共查询到19条相似文献，搜索用时 187 毫秒
1.
为降低HNIW的合成成本，节省钯催化剂用量，以六苄基六氮杂异伍兹烷(HBIW)的一次氢解产物四乙酰基二苄基六氮杂异伍兹烷(TADIW)作为反应基质，采用市售无机试剂使TADBIW分子上的两个苄基脱掉，实现了无钯脱苄的目的，分别合成出了四乙酰基二亚硝基六氮杂异伍兹烷(TADNSIW)和四乙酰基二硝基六氮杂异伍兹烷(TADNIW)，得率分别为80．0％和70．6％；由TADNSIW经氧化、硝化合成了六硝基六氮杂异伍兹烷(HNIW)，得率为96．2％，HNIW的纯度达到98．0％以上；由TADNIW和100％硝酸反应合成HNIW，得率为96．0％，纯度高于98．0％；由TADBIW采用一锅煮合成了HNIW，得率为82．2％，纯度在98．0％以上。 相似文献
2.
通过2则具体实例讨论了高效液相色谱(HPLC)分析法在实验教学中的应用。一则是在实验选修课中应用HPLC分析法分析学生自己合成的六苄基六氮杂异伍兹烷(HBIW)的纯度;另一则是在本科生的实践课中,引导学生参与课题研究,应用HPLC分析法建立六硝基六氮杂异伍兹烷(HNIW)的标准曲线,HNIW线性浓度范围为0.08～1.5 mg/mL,同时,采用内标法分析不同HNIW样品的纯度,进行了方法重复性的比较。结果表明,该方法标准偏差小于1%,满足实验要求。最后,针对HPLC分析法的影响因素,如柱温、流动相和内标物进行了讨论。 相似文献
3.
4.
测得新型含能材料六硝基六氮杂异伍兹烷的热分解数据，处理后看到热分解动力学参数，求出其热分解活化能。 相似文献
5.
六苄基六氮杂异伍尔兹烷是一种新合成的氮杂笼形化合物，其结构特殊，它的一些衍生物在含能材料等领域得到了广泛的研究．本文在介绍该化合物的合成、形成机理的同时，对其合成工艺进行了改进，用价廉、无毒的乙醇、丙酮等溶剂代替原合成方法中毒性很大的乙腈溶剂，效果良好． 相似文献
6.
以1,4,7,10-四氮杂环十二烷(Cyclen)为原料合成了一种新型四氮杂大环化合物,目标化合物经1HNMR、质谱、元素分析等表征. 相似文献
7.
尹国杰 《洛阳工业高等专科学校学报》2014,(2)
由格氏试剂与4,5-二氮杂-9-芴酮反应合成了标题化合物C17H12N2O·H2O,并通过X-射线衍射法确定了其晶体结构。在每个不对称单元中包括两个有机分子和两个水分子,每个分子中两个4,5-二氮杂芴环几乎在一个平面上,4,5-二氮杂芴环平面与相应苯环平面的二面角分别是80.49(6)°和76.57(7)°。并且,由于桥联溶剂水分子的存在,使得整个晶体通过O—H…N和O—H…O氢键堆积而成为三维的网状立体结构。 相似文献
8.
匡华 《职教通讯(江苏技术师范学院学报)》2004,10(2)
以乙酰乙酸甲酯、邻硝基苯甲醛、18%氨水或碳酸氢铵为原料,经Hantzsch反应合成2,6-二甲基-4-(2-硝基苯基)-3,5-二甲氧酰基-1,4-二氢吡啶(硝苯吡啶).利用正交试验得到最佳反应条件,并对反应方法进行改进. 相似文献
9.
10.
合成了新型四氮杂大环化合物：５,１２－二苯基－７,１４－二甲基－１,４,８,１１－四氮杂环十四烷－Ｎ,Ｎ″－二乙酸－二硝酸的水合物（Ｈ２Ｌ·２ＨＮＯ３·３５Ｈ２Ｏ）．用元素分析和红外光谱对其组成进行了确定,并对结果进行了讨论 相似文献
11.
