工业园区边界污染气体定量分析及来源研究

工业园区中边界污染气体的浓度不仅受工业园区无组织污染源的排放影响，也受园区道路机动车尾气的扩散影响。利用AG-FTIR-DA3000型开放光程傅里叶变换红外光谱（Open-FTIR）测量系统，对厂区边界污染气体进行实时在线测量，确定污染气体厂界实测浓度。同时，针对机动车尾气扩散影响厂区边界污染气体浓度的问题，通过AG-FTIR-DX4000型便携式傅里叶变换红外光谱（FTIR）测量系统，确定不同排放标准下机动车尾气污染源浓度。利用便携式FTIR测量结果、风速风向、大气稳定度、车流量等变量因素建立参考坐标，给出了高斯扩散的数理模型。并结合Open-FTIR，对Open-FTIR的测量路径进行积分计算并构建点线源扩散模型，从而建立各种排放标准的烟团线源扩散表。将Open-FTIR实测浓度与构建的点线源扩散模型模拟浓度相结合，分析工业园区边界污染气体的来源。结果表明：厂区边界污染气体主要包括一氧化碳、甲烷、乙烯、乙醛、丙烯、甲醇、丙醛、异丁烯、甲醛、二氧化硫，其中一氧化碳、甲烷、乙烯浓度受机动车尾气的扩散影响。早晚高峰期时，机动车尾气的扩散对边界污染气体浓度影响较大；非高峰期，在1:00时与4:00—6:00时浓度骤升，出现高浓度点，不符合机动车尾气模型排放规则，主要受园区排放影响。其最高浓度与集中浓度分别为：5.50与4.00 mg·m-3；1.85与1.60 mg·m-3；78.00与40.00 μg·m-3。对比扩散表，符合尾气扩散浓度分布结果。其他测量结果组分的最高值和平均值依次为：1.65与1.40 mg·m-3；2.60与1.27 mg·m-3；43.53与11.40 mg·m-3；310.23与839.05 μg·m-3；76.32与38.96 μg·m-3；47.70与25.20 μg·m-3；1.33与1.16 mg·m-3。该研究不仅实现了工业园区边界多组分污染气体的实时在线测量，同时结合外场环境及便携式FTIR测量结果实现了边界污染气体浓度的混合测定。为今后对工业园区边界污染气体的来源判断提供了一种分析思路。     

Optimal brushless DC motor design using genetic algorithms

This paper presents a method for the optimal design of a slotless permanent magnet brushless DC (BLDC) motor with surface mounted magnets using a genetic algorithm. Characteristics of the motor are expressed as functions of motor geometries. The objective function is a combination of losses, volume and cost to be minimized simultaneously. Electrical and mechanical requirements (i.e. voltage, torque and speed) and other limitations (e.g. upper and lower limits of the motor geometries) are cast into constraints of the optimization problem. One sample case is used to illustrate the design and optimization technique.     

Functional MRI changes in the central motor system in myotonic dystrophy type 1

Myotonic dystrophy type 1 (DM1) is a multisystemic disease involving multiple organ systems including central nervous system (CNS) and muscles. Few studies have focused on the central motor system in DM1, pointing to a subclinical abnormality in the CNS. The aim of our study was to investigate patterns of cerebral activation in DM1 during a motor task using functional MRI (fMRI). Fifteen DM1 patients, aged 20 to 59 years, and 15 controls of comparable age were scanned during a self-paced sequential finger-to-thumb opposition task of their dominant right hand. Functional MRI images were analyzed using SPM99. Patients underwent clinical and genetic assessment; all subjects underwent a conventional MR study. Myotonic dystrophy type 1 patients showed greater activation than controls in bilateral sensorimotor areas and inferior parietal lobules, basal ganglia and thalami, in the ipsilateral premotor area, insula and supplementary motor area (corrected P<.05). Analysis of the interaction between disease and age showed that correlation with age was significantly greater in patients than in controls in bilateral sensorimotor areas and in contralateral parietal areas. Other clinical and MR characteristics did not correlate with fMRI. Functional changes in DM1 may represent compensatory mechanisms such as reorganization and redistribution of functional networks to compensate for ultrastructural and neurochemical changes occurring as part of the accelerated aging process.     

