深埋储层水对吡咯类含氮化合物的蚀变作用

深埋地质体中广泛分布着储层水,在一定的温度和压力下,水可能会与吡咯类含氮化合物发生一定程度的有机氮—无机氧化学交换。对吡咯与水反应体系的热力学问题进行了探讨,发现当温度高于373.15K时,热力学上吡咯与水就可能发生反应。随着温度升高,反应过程正向进行程度增大,即从热力学的角度看,升高温度对反应有利。利用高温高压模拟装置对吡咯与水反应体系进行了初步的模拟实验研究,通过气相色谱和傅立叶变换红外光谱等分析手段对实验结果进行了进一步验证。结果表明,吡咯和水能够发生化学反应,主要生成呋喃和氨气。研究结果为探讨影响深埋储层中吡咯类含氮化合物保存与分布的有机—无机相互作用机制,提供了热模拟实验依据。     

An experimental investigation of Stichococcus sp. cultivation conditions for optimal co-production of carbohydrates,proteins and lipids following a biorefinery concept

In this study, a Taguchi design of experiments was employed to systematically investigate the effect of five selected process input variables (i.e., illumination flux, aeration rate, CO₂ supply rate, NaNO₃ -nitrogen source-concentration and salinity) on the cultivation profile of Stichococcus sp. The process response variables were the concentrations of biomass, carbohydrates, proteins, lipids and total products. Through a sensitivity analysis study, aeration was found to have the major effect on biomass growth and carbohydrates accumulation. On the other hand, the production of proteins and total products was significantly affected by NaNO₃, while the lipids accumulation was triggered primarily by CO₂. From the statistical analysis of the experimental data, a regression model was developed, correlating the concentrations of biomass and biochemicals with the process input variables. Three individual operating policies, maximizing the concentrations of either biomass-carbohydrates, or proteins-total products, or lipids, were simulated and experimentally verified. The second operating policy complies more with the operation of a potential biorefinery plant. Under this strategy, the cultivation of Stichococcus sp. resulted in biomass and total products concentrations equal to 3.20 and 2.51 g L⁻¹, respectively. The mass fractions of these biochemicals with respect to the dry biomass were: carbohydrates 40.63%, proteins 26.25% and lipids 11.56%.     

Statisticians as innovation leaders

Innovation leading to business growth is increasingly important in many industries. We discuss the unique roles that statistics and statisticians can play in facilitating and leading innovation efforts. Many of the statistical tools to improve quality can also be used to generate more business value through innovation. We also believe that many applied statisticians are especially well positioned to drive and even lead innovation efforts. For statisticians to be successful in leading innovation, they will need to strengthen their skills beyond what they have traditionally needed in the past, but we believe this will be worth the effort.     

CO-OFDM系统中一种改进的基于线性内插的相位噪声补偿算法

为补偿CO-OFDM系统中相位噪声引起的干扰,提出了一种改进的基于线性内插的相位噪声补偿算法.该算法利用共轭导频估计相位噪声的均值,然后通过线性内插获得相位噪声的估计值,最后通过频域补偿来恢复出调制信号.此外针对求幅角的非线性运算中存在的相位周跳的问题,文章提出的修正方法能够有效地改善周跳情况的发生.分析与仿真表明:该算法在不同线宽条件下均能提升一定的SNR增益且算法的复杂度低.     

晋东南-荆门特高压线路保护浅析

介绍了晋东南—南阳-荆门特高压交流1000kV试验示范工程的线路、变压器、电抗器、断路器等保护的配置情况,重点分析了特高压线路保护联跳三相新功能的技术要求和厂家实现该功能的保护逻辑,论述了采用纵联标识码后光纤差动保护和光纤纵联距离保护在通道自环、同步采样、通讯时钟等通讯方式的设定方法,简要介绍了特高压经高阻接地故障的新特点,并对比分析了南瑞继保和四方线路保护实现上述功能的异同和有别于超高压线路保护的特点。     

Effect of the friction riveting process parameters on the joint formation and performance of Ti alloy/short-fibre reinforced polyether ether ketone joints

