一株在微生物燃料电池中可以利用喹啉发电的产电假单胞杆菌Q1的产电特性研究

A rhizobox experiment was conducted to compare iron (Fe) oxidation and changes of pH, redox potential (Eh) and fractions of zinc (Zn) and lead (Pb) in rhizosphere and non-rhizosphere soils of four emergent-rooted wetland plants (Echinodorus macrophyllus, Eleocharis geniculata, Hydrocotyle vulgaris and Veronica serpyllifolia) with different radial oxygen loss (ROL) from roots. The results indicated that all these wetland plants decreased pH and concentration of Fe(Ⅱ) but increased the Eh in the rhizosphere soils. Pb and Zn were transformed from unstable fractions to more stable fractions in the rhizosphere soils, so decreasing their potential metal mobility factors (MF). Among the four plants, E. macrophyllus, with the highest ROL and root biomass, possessed the greatest ability in formation of Fe plaque and in the reduction of heavy metal MFs in the rhizosphere soil. Wetland plants, with higher ROLs and root biomass, may thus be effective in decreasing potential long-term heavy metal bioavailabilities.     

子宫内膜异位症大鼠模型复制

取Wistar大鼠30只,用手术移植的 方法把自体子宫内膜组织2块分别移植到壁 腹膜与子宫系膜处,建立子宫内膜异位症大 鼠模型。术后4周,再次开腹,观察异位内膜 的存活情况、与周围组织的粘连程度及病理 学变化。结果发现腹膜和子宫系膜处移植内 膜的成活率及病灶的体积差异无显著性(P >0.05),腹膜处病灶与周围组织的粘连程度 显著轻于子宫系膜处病灶(P<0.01),移植 物外观呈囊状,表面有血管,光镜下观察见子 宫内膜细胞、间质细胞、腺体和血管,与正常 在位内膜相比腺体减少。该模型复制方法简 便,成功率高,是研究子宫内膜异位症较理想 的动物模型。     

Determination of five macrolide antibiotic residues in raw milk using liquid chromatography-electrospray ionization tandem mass spectrometry

A confirmatory method using liquid chromatography-electrospray ionization tandem mass spectrometry for determination of five macrolide antibiotics including spiramycin, tilmicosin, oleandomycin, erythromycin, and tylosin in raw milk is presented. Macrolides were extracted from raw milk by acetonitrile, and sample extracts were further cleaned up using solid-phase extraction cartridges. Data acquisition was achieved using multiple reaction monitoring, that is, two transitions, to provide a high degree of sensitivity and specificity. Matrix-matched standard calibration curves with the use of roxithromycin as an internal standard were utilized to achieve the best accuracy of the method. Both a conventional validation procedure and a designed experiment were applied to study the accuracy and precision of the method. The measurement uncertainty arising from accuracy and precision was estimated. The method accuracy, expressed as a percentage of overall recovery, was approximately 100%, and its intermediate precision was <10%. LC-ESI/MS/MS method detection limits (S/N > or = 3:1) of five macrolides were <0.3 microg/kg.     

添加植酸酶对生长猪玉米豆粕型饲粮养分消化利用率的影响

选用体重2 0 kg左右的杜×长×大三元杂去势公猪,随机分为4组,进行消化代谢试验,测定玉米豆粕型基础饲粮(Ⅰ组)和以植酸酶250 U/kg(Ⅱ组)、500 U/kg(Ⅲ组)、750 U/kg(Ⅳ组)取代基础饲粮中40%、60%、80%的磷酸氢钙的试验饲粮中的粗蛋白质等养分的消化利用率。采用全收粪法进行两期消化代谢试验。结果表明:与对照组(Ⅰ组)相比,Ⅱ、Ⅲ、Ⅳ组的蛋白质表观消化率分别提高了3.50%、2.45%、2.32%,组间差异不显著(P>0.05);蛋白质生物学价值分别提高了5.75%、6.29%、6.62%,组间差异不显著(P>0.05);粗纤维表观消化率分别提高30.09%、54.10%(P<0.05)、13.07%;钙的表观消化率分别提高了4.02%、13.82%(P<0.05)、2.20%;磷的表观消化率分别提高了8.20%、47.36%(P<0.05)、13.39%;饲粮可消化能分别提高了1.89%、7.69%(P<0.05)、4.83%。     

