Properties and Characterization of Modified HZSM—5 Zeolites

Physicochemical and catalytic properties of phosphorus and boron modified HZSM-5 zeolites treated with 100% steam at 673K were investigated.The acidity and distribution of acidic sites were studied by infrared spectroscopy using pyridine as probe molecule and temperature programmed desortion (TPD) of ammonia.The structure of the samples was characterized by XRD,and the textural properties of the catalysts were determined by nitrogen isothermal adsorption-desorption measurements and scanning electron microscopy(SEM).The XRD results show that the modified samples have no novel crystalline phase,indicating a high dispersion of phosphorus and boron species.After treatment,the microporous volume and surface area of the samples markedly decrease,implying the bolockage of the channel.The nitrogen adsorption-desorption measurements suggest that the isothermal type of all samples is a combination of isothermal type Ⅰ and Ⅳ，and all hysteresis loops resemble the H4-type in the IUPAC classification.The total acidity of the modified samples,determined by pyrldine adsorption IR and TPD of ammonia,decreases in contrast to that of the parent HZSM-5.The conversion of n-heptane over P and B steammodified HZSM-5 is higher than that of P and B-modified HZSM-5 zeolites but lower than that of the parent HZSM-5.     

碱性水蒸气处理的ZSM-5沸石酸性质及孔结构的影响

 采用XRD，NH3－TPD，比表面积和孔结构测定等研究了在不同温度下用含10％NH3的水蒸气处理时HZSM－5沸石n（Si）／n（Al）＝25）酸性质及孔结构的变化规律．结果表明，随着处理温度的提高，HZSM－5的结构未发生明显的变化；样品的总酸量下降很快，但弱酸分布量相对提高，而强酸分布量相对下降；提高处理温度，样品的比表面积和微孔体积减小，二次孔或中孔体积及外表面积有增大的趋势．     

两种异马来二氰基二硫烯镍(II)-取代苄基喹啉鎓盐的制备及其光谱性质和晶体结构

以甲醇为溶剂,将异马来二氰基二硫烯酸钾[K2(i-mnt)]和六水氯化镍分别与溴化4-溴苄基喹啉盐([4-BrBzQl]Br)或溴化4-硝基苄基喹啉盐([4-NO2BzQl]Br)直接反应,得到两种新的离子对配合物[4-BrBzQl]2[Ni(i-mnt)2](1)和[4-NO2BzQl]2[Ni(i-mnt)2](2);测定了其红外光谱和紫外-可见光谱,并利用X射线衍射表征了配合物1的晶体结构.结果表明,配合物[4-BrBzQl]2[Ni(i-mnt)2]为三斜晶系,P-1空间群,其每个不对称单元含半个[Ni(i-mnt)2]2-阴离子和1个[4-BrBzQl]+阳离子,晶体中的阴、阳离子通过静电作用和C-H…S、C-H…N氢键作用形成网络结构.     

巯基棉富集─火焰原子吸收分光光度法测定水中的微量铁

本文详细考查了巯基棉富集Ｆｅ（Ⅲ）的条件，发现微量铁（Ⅲ）在ｐＨ值为５－８的条件下能为巯基棉定量吸附．１ｍｏｌ／Ｌ盐酸５ｍＬ能将巯基棉吸附的Ｆｅ（Ⅲ）定量洗脱，０．１ｇ巯基棉的饱和吸附量为９０μｇ，样品分析测定结果的相对标准偏差小于３．４％，９８．４％－９８．８％。     

低温液体无损贮存压力升高的实验与计算

准确、简单地预测低温液体无损贮存时的压力升高具有重要的实用价值。对一低温容器利用液氮为介质进行了多次无损贮存实验,利用多元线性回归方法对实验数据进行分析和检验。分析表明无损贮存时间、初始充满率对压力升高的影响较大,而环境温度的影响可以忽略,并拟合出了压力升高的计算公式。计算结果和实验结果在很大范围内能够较好地吻合。该种计算方法在预测低温液体无损贮存压力升高时有较高的准确性与可靠性。     

Sonochemical preparation of carbon nanosheet from carbon black

Preparation of carbon nanosheet via ultrasound irradiation of carbon black under ambient conditions was reported for the first time. The structure of resulting carbon nanosheet was characterized by TEM, HRTEM, EDX and AFM. The experimental results showed that the carbon nanosheet is composed of ordered graphite carbon layers with a thickness of several nanometers.     

Bifurcations of Double Homoclinic Loops with Inclination Flip and Nonresonant Eigenvalues

In this work, bifurcation analysis near double homoclinic loops with Ws inclination ?ip of Γ1 and nonresonant eigenvalues is presented in a four-dimensional system. We establish a Poincar´e map by constructing local active coordinates approach in some tubular neighborhood of unperturbed double homoclinic loops. Through studying the bifurcation equations, we obtain the condition that the original double homoclinic loops are persistent, and get the existence or the nonexistence regions of the large 1-homoclinic orbit and the large 1-periodic orbit. At last, an analytical example is given to illustrate our main results.     

Effect of Carbon Black Nature on Vulcanization and Mechanical Properties of Rubber

The influence of the basic properties of carbon black, such as structure, panicle size, and surface activity on the vulcanization and mechanical properties of filled natural rubber compounds was investigated in detail. This is important for a better understanding of the rubber performance and the mechanism of reinforcement. In particular, the effect of carbon black surface activity, which was changed by introducing one kind of hindered amine light stabilizer on rubber reinforcement is emphasized.     

一类带有不育控制的离散单种群模型

建立一类不育控制下的害鼠种群的离散模型.首先利用三个Jury条件,得到平衡点的局部渐近稳定性的充分条件.其次利用李雅普诺夫函数和细致分析法分别给出了零平衡点全局稳定及持续生存的充分条件.最后给出了平衡点全局稳定的数值模拟.     

一维发光镉配位聚合物的合成、晶体结构及识别性能

采用芳香取代的咪唑二羧酸配体2-(对氰基)苯基-4,5-咪唑二羧酸(p-CNPhH₃IDC) ,在含氮螯合配体 2,2'-联吡啶(2,2'-bipy)的存在下,利用水热反应,制备了一个具有混合配体的一维链状配位聚合物:[Cd(p-CNPhHIDC)(2,2'-bipy)]_n(1)。 通过元素分析、傅里叶变换红外光谱仪以及单晶X射线衍射等技术手段研究了配位聚合物1的结构和性能。 结果表明,该配位聚合物稳定性较好,在231.6 ℃前结构稳定。 经乙睛、甲醇、乙醛等溶剂浸泡后,配位聚合物1的荧光强度发生了一定程度的减弱(乙醛和CH₂Cl₂)或增强(DMF、硝基苯、丙酮),仅有吡啶溶剂使其荧光发射波长发生了60 nm的蓝移,显示其对吡啶有比较好的识别作用。