麦秸及其烟尘中正构脂肪酸的组成

在不同燃烧条件下对6种麦草进行焚烧,并利用GC/MS对麦秸和烟尘中的正构脂肪酸进行了测定.结果表明,烟尘中含有碳数C8~C32的正构脂肪酸.在明火烟尘中,正构脂肪酸总含量分布于1 509.3~10 543.7 mg·kg-1之间,平均值为5 871.2mg·kg-1.其轻(C8~C16)、重(C17~C32)正构脂肪酸含量之比(L/H)为0.8~5.3,平均值为2.8;C14/C16、C28/C16、C30/C16等比值的平均值分别为16.5%、14.1%、11.4%.正构脂肪酸呈双峰式分布,其主峰碳数是C16,次峰碳数是C28或C30,且具有显著的偶碳数优势.其碳优势指数(CPI)和平均碳链长度(ACL)的平均值分别为19.8和18.2.在闷烧烟尘中,正构脂肪酸的总含量为5 799.3~37 244 mg·kg-1,平均值为15 838.6 mg·kg-1.其L/H值介于1.2~5.6之间,平均为4.2;C14/C16、C28/C16、C30/C16的平均值分别为12.7%、10.1%、6.0%.闷烧烟尘中正构脂肪酸的分布模式与明火烟尘的类似,其CPI和ACL的平均值分别为24.7和17.7.总之,虽然两类烟尘和麦秸中的正构脂肪酸均具有类似的分布模式和偶碳数优势,但三者在组成上仍然存在明显的差别.这有助于识别大气气溶胶中麦秸及其燃烧排放的正构脂肪酸.     

表面活性剂Burkholderia xenoborans LB400体系对低氯代PCBs的好氧强化降解

增强多氯联苯(PCBs)的水溶性是强化PCBs微生物降解的主要控制因素之一,本研究选取了PCB5(2,3-CB)和PCB31(2,4',5-CB)作为低氯代PCBs的典型代表,以曲拉通100(TX-100)、吐温80(Tween 80)、鼠李糖脂粗提物(RL crude)3种表面活性剂和β-环糊精( HPCD)联合Burkholderia xenoνorans LB400构建PCBs好氧降解体系,测试了它们对PCB5和PCB31的溶出率及微生物生长的影响.结果表明,TX-100(CMC＝194 mg·L-1)、 Tween 80(CMC＝13.1 mg·L-1)、 RL crude(CMC＝50 mg·L-1)浓度在1~7 CMC 时和 HPCD 浓度在500~1500 mg·L-1时对 PCB5和 PCB31溶出率分别达到54.7％~100％、59.8％~100％;10.5％~40.8％、6.8％~31.6％;10.3％~19.9％、3.3％~11.6％和19.5％~34.2％、4.2％~10.7％. TX-100浓度在1~7 CMC时对B. xenoνorans LB400生长的抑制率达到30.3％~45.8％,而Tween 80浓度在0.1~1 CMC时对其生长的抑制率为10.0％~15.4％; RL crude 本身能作为底物促进 LB400的生长,而 HPCD 对其生长无明显影响. B. xenoνorans LB400对PCB31(5 mg·L-1)的降解效率在添加表面活性剂后有不同程度的提高：TX-100,23.7％~65.5％; Tween 80,14.6％~44.3％;RL crude,9.6％~27.2％;HPCD,15.3％~20.7％;而表面活性剂对PCB5(10 mg·L-1)的降解效率则无明显影响.表面活性剂主要通过增大溶液中PCBs-表面活性剂的胶束浓度来提高LB400对PCBs的降解效率,在水溶液培养体系中当设置TX-100和Tween 80浓度分别在1和7 CMC时,PCB31的降解效率达到100％和81.7％,而此时B. xenoνorans LB400生长的抑制率为30.3％和5.4％.     

