共查询到20条相似文献,搜索用时 15 毫秒
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以辣根过氧化物酶(horseradish peroxidase,HRP)为目标蛋白,N-异丙基丙烯酰胺(NIPAM)为单体,采用原位沉淀聚合法,在37℃,NIPAM和HRP质量比为6∶1的条件下,制备了粒径大小为13.7 nm,zeta电位是(-3.7±0.3)mV的温度响应型辣根过氧化物酶纳米胶囊(nHRP).采用基质辅助激光解吸电离飞行时间质谱仪(MALDI-TOF MS)、透射电镜(TEM)、动态光散射仪(DLS)和紫外-可见光分光光度计(UV-Vis)等对HRP的修饰度,nHRP的微观结构、粒径大小、催化活性、温度响应性能和热稳定性能进行了表征.研究表明,制备的辣根过氧化物酶纳米胶囊单分散性较好;在环境温度高于33℃时,nHRP出现响应变化,其粒径大小变化显著,且呈可逆性;nHRP相比HRP原酶热稳定性显著提高;50℃时,将nHRP高速离心,可使酶多次有效地分离和回收. 相似文献
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根据不同温度下酞侧基聚芳醚酮(PEK—C)的应力松弛曲线及时-温等效原理,得到了PEK—C在任意参考温度下的总曲线.应用Kohlrausch—Williams-Watts(KWW)模型定量解释了应力松弛现象的温度依赖性,并通过KWW模型建立了应力松弛现象与屈服行为间的相关性. 相似文献
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THE PRECURSOR OF INSTABILITY FOR NONLINEAR SYSTEMS AND ITS APPLICATION TO EARTHQUAKE PREDICTION 总被引:6,自引:0,他引:6
By analysing the instability process of various nonlinear systems, we conclude that their instability precursors are the continual heightening of the response rate or response ratio.Applying this theory to earthquake prediction, we adopt the periodical change of the stress in crust caused by the tide-generating force as the loading and unloading. If we can measure the ratio of the response (such as crust deformation, gravity and seismicity) during the loading period to that during the unloading period, this parameter must contain some characteristic information about the seismogenic process.With nine earthquakes (M≥7) data that occurred in Chinese mainland during 1970-1988, we take the sum of square root o?energy of small earthquakes, which is called the released strain by Benioff, as the response to the tidal loading and unloading. We find that the response ratios of seven earthquakes increase obviously before the main earthquakes. 相似文献
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REE AND Sr, Nd, Pb ISOTOPIC GEOCHEMISTRY OF HUANGYISHAN BASALT, KUANDIAN, LIAONING, NORTHEAST CHINA 总被引:1,自引:0,他引:1
In the light of major element geochemistry, mineral chemistry and REE and isotopic data, the small but apparent isotopic differences between the Cenozoic volcanic rocks east and west of the Tancheng-Lujiang fault are believed to be caused by the mixing and metasomatism of crustal and mantle material in tho mantle source region in response to Pacific plate subduction. The presence of phlogopite and pargasite in mantle xenoliths lends strong support to mantle metasomatism. 相似文献
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强酸和弱酸阳离子交换树脂与盐酸维拉帕米的静态交换反应特性研究 总被引:4,自引:0,他引:4
离子交换树脂是一类功能高分子材料,本文研究了强酸(001×7)和弱酸(110)阳离子交换树脂与钙通道阻滞剂盐酸维拉帕米(VH)的交换反应特性。结果表明,001×7和110树脂与VH的交换率、树脂载药量及反应平衡常数均分别随温度的升高而增加和减少;298K时,两树脂与VH进行交换反应的自由能ΔG°(kJ/mol) 分别为8.5503和6.0911,交换反应热ΔHm°(kJ/mol)分别为100.29和 -22.77;交换反应熵(kJ/mol·K)分别为0.3077和 -0.0968,表明001×7与VH的交换反应是吸热反应,且属于熵增加的反应,即升高温度有利于交换反应的进行;而110与VH 树脂的交换反应是放热反应,且该反应是熵减少的反应,即升高温度不利于交换反应的进行。 相似文献
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用乙烯为原料在双功能催化剂体系的作用下通过二聚和共聚合反应,直接合成线性低密度聚乙烯(LLDPE).所用二聚反应催化剂为钛酸正丁酯(Ti(OBu)_4),共聚催化剂为TiCl_4/MgCl_2(ZM-1催化剂).研究了二聚反应动力学行为及影响双功能催化剂体系动力学过程的一些因素.结果表明利用这两种催化剂组成双功能催化剂体系能够很方便地制得密度范围在0.90-0.93,Et/1000C在10-40的LLDPE. 相似文献
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用圆二色谱(CD)研究海藻酸钠对钙锌离子的选择 总被引:1,自引:0,他引:1
用圆二色谱对海藻酸钠与钙锌离子相互作用的稳态溶液-凝胶过程进行了研究,结果表明该过程分前后两个阶段,在临界点之前第一阶段内,海藻酸钠构象的变化与阳离子用量成线性关系。对海藻酸钠与钙锌离子的选择识别和相互作用研究表明,钙离子与海藻酸钠的G、M单元相互作用差别很大,锌离子与G、M单元相互作用的差别比较小,锌离子对G、M单元的识别作用不如钙离子。锌离子与海藻酸钠形成凝胶时,交联点比钙离子的多。 相似文献
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Ludwig Maier Marvin M. Crutchfield 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):45-51