Characterization of Motor Oil by Laser-Induced Fluorescence

A new laser-induced fluorescence method is presented to classify brands of motor oil. A 266-nanometer radiation was employed to collect sixty sets of fluorescence spectra for each brand. Cluster analysis and support vector machine were employed to distinguish motor oils with principal component analysis, which was applied to extract spectral characteristics. The recognition accuracy was up to 100 percent. The results demonstrate that laser-induced fluorescence offers rapid response, high recognition, and high sensitivity for the classification of motor oils.     

Task complexity effect on vocal reaction time in aged speakers

The aged population is at risk for impaired speech communication due to the increased likelihood of deterioration of central nervous system (CNS) processes that underlie cognition, language, and/or speech motor control. Vocal reaction time (RT) may provide a means of quantifying the efficiency of CNS processes that underlie speech production. The present study used a simple RT paradigm to investigate effects of the complexity of the required task on vocal RT in normal young and aged speakers. Task complexity was represented by two levels: a single word and a short sentence. Only the aged subjects showed a significant task complexity effect on vocal RT. Furthermore, the between-group RT difference increased as a function of task complexity. Specific causes for the increase in vocal RT for the aged subjects are presently unknown, but likely reside in altered respiratory biomechanics and reduced efficiency of CNS motor processing.     

DSC study on the motor protein myosin in fibre system

We have examined by DSC the complexes of myosin with actin in fibre system in the absence of nucleotides and the intermediate state of ATP hydrolysis by mimicking stable complex with myosin and ADP and beryllium fluoride in muscle fibres. Comparing the DSC results with other structural analogues of phosphate P_i leads the conclusion that the AM.ADP.BeF_x complex favours the AM.ADP.P_i complex in fibre system. The deconvolution of DSC scans resulted in four transitions, the first three transition temperatures were almost independent of the intermediate state of the muscle, the last transition temperature was shifted to higher temperature, depending on the actual intermediate states of ATP hydrolysis. In AM.ADP.V_i state the transition temperature at the second and third transitions (actin binding domain and myosin rod) varied only slightly, whereas the last one (the fourth transition) shifted markedly to higher temperature depending on the ternary complex, e.g. in case of ADP plus BeF_x it was 77.7 °C, the highest value in weakly binding state of myosin to actin. The sum of calorimetric enthalpies of the first and last curves was practically constant, but their fractions depended on the state of the muscle. In strongly binding state of myosin to actin (rigor, ADP state) the fraction of the first transition was much larger, than the last one, whereas in weakly binding state of myosin to actin, the fraction of the first transition decreased at the expense of the last one. It supports also the view that these transitions are parts of the same portion of the myosin molecule.     

Worker deployment in dual resource constrained systems with a task-type factor

This paper investigates worker learning and forgetting phenomenon in a dual resource constrained system (DRC) setting. Worker learning and forgetting in two and three stage DRC systems are modeled according to the dual-phase learning and forgetting model (DPLFM), which is based on the theory that a task has separate cognitive and motor requirements. Results show that the task-type (with respect to its learning rate and proportion of cognitive and motor requirements) affects the performance of training and deployment policies in DRC systems, and as such it should be included in future DRC research.     

Effects of adenosine triphosphate concentration on motor force regulation during skeletal muscle contraction

We employ a mechanical model of sarcomere to quantitatively investigate how adenosine triphosphate (ATP) concentration affects motor force regulation during skeletal muscle contraction. Our simulation indicates that there can be negative cross-bridges resisting contraction within the sar-comere and higher ATP concentration would decrease the resistance force from negative cross-bridges by promoting their timely detachment. It is revealed that the motor force is well regulated only when ATP concentration is above a certain level. These predictions may provide insights into the role of ATP in regulating coordination among multiple motors.