论河北省高职教育发展的现状与未来

近年来,河北省的高职教育已经取得了很大的成果,然而有些院校仍然存在盲目设置专业、“双师型”教师短缺、缺乏对毕业生指导等不足。展望未来,河北高职教育应集团化,与企业密切加强合作,加大对第三产业高职人才的培养工作,同时高职院校应对周边群众提供教育与技术支持等工作。     

不同纤维素降解菌对玉米秸秆的降解效果

该研究旨在探索不同纤维素降解菌对玉米秸秆降解效果的差异性,为秸秆资源化利用提供参考。利用筛选自宁夏秸秆堆、畜粪和土壤中的四株纤维素降解菌,分别为黄曲霉(Aspergillusflavus)Z5-3菌株,非洲哈茨木霉(Trichoderma afroharzianum)Z6-4菌株,藤黄单胞菌(Luteimonas sp.)X11-1菌株,施氏假单胞菌(Pseudomonas stutzeri)X3-5-1菌株,通过室内控温秸秆堆肥发酵试验,研究添加不同纤维素降解菌后堆肥温度、pH值、碳损失、氮损失、有效养分含量的变化规律。试验结果表明,与对照(不加菌处理)比较,加菌处理提前1-2 d进入高温期,最高温度提高了0.3-1.3℃,且细菌处理较真菌处理提前1 d进入高温期,最高温度提高了0.5-0.7℃。pH值总体呈先增加后降低的趋势,且在高温期达到最大值。与对照相比,加菌处理NH3和CO2累积释放量具有降低趋势。以全氮含量变化计,细菌X11-1、X3-5-1处理的氮损失分别为26.14%和26.57%,真菌Z5-3、Z6-4处理分别为36.49%和34.19%,表明添加不同纤维素降解菌可不同程度地降低堆肥物料中的碳损失和氮损失,其中细菌处理保氮效果显著优于真菌处理。与对照相比,细菌X11-1、X3-5-1处理、真菌Z5-3、Z6-4处理分别提前腐熟5、2、2、2d,表明添加纤维素降解菌可减少堆肥物腐熟时间,促进物料养分浓缩。综合判断,玉米秸秆堆肥中加入纤维素降解菌,有利于降低物料的碳、氮损失,且细菌的保氮效果优于真菌,其藤黄单胞菌X11-1处理最先达到腐熟,为最佳处理。     

Enhanced bioaccumulation of pentachlorophenol in carp in the presence of multi-walled carbon nanotubes

The impact of suspended particles on the bioavailability of pollutants has long been a controversial topic. In this study, adsorption of pentachlorophenol (PCP) onto a natural suspended particulate matter (SPM) and multi-walled carbon nanotubes (MWCNTs) was studied. Facilitated transports of PCP into carp by SPM and MWCNTs were evaluated by bioaccumulation tests exposing carp (Carassius auratus red var.) to PCP-contaminated water in the presence of SPM and MWCNTs, respectively. Desorption of PCP on SPM and MWCNTs in simulated digested fluids was also investigated. The results demonstrate that MWCNTs (K _F?=?7.99?×?10⁴) had a significantly stronger adsorption capacity for PCP than the SPM (K _F?=?19.0). The presence of SPM and MWCNTs both improved PCP accumulation in the carp during the 21 days of exposure, and the 21 days PCP concentration in the carp was enhanced by 25.9 and 12.8 % than that without particles, respectively. The enhancement in bioaccumulation by MWCNTs was less than that by the SPM. Considerably more PCP was accumulated in the viscera of the fish (BCF?=?519495 for SPM and 148955 for MWCNTs), and the difference in PCP concentrations between different tissues became greater with particles. PCP desorption in the simulated digestive fluids was faster than that in the background solution. Compared to MWCNTs-bound PCP, more SPM-bound PCP was desorbed, and K _F of desorption for SPM was at least 4 orders of magnitude higher than that for MWCNTs, which can explain the greater enhancement in bioaccumulation in the presence of SPM. Particle-bound pollutants might pose more risk than pollutants alone.     

不同材料负载Ani/TiO2光降解印染废水

使用常见的工业材料:玻璃、铝片和镍网为载体,苯胺(Ani)作为氮掺杂剂,通过溶胶-凝胶法,制备了不同材料负载Ani/TiO2,并研究其在降解以酸性品红模拟的印染废水的光催化氧化性能。结果表明,玻璃、铝片和镍网负载Ani/TiO2最佳N/Ti值分别为0.250、0.040和0.040,并验证了N掺杂TiO2在日光利用方面的优势,提高了光催化剂的实际应用性;最佳pH值均为6～8;最佳处理初始浓度分别为10、12和12 mg/L;其光催化活性都会随着溶液深度的增加而降低;氧化剂硝酸铁的最佳投加浓度均为0.5×10-5到1.0×10-5mol/L;综合来看,玻璃负载Ani/TiO2的活性最高,铝片负载Ani/TiO2次之,镍网负载Ani/TiO2最差。     

氯消毒再生水中4种卤乙酸的测定和影响因素分析

再生水在回用过程中氯消毒副产物对人体产生的危害逐渐引起人们的关注.在USEPA552.3(2003)标准方法的基础上,建立了适用于检测再生水中氯消毒副产物4种卤乙酸(haloacetic acids,HAAs)的分析方法,并对加氯量、UV254、氨氮浓度等影响因素及控制方法进行了研究.研究表明,方法前处理过程简单、安全,内标、HAAs组分峰在谱图分辨良好;4种HAAs在浓度范围1～150 μg/L内呈线性关系,校准曲线相关系数均大于0.999;加标回收率在82.27％～119.9％之间,满足标准方法的要求;HAAs浓度随加氯量的增大而增大,随氨氮浓度的增大而减小,随UV254的变化不明显;先加氨后加氯的消毒方式产生的HAAs浓度最低,两点加氯产生的HAAs总量要少于单一点加氯.     

