基于μC/OSⅡ的网络视频监控系统设计与实现

网络视频监控广泛应用于工业生产、国家安防及日常生活中,其融合了计算机、多媒体通讯及网络等多项技术,具有广泛的应用前景和研究价值.文章提出了一种基于嵌入式μC/OSⅡ的网络视频监控系统设计方案,解决了嵌入式操作系统移植困难的问题,着重论述了以视频编解码芯片和嵌入式芯片为终端的硬件平台及以操作系统μC/OSⅡ为服务器的软件平台的关键技术和实现方法.目前,该系统已成功应用于学科实验室,实践证明,此网络视频监控设计方案合理,运行稳定,对类似设计具有一定的参考价值.     

啤酒酵母吸附去除水中Cu(Ⅱ)的研究

通过以实验室培养的啤酒酵母作生物吸附剂对Cu（Ⅱ）进行了研究.结果表明：啤酒酵母对Cu^2＋的吸附是一个快速的过程,最佳pH为4,其等温吸附过程以Langmuir等温吸附模型拟合效果最好.此外,菌体用量也会影响啤酒酵母对的吸附效果,其经济的菌体用量浓度与Cu^2＋浓度比约为100：1.     

Adsorption and desorption of Cu(Ⅱ) and Pb(Ⅱ) in paddy soils cultivated for various years in the subtropical China

The adsorption and desorption of Cu(Ⅱ) and Pb(Ⅱ) on upland red soil,and paddy soils which were originated from the upland soil and cultivated for 8,15,35 and 85 years,were investigated using the batch method.The study showed that the organic matter content and cation exchange capacity (CEC) of the soils are important factors controlling the adsorption and desorption of Cu(Ⅱ) and Pb(Ⅱ).The 15-Year paddy soil had the highest adsorption capacity for Pb(Ⅱ),followed by the 35-Year paddy soil.Both the 35-Year paddy soil and 15-Year paddy soil adsorbed more Cu(Ⅱ) than the upland soil and other paddy soils.The 15-Year paddy soils exhibited the highest desorption percentage for both Cu(Ⅱ) and Pb(Ⅱ).These results are consistent with the trend for the CEC of the soils tested.The high soil CEC contributes not only to the adsorption of Cu(Ⅱ) and Pb(Ⅱ) but also to the electrostatic adsorption of the two heavy metals by the soils.Lower desorption percentages for Cu(Ⅱ) (36.7% to 42.2%) and Pb(Ⅱ) (50.4% to 57.9%) were observed for the 85-Year paddy soil.The highest content of organic matter in the soil was responsible for the low desorption percentages for the two metals because the formation of the complexes between the organic matter and the metals could increase the stability of the heavy metals in the soils.     

柠檬酸-Fe（Ⅱ）／K2S2O8降解泥水体系中敌草隆的研究

研究了泥水体系中柠檬酸-Fe（Ⅱ）／K2SO8降解敌草隆时各影响因子的作用机制,通过正交实验确定了反应的最佳操作条件为：K2SO8浓度为2．0mmol／L,Fe（Ⅱ）浓度为1．0mmol／L,柠檬酸浓度为0．5mmol／L,反应时间为120min,pH=7．0。此奈件下,0．1mmol／L敌草隆降解率可达97．6％。采用分子探针竞争实验鉴定了体系中产生的硫酸根自由基。     

表面活性剂对污染土壤中重金属Cu(Ⅱ)的洗脱试验研究

采用批平衡法比较研究了阴离子表面活性剂十二烷基苯磺酸钠(SDBS)、非离子表面活性剂辛基酚聚氧乙烯醚(TX100)及其混合物(SDBS-TX100)对土壤中铜的洗脱作用.重点研究了表面活性剂浓度、清洗时间、溶液pH值、土水比、无机盐等因素对洗脱作用的影响.结果表明,表面活性剂对Cu(Ⅱ)污染土壤的洗脱作用存在较大差异.当表面活性剂初始浓度相同时,单一SDBS较不同质量配比的混合SDBS-TX100和单一TX100洗脱效果好;6 000 mg.L-1SDBS对Cu(Ⅱ)的洗脱效率达到46.3%,分别是同浓度SDBS-TX100(3∶1)、SDBS-TX100(1∶1)、SDBS-TX100(1∶3)和单一TX100洗脱效率的5.8、10.8、10.8和19.3倍;1∶10土水比条件下,清洗时间为24 h时,各表面活性剂体系都达到最好清洗效果;溶液pH值对表面活性剂洗脱Cu(Ⅱ)有显著影响,随着溶液pH值升高,表面活性剂的洗脱能力逐渐下降,强酸性条件下(pH=1.50),洗脱率最高可达95%;土水比越小表面活性剂对土壤中Cu(Ⅱ)的洗脱效果越好;无机盐对表面活性剂的洗脱能力影响不大,但是过量Mg2+(浓度>500...     

