Further evidence of nuclear reactions in the Pd/D lattice: emission of charged particles

Almost two decades ago, Fleischmann and Pons reported excess enthalpy generation in the negatively polarized Pd/D-D₂O system, which they attributed to nuclear reactions. In the months and years that followed, other manifestations of nuclear activities in this system were observed, viz. tritium and helium production and transmutation of elements. In this report, we present additional evidence, namely, the emission of highly energetic charged particles emitted from the Pd/D electrode when this system is placed in either an external electrostatic or magnetostatic field. The density of tracks registered by a CR-39 detector was found to be of a magnitude that provides undisputable evidence of their nuclear origin. The experiments were reproducible. A model based upon electron capture is proposed to explain the reaction products observed in the Pd/D-D₂O system.

铅在棉秆基活性炭上的吸附动力学与热力学

以棉秆与棉秆纤维为原料,利用磷酸活化法制备了低成本的高比表面微孔棉秆基活性炭,通过静态实验研究了活性炭对水溶液中铅的吸附特性,测定了溶液pH值、吸附时间、溶液温度对吸附的影响,探讨了吸附动力学、热力学及吸附机制.根据低温液氮(N2/77K)吸附测定数据,以BET方程、BJH法及H-K法对活性炭孔结构进行了表征,以Boehm滴定、FTIR、零电荷点pHPZC测定及元素分析定量表征活性炭表面含氧官能团.结果表明,以棉秆和棉秆纤维为原料制备的活性炭的比表面积分别为1570和1731m2·g-1,含氧酸官能团含量分别为1.43和0.83mmol·g-1,均高于商业活性炭ST1300.静态吸附实验表明,棉秆基活性炭对铅有较大的吸附容量和吸附效率,最大吸附量超过120mg·g-1,溶液pH对吸附有较大的影响,吸附量随时间增大而增大,在5min内可达饱和吸附量的80%;吸附动力学数据符合假二级方程,Freundlich方程能更好地描述等温吸附行为;热力学研究表明,吸附吉布斯自由能(ΔG0)0,而焓变(ΔH0)0,说明吸附为吸热的自发反应过程,升温有利于吸附,离子交换可能在吸附过程中起了重要作用.     

夏秋季石家庄大气污染变化特征观测研究

研究了石家庄夏秋季节大气污染状况及2008奥运前后大气污染物浓度变化特征.2007和2008年夏秋季节,使用全自动在线观测仪器对石家庄大气环境质量进行连续监测,目的是阐明奥运期间石家庄污染物减排对当地大气环境的改变,探讨石家庄地区产生的大气污染物对北京及周边地区可能的影响.结果表明,除了氮氧化物,其他污染物均有超标情况出现,其中夏秋季节O3浓度较高,小时最大浓度值平均(O3-Max)分别为(177.2±63.0)和(105.8±61.7)μg·m-3,NO和NO2在夏秋季节的浓度分别为(4.5±4.0)、(32.7±12.4)μg·m-3和(21.5±16.9)、(60.5±16.9)μg·m-3,SO2浓度分别为(72.0±27.5)和(92.0±44.4)μg·m-3,PM2.5和PM10浓度达到(102.3±47.6)、(153.3±58.3)μg·m-3和(95.8±50.0)、(147.4±67.0)μg·m-3;奥运期间各类污染物浓度显著下降,NOx、O3-Max、SO2、PM2.5和PM10浓度分别为(43.8±15.0)、(142.0±54.9)、(52.4±18.8)、(76.7±35.1)和(116.5±38.8)μg·m-3,其中SO2、PM2.5和PM10分别较2008年监测期间平均值降低34.6%、22.8%和21.0%.本研究系统分析了夏秋季节石家庄大气污染状况,为评估当地大气污染控制措施提供了科学依据.     

The recycling cycle of materials as a design project tool

Currently, a large number of companies consider recycling of materials as an opportunity to maximize profits and to reduce the environmental impact generated by these materials after they are disposed. However, there is also a strong constraint on the use of recycled materials mainly due to the lack of technical/scientific information, which would relate their physical properties to their recycling cycle. This information should be used in the initial phase of the product design to serve as reference for the simulation of a project to point out the physical properties obtained from recycling the Projected material (Pm). Thus, it would be possible to foresee some recycling strategy to keep the good characteristics of recycled materials by encouraging their use, regardless of the product to be designed.Therefore, the Recycling Cycle of Materials (RCM) is a tool that provides scientific/technical support in the selection of materials. It uses the information related to the physical properties of the Pm as a parameter for product design after five recycling cycles. For the case study, this tool has been applied to obtain the basic material of ABS/PC blend. Subsequently, this blend was evaluated using DSC, FTIR, traction and impact methods to obtain delimiting data for the definition of the mechanical properties resulting from the application of RCM.     

北京转河河岸带生态修复对河流水质的影响

以北京转河为例,探讨一系列河岸带生态修复措施(尤其是河漫地和护岸的改造)对河流水质的影响.于2009年7～9月进行实地调查,沿河岸选取13个采样点,并定期采集水样,测定其中营养物质和溶解氧(DO)等的浓度.结果表明,转河氨氮(NH4+-N)、硝氮(NO3--N)、总磷(TP)和DO的浓度均有非常明显的季节变化.在居民用...     

