不同施肥方式对玉米种植的影响之综合评价

本试验通过使用6种不同的肥料种植玉米来探究施肥方式对于减少农田地表径流氮磷流失作用,改善土壤结构及土壤重金属含量、提高玉米产量,增加农民经济收入的综合效益。试验结果表明:在等量氮肥情况下,化肥处理茎秆直径及穗位均处于较低水平,沼肥+生物炭处理的经济学产量与生物学产量均最高,“沼肥+生物炭”处理氮流失量最少,较化肥处理少61.24%,磷流失量较堆沤肥处理少144%;生物炭的吸附能力使土壤中Cr、Zn含量降低;不同肥料处理的利润为:“沼肥+生物炭”处理>全沼肥处理>“沼肥+化肥”处理>全化肥处理>空白处理>堆沤肥处理。通过环保指标、经济指标、生长指标综合评定,沼肥+生物炭、全沼肥以及“沼肥+化肥”3种模式最适用于星云湖流域,既可以保护流域环境、保证作物产量,还可以降低生产成本、增加农户收入。     

阿科蔓生态沟渠强化处理D-A~2O工艺出水研究

设计了1#(沉水型)、2#(挺水型)、3#(50%沉水型+50%挺水型)阿科蔓生态沟渠,分别强化处理分区进水式D-A2O装置出水。结果表明,3套阿科蔓生态沟渠连续运行30 d后启动成功;生态沟渠的阿科蔓最优配置为50%沉水型阿科蔓+50%挺水型阿科蔓,且其最佳HRT为9h。控制3#生态沟渠于最佳HRT、水温为(24±1)℃条件下运行,其对COD、TN、NH3-N、TP的平均去除率分别可达55.30%、57.78%、58.10%、54.08%。基于试验结果,阐明了3#阿科蔓生态沟渠所具有的双层分阶段多生物相特点和阿科蔓生态基的微孔结构是其污染净化能力较强的主要原因。     

Development of a methodology for cost determination of wastewater treatment based on functional diagram

This work describes a methodology developed for determination of costs associated to products generated in a small wastewater treatment station for sanitary wastewater from a university campus. This methodology begins with plant component units identification, relating their fluid and thermodynamics features for each point marked in its process diagram. Following, its functional diagram is developed and its formulation is elaborated, in exergetic base, describing all equations for these points, which are the constraints for exergetic production cost problem and are used in equations to determine the costs associated to products generated in SWTS. This methodology was applied to a hypothetical system based on SWTS former parts and presented consistent results when compared to expected values based on previous exergetic expertise.     

基于U盘下嵌入式Linux—iptables的防火墙设计与实现

在对现有防火墙技术分析的基础上,参加学校组织的《大学生创新性实验计划》项目的前提下,描述了一种基于嵌入式U盘Linux--iptables下的小型防火墙。网络管理员可以很方便地通过Linux启动计算机的U盘对其进行配置与管理。该系统具有很好稳定性与可扩展性,能很好地满足小型企业局域网的安全需求,并给出了基于U盘的防火墙的实现。     

重庆某萤石-重晶石矿浮选试验

重庆某萤石-重晶石矿BaSO₄和CaF2品位分别为52.57%、32.77%,主要目的矿物为重晶石、萤石,脉石矿物是方解石、石英和其他少量杂质,较为复杂难选。为回收利用矿石中的重晶石和萤石,进行了选矿试验。结果表明,相比重晶石优先浮选再浮选萤石流程,重晶石、萤石混合浮选-分离浮选原则流程指标更好。在磨矿细度-0.074 mm占75%、混合浮选以十二烷基硫酸钠为捕收剂,酸性水玻璃、栲胶和硫酸铝组合抑制剂,重晶石浮选以碳酸钠为调整剂、酸性水玻璃为抑制剂,萤石浮选以栲胶、硫酸铝、木质素磺酸钠和NaF为组合抑制剂、油酸为捕收剂,原矿经1粗1扫混合浮选-混合精矿1粗2精1扫重晶石优先浮选-重晶石浮选尾矿1粗4精1扫萤石浮选闭路流程选别,可获得产率52.44%、BaSO₄品位94.83%、回收率97.00%的重晶石精矿和产率30.33%、CaF₂品位90.06%、回收率82.86%萤石精矿,实现了可浮性相近的萤石、重晶石的有效分离,对类似矿石的开发利用具有一定的参考价值和指导意义。     