Ju-qing Huang Rui-ting Qi Mei-rong Pang Cong Liu Guang-yu Li Ying Zhang 《Journal of Zhejiang University. Science. B》2017,18(2):138-151
Bamboo shavings, the outer or intermediate layer of bamboo stems, are the bulk of by-products produced in bamboo processing. In this study we investigated the isolation, chemical characterization, and immunostimulatory activity in vitro of the hemicelluloses from bamboo shavings. Shavings were first pretreated by steam explosion. The optimal pretreatment was found to be steam explosion at 2.2 MPa for 1 min. Following this pretreatment, the yield of hemicelluloses reached (2.05±0.22)% (based on the dry dewaxed raw materials), which was 5.7-fold higher than that of untreated samples. Bamboo-shavings hemicellulose (BSH) was then prepared by hot water extraction and ethanol precipitation from the steam-exploded shavings. Purification of BSH by anion-exchange chromatography of diethylaminoethanol (DEAE)-sepharose Fast Flow resulted in a neutral fraction (BSH-1, purity of 95.3%, yield of 1.06%) and an acidic fraction (BSH-2, purity of 92.5%, yield of 0.79%). The weight-average molecular weights (M w) of BSH-1 and BSH-2 were 12 800 and 11 300 g/mol, respectively. Chemical and structural analyses by Fourier transform infrared spectroscopy (FT-IR), 1D (1H and 13C) and 2D (heteronuclear single quantum correlation (HSQC)) nuclear magnetic resonance (NMR) spectra revealed that BSH-1 was O-acetylated-arabinoxylan and BSH-2 was O-acetylated-(4-Omethylglucurono)- arabinoxylan. BSH-1 had a higher content of acetyl groups than BSH-2. For the immunomodulatory activity in vitro, BSH and BSH-2 significantly stimulated mouse splenocyte proliferation while BSH-1 had no effect; BSH, BSH-1, and BSH-2 markedly enhanced the phagocytosis activity and nitric oxide production of the murine macrophage RAW264.7 in a dose-dependent manner. Our results suggest that the water-extractable hemicelluloses from steam-exploded bamboo shavings are naturally acetylated and have immunostimulatory activity. 相似文献
12.
13.
Self-made enriched 10B boric acid as raw material was purified by recrystallization. The effects of final crystallization temperature, crystallization time, stirring speed, crystallization frequency and other factors on the purity were investigated. The appropriate operating condition was that the final crystallization temperature and time were 5°C and 10 h respectively under a low-speed stirring for crystallizing twice, which would make the purity and yield of boric acid reach 99.94% and 95.36%, respectively. Taking this as foundation, recrystallization process was optimized with acetone as anti-solvent, whose amount was the most important index. The boric acid solution was added into acetone and recrystallized under the same condition, and the purity and yield of boric acid would reach 99.98% and 99.61%, respectively. The product detected by XRD was confirmed as boric acid crystal. Main ion concentration in the product was detected by ICP, which basically met the national standard of high purity. Crystal morphology of boric acid was observed by SEM. 相似文献
14.
温度对TiO2-膨润土紫外光降解十二烷基苯磺酸钠的影响 总被引：1，自引：1，他引：0
投加0.5‰的TiO2-膨润土光催化剂于浓度为20 mg/L的十二烷基苯磺酸钠(SDBS)溶液中,在紫外光照射下,在温度分别为10、20、30℃下,反应2 h后的溶液中的SDBS分别降解了86.0%,89.5%和90.5%,反应6 h后降解率分别达98.0%,98.8%和99.3%,可见温度对TiO2-膨润土复合光催化剂降解水溶液中的SDBS的影响不明显。溶液的COD值受温度影响较大,温度越高,COD值降低越多,在10、20、30℃条件下,反应6 h后溶液的COD值分别降低50.6%,58.1%和97.0%。TiO2-膨润土光催化剂降解水溶液中SDBS的反应为一级反应,符合Langmuir-Hinshelwood方程。同样条件下,环境温度由10℃增加到30℃时光催化反应速率常数由0.0105增大到0.0137,增加了30%。 相似文献
15.
