大气气溶胶性质及其卫星遥感反演

论述了大气气溶胶的物理性质(含微物理性质)、化学性质及光学性质,特别是黑碳气溶胶的物理、化学和光学性质及其对气候强迫作用和对人居环境的影响,同时对光化学形成的二次气溶胶进行了简要介绍.指出一般气溶胶具有负气候强迫效应,而黑碳气溶胶具有较强的正气候强迫效应.在分析影响气溶胶性质的各种因素时发现,气溶胶性质除受外在环境因素影响外,也受内在的自身因素的相互影响.对卫星遥感气溶胶的原理及其在卫星遥感反演中气溶胶多种性质间复杂的相互关系进行了论述,并针对未来气溶胶的研究提出建议.      

黑磷纳米片制备、表征及其对斜生栅藻的毒性效应

黑磷纳米片（Black Phosphorus nanosheets,BPNSs）具有广泛的应用前景,而关于BPNSs的安全性研究还十分匮乏.为探究BPNSs对水生生物的毒性作用,本研究通过液相剥离法制备得到厚度为（58.05±36.48） nm,横向尺寸为（541.25±176.22） nm的BPNSs,选择初级生产者斜生栅藻（Scenedesmus obliquus）为受试生物开展了毒性效应研究.将斜生栅藻暴露于0、10、50、100 mg·L^-1 BPNSs中,结果表明：各浓度的BPNSs均抑制斜生栅藻的生长,120 h时的EC₅₀为74.86 mg·L^-1;与对照组相比,各处理组叶绿素a （Chlorophyll a）含量降低且呈剂量-效应关系,表明BPNSs对斜生栅藻光合系统产生了损害;暴露48 h后3个处理组的活性氧（Reactive oxygen species,ROS）含量显著升高,表明BPNSs对斜生栅藻造成了氧化损伤;显微观测（100×）发现处理组的藻细胞被BPNSs包裹,表明BPNSs可能通过吸附作用团聚在斜生栅藻表面;场发射电子扫描显微镜（FE-SEM）观测发现处理组的藻细胞形态受到显著破坏,表明BPNSs对斜生栅藻产生了物理损伤.本实验结果能够为后续BPNSs在水环境食物链中的潜在富集风险相关研究提供理论支撑.     

土壤生态系统中黑碳研究的几个关键问题

因人类活动的影响,全球大气C02浓度自1750年以来呈现逐步上升的趋势。农业生产活动与气候变化紧密相关,因土地利用方式的改变以及高度集约化的粮食、食物生产等农业活动都有可能增加CO2等温室气体的排放。如何遏制和减少大气中的CO2浓度是当前的热点问题,黑碳这一物质形式有可能为这一问题的缓解或解决提供新途径。生物质黑碳是生物质材料在低氧或无氧状态下经热裂解而形成的一种富含碳元素的有机连续体,其中碳（C）元素的含量高达70％-80％,并且大多以稳定的芳香环形式而存在。人类生存环境中所形成黑碳的80％以上最终都要归于土壤,且由于其较强的抗分解能力而长期滞留于土壤环境中。利用黑碳的这些特性及其碳封存能力,实施积极而有效的土壤管理措施,有可能增加土壤生态系统中的碳储存,从而为人类社会应对全球气候变化提供新的机遇。在文献资料调研的基础上,描述了土壤中黑碳的来源及其增加土壤碳储存、减缓陆地生态系统碳循环的潜力;阐释了量化土壤中黑碳的重要性以及精确测定土壤黑碳含量的关键所在;揭示了黑碳在土壤环境中的稳定性,探讨了外源黑碳与土壤本体有机碳的相互作用关系,并分析了黑碳对土壤温室气体排放的影响及其不确定性。揭示这些问题有助于客观评价黑碳能否作为一个有效的土壤有机碳库,也益于明确黑碳在全球碳循环以及中国农业减排过程中的作用与地位。     

磁芬顿处理酸性黑10B模拟废水的实验研究

研究不同磁化时间、磁场强度和催化氧化各种影响因素下芬顿试剂对酸性黑10B染料模拟废水的去除率。结果表明:对于100mL酸性黑10B染料模拟废水,在pH=3,FeSO4.7H2O=500mg,H2O2=0.4mL条件下,反应20min,COD去除率达90.3%。外加磁场磁场强度为427.8mT的作用下,磁化反应20min,COD的去除率提高了3.7%。     

The dilemma of pest suppression in the conservation of endangered species

In the conservation of endangered species, suppression of a population of one native species to benefit another poses challenges. Examples include predator control and nest parasite reduction. Less obvious is the control of blood-feeding arthropods. We conducted a case study of the effect of native black flies (Simulium spp.) on reintroduced Whooping Cranes (Grus americana). Our intent was to provide a science-driven approach for determining the effects of blood-feeding arthropods on endangered vertebrates and identifying optimal management actions for managers faced with competing objectives. A multiyear experiment demonstrated that black flies reduce nest success in cranes by driving incubating birds off their nests. We used a decision-analytic approach to develop creative management alternatives and evaluate trade-offs among competing objectives. We identified 4 management objectives: establish a self-sustaining crane population, improve crane well-being, maintain native black flies as functional components of the ecosystem, and minimize costs. We next identified potential management alternatives: do nothing, suppress black flies, force crane renesting to occur after the activity period of black flies, relocate releases of cranes, suppress black flies and relocate releases, or force crane renesting and relocate releases. We then developed predictions on constructed scales of 0 (worst-performing alternative) to 1 (best-performing alternative) to indicate how alternative actions performed in terms of management objectives. The optimal action depended on the relative importance of each objective to a decision maker. Only relocating releases was a dominated alternative, indicating that it was not optimal regardless of the relative importance of objectives. A rational decision maker could choose any other management alternative we considered. Recognizing that decisions involve trade-offs that must be weighed by decision makers is crucial to identifying alternatives that best balance multiple management objectives. Given uncertainty about the population dynamics of blood-feeding arthropods, an adaptive management approach could offer substantial benefits.     

