肝硬化门脉血流的彩色多普勒检测

应用彩色多普勒对肝硬化门脉高压患者进行门脉血流动力学检测，结果表明治疗前门脉血流量增加，治疗１个月后重复检测门脉血流量明显下降，前后测值比较差异极显著（Ｐ〈０．００１）。彩色多普勒检测门脉血流动力学变化简单易行、无创，值得临床推广。     

金属络合物分子间交换反应的核磁共振研究Ⅲ.噻吩甲酰三氟丙酮铝与苯甲酰丙酮铝体系分子间配体交换的19F NMR研究

用¹⁹F NMR研究了噻吩甲酰三氟丙酮铝与苯甲酰丙酮铝体系分子间的团体交换反应,求得了交换反应的平衡常数及自由能,结果表明交换反应有利于混合配体络合物生成,平衡时混和溶液中各组分分布偏离统计分布。     

工艺参数对电去离子技术浓缩分离含镍离子溶液的影响

采用浓缩室填充树脂的强化电去离子(EDI)对含Ni2+溶液进行了浓缩分离,从中研究了工作电压、淡化室隔板厚度、原水浓度及组分对EDI分离性能的影响.结果表明,在15V电压下,EDI以增强传质模式运行可在较低能耗下获得高质量的出水;电压增大使淡水室内发生水解离而产生结垢,影响EDI的稳定运行.淡化室隔板由3 mm增至5 mm时,膜堆电阻增大,分离效率降低.对于含Ni2+为50 mg·L-1的NiSO4原水,在优化条件下,浓、淡水出水中Ni2+浓度分别为11 031和2.78 mg·L- 1,Ni2+的浓缩倍数达223.对于含Ni2+和Cu2+各25 mg·L-1的双组分原水,EDI对Cu2+有更好的浓缩效果.实验结束时,浓水出水中Ni2+、Cu2+浓度分别为3 258和4 690 mg·L-1,浓缩倍数分别为130和187;淡水出水中Ni2+及Cu2+浓度分别为4.71和3.71 mg·L-1.     

科技论文撰写中的常见问题及其规避

在知识经济时代,从事科学研究籍此撰写科技论文是研究者必备的基本素质和能力,也是提升高校科技创新实力的重要因素.为此,从撰写科技论文入手,针对行文中有关题名、摘要、关键词、引言、正文及参考文献引用中的常见问题,提出了规避思路.以引起重视或写作参考.     

Efficient Fluorescent Recognition of Carboxylates in Aqueous Media Using Facilely Electrosynthesized Poly(9-Aminofluorene)

A variety of carboxylates were recognized using poly(9-aminofluorene) (P9AF) in the HEPES buffer (pH 7.4), and a proposed possible mechanism was proposed as following. The intermolecular hydrogen bonding interactions resulted in electron transfer between P9AF and carboxylates. P9AF was facilely electrosynthesized in boron trifluoride diethyl etherate and could be used as an efficient fluorescent sensing material for the detection of AcO^?. On binding to AcO^?, fluorescence quenching of P9AF was demonstrated by a maximum 80 % reduction in the fluorescence intensity, while no obvious fluorescence change could be observed in the presence of some other common anions. Some different carboxylates could be recognized at different levels by P9AF. Substituent groups in carboxylates could affect the intermolecular interaction between carboxylates and P9AF. These could be explained by a possible mechanism that hydrogen bonding was the main way of intermolecular interactions between P9AF and carboxylates, which was further confirmed by absorption spectra monitoring and density functional calculations. The significant advantage of this strategy is that it does not require a prequenching procedure and the polymer can be used directly for analyte detection.     

Relations of Keune symbols

In this paper, we extend the symbols that Keune defined for commutative rings in 1981 to the non-commutative case and discuss their relations. These relations are similar to those of the commutative case.     