宝鸡市经济增长与环境空气综合污染指数关系研究

文章以空气综合污染指数法分析了宝鸡市2006年-2011年的环境空气质量状况,分析结果表明宝鸡市环境空气质量逐年变好。以人均GDP为经济指标,以空气综合污染指数为环境指标,建立经济增长与环境空气质量之间的计量模型,进行环境库兹涅茨曲线实证研究。研究结果表明,宝鸡市经济增长和环境空气质量的关系符合库兹涅茨曲线"拐点"后的下降部分。证明该市2006年-2011年的环境空气质量与人均GDP处于良性发展状态。     

低溶解氧对苦草生长的影响

针对太湖梅梁湾生态净化示范区内重建的沉水植物存在的腐烂死亡问题及伴随的底层水体溶解氧偏低现象,在室外模拟生态系统内进行了低氧对沉水植物（苦草）生长的影响试验。结果表明：无论沉积物类型如何,一个月的低氧处理（溶解氧平均值为1.6 mg/L）对苦草株重、株高、分蘖数及叶片数等指标的影响均不明显,对块茎的影响则较显著,表现为块茎数量与重量显著下降。对岸边沉积物处理组而言,低氧对苦草根系的影响显著,表现为根须变细且数量增加,根系活力明显下降,中心沉积物处理组则不显著。同时,低氧处理使岸边沉积物处理组的沉积物氧化还原电位显著下降、水体营养盐浓度上升,尤其是磷酸盐浓度显著增加,中心沉积物处理组的环境理化因子变幅则相对较小。分析认为,低氧对苦草生长的影响虽不明显,但对其种群扩张有潜在的不利作用;梅梁湾生态净化示范区内沉水植物的腐烂死亡,低氧的作用是次要或间接的。     

Effects of cerium on growth and physiological mechanism in plants under enhanced ultraviolet-B radiation

Effect of cerium （Ce^3＋） on the growth, photosynthesis and antioxidant enzyme system in rape seedlings （Brassica juncea L.） exposed to two levels of UV-B radiation （T1： 0.15 W/m^2 and T2：0.35 W/m^2） was studied by hydroponics under laboratory conditions. After 5 d of UV-B treatment, the aboveground growth indices were obviously decreased by 13.2%-44. 1%（T1） and 21.4%-49.3% （T2）, compared to CK, and except active absorption area of roots, the belowground indices by 14.1%-35.6%（T1） and 20.3%-42.6% （T2）. For Ce＋UV-B treatments, the aboveground and belowground growth indices were decreased respectively by 4.1%-23.6%, 5.2% -23.3%（Ce＋T1） and 10.8%-28.4%, 7.0%-27.8%（Ce＋T2）, lower than those of UV-B treatments. The decrease of growth indices appeared to be the result of changes of physiological processes. Two levels of UV-B radiation induced the decrease in chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency by 11.2%-25.9%（T1） and 20.9%- 56.9%（T2）, whereas increase in membrane permeability and activities of antioxidant enzymes including superoxide dismutase（SOD）, catalase （CAT） and peroxidase （POD） by 6.9%, 22.8%, 21.5%, 9.5%（T1） and 36.6%, 122.3%, 103.5%, 208.9%（T2）, respectively. The reduction of the photosynthetic parameters in Ce＋UV-B treatments was lessened to 3.2%-13.8%（Ce＋T1） and 4.9%-27.6%（Ce＋T2）, and the increase of membrane permeability and activities of antioxidant enzymes except POD in the same treatments were lessened to 2.4%, 8.4%, 6.6%（Ce＋T1） and 30.1%, 116.7%, 75.4%（Ce＋T2）. These results indicate that the regulative effect of Ce on photosynthesis and antioxidant enzymatic function is the ecophysiological basis of alleviating the suppression of UV-B radiation on growth of seedlings. Furthermore, the protective effect of Ce on seedlings exposed to TI level of UV-B radiation is superior to T2 level.     