Pb（II） biosorption using chitosan and chitosan derivatives beads： Equilibrium, ion exchange and mechanism studies

The study examined the adsorption of Pb(II) ions from aqueous solution onto chitosan, chitosan-GLA and chitosan-alginate beads. Several important parameters influencing the adsorption of Pb(II) ions such as initial pH, adsorbent dosage and di erent initial concentration of Pb(II) ions were evaluated. The mechanism involved during the adsorption process was explored based on ion exchange study and using spectroscopic techniques. The adsorption capacities obtained based on non–linear Langmuir isotherm for chitosan, chitosan-GLA and chitosan-alginate beads in single metal system were 34.98, 14.24 and 60.27 mg/g, respectively. However, the adsorption capacity of Pb(II) ions were reduced in the binary metal system due to the competitive adsorption between Pb(II) and Cu(II) ions. Based on the ion exchange study, the release of Ca2+, Mg2+, K+ and Na+ ions played an important role in the adsorption of Pb(II) ions by all three adsorbents but only at lower concentrations of Pb(II) ions. Infrared spectra showed that the binding between Pb(II) ions and the adsorbents involved mostly the nitrogen and oxygen atoms. All three adsorbents showed satisfactory adsorption capacities and can be considered as an e cient adsorbent for the removal of Pb(II) ions from aqueous solutions.     

北京西山采石场不同自然恢复期主要植物叶绿素荧光特征

本次调查中共记录到35种植物,其中矿区28种植物,非矿区27种植物。矿区和非矿区共有种有20种。测定同时出现在矿区及非矿区的8种植物的荧光动力学曲线,发现白莲蒿(A.sacrorum)、臭椿(Ailanthus altissima)、杠柳(Periplo-ca sepium)、黄栌(Cotinus coggygria)及荆条(Vitex negundo Var.Canna-bifolia)在矿区和非矿区生长状况差异不显著。胡枝子(Lespedeza bicolo)、酸枣(Ziziphus jujuba var.spinosa)及榆树(Ulmus pumila)在矿区生长良好,这说明矿区恶劣的土质条件虽然影响着一些植物的生长,但是良好的光照条件却为这些植物的生长提供更多的机会。     

铁掺杂介孔氧化硅-石墨化炭复合物对橙黄Ⅱ的吸附

利用水热法合成铁掺杂介孔氧化硅-石墨化炭复合物(Fe MS),并对其进行结构表征,发现其具有介孔结构,且高铁含量的Fe MS含有明显的石墨化炭物种.比较了传统吸附剂活性炭、SBA-15及Fe MS分别对橙黄Ⅱ的吸附性能,考察了初始p H、投加量、初始浓度、吸附时间对吸附的影响,并对吸附过程进行了动力学研究和吸附等温模型的模拟.结果表明:Fe MS对橙黄Ⅱ有很好的吸附性能,且高铁含量的Fe MS吸附量优于低铁含量;Fe MS吸附橙黄Ⅱ的最佳p H值为7,最高吸附量能达到1108 mg·g-1;初始浓度对橙黄Ⅱ吸附效率有明显的影响;对低浓度的橙黄Ⅱ,可在120 min内达到吸附平衡;Fe MS对橙黄Ⅱ的吸附动力学数据符合准二级动力学模型;Fe MS对低浓度橙黄Ⅱ的吸附符合Henry等温模型,饱和吸附量与橙黄Ⅱ的浓度有关.     

低浓度Fe(Ⅱ)和Mn(Ⅱ)催化氧化脱除烟气中SO2的研究

生物法烟气脱硫是一种新的脱硫工艺,不仅可以较好地解决SO2废气对环境的污染问题,而且将烟气脱硫与单质硫的生产联系在一起,能带来一定的经济效益。将生物法烟气脱硫过程分成两个阶段：SO2的吸收过程和含硫吸收液的生物脱硫过程。本文重点研究了第一阶段的SO2吸收过程。考察了温度、pH值对SO2的吸收的影响,水溶液中低浓度的Fe(Ⅱ)和Mn(Ⅱ)对SO2的催化氧化,以及低浓度的Fe(Ⅱ）和Mn(Ⅱ)协同催化氧化SO2,并初探了引入甲醇和亚纳米SiO2颗粒作为添加剂对脱硫的影响及其机理。     

TiO_2/活性炭的微波制备及其对橙黄Ⅱ染料的光催化降解

采用微波辐射法制备TiO2/活性炭(TiO2/AC)复合光催化剂,并利用该催化剂对橙黄Ⅱ进行光催化降解。考察了乙醇与钛酸丁酯(TNB)的体积比,水、乙酸和活性炭的加入量,微波功率,微波辐射时间,煅烧温度等因素对TiO2/AC催化活性的影响,确定了制备TiO2/AC的最佳工艺条件以及TiO2/AC光催化降解橙黄Ⅱ的工艺条件。结果表明,制备TiO2/AC的最佳工艺条件为:乙醇与钛酸丁酯(TNB)体积比为8∶1(即乙醇24 mL,钛酸丁酯3 mL),水、乙酸和活性炭的加入量分别为0.8mL、0.6 mL和2 g,微波功率500 W,微波辐射时间1 min,煅烧温度500℃,煅烧时间为2 h。在TiO2/AC用量为0.3 g、反应时间为1 h、pH为3的条件下,25 mg/L橙黄Ⅱ溶液的降解率达95%以上。