CuO/zeolite catalyzed oxidation of gaseous toluene under microwave heating

The development of a combined process of catalytic oxidation and microwave heating for treatment of toluene waste gas was described in this work. Toluene, a typical toxic volatile organic compound, was oxidized through a fixed bed reaction chamber containing zeolite-supported copper oxide (CuO/zeolite) catalyst mixed with silicon carbide (SiC), an excellent microwave-absorbing material. The target compound was efficiently degraded on the surface of the catalyst at high reaction temperature achieved by microwave-heated SiC. A set of experimental parameters, such as microwave power, air flow and the loading size of CuO etc., were investigated, respectively. The study demonstrated these parameters had critical impact on toluene degradation. Under optimal condition, 92% toluene was removed by this combined process, corresponding to an 80%–90% TOC removal rate. Furthermore, the catalyst was highly stable even after eight consecutive 6-h runs. At last, a hypothetical degradation pathway of toluene was proposed based on the experimental data obtained from gas chromatography-mass spectrum and Fourier transform infrared spectroscopy analyses.     

HSE管理体系成熟度评价研究

为了提高企业HSE管理体系绩效,考察其接近最佳状态的程度,需要对HSE管理体系成熟度进行评价.通过分析HSE管理体系、安全生产标准化的理论,考察两者的联系和区别;依据ISO14000标准、OHSAS18000标准和企业自身的HSE管理体系,结合安全生产标准化评定标准,提出HSE管理体系运行绩效评价标准;依据企业的HSE目标,考察其HSE管理绩效,提出HSE管理绩效的评价标准.综合考虑HSE管理体系运行绩效和HSE管理绩效,对HSE管理体系成熟度进行评价.研究表明,可以通过HSE管理体系与安全生产标准化的整合,对企业自身的HSE管理体系成熟度进行评价,持续改进HSE管理体系绩效.     

脑干血管母细胞瘤的外科治疗

脑干血管母细胞瘤位置深,解剖结构复杂,但临床症状轻微,多以头痛为首发症状,发现肿瘤时体积多已较大.手术是目前治疗脑干血管母细胞瘤的主要手段.手术前应对肿瘤进行适当的处理,选择合适的手术时机,手术中依据病变部位采取适当的手术入路,尽量彻底地切除病变.神经影像学新技术为术者了解神经传导束的位置及走行提供了重要的信息.参24.     

Nuclear magnetic resonance imaging for studies of flow and transport in porous media

Nuclear magnetic resonance imaging (NMRI) methods for visualization of fluid flow and transport in porous media are reviewed in this paper. They are illustrated with experiments showing applications of velocity imaging, NMRI measurements of multiphase flow, and NMRI measurements of density flow. The latter two are compared with numerical simulations. The examples show the capacity of NMRI to give structural information both of the medium and the fluid distributions as well as their temporal development. The resulting data can be used in a black box-white box comparison and as benchmarks for numerical models.     

Experimental study on effect of anion surfactant on degradation rate of aldicarb in soil

Degradation kinetics of aldicarb [2-methyl-2-(methylthio) propionaldehyde O-(methyl carbamoyl) oxime] in surface and subsurface soil containing different levels of sodium dodecylbenzenesulfonate (SDBS) were determined to understand complex effect of SDBS on aldicarb degradation process. The results showed that degradation curves of aldicarb in soil can be described with first order kinetics formula and the degradation rate constant. k (d(-1)), in surface soil was larger than that in subsurface soil. SDBS can accelerate the degradation of aldicarb in soil and there was a good linear relationship between degradation rate constant and the logarithm of SDBS concentration. The possible reasons were that SDBS could change pH value of soil, have solubilization effect on aldicarb, and be used as carbon source of microorganisms. But SDBS had a larger promotion to the degradation of aldicarb in surface than in subsurface soil. When SDBS concentration was 1000 mg/kg of dried soil the first order degradation rate constant of aldicarb could be increased by 56.6 percent in surface soil and by 27.6 percent in subsurface soil, respectively.     

河西走廊水危机埋下灾患

"敕勒川,阴山下,天似穹庐,笼盖四野;天苍苍,野茫茫,风吹草低见牛羊".这个在古老漠北曾有的丰茂自然景象,用来描写历史上的河西走廊,也恰如其分.     

不同城市化速度地区建设用地演变驱动力比较研究

以深圳和武汉为例,选择与建设用地相关性大的10项社会经济指标,采用简单的逐步回归方法对城市化速度存在较大差异的2个城市建设用地演变驱动力进行了比较分析,对2个城市驱动力的共性和差异给出了合理解释,可增强对城市化过程中建设用地演变机理的动态理解,为抑制建设用地的过快增长提供参考。     

Coalbed methane reservoir data and simulator parameter uncertainty modelling for CO2 storage performance assessment

Laboratory studies and a number of field pilots have demonstrated that CO₂ injection into coal seams has the potential to enhance coalbed methane (CBM) recovery with the added advantage that most of the injected CO₂ can be stored permanently in coal. The concept of storing CO₂ in geologic formations as a safe and effective greenhouse gas mitigation option requires public and regulatory acceptance. In this context it is important to develop a good understanding of the reservoir performance, uncertainties and the risks that are associated with geological storage. The paper presented refers to the sources of uncertainty involved in CO₂ storage performance assessment in coalbed methane reservoirs and demonstrates their significance using extensive digital well log data representing the Manville coals in Alberta, Canada. The spatial variability of the reservoir properties was captured through geostatistical analysis, and sequential Gaussian simulations of these provided multiple realisations for the reservoir simulator inputs. A number of CO₂ injection scenarios with variable matrix swelling coefficients were evaluated using a 2D reservoir model and spatially distributed realisations of total net thickness and permeability.     

温度、曝气和沉积物对绿潮硬毛藻分解的影响

为了解绿潮优势种——硬毛藻在温度、曝气和沉积物作用下的分解过程及三因素的效应大小,通过室内模拟研究了不同环境条件下硬毛藻早期分解过程中生物量、分解速率及藻体磷释放率的变化,分析了不同环境因子对藻体分解影响的效应大小.结果表明,高温(20~30℃)和添加沉积物均能促进硬毛藻的腐烂分解及藻体磷素释放,其中,30℃条件下含沉积物处理的最大分解速率可达12.13%·d-1,14 d后藻体磷释放率为90%以上.曝气一方面可通过扰动加速藻体生物量的损失和分解速率,另一方面提供了好氧环境,抑制了藻体生物分解和磷素释放,因而其影响效应较低.研究表明,高温和添加沉积物均可加速丝状硬毛藻的分解和藻体磷素释放,夏季应及时清除水体中滋生和衰亡的藻体.     

南淝河水-沉积物中重金属的分布规律、环境评价与溯源研究

系统分析了南淝河丰水期和枯水期表层水及沉积物中As、Cd、Cr、Cu和Pb的含量,结果表明:Cd污染最为严重,表层水中Cd含量属于劣Ⅴ类地表水标准,沉积物中Cd含量超过合肥市土壤背景值,最高值达到背景值的7.5倍;单因子水质指数法评价结果显示Cd未达到水体功能区目标,其余元素基本达到了水体功能区目标,地累积指数评价结果表明各采样点污染程度在无污染到轻度污染之间,潜在生态风险指数评价结果显示各采样点均属于中度生态危害水平,3种评价结果均显示Cd是主要污染因子。主成分分析结果表明南淝河沉积物中不同时期重金属污染来源存在一定差异性和多样性。