Preparation of the Biomass-based Magnetic Composite Adsorbent and Its Application in Wastewater Treatment

随着近代工业的迅猛发展，染料废水及重金属废水对生态环境和人类健康带来广泛而持久的危害。作为生物质的一类，农林废弃物具备廉价、比表面积大和官能团丰富的特点，其作为吸附剂在水处理中的应用得到了广泛研究，其中酸改性农林废弃物提高其吸附性能是当前的研究热点，但酸改性后所产生的滤液一般被直接排放，容易造成二次污染。本研究利用磷酸（phosphoricacid，PA）改性笋壳（bambooshootshell，BSS）后所得滤液中的酸溶纤维（BSSfiber，BSSF）与壳聚糖（chitosan，CS）和Fe3O4粉末共混均匀并经过三聚磷酸钠（sodiumtripolyphosphate，STPP）交联后...With the fast development of modern industry, wastewater pollution of dyes and heavy metals is becoming more and more serious, causing a series of environmental and health problems. Agricultural and forestry waste (AFW), one category of biomass, is suitable for water treatment because of its low cost, large specific surface area and abundant functional groups. Acid modified AFW as an adsorbent use...学位：工学硕士院系专业：化学化工学院_工程硕士(化学工程)学号：2062013115149

Study on Classification and Identification of Time Series Stationarity

平稳性检验是时间序列回归分析的一个关键问题,已有的检验方法在处理海量时间序列数据时显得乏力,检验准确率有待提高。采用分类技术建立平稳性检验的新方法,可以有效地处理海量时间序列数据。首先计算时间序列自相关函数,构建一个充分非必要的判定准则;然后建立序列收敛的量化分析方法,研究收敛参数的最优取值,并提取平稳性特征向量;最后采用k-means聚类建立平稳性分类识别方法。采用一组模拟数据和股票数据进行分析,将ADF检验、PP检验、KPSS检验进行对比,实证结果表明新方法的准确率较高。Stationarity test is a key problem of time series regression analysis,existing methods of stationarity test can hardly deal with the massive data,the test accuracy needs to be improved.Based on the analysis of classification,this paper would build a new method for stationarity test,which could effectively deal with massive time series data.Firstly,it calculates the autocorrelation function and then construct a fully and non-necessary criterion;secondly,establish a kind of quantitative analysis of sequence convergence,the optimal value of the sequence convergent parameter is given out,and then take out the characteristic of stationarity;finally,the k-means clustering algorithm is used to establish stationarity classification and recognition method.This paper makes empirical analysis with a set of simulated data and agroup of stock data,which results show that our method's accuracy is not only higher than that of the ADF test,and than that of KPSS test and PP test.教育部青年基金项目《海量金融时间序列数据平稳性检验方法研究》(13YJCZH044

Study on the Indirect Determination of Chitosan by Square Wave Voltammetry

建立了以茜素红(AR)为电活性探针方波伏安法间接测定无电活性的壳聚糖(CS)的新方法。在0 1mol/LHAc＿NaAc(pH4 5)缓冲溶液中,AR与CS＿AR在GCE上均能形成一准可逆的吸附伏安峰(Vpc=-0 46V,Vpa=-0 41V)。实验表明,CS在低浓度(1 25×10-8～2 5×10-7mol/L)和高浓度(2 5×10-7～1 25×10-5mol/L)的条件下对体系的峰电流分别具有线性增敏和减敏效应。采用标准加入法测定了不同样品中壳聚糖的含量,其回收率在97 33%～102 00%之间,结果满意。广西壮族自治区自然科学基金资助项目(0141037;0342018