Emissions and distribution of methyl bromide in field beds applied at two rates and covered with two types of plastic mulches

A field experiment was conducted to compare two plastic mulches and two application rates on surface emissions and subsurface distribution of methyl bromide (MBr) in field beds in Florida. Within 30 minutes after injection of MBr to 30 cm depth, MBr had diffused upward to soil surface in all beds covered with polyethylene film (PE) or virtually impermeable film (VIF) and applied at a high rate (392 kg/ha) and a low rate (196 kg/ha). Due to the highly permeable nature of PE, within 30 minutes after injection, MBr volatilized from the bed surfaces of the two PE-covered beds into the atmosphere. The amount of volatilization was greater for the high rate-treatment bed. On the other hand, volatilization of MBr from the bed surfaces of the two VIF-covered beds were negligible. Volatilization losses occurred from the edges of all the beds covered with PE or VIF and were greater from the high rate-treatment beds. Initial vertical diffusion of MBr in the subsurface of the beds covered with PE or VIF was mainly upward, as large concentrations of MBr were detected from near bed surfaces to 20 cm depth in these beds 30 minutes after injection and little or no MBr was found at 40 cm depth. The two VIF-covered beds exhibited greater MBr concentrations and longer resident times in the root zone (0.5–40 cm depth) than corresponding PE-covered beds. Concentrations of MBr in the root zone of the high rate-treatment beds were 3.6–6.1 times larger than the low rate-treatment beds during the first days after application. In conclusion, VIF promoted retention of MBr in the root zone and, if volatilization loss from bed edges can be blocked, volatilization loss from VIF-covered beds should be negligible.     

不同氧浓度下脱脂餐厨垃圾燃烧特性及动力学研究

利用热重分析法和Coats-Redfern积分法,对不同氧浓度下脱脂餐厨垃圾的燃烧特性进行研究,得到了各试样的着火温度、燃烬温度及综合燃烧特性指数,并通过燃烧动力学分析得到各试样的活化能。实验结果表明,燃烧温度从室温升至1 000℃时,脱脂餐厨垃圾燃烧过程可分为3个失重阶段:水分析出阶段、挥发分析出及燃烧阶段和固定碳燃烧阶段;随着氧浓度的升高,脱脂餐厨垃圾最大失重率以及燃烧特性指数等燃烧特性参数都有显著变化。根据Coats-Redfern积分法计算得低温和高温阶段的活化能分别为83.76~91.2 k J/mol和95.25~141.7 k J/mol。     

溴掺杂TiO_2光催化剂的制备与性能研究

以KBr和Ti(SO4)2为原料,通过水热法制备了高催化活性的溴掺杂纳米TiO2(Br-TiO2)光催化剂,利用XRD、XPS、TEM、BET和UV-Vis DRS等测试手段对其进行了表征。通过苯酚降解实验评价了Br-TiO2的光催化活性。结果表明,700℃焙烧、溴与钛的摩尔比为0.35∶1时,Br-TiO2具有最佳光催化活性。该催化剂为晶体发育完整的锐钛矿相TiO2,粒径平均大小为50 nm,比表面积为16.81 m2/g,在紫外区的吸收得到加强,光催化能力优于Degussa P-25。确定了降解苯酚的最佳条件:催化剂投加量为0.5 g/L,苯酚初始浓度为10 mg/L,pH值为6.0。     

GIS在水稻“寒露风”冷害监测预警中的应用

水稻低温冷害是广西的主要农业气象灾害,低温冷害的实时监测预警对农业趋利避害和减轻灾害损失十分重要。依托GIS技术和统计学方法,利用1∶25万的经度、纬度、海拔高度等广西基础地理信息数据,按照1 km×1 km的较高空间分辨率,对低温冷害的相关气象数据进行细网格空间分析推算,结合广西水稻生长发育状况和"寒露风"低温冷害受害指标,实现对广西水稻冷害发生发展及其强度、范围的实时监测预警,并以2010年10月上中旬冷害过程为例检验了监测效果,与冷害实际情况比较相符。     

Improved soil fumigation by Telone C35 using carbonation

Soil fumigation to control pests and pathogens is an important part of current agricultural practice. A reduction in fumigant emissions is required to ensure worker safety and environment health. A field trial in Florida was conducted to investigate whether carbonating Telone C35? ((Z)- and (E)-1,3-dichloropropene with 35 % chloropicrin) would improve the delivery of the fumigant to such an extent that the application rate could be decreased without sacrificing efficacy. All treatments were carried out in three replications in a complete block design. The use of carbon dioxide (CO(2)) to carbonate and pressurize Telone C35 provided quicker and deeper distribution initially compared to application by nitrogen gas (N(2)) pressurization. The deeper distribution of Telone C35 components found with CO(2) application may have lowered the initial concentration of Telone C35, but it did not appreciably alter the disappearance rate of the three chemicals, chloropicrin, (Z)- and (E)-1,3-dichloropropene. The faster vertical distribution within the bedded soil of the Telone C35 by CO(2) did enhance volatilization of the active ingredients into the atmosphere compared to volatilization of similar reduced rate applied by N(2) pressurization. However, the cumulative amount volatilized from the carbonated fumigant beds at 75 % application rate was lower than the cumulative amount emitted by full rate of Telone C35 using N(2). The efficacy of the carbonated Telone C35 at a lower application rate was statistically equivalent to that of non-carbonated fumigant using N(2) pressurized injection at a higher application rate, based on weed enumeration and the root-knot nematode galling index.