The feasibility of friction riveting on short carbon fibre-reinforced thermoplastic polymers was investigated in this work. A design of experiments (DoE) was used to investigate the impact of rotational speed, friction time, friction pressure and forging pressure on joint formation and performance. The joint formation was studied using the mushrooming efficiency, the rivet penetration depth and the mechanical energy input. The tensile pull-out force was used to describe the mechanical performance of the investigated metallic-insert joints made of grade 3 titanium and short carbon fibre-reinforced polyether ether ketone (PEEK). All samples were scanned with X-rays before any mechanical testing to acquire the dimensions of the anchored rivet inside the reinforced polymer, elucidating their correlations with the mechanical performance. The DoE model can be used to tailor joint formation and performance. A parameter-set that improves the pull-out performance was determined using an analysis of variance. The analysis revealed that high rotational speed, friction time and forging pressure caused high pull-out forces. The metallic-insert joints reached high pull-out tensile strength between 6.3 kN and 10.7 kN. The dimensions of the deformed metallic rivet were correlated with the mechanical performance of the joint: the larger the widening of the rivet tip, the higher the pull out force was. Furthermore, widening of the rivet tip by 70% led to the maximal tensile pull-out force (10.7 kN), corresponding to the base material strength of the titanium rivet (10.7 kN). At this threshold value (70%), the failure mode also changed from failure mode III (pull-out of rivet) to failure mode I (rivet failure).     

Application of inserts for suppression of coupled dynamic–acoustic effects during confined granular flow in silos

The paper discusses methods to prevent coupled dynamic–acoustic effects during silo flow by means of inserts. Laboratory tests were carried out with a perspex and steel model silo with different inserts along the wall. As bulk solids, sand, polymer granulate and PET flakes were used. An effective method for a reduction of dynamic–acoustic phenomena during silo flow was elaborated. It was verified in large metal silos.     

Design and analysis of an outpatient orthopaedic clinic performance with discrete event simulation and design of experiments

Considering that demand for healthcare services is constantly increasing, outpatient services must improve their performance. Being able to satisfy the demand with a limited outpatient service capacity is an important operational challenge. The objective of our research consists in studying the relationships and interactions between patient flows, resource capacity (number of consulting rooms and number of nurses) and appointment scheduling rules in order to improve an outpatient orthopaedic clinic performance. Discrete event simulation is used to model outpatient flows. An experimental design was developed to test how to assign consulting rooms and nurses to each orthopedist considering four appointment scheduling rules and three patient flow types of varied complexity. Analysis of variance and the Tukey test are used to evaluate the simulation results. Our conclusion is that in order to improve the outpatient orthopaedic clinic performance, resources (consulting rooms, nurses) and appointment scheduling rules must be adapted to the different patient flows.     

Multi-response non-parametric profiling using Taguchi's qualimetric engineering and neurocomputing methods: Screening a foaming process in a solar collector assembly

Taguchi's data programming techniques in synergy with data analysis tactics based on artificial neural networks have been fruitful in illuminating intricate manufacturing phenomena. We present a non-parametric approach to treat multi-response multi-factorial datasets created with Taguchi's orthogonal-array samplers. Replicated response datasets are compressed utilizing the signal to noise ratio and then they are homogenized by simple rank-ordering. The multiple response layout is reduced to the more tractable uni-response arrangement by using the super-ranking concept to enact the fusing of the individual responses. The ‘ranked-and-fused’ dataset is subjected to conversion by linear and three-layer perceptrons. The performance of a group of examined effects is assessed according to the perceptrons’ sensitivity analysis output. Using Wilcoxon's one-sample test, statistical significance is assigned to the accumulated ranking scores obtainable from a series of independent perceptron runs. We discuss the efficiency status for each of the two engaged perceptron options on affecting prediction accuracy as well as the influence of data fusion on the SNR-compressed datasets. Our robust neurocomputing solver is elucidated in a concurrent screening of three foam characteristics which are encountered in popular solar-collector assembly operations. Seven controlling factors were profiled and it was found that the temperature of the polyol additive is the sole statistically predominant effect. Finally, through our industrial paradigm, we illustrate the superiority of the fusing principle for downsizing stochastically multiple characteristics and thus gaining faster and more accurate perceptron predictions. We show that the proposed method outperforms the outcomes obtained by the desirability analysis. We identify the points of superiority to the crisper resolution in locating effect dominance accompanied with recovered stochastic significance.     

基于CDMA导频信号的动目标探测方法

论述了一种利用CDMA下行导频信号进行动目标探测的方法。根据CDMA导频信号良好的无源探测性能,通过在时频域内对实时数据进行长时间相干已积累来提取目标信息,给出了一个基于单接收机的实验系统,并通过该系统完成了动目标的多普勒频率和距离检测。实验结果证明了CDMA信号用作无源探测是可行的。