化合物[{（NCHCHNCH_3）CH}_3] Li Cl的合成与晶体结构

甲基咪唑与氯化锂反应成功地合成了[{（NCHCHNCH3）CH}3LiCl]。化合物通过了元素分析,核磁和x-ray衍射表征。晶体结构表明其晶体属单斜晶系,空间群为C c,化学式为C12H18N6ClLi,晶胞参数为a=13.556（4）A°,b=9.061（3）A°C=12.287（4）A°,α（deg）=90 deg,β（deg）=93.671（6）deg,γ（deg）=90 deg,V（A°3）=1506.2（8）A°3,Z=4,最终R1=0.058,wR2=0.149.     

混凝土环境中BFRP筋耐久性能试验研究(英文)

针对玄武岩纤维增强树脂基复合筋(BFRP)在混凝土环境中的耐碱性能进行了加速腐蚀试验研究.腐蚀试验环境包括3种,分别为自来水、盐水及室内空气环境,将包裹有混凝土保护层的BFPR筋试件分别放置在上述3种环境中,试验同时采用碱溶液直接浸泡BFRP筋作为对比,对直接碱溶液浸泡环境与混凝土包裹环境之间的加速系数进行了研究.试验采用60℃的高温进行加速.试验结果表明:自来水和盐水浸泡对于包裹有混凝土的BFRP筋试件没有明显差异.分析认为,与混凝土内部高碱性的孔隙溶液接触是BFRP筋退化的主要原因,当经受高温和高湿环境共同作用时,混凝土环境中BFRP筋的退化将明显加速;BFRP筋的退化速率在初期较快,随着龄期的增长,退化速率降低.基于试验数据分析表明,对于所采用的BFRP筋,60℃饱和吸湿混凝土环境下,BFRP筋2.18 a的退化程度与60℃碱溶液直接浸泡环境下1 a的退化程度相当.     

纯铁膜的阻温特性

采用直流磁控溅射的方法 ,制备了一系列不同厚度的纯铁膜 ,并测量了它们的阻温 (R -T)特性。研究表明 ,样品的R -T特性与镀膜时间 ,即膜的厚度有关。在同一系列中 ,随样品厚度的增加 ,R -T关系呈现出由半导体特性向金属性渡越的特征     

高纯度无水氯化锌的一种实验室制备方法

利用管式炉,在实验室将氯化锌固体经过除水、升华、分装等步骤,制成高纯度无水氯化锌,并将其密封在充满氮气的玻璃管中,得到已知重量的无水氯化锌样品,为实验室制备少量高纯度无水氯化锌找到了一种实用的方法.     

固体催化剂FeCl3·6H2O/C催化合成油酸丁酯

研究了以活性炭固载氯化铁为催化剂,油酸和正丁醇为原料合成油酸丁酯,通过正交试验及单因素检验,考察了反应条件对酯化率的影响.结果表明当油酸的用量为0.1 mol时,醇酸摩尔比为1.6、催化剂用量为4 g、带水剂甲苯为15 cm3、反应温度为393-418K、反应时间为1.0 h,醇化率可达96%以上.     

硫酸铁催化合成乙酸乙酯

在硫酸铁存在下，乙醇与冰醋酸发生酯化合成了高收率的乙酸乙酯．研究了硫酸铁、乙醇和冰醋酸用量对酯化反应收率的影响．乙酸、乙醇和硫酸铁的恰当摩尔比为1：2．5：0．025，回流反应1h，产品收率达42．6%。     

稀土氯化物生产条件的研究

通过对稀土分离的试验，提出了稀土氯化物的生产条件，对产品进行质量分析，结果满意．     

Synthesis and Crystal Structure of 1D Chloride Bridged Cadmium（ Ⅱ ） Chain

1INTRODUCTION Transition metal complexes with polypyridyl ligands such as2,2-bipyridine(bipy)and1,10-phenanthroline(phen)are well investigated[1-4],and some of them can be used as DNA mole1cule probes[5-10].Though a series of species of[CdX(phen)]+,[CdX2(phen)],[CdX3(phen)]-,[CdX(phen)2]+and[CdX2(phen)2](X=Cl-,Br-)have been demonstrated existing in aqueous solution[11],only[CdCl2(phen)2]has been structural characterized[12].Under hydrothermal condition,however,1D chloride bridged c…     

The development of students' justifications for their positions regarding two theoretical models: Electron cloud or sodium chloride crystal—After engaging in different learning activities

The purpose of this study was to explore high school students' ideas regarding two theoretical scientific models, either electron cloud or sodium chloride crystal, in the context of active learning in small groups. Conversations among peers regarding these models took place during two types of active learning activities: small-group discussion and whole-class debate. The study was conducted in four different high school classes, each of which was in a different school for girls in Oman. The study included 108 grade 10 female students. Two of the classes discussed the electron cloud and the other two classes discussed the sodium chloride model. Qualitative data included students' written responses to prompts, class worksheets, and field notes of student ideas in class debates. In each class, the teacher used a teaching sequence during which the participants expressed their justifications for their positions in writing regarding the particular model on five different occasions, as they progressed through three interactive small group learning activities. The participants' written responses were analyzed using a coding scheme comprising of eight different categories describing the participants' type of justifications regarding the theoretical scientific models: nonsense, approval, mental, experimental, appreciative, external, structural, and modeling. The findings indicated that participants' justifications for their positions regarding theoretical scientific models tended to change over time following each group learning activity. Participants focused their discussion more on external factors, such as the teacher, textbook, religion, and media, after discussions with peers in small groups. In contrast, later their attention focused more on the submicroscopic structural orientations of the model under study during and after engaging in a debating activity. The researchers reasoned that the nature of cognitive demands during each type of active learning activity might play a role in this regard. However, further research to advance the understanding of this phenomenon is needed.     

丙酸糠醇酯的合成研究

以糠醇和丙酰氯为原料，以吡啶为催化剂，无水碳酸钠为缚酸合成了丙酸糠醇酯，并考察了反应物的配料比，催化剂，缚酸剂，带水剂的用量等因素对反应的影响。