Saccharide production is critical to the devel-opment of biotechnology in the field of food and biofuel.The extraction of saccharide from biomass-based hydro-ly
Industry and academia have been making great ef-forts in improving refresh rates and resolutions of display de-vices to meet the ever increasing needs of consum
A sequent is a pair(Γ,△),which is true under an as-signment if either some formula in Γ is false,or some formula in △ is true.In L3-valued propositional log
针对目前奈奎斯特采样方式对信号进行采集所产生的数据量较大的问题,提出一种基于压缩感知并结合神经网络的滚动轴承故障信号检测方法,通过K-奇异值分解算法构造冗余字典,利用神经网络以映射后观测矩阵的前一部分值预测全部观测值,实现信号的二次压缩,最终利用子空间追踪算法基于预测出的观测矩阵对信号进行重构,通过重构信号频谱可获得轴承故障信息.经过对测量矩阵、算法参数及神经网络等内容的分析,可在较少的数据量下以较高精度实现对滚动轴承故障信息的提取,并通过仿真对比实验证明了方法的有效性,在总压缩比为0.72~0.92时,
持续雾霾天气给北京电网在新形势下的安全可靠运行提出了污染新问题与安全新挑战.为研究雾霾天气下北京地区外绝缘积污特性及其对电网输变电设备的影响,本文通过研究北京地区
采用高温固相法一步合成掺杂钠型碳包覆Li1-xNaxMnPO4纳米材料,利用现代仪器分析手段表征了材料的物相、形貌和晶体结构,并考察了其作为锂离子电池正极材料的电化学性能. XRD分析结果表明,钠的掺杂没有改变LiMnPO4材料的橄榄石型正交结构,样品的结晶度好、纯度较高;SEM分析结果显示,随着钠含量的增加,样品粒径逐渐减小,当钠含量为20%时,颗粒直径减小到50 nm;TG分析结果说明,在样品制备过程中采用550℃的煅烧温度完全可行;B
Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater.Herein,
为了提升基本Boost变换器的电压增益,降低开关器件电压应力,提出一种基于耦合电感倍压的有源开关电感高增益变换器。变换器中两个耦合电感的原边组成有源开关电感结构,并引入二极管-电容支路作为无源钳位回路用来吸收漏感能量。利用变换器漏感等效电路模型分析了变换器工作模态,采用伏秒积平衡方法推导得到了变换器电压增益,并给出开关管和二极管电压应力。分析表明,两个耦合电感倍压单元可提升变换器的电压增益,耦合电感匝数比越大、耦合度越大,电压增益也越高,开关管的电压应力也越低。实验样机测试结果验证了理论分析的正确性,表明
Hydrogen fuel has been embraced as a potential long-term solution to the growing demand for clean energy.A membrane-assisted separation is promising in producin
We demonstrate the fabrication of a new DNA sensor that is based on the optical interactions occurring between oligonucleotide-coated NaYF4:Yb3+;Er3+upconversio