复合改性硬质沥青的制备及微观结构

以秦皇岛AH-70为基质沥青,外掺改性胶粉、SBS和硬沥青制备复合改性硬质沥青,考察制备方法(四步剪切法和三步剪切法)、剪切时间及外掺剂对其性能的影响,对制备过程中的微观相态进行研究。结果表明:四步剪切法所制备的复合改性硬质沥青性能优于三步剪切法,每步较合适的剪切时间为60、60、30和20 min,在此工艺条件下,胶粉、SBS和硬沥青的掺量分别为20%、2%、20%,所制备的复合改性硬质沥青的性能均满足浇注式沥青的指标要求;复合改性硬质沥青的制备是一个复杂的物理化学过程,既存在物理共混又发生化学反应,同时制备过程中其相态结构发生转变,由沥青为连续相、SBS为分散相,转变为沥青和SBS为双连续相,最后又转变为沥青连续相、SBS分散相。     

吡嗪类碳酰肼化合物与CT-DNA相互作用及体外抑菌

以5-氯吡嗪-2-羧酸甲酯和水合肼为原料,经亲核取代和脱水缩合反应合成了3种新型吡嗪类碳酰肼化合物C13H14N6O(a)、C13H14N6O2(b)和C12H12N6O2(c)。采用元素分析与核磁共振氢谱对化合物a~c进行了表征,结果表明合成的产物即为目标化合物。通过溶剂挥发法培养得到了化合物a的单晶并利用X-射线单晶衍射测定化合物a的晶体结构为单斜晶系。根据紫外-可见光谱可知,化合物a~c均以插入模式与CT-DNA作用。利用微量热实验测定了化合物a~c与CT-DNA的相互作用,发现反应过程放热,热效应ΔH依次为-5.77×103、 -5.50×103和-5.96×103 kJ·moL-1,反应时间均小于40 min。通过分子对接模拟计算明确了化合物a和b与DNA的具体结合位点包括A链DC4和DG5以及B链DC4、 DG5和DA6,化合物c与DNA的具体结合位点包括A链DC4和DG5以及B链DC4和DG5。采用牛津杯法测定了化合物a~c对枯草芽孢杆菌、金黄色葡萄球菌、铜绿假单胞菌以及大肠杆菌四种细菌的抑菌活性,结果表明化合物a~c均对铜绿假单胞菌表现出优于阳性对照组四环素的抑菌活性。     

Electrosyntheses and characterization of polyalkylenedioxybenzenes

Direct anodic oxidation of 1,2-methylenedioxybenzene (MDOB) and 1,2-ethylenedioxybenzene (EDOB), analogues of 3,4-alkylenedioxythiophene and 3,4-alkylenedioxypyrrole, led to the formation of polyacetylene derivatives, poly(1,2-methylenedioxybenzene) (PMDOB) and poly(1,2-ethylenedioxybenzene) (PEDOB), on a platinum sheet in pure boron trifluoride diethyl etherate (BFEE). IR, ¹H NMR, ¹³C NMR and quantum chemistry calculations confirmed that the polymerization occurred at C(4) and C(5) position on the benzene ring of the monomer, making the main backbone of PMDOB and PEDOB similar to polyacetylene. Both dedoped PMDOB and PEDOB in DMSO solution showed good fluorescence properties with quantum yields of 0.13 and 0.27, emitting blue and green light under excitation of 365 nm, respectively. PMDOB showed electrochromic properties from grass green (doped) to light nacarat (dedoped). PEDOB changed it from bottle green (doped) to nacarat (dedoped). Doped PMDOB and PEDOB own electrical conductivities of 0.1 S cm⁻¹ and 0.17 S cm⁻¹, respectively.     

2004—2012年河南五地市粮食产量影响因子的灰色关联分析

选择了农业从业人员、农业机械总动力、农村用电量、农用化肥使用折纯量、农用塑料薄膜使用量、农药使用量、粮食作物播种面积、粮食单产等8个因子,运用灰色关联分析方法,对河南省周口、信阳、商丘、驻马店、南阳五地市2004—2012年粮食产量进行关联性分析.结果表明,8个因子对这5个地市粮食产量影响排名差别较大,基于此,提出粮食增产稳产的建议.