基于机器视觉的FPC角度定位算法的研究

自动上料设备在柔板的加工工艺中起着极为重要的作用,由于柔板的特性和加工工艺要求,基于视觉定位的自动上料设备成为了主流,而视觉定位中,主要任务是获得工件相对于标准位置的偏移量以及偏转角度,其中偏转角度对精度的影响很大,成为定位研究的难点和关键点。在对上料过程中定位的重要性论述后,重点分析推导了角度定位算法,为以后的工程应用奠定了理论基础。     

深部找矿钻探施工工艺与方法

介绍了在老矿区深部进行找煤所采用的工艺与方法,即在采空煤层井段采用风动潜孔锤钻进方法进行施工,在钻穿采空煤层后在深部采用绳索取心钻进方法施工。对施工中遇到的技术问题所采用的方法及取得的经验与教训进行了阐述。     

Magnetic Properties of Co 2D Antidot Arrays with Hexagonal Holes Using Colloidal Crystal Template Method

In this work, Co_2D antidot arrays with well-ordered hexagonal holes ranging in size from 1.3 to 6.2 lm were fabricated by colloidal crystal template method. The geometry configuration and magnetic properties of the samples were investigated. An enormous increase in coercivity and squareness, as compared with the corresponding continuous film, was observed. Magnetic properties of Co_2D antidot arrays showed a close dependence on pore diameter. According to geometric calculation, the effect of the pore diameter on magnetic properties was also discussed. The Co_2D antidot arrays obtained by this method are promising candidates for high-density information storage.     

质谱技术在食物过敏原检测中的研究进展

食物过敏是当前食品安全领域比较突出的问题,相应的过敏原检测方法研究也越来越受重视。相比于传统的免疫学检测方法,质谱技术在检测加工后以及复杂基质中的食物过敏原中,具有高通量和高灵敏性等优点,被广泛应用于食物过敏原的检测。本文主要从定性和定量2方面介绍了质谱技术在食品过敏原检测中的研究进展。相关研究对牛乳、鸡蛋、小麦和榛子(坚果类)等主要食物过敏原均有涉及。在定性研究中,以肽质量指纹图谱法和肽碎片离子鉴定法为主,鉴定食物中的过敏原蛋白。在定量研究中,通过标记/无标记技术,也能够实现对微量的目标蛋白进行相对/绝对定量。质谱技术应用于食物过敏原检测中,将有助于提升过敏原检测能力,降低食物过敏安全风险。     

Monitoring multi-class pesticide residues in fresh grape by hollow fibre sorptive extraction combined with gas chromatography–mass spectrometry

A fast and sensitive multi-residue analysis method is reported for simultaneous determination of 25 pesticides of chemical classes which are spiked into fresh grape. The sample pretreatment method involves extraction and clean-up in one step with SiO₂ hollow fibre from 1.0 mL fresh grape slurry to minimise the matrix effects, and determination by gas chromatography–mass spectrometry with selective ion monitoring mode. The validation of the optimised method in terms of linearity, precision, recovery and repeatability showed that the proposed procedure is sensitive (the limits of detection were in the range of 0.0009–0.0084 μg mL⁻¹ for 25 pesticides), precise and repeatable (average recoveries were between 61% and 108% with relative standard deviations from 4.0% to 12.4 %). The proposed method was also applied to the analysis of these groups of pesticides in fresh grape sample purchased from the local markets of Lanzhou (China), while no residues of the selected pesticides were detected in the sample.     

基于孟塞尔色理论的产品调和配色研究

通过对孟塞尔色立体的分析,对产品色彩设计评价环节进行研究,以孟氏色系调和理论为基础,通过色力矩和审美度计算等方式,构建了色彩设计计算机评价的基础平台.     

Diversifying Top-k Routes with Spatial Constraints

Journal of Computer Science and Technology - Trip recommendation has become increasingly popular with the rapid growth of check-in data in location-based social networks. Most existing studies...     

Ammonium removal by a novel magnetically modified excess sludge

Disposal of nitrogen nutrient and excess sludge is a keen concern in wastewater treatment plants. This study describes a simple method of preparing an economical adsorbent, i.e., magnetic excess sludge (MES) by compounding the excess sludge with Fe₃O₄ nanoparticles. Ammonia–nitrogen removal from simulated wastewater was investigated by using the MES as an adsorbent. The MES had an adsorption efficiency of up to 90% for ammonium removal. Highly efficient separation of adsorbed ammonium on the MES could be magnetically separated from wastewater within 30 s. The operating conditions for ammonium adsorption were optimized at MES dose of 20 g/L, initial ammonium concentration of 45 mg/L and operating temperature of 298–308 K. The equilibrium data of ammonium adsorption on the MES showed a good agreement with the Langmuir isotherm, while the kinetic data were best fitted by the pseudo-second-order model. FTIR analysis indicated that various functional groups, such as hydroxyl and carboxyl groups, existed on the surface of the MES and contributed to the excellent capability for ammonium adsorption. These results suggest that the MES is a promising candidate for removing ammonium from wastewater and recycling excess sludge to ease its disposal at low cost.     

低相噪全相参毫米波频率合成源研究

研制出一种小步进全相参毫米波频率合成源.本振部分,对直接数字式合成频率、参考分频比和环路分频比进行三重调节,抑制了直接数字频率合成的杂散,提高了频率分辨率;发射部分,采用二次混频电路,避免了调谐电压预置,简化了电路,并保证了发射信号和本振信号相参.该系统输出在Ka频段,带宽400MHz,步进<1MHz.测试相噪<-90dBc/Hz@10kHz、-97dBc/Hz@100kHz,杂散为-60dBc,跳频时间<15us.     

高压级涡轮的气动优化设计改型

蒸汽轮机高压级涡轮多为低展弦比直叶型设计,此类涡轮的二次流损失占整个流动损失的比重较大,现在的设计技术能够较好地设计出优秀的S1面叶型,但较难把握全三维的二次流损失。文中通过对单级某高压级涡轮导叶的优化设计改型,得到了较好的控制二次流损失的全三维直叶型。结果表明:最优全三维直叶型不是最优S1面叶型,二次流损失在流动中比重较大,设计中不容忽视;采用优化设计的方法,能够非常有效地提供最优直叶型,缩短设计周期。