必然带来一系列的生态性后果。从城市现代化的目标之一是改善旧住区生态环境出发,文章提出了必须要有相应的环境对策五点。     

重点师大与普通师范院校学生性格类型分布特点比较

性格是人的个性心理特征的主要内容,它直接影响人们的心理活动和行为。性格类型是在一类人身上所共有的性格特征的独特结合。研究大学生的性格及其类型,对政治思想教育工作克服一刀切、一个模式的教育方式和简单化的现象,增强针对性,有着十分重要的意义。为此,我们在这方面进行了一些探索。根据1991年上半年对华东师大和江西师大、温州师院、阜阳师院等高等师范院校1430名大学生(其中重点师大694名、普通师范院校736名)     

人X染色体单拷贝序列的分离及鉴定的研究

本研究以人/鼠(CHO-K1)细胞总DNA为探针对人X染色体DNA文库进行了3轮筛选,单拷贝顺序的检出率为1.45％。其中DXFD52,71,73,75分别与一组含人X染色体及不含人X染色体的人/鼠杂种细胞DNA进行Southern杂交分析,确定DXFD52,71,73,75含人X染色体专性DNA顺序。采用染色体原位杂交的方法,将DXFD52精确定位于Xq12-q13。并对其进行了部分DNA顺序分析,结果证实DXFD52是人基因组中至今未被分离到的一个单拷贝DNA片段。继而对DXFD52进行限制性酶切图谱分析,并以其为探针在中国重庆地区正常人群中(随机个体38例、3个正常家系成员11例)进行了RFLP研究,发现该探针具有识别Hind Ⅲ,Bgl Ⅱ,Hinf Ⅰ的RFLP。     

Isolation, Mapping, DNA Sequence and RFLPs Studies of Random Single-Copy DNA Segments on Human X Chromosome

Using the total human/mouse DNA as the probe, screening has been carried out three times with in situ plaque hybridization to obtain the single-copy DNA sequence from the human X chromosome genomic library. The effective rate of screening is 1. 45%. DNAs from clones containing single-copy inserts have been analyzed by a panel of hybrid cells with or without human X chromosome. Three segments, designated by DXFD52,73,75, are mapped to the X chromosome. DXFD52 has been precisely localized on Xq12-q13 with in situ chromosomal hybridization. DXFD52 has been partially sequenced. The results indicate that DXFD52 is a new isolated single-copy segment on the X chromosome. Great progress in the RFLPs study with DXFD52 has been achieved in the population of Chongqing, Sichuan Province. The results show that the DXFD52 can be used to detect the RFLP with Hind Ⅲ, Bgl Ⅱ, and Hinf Ⅰ. DXFD52 will be a potential "landmark" for the construction of the complete linkage map of human genome and the analysis of genomic s     

水稻三化螟性信息素的研究——Ⅱ.化学结构鉴定和田间诱捕试验

本文采用单个性信息素腺体分析技术、高效毛细管色谱、色质联用、触角电位、微化学反应和田间试验得知水稻三化螟性信息素有16:Ald(Ⅰ)、(Z)-9-16:Ald(Ⅱ)和(Z)-11-16:Ald(Ⅲ)等三个组份。据单个雌蛾性信息素腺体的分析结果表明:腺体中三个组份的比例平均为18.8(Ⅰ):27.1(Ⅱ):54.1(Ⅲ)(％)。按上述三元组份比例配制的诱芯在田间显示强烈的引诱作用,单盆每天最高诱捕数达45头雄蛾,平均每天诱捕15.8头雄蛾。     

阿片受点不可逆部分激剂A-α-CAO的药理研究

A-α-CAO对小鼠(icv)具有弱而短暂的镇痛作用并能拮抗吗啡(Mor)镇痛效应3—4d。未见A-α-CAO有成瘾倾向。小鼠输精管(MVD)试验表明A-α-CAO为阿片受点部分激剂,Ke为9×10~(-9)mol/L。保温时间较长或剂量较大,其拮抗效应经多次冲洗仍然存在,激剂作用亦不能被纳洛酮(N_x)翻转。A-α-CAO对豚鼠回肠纵肌(GPI)呈完全激剂效应,IC_(50)为5.7×10~(-10)mol/L,冲洗不能除去此种作用,但可被N_x翻转。在大鼠输精管(RVD)和兔输精管(RbVD)上A-α-CAO呈抗剂效应,pA_2值分别为7.5和7.6,作用也不易被冲洗除去。A-α-CAO可抑制~3H-依托啡(~3H-Etor)与小鼠脑勻浆P_2制备的特异给合,IC_(50)为3.2×10~(-9)mol/L,冲洗6次后A-α-CAO对~3H-Etor高亲合力结合的抑制仍达96％。     

A MODEL STUDY ON MODE OF BONDING OF CISPLATIN WITH DNA

The interaction of cis-[Pt(NK_3)_2Cl_2] with nucleosides, as constituents of DNA, was studled by spectrophotometric, ~(13)C NMR and CNDO/2 methods. The apparent stability constants of the complexes formed and the initial rate of formation were determined. The sites of binding of nucleoside (or nucleotide) with Cisplatin were ascertained and the electronic structure of the model coordination compounds of Cisplatin and guanine was calculated by MO approach. On the basis of the obtained results, the mechanism of the antitumour action of Cisplatin was discussed, and a new possible mode of bonding of Cisplatin with DNA was proposed.     

STUDIES ON SEX PHEROMONE OF YELLOW RICE BORER, Scirpophaga incertulas (Walker), Pyralidae, Lepidoptera——IDENTIFICATION OF CHEMICAL STRUCTURE AND FIELD TRAPPING TESTS

The natural sex pheromone of the yellow rice borer, Scirpophaga incertulas is known to consist of 3 components: 16: Ald (Ⅰ), (Z)-9-16: Ald (Ⅱ) and (Z)-11-16: Ald (Ⅲ) by using single sex pheromone gland technique, high performance capillary CC, GC-MS, EAG, micro-chemical reaction as well as field trapping tests. Analysis of single sex pheromone gland showed that the precise ratio of the 3 components is 18.8 (Ⅰ): 27.1 (Ⅱ): 54.1 (Ⅲ) (％). The septura lure made according to the above precise blending showed strong attractancy in the field trapping tests. Maximun catch of a trap was 45 males/ day in the first generation in Guangxi Zhuang Autonomous Region. The average catch per day was 15.8 males.