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As a nanoparticle support material, carbon nanotubes (CNTs) provide a certain potential activation of catalysis in heterogeneous catalytic organic reactions. Herein, an efficient Ag/CNT‐catalyzed synthesis of enamines via hydroamination of activated alkynes with aromatic amines has been described. This catalyst still retains catalytic activity after being recycled and reused three times. In addition, it represents a green and environmentally friendly process for preparation of enamines. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Yue Hangbo Xu Chao Yao Jiachang He Ming Yin Guoqiang Cui Yingde Yang Chufen Guo Jianwei 《Cellulose (London, England)》2022,29(10):5869-5881
Cellulose - The development of plant adhesive with good bonding strength, water resistance and thermal stability remains challenging to replace formaldehyde-based adhesive resins that usually... 相似文献
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Sun Jinfei Zhu Dongsheng Yin Yingde Li Xiuzhen 《Journal of Thermal Analysis and Calorimetry》2018,132(3):1579-1591
The objectives of this study were to verify thermal properties, degree of conversion, and morphological features of several dimethacrylate polymers with different glycerol content and obtain the better proportion system to decrease cost of final polymer. These polymers were synthesized by photopolymerization, which has economic and ecological advantages. The glycerol can be used as a coinitiator in photopolymerization and has the advantage of being inexpensive and non-toxic; thus, it is in the scope of the green chemistry principles. Simultaneous thermogravimetry–differential thermal analysis and derivative thermogravimetric, differential scanning calorimetry, middle infrared spectroscopy, and scanning electronic microscopy were used to determine thermal properties, degree of conversion, and morphological characteristics of polymers obtained. The thermoanalytical results showed that glycerol addition in the dimethacrylate system caused few modifications in the thermal stability of the polymer and thermal events when compared with pure polymers (without glycerol). Two dimethacrylate systems (UDMA/glycerol and Bis-GMA/glycerol) showed good results for conversion degree and morphological aspects when compared with pure systems. 相似文献
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目的:观察硒化螺旋藻(Se-spirulina)对黄曲霉毒素B1(AFB1)致肝癌作用的影响。方法:实验动物按随机区域分组法分为A、B、C组,每组15只,A、B、C组分别为高剂量组、低剂量组、对照组,各组动物腹腔注射AFB1两周,A、B组大鼠在接受AFB1期间分别喂食含量分别为9.3×10-3和2.3×10-3的硒化螺旋藻混合饲料,8周后处死动物,观察各组动物肝组织内γ-谷氨酰转肽酶阳性肝细胞增生灶(-γGT灶)的数量(个/cm2)和大小(mm2/个)。结果:高、低剂量硒化螺旋藻均能抑制AFB1诱发的-γGT灶的数量和大小,高剂量组、低剂量组-γGT灶的数量分别为(0.90±1.07)个/cm2和(3.72±4.72)个/cm2,均低于对照组(6.10±6.30)个/cm2,高剂量组与对照组相比有显著意义(P<0.05),抑制率分别为85%和39%;高剂量组、低剂量组-γGT灶大小分别为(0.24±0.28)mm2/个和(1.94±2.32)mm2/个,均低于对照组(2.36±3.76)mm2/个,但无显著意义(P>0.05),抑制率分别为90%和17%。结论:硒化螺旋藻有抑制AFB1诱发大鼠肝癌前病变的作用,而高剂量硒化螺旋藻的抑制作用更优。 相似文献
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将大豆蛋白(SPI)经预热处理、EDTAD酰化和戊二醛交联,制备出改性大豆蛋白凝胶.通过红外与化学法研究了改性大豆蛋白分子的结构变化,结果表明,经EDTAD改性,大豆蛋白分子的侧链基团和分子链构象均发生变化;侧链的游离氨基与EDTAD发生酰化反应,为蛋白质分子链引入羧基;基团分析数据显示,改性大豆蛋白分子中游离氨基数减少,羧基数增加,增加的羧基数与减少的氨基数之比约为3:1.研究了改性大豆蛋白凝胶的溶胀率变化,并对溶胀数据进行数学处理,分析了不同mEDTAD:mSPI的凝胶的溶胀过程规律,结果显示,mEDTAD:mSPI为0,0.05,0.1和0.2的改性大豆蛋白凝胶在水中的溶胀率为24.2,54.01,87.27和95.87,说明分子链引入一定量的EDTAD使凝胶溶胀率增大;其溶胀特征指数为0.5,表现为Fickian扩散.研究了改性凝胶在不同pH下的溶胀过程规律,结果显示,在pH4.30和6.08时,凝胶溶胀特征指数n范围是0.5n1,表现为non-Fickian扩散,而在碱性pH10.04,凝胶特征溶胀指数为0.5,仍表现为Fickian扩散.改性大豆蛋白凝胶溶胀率对pH变化具有敏感性,其溶胀-消溶过程曲线呈"W"形,显示凝胶具形状记忆功能. 相似文献
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N-乙烯吡咯烷酮/甲基丙烯酸-β-羟乙酯无规共聚物凝胶对蛋白质吸附机理的研究 总被引:3,自引:0,他引:3
用紫外分光光度法研究了牛血清白蛋白(BSA)在N-乙烯吡咯烷酮(NVP)/甲基丙烯酸-β-羟乙酯(HEMA)共聚物水凝胶上的吸附量.结果表明,BSA在凝胶上的吸附关系既可用Langmuir方程描述,又可用计量置换吸附Freundlich方程描述,且用Langmuir方程描述更为优越.研究了凝胶对BSA的吸附动力学行为,建立牛血清白蛋白的吸附动力学模型,发现用Bangharm方程对BSA吸附动力学曲线拟合程度较好,Bangharm方程可以较好地描述BSA在NVP/HEMA凝胶上的吸附动力学行为. 相似文献
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The elastic scattering Green function method has been developed to describe the I–V characteristics of molecular wires. The
molecular electronic structure and the interaction between the molecule and the gold surface are two key factors for the charge
transport properties of molecular wires in the formulas. Anab initio calculation at the hybrid density functional theory level is carried out to obtain the electronic structure of 4-4′-dimercaptodibenzene
molecule. The frontier orbit theory and the perturbation theory are employed to determine the constant of the interaction
energy between molecule and surface quantitatively. The numerical results show that the bonding between the sulfur atom and
the gold atoms corresponds mainly to the covalent bond. Some molecular orbits are extended over molecule and gold cluster
that certainly give channels for the charge transport, other molecular orbits are localized and the charge transport can take
place by tunnel mechanism. At zero bias region, there exists a current gap. With the increasing bias, the conductance of the
wire takes a shape of plateaus. 相似文献
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双环戊二烯加氢异构化合成金刚烷 总被引:14,自引:0,他引:14
采用固定床反应器考察了双环戊二烯连续催化加氢合成桥式四氢双环戊二烯反应性能,筛选出具有良好催化性能的23%Ni/γ-Al2O3催化剂.以桥式四氢双环戊二烯为原料,采用不同类型的沸石催化剂研究了金刚烷的合成,并考察了沸石骨架阳离子改性和表面负载过渡金属等对其催化性能的影响.在n(cat)/n(reactant)=0.25,p(H2)=1.1MPa,θ=250℃,t=3h的条件下,采用三元负载型催化剂0.8%Pt-0.2%Re-3%Co/ReUSY可得到收率为27.7%的金刚烷. 相似文献