Arbuscular mycorrhizal fungi alter the response of growth and nutrient uptake of snap bean（Phaseolus vulgaris L.） to O_3

The effects of arbuscular mycorrhizal fungi (AMF) Glomus mosseae on the responses to elevated O3 in growth and nutrition of snap bean (Phaseolus vulgaris L. cv Guangzhouyuan) were investigated. Exposure was conducted in growth chambers by using three O3 concentrations (20 (CF), 80 (CFO1) and 120 nL/L (CFO2); 8 hr/day for 75 days). Results showed that elevated O3 slightly impacted overall mycorrhizal colonization, but significantly decreased the proportional frequency of hypha and increased the proportional frequency of spores and vesicles, suggesting that O3 had significant effects on mycorrhizal structure. Elevated O3 significantly decreased yield, dry mass and nutrient contents (N, P, K, Ca and Mg) in both non-mycorrhizal and mycorrhizal plants. However, significant interactive effects were found in most variables due to that the reduction by O3 in the mycorrhizal plants was less than that in the non-mycorrhizal plants. Additionally, AMF increased the concentrations of N, P, Ca, and Mg in shoot and root. It can be concluded that AMF alleviated detrimental effects of increasing O3 on host plant through improving plant nutrition and growth.     

Photocatalytic activity of Fe-doped CaTiO3 under UV-visible light

The photocatalytic degradation of methylene blue（MB） over Fe-doped CaTiO3 under UV-visible light was investigated. The as-prepared samples were characterized using X-ray diffraction（XRD）, scanning electron microscope（SEM） equipped with an energy dispersive spectrometer（EDS） system, Fourier transform infrared spectra（FT-IR）, and UV-visible diffuse reflectance spectroscopy（DRS）. The results show that the doping with Fe significantly promoted the light absorption ability of CaTiO3 in the visible light region. The Fe-doped CaTiO3 exhibited higher photocatalytic activity than CaTiO3 for the degradation of MB.However, the photocatalytic activity of the Fe-doped CaTiO3 was greatly influenced by the calcination temperature during the preparation process. The Fe-doped CaTiO3 prepared at500°C exhibited the best photocatalytic activity, with degradation of almost 100% MB（10 ppm）under UV-visible light for 180 min.     

Fast increasing of surface ozone concentrations in Pearl River Delta characterized by a regional air quality monitoring network during 2006-2011

Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone(O3), NO2and total oxidant(Ox) were analyzed by both linear regression and cluster analysis. A fast increase of regional O3concentrations of 0.86 ppbV/yr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0.61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories – rural stations(non-urban) and suburban/urban stations. The O3concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime(13%/yr referred to 2006 level) was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3production is mainly volatile organic compounds(VOC)-controlled. However, the photochemical O3production is sensitive to both NOx and VOC for O3pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.     

粉煤灰负载Fe2O3脱除气态单质汞的试验研究

在固定床反应器中研究了利用燃煤电厂固废粉煤灰(FA)负载Fe2O3所制备的Fe2O3/FA催化剂对气态Hg0的脱除情况,发现Fe2O3/FA具有较高的脱除Hg0的能力.同时,考察了Fe2O3负载量、温度、空速、Hg0浓度、烟气成分等对Fe2O3/FA脱除Hg0的影响.结果表明,Fe2O3/FA对Hg0的脱除能力随Fe2O3负载量(1%~10%)的增加和温度(120~200℃)的升高而增强;Fe2O3/FA在较低的空速和Hg0浓度条件下表现出了更高的脱除Hg0的活性;HCl和O2促进了Fe2O3/FA对Hg0的脱除,而SO2和H2O抑制了Fe2O3/FA对Hg0的脱除.逐级化学提取实验结果证实,Fe2O3将Hg0氧化为Hg2+的化合物并吸附在FA上,这是Fe2O3/FA具有较高的脱除Hg0能力的原因.     

Cu-Al2O3中骨架铜类芬顿催化去除水中有机污染物

为解决传统铁基芬顿催化剂在水体通常酸碱(pH6)条件下活性低的问题,采用简单共沉淀法制备了Cu掺杂的Al_2O_3类芬顿催化剂.通过X射线衍射(XRD)、X射线光电子能谱(XPS)和紫外可见(UV-vis)吸收光谱分析表明,Cu-Al_2O_3中铜掺杂的质量分数低于4.77%时,催化剂中铜主要以Cu~(2+)和Cu~+的形式共存于Al_2O_3的骨架结构中,形成Al—O—Cu键;过量的铜掺杂会导致外骨架铜物种如铜氧化物团簇的存在.以难降解有机污染物2-氯苯酚(2-chlorophenol,2-CP)和染料罗丹明B(Rhodamine B,Rh B)为目标污染物,对Cu-Al_2O_3的类芬顿催化性能进行了详细地研究.结果表明,骨架铜物种在中性温和条件下对2-CP和Rh B显示出很高的催化去除效率和稳定性,反应2 h,Cu-Al_2O_3(Cu质量分数4.77%)对2-CP的去除率达到54%,相应的TOC去除率达到49%,而铜离子溶出浓度仅为0.025 5 mg·L-1,而Cu-Al_2O_3(Cu质量分数7.58%)由于外骨架铜的存在导致催化活性增加缓慢和稳定性下降.ESR测试结果表明,·OH和HO_2~-/O_2~-·是反应中主要的活性物种.