阳离子淀粉在瓦楞纸生产中的应用试验

本文介绍阳离子淀粉用作造纸湿部添加剂的工艺及其使用效率。用全废纸浆造瓦楞纸,使纸的质量提高一个等级,达到部颁特级标准。     

丙二酸亚异丙酯衍生物的构象分析与分子集团结构适应理论

本文根据5-取代丙二酸亚异丙酯的核磁共振谱,利用“分子集团结构适应理论”观点,阐述了5-取代丙二酸亚异丙酯的构象,表明此化合物一般具有椅式构象;当取代基中含有芳基及羰基时,显示了这些基团对2-位甲基的远程屏蔽及远程去屏蔽效应,从而认为此时以船式构象存在。     

含咪唑功能基螯合树脂的研究进展

咪唑环是一种含有两个配位原子的功能基,能与重金属离子形成稳定配合物。将其接枝到有机或无机高分子上,制得的含咪唑功能基的螯合树脂,不仅对重金属离子表现出良好的吸附选择性能,且回收操作简单、回收利用率高。本文对该类螯合树脂的研究进展进行了综述。     

人工神经网络及其在色谱中的应用

本文对人工神经网络（ＡＮＮ）在色谱保留机理的研究和保留值的预测,溶质分子构型与色谱保留的定量关系（ＱＳＲＲ）,谱图解析等方面的应用做了综述。着重介绍了ＢＰ网络的发展及其在色谱领域中的应用,并对ＡＮＮ在色谱中的应用前景做了预测。     

毛细管电色谱柱内径对电渗流与电压关系的影响

考察不同内径的毛细管电色谱柱中分离电压对电渗流的影响，在不同内径的毛细管电色谱柱中，电渗流与电压都呈较好的线性关系，与毛细管电色谱柱的内径无关，由于焦耳热的影响，在电压变化幅度较大的情况下，电渗流与电压的关系曲线呈线性弯曲，在大内径毛细管电色谱柱上更加明显。     

窄分布聚甲基丙烯酸甲酯的合成与表征

甲基丙烯酸甲酯(MMA)的阴离子聚合,由于其聚合反应的特殊性和复杂性,早就引起人们的关注。长期以来,在各种引发剂、溶剂和温度等条件下都做了大量的研究。其中有关窄分布聚甲基丙烯酸甲酯(PMMA)合成方面的研究甚少。Anderson等用     

己内酰胺碱性催化聚合应用于纺丝

对碱性催化的己内酰胺快速聚合应用于纺丝进行了研究,采用了合适的分子量稳定剂,控制了聚合进程,得到粘度稳定的聚合体,并且进行了连续聚合直接纺丝的扩大试验,取得了持续稳定运转的结果,纺出产品复丝,其抗张强度为5—6克/(代糸),延伸为19—25％,与水解聚合方法同类产品丝相仿。所需的聚合时间为2—2.5小时,而通常水解聚合过程则需要20—30小时以上。     

溶液pH值对聚邻甲苯胺电化学性质的影响

本文报道了溶液pH值对聚邻甲本胺电化学性质的影响。研究结果表明,电化学合成的聚邻甲苯胺的循环伏安曲线、氧化电位、膜的颜色、充放电容量、紫外可见光谱以及氧化还原活性都受到溶液pH的影响。在低pH值的溶液中,随着扫描电位的变化,聚邻甲苯胺膜的颜色可逆地变化,而在pH4.13的溶液中进行扫描时,膜的颜色不变化,电化学活性也消失。     

炭黑结合橡胶对天然橡胶性能的影响

本文研究了天然橡胶(NR)与五种不同类型炭黑的结合橡胶对其混炼胶的应力-应变、流变性质等的影响。结果表明,NR与炭黑的结合橡胶量随炭黑结构和表面积增加而增加。结合橡胶的增加使NR在低剪切下的本体粘度、弹性恢复性和强度增加,塑性和粘着性降低;在高剪切下流动性变差,挤出物收缩则有所下降。此外,结合橡胶的增加也增加了硫化胶的交联度,因此模量、硬度和耐磨性提高,抗张强度和伸长率却有所下降。     