用树轮δ13C重建过去300年大气CO2浓度

The annual series of δ13C were measured in tree rings of three Cryptomeria fortunei disks （OF-1, OF-2, and OF- 3） collected from West Tianmu Mountain, Zhejiang Province, China, according to cross-dating tree ring ages. There was no obvious decreasing trend of the δ13C annual time series of CF-2 before 1835. However, from 1835 to 1982 the three tree ring δ13C annual series exhibited similar decreasing trends that were significantly （P ≤ 0.001） correlated. The distribution characteristics of a scatter diagram between estimated δ13C series of CF-2 from modeling and the atmospheric CO2 concentration extracted from the Law Dome ice core from 1840 to 1978 were analyzed and a curvilinear regression equation for reconstructing atmospheric CO2 concentration was established with R2 = 0.98. Also, a test of independent samples indicated that between 1685 and 1839 the reconstructed atmospheric CO2 concentration .using the δ13C series of CF-2 had a close relationship with the Law Dome and Siple ice cores, with a standard deviation of 1.98. The general increasing trend of the reconstructed atmospheric CO2 concentration closely reflected the 10ng-term variation of atmospheric CO2 concentration recorded both before and after the Industrial Revolution. Between 1685 and 1840 the evaluated atmospheric CO2 concentration was stable, but after 1840 it exhibited a rapid increase. Given a longer δ13C annual time series of tree rings, it was feasible to rebuild a representative time series to describe the atmospheric CO2 concentration for an earlier period and for years that were not in the ice core record.     

茂名小良水土流失的灰色预测

运用灰色系统理论对水土流失的影响进行了灰色预测,建立小良水土流失的预测模型,旨在为小良的水土流失的治理提供科学依据,促进小良的可持续发展。     

伪钝绥螨对北方环境条件适应性的研究

伪钝绥螨在11.23～36℃的温度范围内均能正常生长,但在30℃以上产卵量降低一半.相对湿度70%以上是其生育的适宜湿度,低湿度下卵的孵化率低,是影响成活率的主要原因.但低湿度并不影响卵的胚胎发育,而是阻碍幼螨的孵化,只要在卵期的最后7～10小时有适宜的湿度,仍有很高的孵化率.该螨取食山楂叶螨或朱砂叶螨均能正常生育,取食苹果、桃的花粉,其产卵量和发育速度与取食叶螨无显著差异.根据伪钝绥螨对环境的要求及我国北方苹果园的生态条件,作者认为有可能在渤海湾一带的苹果产区定居,并能对害螨发挥较好的控制作用.     

基于CMIP6气候模式的贵州省极端降水情景预估

为探究气候变化下贵州省极端降水未来变化特征,基于台站观测和5个CMIP6模式的逐日降水资料,利用Delta降尺度、趋势分析等方法,分析了4种极端降水指数的历史与未来变化时空特征。结果表明：(1)利用Delta修正过后的CMIP6模式数据取得了良好的效果,适用于贵州省极端降水的预估。(2)在1961—2019年的历史时期,贵州省的R95P,R25mm和CWD均呈南高北低的空间分布,而R95C呈明显的东中西差异;除CWD外,其它3个极端降水指数在1961—2019年均呈不明显的增加趋势。(3)未来3种SSPs情景下,无论是在时间还是空间上,4个极端降水指数均呈上升的趋势。(4)相较于历史时期,4个极端指数除R95C外均有增有减。R95P与R25mm在空间变化上相似,都表现为西北部较历史时期有减少,其余地区则表现为增多,且随SSPs升高而增大;CWD在中南部地区表现为减少,其余地区为增加,以北部较为明显,且在SSP126情景下最为显著;R95C则在整个地区都较历史时期增多,在中西部变化最明显,且在SSP245情景下最显著。总体而言,在气候变化背景下,贵州省的极端降水随SSPs的不同而变化,但...     

Interactions of organic phosphorus with soil minerals and the associated environmental impacts: A review

As an important part of the soil phosphorus(P) pool, organic P(OP) is widely found in terrestrial and aquatic environments(e.g., soils and sediments).The interfacial behavior of OP on natural minerals affects the transport, transformation, and bioavailability of P in the environment. This paper reviews the processes involving adsorption-desorption, dissolution-precipitation, and enzymatic/mineral-mediated hydrolysis of OP at the mineral-water interface, and their subsequent effects on OP speciat...     

牛粪和玉米秸秆混合好氧堆肥过程分层规律

好氧堆肥过程常存在分层现象,对于发酵产物的均一性和整体质量存在影响。为探究好氧堆肥物料病原菌灭活的分层情况,该研究以不翻抛（T1）为对照组,设置3组好氧堆肥试验（T2高温期翻抛、T3降温期翻抛、T4高温期和降温期翻抛）,对牛粪好氧堆肥过程中常规理化性质和病原菌去除效率等进行分析,并利用克里格法（KRIGING）对堆体不同位置的温度和含水率进行插值分析。结果表明,4个处理发酵温度均达到了《畜禽粪便堆肥技术规范》要求,高温期最长的处理为T3和T4,达到7 d,T4处理的病原菌去除率最高,达到97.15%;从分层规律来看,堆体含水率从高到低为上层、中层、下层;好氧堆肥物料病原菌去除效率顺序从高到低为中层、下层、上层,4个处理病原菌去除率均不低于95.56%。综合考虑,高温期和降温期翻抛（T4处理）更有利于牛粪和秸秆混合堆肥物料整体实现无害化。该研究可为牛粪好氧堆肥过程中病原菌杀灭和翻抛参数的优化提供技术指导。