Environmental pollution,hydropower and nuclear energy generation before and after catastrophe: Bathtub-Weibull curve and MS-VECM methods

In this paper, the life span of hydro and nuclear energy generations and the relationship between hydro and nuclear energy generations, environmental pollution, and economic growth were investigated for Japan covering the period of 1960–2018 by employing the Bathtub-Weibull curve and Markov switching-vector error correcting (MSVEC) method, respectively. According to the Bathtub-Weibull curve analysis, a rising failure rate for nuclear energy was found, indicating that the life of nuclear energy has expired, but a decreasing failure rate for hydroelectric energy has been detected. Then two different MSVEC models were used. The MSVEC method, unlike traditional approaches, determines the relationship between variables under different regimes. The results of MSVEC methods indicate three important points. First, regime-dependent asymmetry and regime changes are crucial for policy recommendations. Second, the shocks to hydropower and nuclear energy generations cause temporary deviations from the long-run growth path in both regimes. Lastly, the increase in hydropower generation leads to a decrease in environmental pollution and an increase in GDP, and an increase in nuclear power generation increases pollution and growth in both regimes.     

A Screening Test for the Determination of Ethylene Sensitivity

Ethephon, which releases ethylene within plant tissues after application, was chosen to perform assessments of the relative sensitivity of crops to ethylene and to determine which stages of plant development were most sensitive. The species chosen were: barley, wheat, oats, canola and field pea, all of which are important crops in the province of Alberta, Canada. Plants were treated with ethephon at one of 7 different stages. Plants were assessed for their vegetative and reproductive growth, including height, biomass, yield and seed quality. Visual symptoms were photographed and documented to compare them with symptoms caused by ethylene applied as a gas. It was concluded that in barley, wheat and canola the late vegetative and early reproductive stages were most sensitive, at least when sensitivity was defined as reductions in yield and quality. As for field pea, ethephon had no effect on yield but did cause increased numbers of pods, which in certain conditions could lead to increased yields. Significant effects on vegetative growth were only observed in the early vegetative stages of development but with no effects on yield. The screening protocol successfully identified sensitive cultivars and growth stages for further investigation of the effects of ethylene exposure.     

生物膜法污水处理用新型纤维素载体的制备与性能

以麦草浆粕为原料,研究开发出了一种适用于生物膜法污水处理的多孔生物膜载体.实验通过对麦草浆粕碱化、黄化制备出酯化均匀的纤维素粘胶,并在此基础上选取合适的发泡成孔技术和纤维素再生工艺得到多孔纤维素载体成品.实验考察了各制备条件对载体性能的影响,总结出了该工艺下性能最优的载体的制备条件.研究结果表明,制得载体的孔隙率可达85%,比表面积在11m2·g-1以上,孔径从100μm～800μm均可人为控制.制得的多孔纤维素载体成本低廉,用于污水处理效果十分良好.     

磷对云龙湖富营养化优势藻及混合藻生长的影响

氮磷等营养盐的增加和藻类的过度增殖是富营养化的主要标志。大多数湖泊水体富营养化受磷元素的制约。研究表明富营养化水体的不同藻类对磷含量的依赖性各不相同。通过研究在相同氮浓度,相同温度条件下,不同磷浓度对纯种小球藻和硅藻以及天然混合藻生长速度的影响,发现在氮浓度充足的情况下,磷含量高促进小球藻生长;对硅藻却没有明显的相关性;天然水体混合藻生长速度与磷浓度呈正相关。     

千岛湖水源水微生物安全性评价

千岛湖作为国家战略水源地,其微生物安全直接关系到千万居民的用水安全.为了研究千岛湖湖水的生物安全性,于2018-2019年采集了金竹牌取水口不同深度的水样,并检测了水样的可生物降解溶解性有机碳(BDOC)、细菌再生长的潜力(BGP)、可培养细菌数、潜在的条件致病菌和细菌群落结构.结果显示,千岛湖水质属地表水Ⅱ～Ⅲ类水,...