窄分布聚甲基丙烯酸甲酯的合成与表征

Synthesis of poly (methyl-methacrylate) (PMMA) in tetrahydrofuran at- 78℃ using al-kyllithium as initiator and its characterazation were studied. It was found that PMMA with harrow molecular weight distribution was obtained using 1,1-Kliphenyl-3-methylpentyllithium and 1,1-diphenyl-hexyllithium as initiators respectively. The sample of PMMA in the molecular weight (M_w) range from 1×10⁴ to 2×10⁶ had M_w'/M_n=1.06-1.20, its product possesses narrow molecular weight distribution and good symmetry, it achived level of PMMA standard sample and may be used it as GPC standard samples.     

分光光度法低浓度区不成线性关系的探讨

本文研究分光光度法低浓度区不成线性的有关因素及其克服方法,以铝-二甲酚橙体系为例,通过对体系不同条件下吸收光谱及其等色点的研究,发现当体系pH渐变时(铝,二甲酚橙浓度固定不变),曲线簇现两个等色点.从对等色点的分析,证明体系形成络合物须按一个反应式进行才能出现等色点,而与反应式是否涉及到两个或三个有色化合物无关.若同时按两个反应式进行,则不能得到等色点,测定时也无线性关系.所以用这个体系进行铝的测定,铝浓度的变化范围只能限于存在等色点的区间才有线性关系. 为了克服常法测定铝时不符线性的现象,本文采用的方法是在二甲酚橙中预先加适量的铝作为显色剂,使反应严格按一个反应式进行,所得结果为一直线.     

ON THE INTERPRETATION OF ABSORPTION SPECTRA OF LEAVES–II. THE NON-ABSORBED RAY OF THE SIEVE EFFECT and THE MEAN OPTICAL PATHLENGTH IN THE REMAINDER OF THE LEAF

Abstract— The sieve effect and scattering within leaves are analysed by the use of a simple model. By plotting the leaf transmittance (corrected for light not entering the leaf) vs the transmittance of an equivalent amount of homogeneous plastid pigments, an intercept is found where the latter is zero. This minimum transmittance represents the fraction of the leaf area devoted to the ray of the sieve effect which strikes no chloroplasts. It varied between 7% and 0.2% in non-senescent leaves. When this was subtracted from the leaf spectrum, the peak absorbance was greater than that of the homogeneous leaf pigments in all cases. The ratio of the leaf absorbance to that of the homogeneous pigments, at the same wavelength, is the apparent optical pathlength, which increases with decreasing absorbance. By plotting this ratio vs the absorbance of the equivalent homogeneous pigment, an intercept is found where the latter is zero. This intercept is interpreted as an estimate of the true mean scattering pathlength. Leaves with high chlorophyll contents had low pathlengths (mean and SD = 2.30 ± 0.25); with moderate and low contents, the values were higher (2.75 ± 0.28, 3.95 ± 0.77). Another application of the model gave values between 3 and 4 for the true scattering pathlength.     

卤代硅烷分子的杂化轨道及结构与性质的关系研究

本文利用最大重迭方法,在分别考虑卤素配体的杂化及中央原子Si的d轨道杂化的基础上,计算了卤代硅烷系列分子实验构型下的杂化轨道,研究了卤代硅烷分子的NMR自旋偶合常数,IR伸缩频率和基团电负性与轨道成份的关系,较明确地反映了这类分子的化学键性质对分子谱学性质的影响。     

THE GLOBAL BIOSTRATIGRAPHICAL CORRELATION OF THE MEISHUCUNIAN STAGE AND THE PRECAMBRIAN-CAMBRIAN BOUNDARY

The Meishucunian Stage is rich in fossils and is characterized by their distinct evolutionsequence, so based on the established zonation of small shelly fossils, the sequence of tracefossils and the stratotype point (China "B", the dividing point between Units 6 and 7 or be-tween fossil zones Ⅰ and Ⅱ), the Meishucun section is more widely applicable to both region-al and intercontinental correlations. In this respect, the stage is well suited for both thecarbonate and the clastic-rock sedimentary regions. The Meishucunian small shelly fossil assem-blages are correlated with those found in Siberia of U.S.S.R., Mongolia, Central England,South Australia and Northwestern Canada. The Meishucunian trace fossil sequence can alsobe broadly correlated with that in the Russian Platform of U.S.S.R., Northwest Europe,Great Britain, Spain, Australia, the Western United States and Southeastern Canada.     