Development of a class-specific polyclonal antibody-based indirect competitive ELISA for detecting fluoroquinolone residues in milk 总被引：1，自引：0，他引：1
Guo-ying Fan Ruo-song Yang Jin-qing Jiang Xin-yao Chang Jun-jie Chen Yong-hua Qi Shi-xiu Wu Xue-feng Yang 《Journal of Zhejiang University. Science. B》2012,13(7):545-554
Modified 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) method was employed to synthesize the artificial antigen of norfloxacin (NOR), and New Zealand rabbits were used to produce anti-NOR polyclonal antibody (pAb). Based on the checkerboard titration, an indirect competitive enzyme-linked immunosorbent assay (icELISA) standard curve was established. This assay was sensitive and had a working range from 0.12 to 68.40 ng/ml, with the half maximal inhibitory concentration (IC50) and limit of detection (LOD) values of 2.7 ng/ml and 0.06 ng/ml, respectively. The produced pAb exhibited high cross-reactivity to fluoroquinolones (FQs) tested, and the IC50 values to enoxacin, ciprofloxacin, and pefloxacin were 3.1, 3.4, and 4.1 ng/ml, respectively. It also indicated that the concentrations of NaOH and methanol in assay buffer should not be higher than 10% and 30%. When spiked in milk at 5, 20, and 50 ng/ml, the recoveries for NOR, enoxacin, ciprofloxacin, and pefloxacin ranged 90.5%–98.0%, 84.0%–95.2%, 94.0%–106.0%, and 89.5%–100.0%, respectively. The results suggest that this class-specific pAb-based icELISA could be utilized for the primary screening of FQ residues in animal-original products. 相似文献
16.
张延琪 《安徽科技学院学报》2006,20(1):30-32
进一步研究了高纯氧化钕(99．5 %)催化合成乙酸异丁酯的性能。采用文献[1]的反应条件,经多次实验证明:实际酯收率只有58％,远达不到文献[1]中数据(酯收率80％)。此外又进一步采用了纳米级氧化钕催化合成酯,酯收率也只有66％左右。因此文献[1]中80％的酯收率有待于进一步商榷和考证。 相似文献
17.
18.
Itiswellknownthat 9,9′ bis(methoxymethyl)fluo reneisparticularlysuitableforthepreparationofZiegler Nat tacatalystsforthefactthatitcanconferqualitiesfarsuperi or ,intermsofbalancedactivityandstereospecificityinthecopolymerizationofolefinsespeciallyinpolypropy lene ,tothosethatareobtainedwiththeethersknowninthepreviousarts[1— 3] . Severalmethodsofsynthesizing 9,9′ bis(methoxymethyl)fluorenefromdifferentrawmaterialshavebeenreportedinEuropeanpatents[4— 5] .Thediethersaregenerallysynthesize… 相似文献
19.
山苍子油多段连续减压精馏提取柠檬醛工艺 总被引：1，自引：0，他引：1
研究多段连续减压精馏山苍子油提取柠檬醛的生产工艺,通过正交实验分析不同操作条件（回流比、塔顶温度和塔釜温度）下所得柠檬醛产品的浓度与得率,得出了该实验流程精馏塔系统的塔顶温度和回流比的控制对产品纯度有显著影响.维持较高的系统绝压为666.612～2 666.447Pa时,阻聚剂和抗氧化剂的添加量最少应达0.3%,可获得该实验系统提取柠檬醛的较佳工艺条件.基于该文原料油生产的柠檬醛纯度最高达95%,得率65%. 相似文献