Glycerol as an efficient mesopore-controlling agent for synthesis of mesoporous-assembled TiO2 nanocrystals and their remarkable photocatalytic H2 production activity

In this work, the mesoporous-assembled TiO₂ nanocrystals were successfully synthesized by a modified sol–gel process under mild conditions with the aid of glycerol, which is a main by-product from biodiesel production via the transesterification of vegetable oils. The synthesized TiO₂ nanocrystals were characterized by various techniques, i.e. N₂ adsorption–desorption, SEM, high resolution TEM, and XRD. The characterization results clearly showed that the glycerol could behave as an efficient mesopore-controlling agent, which induced the mesoporous-assembled characteristic of the synthesized TiO₂ nanocrystals with very narrow pore size distribution. The synthesized mesoporous-assembled TiO₂ nanocrystals were applied for hydrogen production from the photocatalytic water splitting. The photocatalytic activity results revealed that the synthesized mesoporous-assembled TiO₂ nanocrystals possessed much higher hydrogen production activity than the commercially available P-25 TiO₂ and ST-01 TiO₂ powders.     

野生牛肝菌元素含量特征分析及其种类鉴别

野生牛肝菌的营养价值及暴露风险关系到消费者的健康安全,并严重影响其市场稳定和贸易出口。本文采用电感耦合等离子体原子发射光谱法和傅里叶变换红外光谱法测定8种野生牛肝菌429份样品中12种元素的含量和光谱数据,分析元素含量特征及食用健康风险,同时基于元素含量、红外光谱、初级融合和中级融合数据分别建立偏最小二乘判别分析和支持向量机(SVM)判别模型,比较其鉴别效果。结果显示:野生牛肝菌富含Ca、Mg、Na、Zn等矿质元素,适量摄入可以补充人体营养需求,同时也应当注意部分牛肝菌的Cd暴露风险;基于中级融合建立SVM判别模型,其训练集和预测集正确率均为100%,能够快速、准确鉴别牛肝菌种类,有效避免因误采误食导致的中毒事件发生。系统性的对牛肝菌进行元素含量分析、健康风险评估和种类鉴别,为其品质安全评估和资源的开发利用提供参考。     

吸附-生物膜理论对生物法净化气态污染物的研究

通过实验,开展了对生物膜填料塔净化甲苯、苯乙烯、CS2、甲醛、NOx等5种气态污染物的模拟研究。结果表明,除甲醛外,吸附-生物膜理论及其动力学模型对于描述生物膜填料塔对低浓度甲苯、苯乙烯、CS2、NOx等4种气态污染物的净化过程具有良好的适用性。对于随入口气体浓度变化模拟计算的各净化效率、出口浓度和生化去除量的模拟计算值与实验值之间具有良好的相关性,相关系数达到了0.92—0.99。     

Effect of surface manganese oxide species on soot catalytic combustion of Ce–Mn–O catalyst

Constructing cerium and manganese bimetallic catalysts with excellent catalytic performance for soot combustion is the research frontier at present. In order to find out the key factors for catalytic soot combustion of Ce–Mn–O catalysts, a series of Ce–Mn–O catalysts with different Ce/Mn proportions were prepared by co-precipitation method. The activity test results show that it increases first and then decreases with the increase of Mn content. The best catalytic activity is obtained for Ce_0.64Mn_0.36 catalyst, which shows a maximum rate temperature (T_m) at 306 °C for CO₂ production in TPO curve. Compared with non-catalytic soot combustion, the T_m decreases by more than 270 °C. Systematical characterization results suggest that when the adsorbed surface oxygen, lattice oxygen, specific surface area and total reduction amount of the catalysts reach a certain value, the key factors leading to the difference of catalytic activity become the readily reducible and highly dispersed surface manganese oxide species and contact performance of the external surface. The surface manganese oxide species is beneficial to improving the low-temperature reducibility of catalysts and the porous surface is conducive to the contact between catalyst and soot. Furthermore, for the soot combustion reaction containing only O₂, the promoting effect of Mn⁴⁺ is not obvious.     

基于敏感Native API的恶意软件检测方法

分析恶意软件传播与破坏的行为特征,包括进程、特权、内存操作、注册表、文件和网络等行为。这些行为通过调用相应的API函数来实现,为此,提出一种基于敏感Native API调用频率的恶意软件检测方法,采用Xen进行二次开发,设计对恶意软件透明的分析监测环境。实验结果表明,使用敏感Native API调用频率能够有效地检测多种未知恶意软件。