THE ROLE OF HEMOGLOBIN IN THE PHOTOTAXIS OF THE NEMATODE Mermis nigrescens

Abstract A dense zone of crystalline hemoglobin in the head has been presumed to be involved in the photosensitivity of Mermis. With the aim of identifying its role, we have studied the wavelength dependence of the phototaxis. Measuring phototaxic efficiency at constant photon fluence rate (intensity), we find that the spectral response curve is approximately fiat from 350–540 nm and falls to an insignificant level by 580 nm. This is unlike the absorptance (fraction absorbed) spectrum of the hemoglobin pigmentation. Also, fluence-rate/response curves at 420 and 500 nm occur at the same fluence rates even though these wavelengths correspond to a maximum and a minimum of hemoglobin absorption. These results prove that the hemoglobin cannot be functioning as the visual pigment in phototaxis but, for reasons discussed, they neither confirm nor rule out a role as a shadowing pigment. The results are consistent with a shadowing role in the presence of contrast enhancement by the nervous system.
A steep fluence-rate dependence suggests that contrast enhancement does occur in Mermis phototaxis. The 420 or 500 nm fluence rate for half-maximal response is 6 times 10 photons s^-1 cm^-2 (about equivalent in effectiveness to pre-dawn twilight). The wide range of sensitivity, 350–560 nm, has interesting implications as to the nature of the visual pigment.
†NATO reaearch collaborator a n leave from the Department of Biophysics. Laboratorium voor Algemene Natuurkunde, Rijksuniversiteit Groningen, Westersin-gel 34. 9718 CM Groningen, The Netherlands.     

交联聚合物线团的形态和尺寸研究

通过建立低压差下核孔膜过滤稀释液的方法 ,研究了低浓度HPAM与AlCit形成的交联聚合物溶液(LPS)中交联聚合物线团 (LPC)的形态和尺寸 .实验结果表明 ,LPC为球形结构 ,由于交联作用 ,其剪切变形程度有限 .低压差下核孔膜过滤法与动态光散射法 (DLS)和扫描电镜法 (SEM)相结合 ,可较为准确地判断LPC的尺寸范围 ,HPAM相对分子质量为 1 1× 10 7～ 1 4× 10 7、浓度为 0 0 2 % ,NaCl浓度 0 2 % ,交联比 2 0∶1的LPS中LPC的直径小于 1 38μm ,相当多的LPC直径在 4 5 0nm以上 ,平均流体力学直径约为 4 92nm .在一定聚合物浓度范围内 ,相同实验条件下 ,随着聚合物相对分子质量的增大 ,LPC尺寸逐渐增大 .LPS制成干片后 ,LPC的尺寸收缩有限 ,利用SEM法直接观测其形态 ,具有一定的准确性 ,可用此法对其进行研究 .     

聚酯酰胺的合成及表征

 用两种方法合成了聚酯酰胺（ＰＥＡ）共聚物．一种是两步法，即先合成对苯二甲酸乙醇酰胺（ＢＡＥＴ）单体，然后与对苯二甲酸乙二酯（ＢＨＥＴ）共缩聚；另一种是一步法．即在酯交换反应中直接添加乙醇胺（ＥＡ）．两种方法制得的聚酯酰胺（ＰＥＡ）共聚物测试证明了为产物，并分析了合成中的化学反应．     

聚酯酰胺的合成及表征

用两种方法合成了聚酯酰胺（ＰＥＡ）共聚物．一种是两步法，即先合成对苯二甲酸乙醇酰胺（ＢＡＥＴ）单体，然后与对苯二甲酸乙二酯（ＢＨＥＴ）共缩聚；另一种是一步法．即在酯交换反应中直接添加乙醇胺（ＥＡ）．两种方法制得的聚酯酰胺（ＰＥＡ）共聚物测试证明了为产物，并分析了合成中的化学反应．