Abstract Dedicated to Professor Martin Schmeisser on the occasion of his 65th birthday. Several phosphonic acids of the type H2O3PCH2OCHRCO2H, R = H, CH3, CO2H; [H2O3P(CH2)x]2 Y, x = 1, 2; Y = O, S; and [o-H2O3P(CH2)]2C6H4 have been synthesized and their capacity to chelate with calcium has been determined. 相似文献
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The surface of calcium carbonate(CaCO_3)particles was modified with stearic acid(SA)and the chemical structures of the product were characterized by FT-IR analysis.The interaction between polydimethylsiloxane(PDMS)and CaCO_3 fillers with different surface character was investigated by means of dynamic rheological and bound rubber tests for uncured compounds and mechanical properties measurements for the corresponding vulcanites.The results of dynamic tests indicate that with the increase of SA mass fract... 相似文献
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Fawzy A. Attaby Sanaa M. Eldin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):59-63
Abstract 2-Amino-1.1.3-tricyanoprop-l-ene (1) reacted with thioglycollic acid to afford the key compound for this study namely: 2-amino-I,I-dicyano-3(2-thiazolin-4-on-2-yl)prop-1-ene 2. 2 reacted with hydrazines to afford the thiazolylmethylaminopyrazole derivatives 3 and 4. The reaction of 2 with diazotised primary aromatic amines afforded coupling products which were cyclised to the hydrazothiazolonylpyridazine derivatives 7. The reaction with aromatic aldehydes gave the his-ylidene derivatives 8. Structures are assigned based on elemental and spectroscopic analysis. 相似文献
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吸附式空调系统的原理及添加剂强化吸附工质性能的研究 总被引:7,自引:0,他引:7
氯化锂晶体具有很高的吸水性能,在吸附式空调制冷系统中常常被用作吸附剂。本文介绍了吸附式空调制冷系统的原理,研究了吸附剂(氯化锂)、吸附质(水汽)的性质;采用高真空吸附重量法测定氯化锂的等温吸附曲线及氯化锂吸附水汽的速率,并通过添加一种既有吸附增稠作用,又能强化氯化锂吸附性能的添加剂,改善氯化锂的等温吸附特性,降低氯化锂的再生温度。采用氯化锂混合吸附剂-水的开式旋转吸附式空调系统,具有显著的节能效果和双重杀菌功能,提供人们所喜爱的舒适空调域(室内温湿度26.7℃/50%RH),同时改善室内空气品质。 相似文献
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The paper introduces the preparation of floating TiO2/beads photocalyst attached to the hollow glass micro-beads surface by sol-gel technique using tetrabutyl titanate as material and the preparation of floating CoPcS/TiO2/beads by dip-coatig technique. The optimal factor of degradation of vegetable oil floating on water using CoPcS/TiO2/beads was studied. The result showed that the removal rate of vegetable oil floating on water can highly reach 90% at the optimal condition (acidity or neutrality, 375W medium-pressure mercury vapour lamp, illumination 2h-3h, lg CoPcS/TiO2/beads). The photocatalytic removal efficiency causing by CoPcS/TiO2/beads was increased rapidly by adding a trace amount of H2O2. 相似文献
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A preliminary study of simulated thermal maturity has been conducted to evaluate the oil, gas and hydrocarbon generation potential of sphagnum coal in the Jinsuo brown coal basin, Yunnan Province and to understand the characteristics of the element composition and biomarkers in the course of thermal alteration. The experimental result was compared with that of xylitic coal, a kind of lithotype of soft brown coal. It is considered that sphagnum coal possesses the potential of forming economic accumulation of oil and gas. Its highest proportion of oil and hydrocarbon generation is 510 mg/g Corg. and 232.1 mg/g Corg. respectively. At an R_(ran)~° value of 2.51%, the ratio of gas generation from sphagnum coal attains to 620.5 ml/g Corg. In view of sphagnum coal being different from the conventional soft brown coal in various respects such as coal forming raw materials and enviroments as well as physico-chemical properties, it is Suggested as a special kind of source rock for coal-generated oil and gas. 相似文献