Xα21基因导入水稻及转基因植株的鉴定

以水稻愈伤组织为受体、质粒pCXK1301为Xα21基因供体,用农杆菌EHA105和PDS－1000／He基因枪转化受体,经Hyg浓度梯度筛选,获得一些转基因水稻植株,GUS检测、PCR扩增和Southern杂交分析表明,报告基因（GUS）、选择标记基因（Hyg^r）和抗白叶枯病基因Xα21都已整合入转化水稻基因组中,Southern杂分析显示了Xα21基因在转化水稻基因组中整合的拷贝数。田间接菌鉴定表现抗白叶枯病。     

城市土地低碳利用模式的变革及路径

随着城市化进程的加快,城市土地开发利用呈现出膨胀式的扩展,特别是在"高消耗、高排放、高污染"的城市发展模式下,不仅造成社会碳排放量快速增长,而且造成城市土地的"碳汇"功能减弱,致使气候变暖、人居环境日益恶化。论文采用文献分析法和综合归纳法,从城市土地的利用结构、空间布局、利用规模与方向等方面,分析城市土地利用模式所存在的问题,结合城市化发展中的土地资源利用、碳排放、生态环境现状,阐述城市土地低碳利用模式构建的必要性,进而探讨构建城市土地低碳利用模式的路径。认为:应从"减排"和"增汇"两方面着手,培育城市土地低碳利用观念,科学规划城市土地的功能分区,构建生态化土地利用模式,形成"政府主导、市场适应、公众参与"的城市土地低碳利用决策机制与模式,从而变革传统的城市土地利用模式,实现城市建设发展的低碳化。     

Effects of medetomidine, a novel antifouling agent, on the burrowing bivalve Abra nitida (Müller)

The effects of medetomidine, a novel antifouling candidate, on the burrowing bivalve Abra nitida were studied. The burrowing behaviour, sediment reworking activity and faeces production were assessed after 24 h exposure of A. nitida to sublethal concentrations of medetomidine. Medetomidine caused a significant decrease in the burrowing response and in the sediment reworking activity. The median effective concentrations (EC50) were 430 nM (86 microg/l) and 4.4 nM (0.9 microg/l), respectively. No effects on the faeces production were detected. Although significant effects of medetomidine on A. nitida were registered, a reversibility of the effects was observed when 24 h-exposed animals were incubated in clean seawater and sediment for 24 h. Considerations relating to the future commercialisation of medetomidine for antifouling purposes are discussed.     

Negative effects of humic acid addition on phytoremediation of pyrene-contaminated sediments by mangrove seedlings

Vegetated (with Kandelia candel seedlings) and non-vegetated mangrove microcosms were employed to remove pyrene from contaminated sediments, and the effects of adding 6.7% humic acid (HA) on such removal were investigated. At the end of 6-month treatment, residual pyrene concentrations in surface sediments (0-2 cm) of the contaminated microcosms reduced from an initial 5.82 to 0.63 microg g(-1) dw, and the reduction was less in HA amended microcosms with the residual pyrene concentration remained at 3.12 microg g(-1) dw. The pyrene removal percentages in microcosms with HA amendment were 29% for surface aerobic sediments and 41% for bottom (anaerobic) sediments, while the respective removal percentages in microcosms without HA amendment were 89% (surface sediments) and 53% (bottom sediments). Microcosms planted with K. candel seedlings had a significantly higher pyrene removal when compared to the non-vegetated ones, and the average removal percentages were 70.9% and 61.4%, respectively. However, when humic acid was added, no significant difference was found between vegetated and non-vegetated microcosms in pyrene removal, both had less than 40% removal, probably because plant growth in humic acid amended contaminated microcosms, in terms of total biomass, was reduced by 50%. Roots of K. candel could accumulate pyrene from contaminated microcosms, and pyrene concentrations in roots harvested from microcosms with and without humic acid addition were 6.01 and 3.46 microg g(-1) dw, respectively. These results suggest that the addition of HA to contaminated sediments decreased the mangrove microcosm's ability to remove pyrene as pyrene was more tightly bound to the organic matter and plant growth was reduced.     

基于物化生化耦合的污水深度脱氮除磷新工艺

为了解决常规污水处理技术无法进行完整的硝化反硝化过程,污水厂出水中氨氮、总氮、总磷偏高以及运行成本较高的问题,以某污水厂排水为研究对象,通过物化与生化耦合,构建化学催化生物耦合床(CCBF)脱氮系统,研究CCBF系统对污水厂排水中氨氮、总氮、总磷和COD的去除效能。结果表明：当DO为5.5~6.0 mg·L⁻¹、RT为8 h、C/N为1.5∶1时,CCBF可将${\rm{NH}}_4^{+} $-N从48.5 mg·L⁻¹降至4.58 mg·L⁻¹、TN从51.2 mg·L⁻¹降至6.5 mg·L⁻¹、TP从6.6 mg·L⁻¹降至0.48 mg·L⁻¹、COD从78.5 mg·L⁻¹降至33 mg·L⁻¹,去除率分别达到89.5%、85.7%、92.5%和57.9%;污水经处理后,氨氮、总氮、总磷、COD均达到城镇污水处理厂污染物排放标准(GB 18918-2002)一级A排放标准。利用Eckenfelder方程对系统脱氮过程进行模拟,求得${n_{{\rm{NH}}_4^ +{\text{-}} {\rm{N}}}} $=0.314 76,n_TN=0.282 21,${K_{{\rm{NH}}_4^ +{\text{-}} {\rm{N}}}} $=0.128 02,K_TN=0.218 59,与水力负荷为0.000 8~0.007 m³·(m²·min)⁻¹的常规生物处理相比,系统内部生物量充足、活性高,物化与生物耦合强化效果明显。     