Interactive effects of O3 exposure on California black oak (Quercus kelloggii Newb.) seedlings with and without N amendment

We examined the short-term separate and combined effects of simulated nitrogen (N) deposition (fertilization) and ozone (O(3)) exposure on California black oak seedlings (Quercus kelloggii Newb.), an ecologically important tree of the San Bernardino Mountains downwind of Los Angeles. Realistic concentrations of O(3) were found to cause statistically and biologically significant negative effects on plant health, including lowered photosynthetic ability, lowered water use efficiency, and increased leaf chlorosis and necrosis. When subjected to abrupt changes in light levels, O(3)-exposed plants showed both a slower and smaller response than O(3)-free plants. Fertilized plants exhibited a significantly greater pre- to post-treatment decline in A at saturated [CO(2)] and a significantly lower level of post-treatment chlorosis than unfertilized plants. Fertilization tended to reduce plant sensitivity to O(3).     

离子液体负载型分子筛的制备及对染料的吸附

为了有效地处理活性黑染料废水,对离子液体负载型分子筛去除水中的活性黑染料进行了研究。首先制备了离子液体负载型吸附材料,分别考察了分散剂种类、离子液体加入量、浸渍时间3种因素对离子液体负载率的影响,确定负载工艺条件为:二氯甲烷作为分散剂、[OMim]BF4离子液体与分子筛质量比1∶2,浸渍时间12 h。其次研究了负载型吸附材料对染料废水的处理效果,考察了吸附材料添加量、溶液pH值、吸附时间对模拟废水活性黑染料去除率的影响,确定吸附工艺条件为:[OMim]BF4离子液体为最佳离子液体、吸附材料添加量0.40 g、pH=6、吸附时间12 h。在此最佳工艺条件下,染料去除率达98.23%。     

电炉炼锡废渣制备白炭黑

以电炉炼锡废渣为原料,经过酸浸处理去除Fe元素后,再用沉淀法制备白炭黑。探索了制备白炭黑的最佳工艺条件。分别采用XRD、FTIR、SEM及粒度分析等技术表征了白炭黑产品的物相、形貌、粒径及其分布。实验结果表明,制备白炭黑的最佳工艺条件为:Na OH溶液浓度8 mol/L、固液比1∶10(干燥废渣质量与Na OH溶液体积比,g/m L)、搅拌速率300 r/min、反应温度90℃、反应时间6 h。在最佳工艺条件下制备的白炭黑产品中Si O2质量分数达92.8%。表征结果显示,所制备的白炭黑产品是由近似球形的颗粒聚集而成的无定形非晶体水合二氧化硅,粒径为95~200 nm的颗粒约占87.5%。     

Ti_5O_9-Ti_4O_7电极电化学处理2,4,6-三硝基苯酚废水

采用压片-烧结法制备了Ti5O9-Ti4O7电极,采用XRD和SEM技术对Ti5O9-Ti4O7电极进行了表征。以自制的Ti5O9-Ti4O7电极为阳极,电解处理含2,4,6-三硝基苯酚(TNP)的模拟废水,考察了电流密度、电解质质量浓度、废水p H、废水温度和反应时间等因素对废水COD去除率和TNP降解率的影响。表征结果显示:该电极的主要成分为Ti5O9,并含有部分Ti4O7;该电极的比表面积较大。Ti5O9-Ti4O7电极电解处理含TNP废水的最佳实验条件为:电流密度20 m A/cm2、电解质Na2SO4质量浓度6.0 g/L、废水p H为7、废水温度30℃。在此最佳条件下电解反应180 min后,COD去除率为90.6%,TNP降解率为93.9%,表明Ti5O9-Ti4O7电极具有较高的催化能力和电流效率。     

秸秆黑碳的制备及吸附特性

基于前期实验确定在氮气保护3种温度(550、650和750℃)制备秸秆黑碳,并用XRD、SEM对其结构、形貌进行了表征,研究它对吡唑酮废水中铵盐吸附去除效果.结果表明,650℃秸秆黑碳改变了晶体的有序度和结晶度,断面微孔道分布疏松均匀规则,具有较大的比表面积,而且有一定数量的纳米级黑碳颗粒;它的吸附特性优于750℃和550℃的秸秆黑碳,吸附率最高为95.31％;650℃秸秆黑碳最佳吸附工艺:吸附温度和饱和时间分别为35℃和4h,吸附振荡频率为100r/min.秸秆黑碳的吸附速率快、适用条件宽是处理铵盐废水的良好材料.