计算机仿真方法在冷库电梯系统的应用研究

通过建立某电梯系统的动力学模型及状态方程，设计了一个具有普遍意义的仿真程序并利用此程序对电梯实例进行提速改造的模拟仿真，结果呈现低衰减率自由振动形态，有关参数均满足GB10058—1997和ISO2372等规定的要求；同时计算出系统固有频率的取值也在许可范围．从理论上论证了改造电梯是安全可靠的．     

采用压滤脱水提取井下粉矿的节能效果

介绍了利用压滤脱水提取矿山井下水仓粉矿技术及其节能效果，值得在各矿山推广应用。     

Theory revision with queries: Horn, read-once, and parity formulas

A theory, in this context, is a Boolean formula; it is used to classify instances, or truth assignments. Theories can model real-world phenomena, and can do so more or less correctly. The theory revision, or concept revision, problem is to correct a given, roughly correct concept. This problem is considered here in the model of learning with equivalence and membership queries. A revision algorithm is considered efficient if the number of queries it makes is polynomial in the revision distance between the initial theory and the target theory, and polylogarithmic in the number of variables and the size of the initial theory. The revision distance is the minimal number of syntactic revision operations, such as the deletion or addition of literals, needed to obtain the target theory from the initial theory. Efficient revision algorithms are given for Horn formulas and read-once formulas, where revision operators are restricted to deletions of variables or clauses, and for parity formulas, where revision operators include both deletions and additions of variables. We also show that the query complexity of the read-once revision algorithm is near-optimal.     

水源水质受DEHP污染的粉末活性炭吸附处理工艺

采用含邻苯二甲酸二(2-乙基己基)酯(DEHP)的试验水样模拟城市取水水源发生DEHP水污染事故,测定粉末活性炭(PAC)对水样中DEHP的吸附性能,考察PAC炭种、吸附时间、DEHP初始浓度和PAC投加量等因素对DEHP的吸附量和脱除率的影响。试验结果表明:木屑PAC具有较大的比表面积,对DEHP具有良好的吸附效果,适用于DEHP水污染的应急处理。应急处理一般的DEHP水污染事故,DEHP污染浓度超标10～30倍时,PAC吸附DEHP的最佳条件为:吸附时间120 min,PAC投加量为20～80 mg/L,PAC对DEHP的吸附过程符合Henry等温式。     

Bijective Composite Mean Value Mappings

We introduce the novel concept of composite barycentric mappings and give theoretical conditions under which they are guaranteed to be bijective. We then focus on mean value mappings and derive a simple procedure for computing their Jacobians, leading to an efficient GPU‐assisted implementation for interactively designing composite mean value mappings which are bijective up to pixel resolution. We provide a number of examples of 2D image deformation and an example of 3D shape deformation based on a natural extension of the concept to spatial mappings.     

Omnidirectional autonomous entry guidance based on 3-D analytical glide formulas

An autonomous entry guidance law is developed based on 3-D analytical glide formulas, where the downrange formula is used to plan the longitudinal reference profile in order to meet the downrange and final energy requirements, and the crossrange formula is used to regulate the bank reversals in order to eliminate the crossrange error. As the analytical glide formulas ignore the effects of the Earth׳s rotation, a series of strategies is proposed for compensating these effects, which provides the guidance with the capability of steering the hypersonic glide vehicle with high Lift to Drag ratio (L/D) to any place of the world accurately. The compensation strategies can be summarized into two parts: (1) the reference profiles are properly adjusted by roughly evaluating the effects of the Earth׳s rotation on the aerodynamic profiles over the whole flight, which can compensate most of the effects; (2) the current effects are accurately evaluated and then the guidance commands are slightly modulated for compensating the remaining effects. Due to careful design, the strategies will not result in drastic changes in the Angle of Attack (AOA) and can keep the bank angle almost constant during most of flight.     

A simple and sensitive aptasensor with rolling circle amplification for viable Cronobacter sakazakii detection in powdered infant formula

Cronobacter sakazakii is a foodborne, emerging opportunistic pathogen that causes severe bacteremia, necrotizing enterocolitis, and sepsis with a mortality rate of up to 80%. In this study, we developed a simple and sensitive fluorescent turn-off aptasensor with rolling circle amplification assay for viable C. sakazakii detection in powdered infant formula. The results showed that the proposed aptasensor has good performance and specificity for detecting viable C. sakazakii in pure culture and powdered infant formula samples within 3 h. Under the optimal reaction conditions, there is a linear relationship between fluorescent intensity at 490 nm and logarithmic concentration of C. sakazakii in the range of 2.7 × 10⁵ to 2.7 × 10² cfu/mL, with a limit of detection of 2.7 × 10² cfu/mL in pure culture. The proposed aptasensor achieved a recovery of 104 to 111% in pure culture, and 96 to 107% in spiked powdered infant formula samples. The proposed aptasensor does not require complicated DNA extraction steps or antibodies, and can be performed at 37°C, making it a convenient and sensitive strategy for C. sakazakii detection.     

Column solid‐phase extraction of sunset yellow and spectrophotometric determination of its use in powdered beverage and confectionery products

A new and simple solid‐phase extraction method for the determination of trace levels of sunset yellow has been developed on Diaion HP 2MG column system. The adsorbed sunset yellow on the resin was eluted with 3 mL of methanol and determined by UV–Vis spectrophotometry at 484 nm. Various experimental parameters such as pH, amount of sunset yellow, flow rates of sample and eluent solutions, resin amount, sample volumes, etc. were investigated. The influences of some alkali, alkali earth and transition metals on the recoveries of sunset yellow were investigated. The recovery values for sunset yellow were higher than 95%. Preconcentration factor was found as 150. The detection limit (three sigma) of the reagent blank for sunset yellow was 5.2 μg L^?1. The relative standard deviations (RSD) of the procedure were found as 3.9%. The validation of the presented procedure was performed by the method of standard addition. The procedure was successfully applied to the determination of trace levels of sunset yellow in powdered beverage and confectionery products.     

基于爱尔兰B表和Excel公式的GSM基站自动配置工具

简要回顾了话务理论。根据爱尔兰B表、Excel公式组合,结合作者的实际工作经验,给出了GSM网络在已知基站配置的情况下,自动计算一个BSC话务量、信道数、载频数、小区数的工具。     

铁精粉环境中圆形料场堆取料机的设计与应用

冶金行业的铁精粉属于大密度的散状物料,目前其存储大多采用露天条形料场的形式,存储过程中存在严重的物料浪费和环境污染问题。本文将在煤炭行业广泛应用的圆形料场系统引入到铁精粉环境中,详细介绍了铁精粉环境中的圆形料场堆取料机设计的关键点、运行工艺、使用维护等。实际工程应用表明,该系统可以很好地运用在铁精粉环境中,减少了铁精粉的浪费,并降低对环境的污染。