新媒体节目的创意与策划

基于对新媒体概念、形态与本质和对节目内容创新内涵的分析,对新媒体节目内容创新的路径、编辑创新进行了探讨,指出节目内容创作方式和手段的多元化、科学化和智能化发展,在此基础上建立新媒体节目的正确策划理念,包括策划对象理念、策划过程理念、主题思想的理念。     

Auto-adaptive Air Distribution and Structure Optimization of Ejector Burner for Biomass Alcohol Fuels

A plenty of studies on the utilization of biomass alcohol fuels have been conducted, but combustion efficiency and stability of this fuels still need to be improved. Based on biomass alcohol fuels (bio-methanol and bio-ethanol), this paper studied auto-adaptive air distribution characteristics and optimum structure parameters of an ejector burner by numerical simulation method. Also, an experiment was conducted to verify the numerical results. The results show that the mole air entrainment ratio (MAER) keeps almost constant when the ejector fuel nozzle exit locates at the segment between the ejector throat and the suction chamber entrance, but a bigger ratio α would lead to a higher MAER till the α is bigger than 8.5 for bio-methanol and 11.5 for bio-ethanol. The bio-ethanol fuel is more beneficial for air carrying role because of its big molecular weight. Operation pressure (P_w) has a little impact on MAER of the two fuels, but the rise of back pressure (P_b) would lead to rapid decrease of MAER for the two fuels. For the optimum structure burners, the MAER can be maintained at the value of theoretical complete combustion. Its changing rate is less than 2.3% for bio-methanol and 2.5% for bio-ethanol when the burner load changes from 30% to 120%, which is highly consistent with the experimental results. The optimum burner can distribute air supply automatically with the changing of burner load.     

Predicted no-effect concentrations for mercury species and ecological risk assessment for mercury pollution in aquatic environment

Mercury(Hg) exists in different chemical forms presenting varied toxic potentials. It is necessary to explore an ecological risk assessment method for different mercury species in aquatic environment. The predicted no-effect concentrations(PNECs) for Hg(Ⅱ) and methyl mercury(Me Hg) in the aqueous phase, calculated using the species sensitivity distribution method and the assessment factor method, were 0.39 and 6.5 × 10-3μg/L, respectively. The partition theory of Hg between sediment and aqueous phases was considered, along with PNECs for the aqueous phase to conduct an ecological risk assessment for Hg in the sediment phase. Two case studies, one in China and one in the Western Black Sea, were conducted using these PNECs. The toxicity of mercury is heavily dependent on their forms,and their potential ecological risk should be respectively evaluated on the basis of mercury species.     

不同晶型纳米TiO_2在斑马鱼体内的富集与清除

为探讨纳米材料的慢性生物效应以及材料结构对生物富集的影响,开展了A-TiO2(锐钛型纳米TiO2)和R-TiO2(金红石型纳米TiO2)在斑马鱼(Danio rerio)体内的长期富集和清除试验.采用半静态暴露试验,试验周期为46 d(暴露阶段28 d,清除阶段18 d),每种晶型设置2个处理组(ρ分别为4.0和10.0 mg/L),测定各时间点斑马鱼体内不同晶型纳米TiO2含量(以w计);以暴露阶段的BAF(生物富集系数)以及清除阶段的排出速率常数、总量清除率为终点,比较斑马鱼对2种晶型纳米TiO2的富集、清除的异同.结果表明:在暴露阶段,A-TiO2在斑马鱼体内的富集量显著高于R-TiO2,10.0 mg/L处理组斑马鱼体内富集量均显著高于4.0 mg/L处理组;4.0和10.0 mg/L的A-TiO2处理组的BAF分别为76.7和105.4 L/kg,略高于R-TiO2(41.6和36.1 L/kg),二者在斑马鱼体内均不具有生物蓄积性.在清除阶段,斑马鱼体内的2种晶型的纳米TiO2均可被排出,清除阶段的清除率为88.0%~100%;斑马鱼体内2种晶型纳米TiO2富集量的下降均符合一阶指数衰减方程,排出速率常数在0.26~1.01 d-1之间.     

废水中α-氯代环己基苯基甲酮的电化学降解

采用石墨电极对含α-氯代环己基苯基甲酮的氯化清洗水进行电化学降解。结果表明,电化学降解对COD的去除效果非常明显,并且随着电流密度增加,COD的去除效率逐渐升高,电流密度由15 mA/cm2增加至100 mA/cm2, COD的去除率从39.7%升高到72.3%;电化学降解作用下,水样可生化性显著提高,降解2 h后,(BOD5)/(COD)由原水的0.22提高到0.46;电化学降解过程中,COD的降解遵循零级反应动力学方程;此外,还对电化学降解过程中α-氯代环己基苯基甲酮的降解途径进行了推测。     