Semi-Random Linear Network Coding for Cloud Storage Redundancy

为了实现数据冗余备份,根据云存储的结构特点和可用性要求,提出半随机线性网络编码(SRLNC)算法,使用有限域GF(2~s)上的单位行向量和随机行 向量组成编码矩阵,对数据块分片、编码后进行冗余存储,采取单位行向量优先的策略进行解码. 分析了该算法的解码方程组存在唯一解的概率,并提出衡量算法运算时间的"每字符运算次数"指标. 实验结果表明,新算法在解码过程的运算时间随结点可用性的增加以指数级减少,当冗余度≤3且结点的可用性≥0.8时,比随机线性网络编码算法的编码运算时 间快33%以上,比解码运算时间快5倍以上,适合应用于"一次写多次读"的云存储系统.According to structural characteristics and availability requirements of cloud storage, a semi-random linear network coding (SRLNC) algorithm is proposed for data redundancy. The data block is split into pieces, encoded by coding matrix composed of unit row vectors and random row vectors on finite fields GF(2~s), stored in data nodes dispersedly. In decoding process, the data block can be restored with the strategy of unit row vectors priority. The probability of unique solution is analyzed for SRLNC decoding equations, a new operations per character index is defined to measure algorithm efficiency. Experiments prove that the operating time of the decoding process in the proposed algorithm exponentially reduces with the increase of the node availability. When the availability of each node≥0.8 and redundancy≤3, the encoding operation of the proposed algorithm is faster up to 33%, and decoding operation of the proposed is 5 times faster than that of random linear network coding algorithm, respectively. It is shown that the proposed algorithm is applicable to "write once read many" cloud storage system

利用微藻处理污水的研究进展

人类经济活动的发展使大量污水进入水体,导致水质恶化,破坏了生态系统的平衡。为降低水污染对生态环境的负面影响,开发经济高效的污染物治理技术迫在眉睫。基于微藻培养的污水处理技术具有环境友好和处理成本低等优点,逐渐替代了传统的物理化学处理法。总结了微藻在污水处理中的研究现状以及技术应用,阐述了微藻净化污水的机理,综述了微藻处理污水技术的发展及其与藻生物质生产偶联的研究现状以及工程实例,在净化污水的同时可获得微藻生物质,通过后续的加工可以生产各种具有经济效益的产品,实现了污水的资源化

空间引力波探测望远镜初步设计与分析/Preliminary design and analysis of telescope for space gravitational wave detection

引力波的直接观测已开启引力波天文学的新篇章,爱因斯坦的百年预言终获证实。空间引力波探测器使得探测0.1 m Hz~1 Hz频段丰富的引力波源成为可能,与地面引力波探测器互为补充,才可实现更加宽广波段的引力波探测,揭开宇宙早期的更多秘密。空间激光干涉引力波探测采用外差干涉测量技术,测量间距百万公里的两自由悬浮测试质量间10 pm量级的变化量。望远镜是激光干涉测量系统的重要组成部分,1 pm的光程稳定性及苛刻的杂散光要求,不同于传统的几何成像望远镜。本文根据空间太极计划任务需求,对望远镜的功能及技术要求进行了分析,并完成了原理样机的初步方案设计,针对百万公里远场波前分布,分析了望远镜系统的敏感性,同时完成了在轨光机热集成仿真,为后面原理样机的研制奠定了技术基础。 The direct detection of gravitational waves opens up a new era of gravitational wave astronomy,and 100-year-old prediction on gravitational wavers by Einstein have been confirmed ultimately. The space gravitational wave detector makes it possible to detect rich sources of gravitational waves in the 0.1 mHz-1 Hz band. The space gravitational wave detector and the ground gravitational wave detector complement each other,and the combination of the two methods can realize the detection of gravitational waves in a broader band,thus uncovering more secrets of the early universe. Spatial laser interferometry gravitational wave detection uses heterodyne interferometry to measure changes in the order of 10 pm between two free-floating test masses that are millions of kilometers apart. Telescope is an important part of the laser interferometry system. Unlike the traditional geometrical imaging telescope,the telescope of the laser interferometry system shall meet the requirements of optical path stability for 1 pm and that of a harsh stray light. Based on the mission requirements of the Taiji Program in Space,this paper analyzes the functions and technical requirements of the telescope and completes the preliminary design of the principle prototype. In this paper,the sensitivity of the telescope system is analyzed according to the wavefront distribution in the far field of one million kilometers. At the same time,the thermal integration simulation in orbit is completed,which lays the technical foundation for the development of the subsequent principle prototypes