摘要：This paper investigates analysis and design of Low-Density Parity-Check （LDPC） coded Bit Interleaved Coded Modulation （BICM） over Additive White Gaussian Noise （AWGN） channel. It focuses on Gray-labeled 8-ary Phase-Shift-Keying （8PSK） modulation and employs a Maximum A Posteriori （MAP） symbol-to-bit metric calculator at the receiver. An equivalent model of a BICM communication channel with ideal interleaving is presented. The probability distribution function of log-likelihood ratio messages from the MAP receiver can be approximated by a mixture of symmetric Gaussian densities. As a result semi-Gaussian approximation can be used to analyze the decoder. Extrinsic information transfer charts are employed to describe the convergence behavior of LDPC decoder. The design of irregular LDPC codes reduces to a linear programming problem on two-dimensional variable edge-degree distribution. This method allows irregular code design in a wider range of rates without any limit on the maximum node degree and can be used to design irregular codes having rates varying from 0.5275 to 0.9099. The designed convergence thresholds are only a few tenths, even a few hundredths of a decibel from the capacity limits. It is shown by Monte Carlo simulations that, when the block length is 30,000, these codes operate about 0.62-0.75 dB from the capacity limit at a bit error rate of 10s.

摘要：以深圳某水质净化厂为研究对象,考察AOA耦合MBBR工艺对实际生活污水的处理效果,验证投加MBBR填料对AOA工艺的促进作用。结果表明,AOA耦合MBBR工艺取得了较好的处理效果,在不投加外碳源的条件下COD、NH_(4)^(+)-N、TN、TP平均出水浓度分别为17.65、0.28、3.58、0.21 mg/L,平均去除率分别为93.15%、98.89%、91.07%、93.24%。耦合工艺在冬季较冷的不利时段有一定的正向作用,且对好氧段的促进作用明显。好氧段MBBR填料富集的专性微生物可强化AOA工艺的硝化作用,提升氨氮和总氮去除率。这为高密度城区水质净化厂的原位扩容改造提供了新的技术思路。

摘要：由于光照条件的变化和光伏组件的特性,大比例分布式光伏接入下光伏发电功率具有很强的波动性,使得净功率预测难度增加。因此,提出大比例分布式光伏接入下电网台区净功率预测方法。通过灰色关联分析法与余弦相似度结合方法,选取与待预测日功率数据最相似的历史日,将其作为时间预测模型的输入。使用AP聚类方法划分光伏电站群,获取待预测光伏电网台区所在的光伏电站群,并将其作为空间预测模型的输入。基于ATT-LSTM和LSSVM方法,设计具有时空关联性的光伏电网台区净功率组合预测模型,将获取的两项功率数据输入至组合模型内,实现分布式光伏接入下电网台区净功率预测。实验结果表明,所提方法的电网台区净功率预测准确度高、整体应用效果好。

摘要：Selective coupling of methyl radicals to produce C_(2) species(C2H4 and C2H6)is a key challenge for oxidative coupling of methane(OCM).In traditional OCM reaction systems,homogeneous transformation of methyl radicals in O_(2)‐containing gases are uncontrollable,resulting in limited C_(2) selectivity and ***,we demonstrate that methyl radicals generated by La_(2)O_(3)at low reaction temperature can selectively couple on the surface of 5 wt%Na2WO4/SiO_(2).The controllable surface coupling against overoxidation barely changes the activity of La_(2)O_(3)but boosts the C_(2)selectivity by three times and achieves a C_(2)yield as high as 10.9%at bed temperature of only 570℃.Structure‐property studies suggest that Na_(2)WO_(4) nanoclusters are the active sites for methyl radical *** strong CH_(3)·affinity of these sites can even endow some methane combustion catalysts with OCM *** findings of the surface coupling of methyl radicals open a new direction to develop OCM *** bifunctional OCM catalyst system,which composes of a methane activation center and a CH_(3)·coupling center,may deliver promising OCM performance at reaction temperatures below the ignition temperature of C2H6 and C2H4(~600℃)and is therefore more controllable,safer,and certainly more attractive as an actual process.

摘要：本文基于现代创意家具设计实例分析,将其创新点进行分类,总结出现代家具创意构思的不同方法,从创意家具设计的空间性、艺术性、文化性等多方面进行剖析,这将有助于我们在家具创意中拓展设计的创新点,从而满足人们对现代家具多元化的审美及情感需求。

摘要：A new series of diaryl urea derivatives bearing N-acylhydrazone moiety were designed and synthesized. All the target compounds were evaluated for their antiproliferative activities against human leukemia cell line （HL-60）, human lung adenocarcinoma epithelial cell line （A549） and human breast cancer cell line （MDA-MB-231） in vitro by standard MTT assay. The pharmacological results indicated that some compounds exhibited promising antitumor activities. Compound 1j showed the most potent antiproliferative activity against the tested three cell lines with IC50 values of 0.13 μmol/L, 0.7 μmol/L and 0.5μmol/L, respectively.

摘要：在本文中，笔者尝试运用产业经济学的一些基本原理就视听新媒体出现后对广电产业结构、产业关联、产业组织、产业博弈，产业安全，产业布局、产业政策等方面可能产生的影响做一些探讨。为了讨论问题方便，文章中把广告、网络、节目制作、相关服务业等称作产业。

摘要：在人类的所有精神元素中,只有体育运动始终伴随着身体的强健与衰弱,这一切的历史和文化线索都深深印刻在人类身体之中,身体铭刻下了体育运动的历史片段。转向于身体视野的人类应该首先关注和捕捉体育运动的历史路径,身体与体育运动的哲学关系就是主仆之间最为信赖和忠诚的情感联系和道德依附。体育运动对于身体的关注,转向于竞技身体、艺术身体视野之中,希望从身体哲学中寻找到体育运动的哲学线索。

摘要：本文简述了旅游出版物形态设计在旅游业中的地位与作用,在调研的基础上分析了北京当前旅游出版物形态设计的发展与现状,就存在的问题提出了相应的对策。

摘要：采用整体磁通路径规划与部件设计相结合的设计方法,得出一种基于挤压工作模式的双线圈磁流变阻尼器。阻尼器在设计形成闭合磁回路基础上,综合考虑磁场性质、磁路性质、阻尼器结构特征以及三者之间的相互作用和对磁回路的反馈作用,得出初始结构参数;采用模拟退火算法对关键参数进行多目标优化,使阻尼器综合性能达到最优,总结得出磁流变阻尼器的设计方法。通过多维度磁场测量实验台对油膜工作面处磁场进行测量,验证了不同激励电流下双线圈磁流变阻尼器的测量值与仿真值吻合性良好。最后,将优化后的双线圈磁流变阻尼器引入到转子系统中,搭建了磁流变阻尼器支承下转子实验台,进行磁流变阻尼器支承下转子系统不平衡响应试验,发现适合的电流作用下,磁流变阻尼器可为转子系统提供有效的阻尼,大幅抑制转子系统在临界转速附近的振动幅值;在过大的电流作用下,磁流变阻尼器的刚度效应起主要作用,其会限制磁流变阻尼器间隙中的油膜挤压作用,进而削弱磁流变阻尼器的阻尼效应。该研究为磁流变阻尼器的设计提供了一定的指导,并具有潜在的应用价值。