纳米金催化光度法快速检测葡萄糖

以抗坏血酸为还原剂,制备了一定粒径的纳米金.所制备的纳米金对葡萄糖与菲林试剂反应有强烈的催化作用,且生成的氧化亚铜微粒在870 nm处的吸光度与葡萄糖含量呈正比.据此,在优化实验条件下,建立了分光光度法检测葡萄糖含量的新方法.该方法灵敏度高、操作简单,可用于葡萄糖的快速检测.     

The effects of mid-flight whole-body and trunk rotation on landing mechanics: implications for anterior cruciate ligament injuries

ABSTRACT

The purpose was to quantify the effects of mid-flight whole-body and trunk rotation on knee mechanics in a double-leg landing. Eighteen male and 20 female participants completed a jump-landing-jump task in five conditions: no rotation, testing leg ipsilateral or contralateral (WBRC) to the whole-body rotation direction, and testing leg ipsilateral (TRI) or contralateral to the trunk rotation direction. The WBRC and TRI conditions demonstrated decreased knee flexion and increased knee abduction angles at initial contact (2.6 > Cohen’s dz > 0.3) and increased peak vertical ground reaction forces and knee adduction moments during the 100 ms after landing (1.7 > Cohen’s dz > 0.3). The TRI condition also showed the greatest knee internal rotation angles at initial contact and peak knee abduction and internal rotation angles and peak knee extension moments during the 100 ms after landing (2.0 > Cohen’s dz > 0.5). Whole-body rotation increased contralateral knee loading because of its primary role in decelerating medial-lateral velocities. Trunk rotation resulted in the greatest knee loading for the ipsilateral knee due to weight shifting and mechanical coupling between the trunk and lower extremities. These findings may help understand altered trunk motion in anterior cruciate ligament injuries.     

Muscle force characteristics of male and female collegiate cross-country runners during overground running

ABSTRACT

Males and females demonstrate unique running mechanics that may contribute to sex-related differences in common running related injuries. Understanding differences in muscle forces during running may inform intervention approaches, such as gait retraining addressing muscle force distribution. The purpose of this study was to compare muscle force characteristics and inter-trial variability between males and females during running. Twenty female and 14 male collegiate cross-country runners were examined. Three-dimensional kinetic and kinematic data were collected during overground running and used to estimate muscle forces via musculoskeletal modelling. Principle components analysis was used to capture the primary sources of variance from the muscle force waveforms. The magnitude of the forces for the hamstrings, gastrocnemius, and soleus muscles were higher across the majority of stance in male runners regardless of footstrike pattern. Males also demonstrated greater inter-trial variability in the timing of the peak gluteus maximus force and the magnitude of local peaks in the gastrocnemius force waveform. Male and female collegiate cross-country runners appear to employ unique lower extremity muscle force characteristics during overground running.     

过碳酸钠热分解动力学研究(Ⅱ)-最佳实验点的确定

采用置信域容积最小为目标的实验设计方法，对过碳酸钠分解动力学实验进行了统计设计，确定了最佳实验点的位置，研究结果表明，在过碳酸钠分解率0．1及0．85两个位置做实验，能够对过碳酸钠分解动力学模型中的两参数k和t0精确估值。     

低浓度苯胺在大孔树脂上吸附的动力学研究

测定了水相中苯胺在NKA—Ⅱ和AB-8这2种大孔吸附树脂上的吸附等温线和吸附速率曲线．结果表明：极性的NKA—Ⅱ对苯胺的吸附量要高于弱极性的AB-8对苯胺的吸附量，苯胺在2种吸附树脂上的相平衡关系符合Freundlich方程；苯胺在NKA—Ⅱ和AB-8上的吸附受腱扩散控制．动态吸附实验和模拟结果表明：模拟透过曲线与实验透过曲线比较吻合，所建立的模型能够较好地描述苯胺在2种大孔吸附树脂填充柱上的吸附透过过程．     

Use of ionic liquids in recycle of palladium catalysts for synthesis of polyketone

Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide salts. The recyclability of palladium composite catalyst in various ionic liquids was investigated.[Pd(bipy)2][BF4]2 showed a lower catalytic activity than [Pd(bipy)2][PF6]2 in similar conditions, although the catalytic activity of each composite catalyst in ionic liquids still existed after 4 successive recycles. It was shown the catalytic activity of palladium composite catalyst was higher than that of the catalyst formed in situ from palladium acetate, 2,2'-bipyridyl, and HA (A=PF6-, BF4-) in ionic liquids. The effects of volume of ionic liquids, reaction time, and the dosage of benzoquinone on the copolymerization were also studied.     

催化动力学分析专家系统

报道一个催化动力学分析专家系统(CKAES),该系统可完成催化动力学分析指示反应体系的确定,测定某元素的反应体系的搜索及有机分子结构显示等.系统主要包括知识库、推理机构、知识获取子系统、解释子系统、有机试剂分子结构显示、动态数据库和理论学习等七大模块.系统采用产生式规则的知识表达方式,正反双向推理技术。知识库与程序相互独立,便于知识库韵扩充与修改。系统还包括浏览知识库、编辑新老文件、文件存取、同DOS交互等多种功能.CKAES使用TurboPROLOG语言编程,经编译生成可执行文件,在IBM PC/XT及其兼容机实现.     

邻二氮菲活化氯离子催化溴酸钾氧化核固红褪色光度法测定痕量氯

基于H2SO4 介质和邻二氮菲存在下 ,Cl-能显著地催化KBrO3 氧化核固红的褪色反应 ,因而提出了一种高灵敏邻二氮菲活化氯离子催化溴酸钾氧化核固红褪色光度法测定痕量氯的新方法。氯含量在0.40～3.2μg/L范围内与△A值符合比尔定律 ,工作曲线的回归方程为ΔA=0.09492 0.1053CCl (μg/L) ,相关系数为r=0.9996,检出限为0.11ug/L。该方法准确、灵敏、操作简便 ,选择性好 ,成功用于水样中的氯含量的测定。     

CuO/γ-Al2O3上H2催化还原氮氧化物的初步研究

采用γ—Al2O3和CuO／Y—Al2O3作为H2催化还原氮氧化物的催化剂，考察了反应温度、活性组分添加、原料配比以及原料气空速等对NO转化率的影响。结果表明：γ—Al2O3本身对于NO还原有一定的催化活性；Cu的添加可以使γ—Al2O3催化剂的NO还原活性明显提高；在考察的温度范围内，CuO／Y-AlO3催化剂活性随反应温度的升高明显增加，最高可达100％。随着反应原料气H2／NO(mol)的降低，NO转化率下降。     

Recovery of Dilute Acetic Acid by Catalytic Distillation Using NKC-9 as Catalyst

The reaction kinetics of dilute acetic acid with methanol using NKC-9 as catalyst was studied at temperatures of 308 K, 318 K, 323 K, 328 K. The kinetic model based on Langmuir-Hinshel-wood rate model was derived and the activation energy was 6.13×104 kJ/kmol. The experiment of recovery of dilute acetic acid was conducted in a packed bed catalytic distillation column. The optimal process parameters and operational conditions determined to make up to 85.9% conversion of acetic acid are as follows:the height of catalyst bed is 1 100 mm, reflux ratio is 4:1, and the ratio of methanol to acetic acid is 2:1. The method can be used as a guide in industrial scale recovery of 15%-30% dilute acetic acid.