CC双键对氟化非晶碳薄膜I-V特性的影响

研究了电子回旋共振等离子体技术沉积的氟化非晶碳 (a_C :F)薄膜的电学性质 .发现对于不同C_Fx 含量的薄膜 ,CC含量的增大对薄膜的导电行为具有不同的影响 .薄膜的直流I_V特性呈现I =aV bVn规律 ,是低场强区的欧姆导电和高场强区的空间电荷限流 (SCLC)组成的导电过程 .由于非晶材料的空间电荷限流与带尾态密度的分布密切相关 ,而a_C :F薄膜中CC的含量决定带尾态密度的分布 ,因此a_C :F薄膜在高场下的空间电荷限流是由薄膜中 CC 决定的导电过程 .     

Economic design of integrated model of control chart and maintenance management

There are two key tools for the control of production processes — Statistical Process Control (SPC) and Maintenance Management (MM), which are traditionally separated (both in science and in business practice), even though their goals overlap a great deal. Their common goal is to achieve optimal product quality, little downtime and cost reduction by controlling variances in the process. Since single or separated parallel applications may not be fully effective, this paper discusses the integration of statistical process control and maintenance, and provides an integrated model of Control Chart (CC) and MM. A mathematical model is given to analyze the cost of the integrated model and the grid-search approach is used to find the optimal values of policy variables (n,h,L,k) that minimize hourly cost. Finally, a numerical experiment is conducted to investigate the effects of cost parameters on the solution of the design.     

一种构造三水平因子超饱和设计的准则和算法

在工业统计试验和其他科学试验中,常遇到因子个数多而所允许的试验次数少的情况,这时要用到超饱和设计,以前的文章仅研究了二水平因子的超饱和设计,本文对于三水平因子的超饱和设计提出了一种基于典则相关意义下的优良性准则和构造算法,并给出了试验次数为９和１８可分别安排到２６和３０个因子的三水平超饱和设计表。     

Stereochemical behavior of geminal and vicinal 77Se–13C spin–spin coupling constants studied at the SOPPA(CC2) level taking into account relativistic corrections

A systematic theoretical study of geminal and vicinal ⁷⁷Se–¹³C spin–spin coupling constants in the series of the open‐chain selenides and selenium‐containing heterocycles revealed that relativistic effects play an essential role in the selenium–carbon coupling mechanism, especially when the coupling pathway includes a triple bond, contributing to about 10–15% of their total values and noticeably improving the agreement of the calculated couplings with experiment. Both geminal and vicinal ⁷⁷Se–¹³C spin–spin coupling constants show marked stereochemical behavior as documented by their calculated dihedral angle dependence that could be used as a practical guide in stereochemical studies of organoselenium compounds. Copyright © 2014 John Wiley & Sons, Ltd.     

基于ZigBee的智慧温室蓄电池监测节点设计

针对传统温室监测节点蓄电池剩余电量问题,提出一种改进的基于ZigBee无线通信技术的温室节点无线监测方案,设计一个经济实用的低功耗ZigBee无线监测节点;以CC2530为主控芯片,通过控制不同的传感器和电池智能管理芯片DS2438及其外围电路,实现温室环境参数和各节点蓄电池电压、电流以及剩余电量的精确测量并实时显示;测试结果表明,系统运行稳定,数据检测精度达到0.001。     

Reprint of: Extreme point and halving edge search in abstract order types

Many properties of finite point sets only depend on the relative position of the points, e.g., on the order type of the set. However, many fundamental algorithms in computational geometry rely on coordinate representations. This includes the straightforward algorithms for finding a halving line for a given planar point set, as well as finding a point on the convex hull, both in linear time. In his monograph Axioms and Hulls, Knuth asks whether these problems can be solved in linear time in a more abstract setting, given only the orientation of each point triple, i.e., the setʼs chirotope, as a source of information. We answer this question in the affirmative. More precisely, we can find a halving line through any given point, as well as the vertices of the convex hull edges that are intersected by the supporting line of any two given points of the set in linear time. We first give a proof for sets realizable in the Euclidean plane and then extend the result to non-realizable abstract order types.     

聚L-白氨酸-碳纳米管修饰电极同时检测对苯二酚和邻苯二酚

用Nafion将单壁碳纳米管(SWCNT)固定到玻碳电极(GCE)上,再利用电化学聚合方法将L-白氨酸(L-LEU)聚合到SWCNT/GCE上,制备得到poly L-LEU/SWCNT/GCE修饰电极。采用循环伏安法(CV)、差分脉冲伏安法(DPV)和电化学交流阻抗法(EIS)研究了对苯二酚(HQ)、邻苯二酚(CC)共存时,二者在修饰电极上的电化学行为。结果表明:此修饰电极对HQ和CC有很好的电催化和分离作用。二者在修饰电极上的氧化还原峰电流与GCE相比显著增强,HQ和CC的氧化峰电位差和还原峰电位差分别为124 mV和131 mV。HQ和CC的检测线性范围分别为2.0×10-7~1.0×10-4、5.0×10-7~1.0×10-4mol/L。检出限分别为8.0×10-8、1.0×10-7mol/L。制备的修饰电极重现性、稳定性良好。在模拟废水中采用该修饰电极对HQ和CC进行检测,结果满意。     

Molecular dynamics simulation of high-pressure densification of fluorozirconate glass

Molecular dynamics simulations have been performed for a fluorozirconate glass and its model crystals in order to investigate the mechanism of the peculiar high-pressure densification phenomenon of the glass. All the polymorphs and the pressure-induced phase-transition of the model crystals were satisfactorily reproduced. The changes in the density, the F⁻ coordination number and the connectivity of ZrF_n polyhedra during the compression-decompression process are investigated under the glassy state. The density increases under high pressure, accompanying the increases in the coordination number and the connectivity. The effect of annealing treatment near T_g is also investigated. The effect was significant around 20 GPa, around which a maximum was found in the treatment-pressure dependence of density after decompression, only for the samples with the annealing treatment before decompression.     

Validation of an analytical method to determine sulfamides in kidney by HPLC-DAD and PARAFAC2 with first-order derivative chromatograms

Six sulfamides were extracted from kidney and analysed by high-performance liquid chromatography with diode array detection (HPLC-DAD): sulfadiazine, sulfamethazine, sulfamethoxypyridazine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline.Two main difficulties arose in identifying and quantifying the analytes. Firstly, the chromatographic peaks of the matrix interferences overlapped with those of the analytes. The uniqueness property of PARAFAC2 solved this problem. Secondly, the gradient elution caused a baseline drift. The first-order derivative of the chromatograms minimized its effect.The analytical method was validated. As the performance criteria detailed in the European Decision 2002/657/EC are based on specific signals, this paper generalizes those criteria for higher-order and non-specific signals. In this sense the proposed methodology is general and can be applied to any chromatographic method (HPLC or GC) with a detector that provide a multivariate signal (MS, DAD, EC, etc.).