污泥生物炭对土壤中Pb和Cd的生物有效性的影响

以污泥为原料,在500 ℃缺氧条件下制备污泥生物炭,结合X射线能谱（EDS）、环境扫描电镜（SEM）和红外光谱（FTIR）等表征手段,分析添加污泥生物炭后污染土壤pH和Pb与Cd化学形态的变化来探究污泥生物炭对土壤中Pb、Cd的固定效果,并用盆栽方式评估添加污泥生物炭对小青菜生物量及体内重金属含量的影响。结果表明：添加污泥生物炭后,污染土壤的pH随平衡时间的延长显著升高;对于单一污染土壤和复合污染土壤,污泥生物炭对Pb和Cd均有较强的固定作用,而污泥生物炭在复合污染土壤中对Pb的固定效果优于在单一污染土壤中;添加污泥生物炭能提高小青菜的生物量,且能有效降低小青菜对污染土壤中Pb和Cd的吸收。     

挣扎与妥协:农村家庭缘何陷入能源贫困“陷阱”

生活能源改进是实现农村低收入家庭福利提升的关键环节之一,而资产的贫困为能源的消费造成了约束,使低收入农户难以实现能源的改进以脱离贫困现状。该文借助"贫困陷阱"的定义,将这种受制于资产贫困的能源使用困境称为能源贫困"陷阱",并从农户心理视角考察了低收入家庭更容易陷入能源贫困的原因。基于2015年中国综合社会调查(CGSS)数据,对能源贫困线进行了重新计算,认为我国现阶段农村能源贫困线应为户均600 kgce/a,并发现不论在任何能源贫困线下,收入偏低农户的能源贫困发生率、能源贫困深度和强度均远高于中高收入农户。基于此,该文同时从消费量和消费倾向两个方面估计了家庭经济状况对能源贫困的影响,结果表明:相对于中高收入农户,收入偏低农户的能源消费呈现出"既未省钱又未增效"的非经济理性特征,其能源消费负担实际更重,而消费结构却更为低效。进一步地,运用中介效应模型对这一非经济理性决策进行了解释,考察了心理因素在能源贫困"陷阱"形成中的作用,结果发现:收入偏低农户更容易表现出消极心理状态,负面的情绪和对未来的悲观预期使其在能源决策中更倾向于选择传统能源,而不愿做出能源改进的尝试。这种消极心理在一定程度上反映了收入偏低农户在能源改进中主观能动性的缺乏。正如"扶贫先扶志",政府在推行因地制宜的能源政策、开展能源基础设施建设的同时,也应该加强对贫困农户的情感帮扶,以使其产生尝试改进能源的内生动力。     

湖北野生食果资源特点及其开发途径

野生食果为营养丰富的食用资源植物。在深入调查的基础上，分析了湖北野生食果资源的特点，提出了野生食果资源开发的对策以及产品深加工的途径，为野生食果资源的开发利用打下了坚实的基础。     

基于景观格局演变的流域生态风险评价与管控——以贵州赤水河流域为例

以岩溶地区典型流域——赤水河流域为研究对象,以2000、2005、2008、2013年4期遥感数据为基础,结合Arc Map的空间分析功能,对流域景观格局演变过程进行分析,构建流域生态风险评价体系与管控措施。研究表明:2000~2013年赤水河流域无风险区、潜在风险区、轻度风险区分别由1.66、2.95、75.41 km~2上升至5.63、21.81、115.45 km~2,而中度、重度风险区却分别下降了35.6和40.27 km~2;历年生态风险演变格局为以城乡建设用地为中心,生态风险由轻度、中度、重度向潜在或无风险区过渡,轻度、中度、重度主要以点状扩散或增加,潜在及无风险区则连片分布于农田区和山地丘陵区;基于不同生态风险区的风险源管控对策,对建立流域生态风险预警机制、降低流域生态环境风险、维护流域生态服务功能具有十分重要的意义。     

基于GF-1号遥感影像的武汉市及周边湖泊综合营养状态指数反演

湖泊水体富营养化的监测评价是湖泊水资源管理和水环境保护的基础性工作。基于GF-1号WFV遥感影像和综合营养状态指数法,通过82个站点实测数据建立多元线性回归和RBF神经网络模型,对武汉市及其周边地区主要湖泊综合营养状态指数进行了反演。反演的结果显示,武汉市及周边大部分湖泊水域处于轻度富营养和中营养状态,局部湖区为中度富营养状态。验证结果表明:GF-1号WFV多光谱数据用于监测大面积湖群水质变化是可行的;两种模型都可以建立实测数据与遥感信息的函数关系,根据函数可以反演湖泊水质综合营养状态指数,进而实现大面积湖泊水质动态监测;而RBF神经网络模型预测的R2为0.742 3,均方根误差为3.72,其反演精度更高,更适合于监测内陆湖泊水质变化。