基于井口涌水量变化类型判断岩溶含水层厚度

针对含水相对均匀的溶洞-裂隙水含水岩组,为判断岩溶含水层厚度,通过对空气潜孔锤钻进工艺施工钻孔井口涌水量变化进行分析,结果发现:利用该工艺施工的钻孔井口涌水量一般会出现稳定型、降低型和增长型三种变化类型;井口涌水量变化类型反映了岩溶含水层是空间尺度上发育的垂向地下水系统,具有分层特征,其厚度与碳酸盐岩岩溶化程度的不均一性耦合,体现了碳酸盐岩岩体内不同空隙的发育规模、密度及其相互间的联系程度;明确了地下水埋深状况以及含水层的构成条件。故采用空气潜孔锤钻进工艺施工的钻孔,在非干孔情形下,可以利用井口涌水量的变化类型判断岩溶含水层厚度。     

降雨对城市草坪温室气体源汇效应的影响

利用静态箱法研究了夏季降雨对上海市城市草坪温室气体排放的影响,结果表明,晴天上海市城市草坪是N_2O和CO_2的源,CH_4的汇;降雨会削弱N_2O和CO_2排放,使得草坪由CH_4的汇转变为排放源。N_2O通量在晴天和雨后分别为1.37±3.47和1.06±2.67μmol/(m2·h),CO_2通量在晴天和雨后分别为13.33±8.59和6.46±2.61mmol/(m~2·h),CH_4通量在晴天和降雨后分别为-0.08±3.77和0.22±6.27μmol/(m~2·h)。明暗箱对比实验显示,草坪生态系统能有效缓解土壤对大气N_2O和CO_2的贡献。N_2O和CO_2通量与光合有效辐射和温度呈显著负相关(p0.01),CH_4和二者相关性不显著。降雨通过降低光合作用和温度,间接削弱城市草坪CO_2和N_2O的排放。降雨可能通过提高含水率抑制城市草坪对CH_4的吸收,促进其排放。     

江汉平原土地资源诅咒效应研究

将资源诅咒的研究领域由传统的矿产资源转向土地资源研究问题域,以近10a江汉平原18个县(市)的统计数据为依据,运用诅咒系数对其进行资源诅咒的实证分析。结果显示,近年来发展滞后的荆州市所辖的监利县、江陵县以及其他7个县市的土地资源诅咒系数大于1,确实存在资源诅咒现象,且江陵县与监利县还属于严重诅咒区。通过对选取指标作进一步的计算分析,得出导致其产生资源诅咒的原因主要为:以土地资源为依托的农业没有得到高效发展,而受到发展观念与投入等束缚,其二、三产业发展同样滞后。根据影响资源诅咒地区产业发展的具体因素,有针对性地给出化解土地资源诅咒的对策建议,为今后资源诅咒地区打破诅咒束缚,持续快速发展指明方向。     

长三角重点生态功能县域生态资产损益核算

限制开发的重点生态功能县域承担着生态保护与经济发展双重使命,如何实现生态与发展互促共进及生态产品价值化是当前面临的极大难点,生态资产损益核算为量化区域资源有偿使用、生态保护修复、生态文明绩效评价等提供了有效途径。以浙江省嵊州市作为长三角地区重点生态功能区的典型县域,基于栅格尺度评估了近20年生态资产存量与流量时空动态变化,并利用地理探测器结合人类活动类型监测分析了生态资产损益的驱动因素。结果表明：2000—2018年,由于森林生态资产质量降低及面积减少,嵊州市近60%区域的生态资产存量呈减少趋势,而生态资产流量总价值与单位面积价值均增益10%以上。相对于自然因素,社会经济因素对嵊州市生态资产损益平均贡献度更大,为17%。县域城镇化导致粮食供给轻微减损,70%以上乡镇生态资产增益,特别是石璜镇生态保护成效较突出。     

Short-term inhalation exposure evaluations of airborne antibiotic resistance genes in environments

Antibiotic resistance is a sword of Damocles that hangs over humans. In regards to airborne antibiotic resistance genes (AARGs), critical knowledge gaps still exist in the identification of hotspots and quantification of exposure levels in different environments. Here, we have studied the profiles of AARGs, mobile genetic elements (MGEs) and bacterial communities in various atmospheric environments by high throughput qPCR and 16S rRNA gene sequencing. We propose a new AARGs exposure dose calculation that uses short-term inhalation (STI). Swine farms and hospitals were high-risk areas where AARGs standardised abundance was more abundant than suburbs and urban areas. Additionally, resistance gene abundance in swine farm worker sputum was higher than that in healthy individuals in other environments. The correlation between AARGs with MGEs and bacteria was strong in suburbs but weak in livestock farms and hospitals. STI exposure analysis revealed that occupational intake of AARGs (via PM₁₀) in swine farms and hospitals were 110 and 29 times higher than in suburbs, were 1.5 × 10⁴, 5.6 × 10⁴ and 5.1 × 10² copies, i.e., 61.9%, 75.1% and 10.7% of the overall daily inhalation intake, respectively. Our study comprehensively compares environmental differences in AARGs to identify high-risk areas, and forwardly proposes the STI exposure dose of AARGs to guide risk assessment.