海绵中氯丙酸脱氯微生物的分离及其初步研究

以氯丙酸为单一碳源,通过富集培养从大连海域繁茂膜海绵中分离筛选得到139株氯丙酸降解菌。经过初步筛选得到35株降解能力较强的菌株。对这些菌株的耐盐试验表明,分离到的大部分菌株均具有较强的盐耐受能力,多数菌株为中度嗜盐菌。其中部分菌株可以在14.6%以上盐度培养基中生长,可能为极端嗜盐菌。多底物降解试验表明,大多数菌株均能降解多种底物,这些菌株可用于有机氯污染环境生物修复。同时也说明海绵对水体中有机氯污染物具有去除作用。     

不同改良方法对盐碱土壤水盐运移效果的影响

以取自山东省东营市的中度盐碱土为研究对象，为探究表层（0~20 cm）掺沙和掺生物炭处理对黄河三角洲地区盐碱土的改良效果，在室内进行了垂直一维积水入渗试验，分别研究两种方法对土壤水分入渗、土壤剖面含水率和含盐量的影响。试验土壤为中度盐碱土(含盐量2.381 g·kg^-1)，试验共设置7个处理，分别是：CK(掺沙或生物炭0%)、S1(掺沙5%)、S2(掺沙10%)、S3(掺沙20%)、C1(掺生物炭0.5%)、C2(掺生物炭1%)、C3(掺生物炭2%)。结果表明：在相同入渗情况下，表层（0~20 cm）掺沙、生物炭均能提高盐渍化土壤中水分入渗效果，掺加生物炭显著提高添加层的蓄水能力，掺沙显著提高掺沙层以下土壤含水率，在土层20~40 cm中，掺沙处理平均土壤含水率比掺生物炭处理提高1.37%；不同改良剂处理下，掺沙更有利于盐碱化土壤脱盐，20%掺沙处理平均脱盐率比掺生物炭处理提高5.26%~13.80%，脱盐区深度增加2.35%~3.92%，达标脱盐区深度增加1.70%~3.00%。根据河沙和生物炭在室内一维垂直积水入渗试验结果来看，土壤表层掺沙能有效解决黄河三角洲地区盐碱化土壤问题，改善土壤水盐分布，为作物生长提供良好的生长环境。     

不同改良剂对滨海盐碱化土壤水盐运移特性的影响

为了探究表层(0~20 cm)掺加不同改良剂对盐碱化土壤改良的效果,以黄河三角洲地区中度盐碱化土壤为研究对象,利用室内一维垂直积水入渗试验,表层掺加2种改良物质,即河沙、生物炭,设置7个处理分别为CK,S1,S2,S3,C1,C2,C3,以研究其改良效果.结果表明:在不同河沙、生物炭用量下,改良措施均能提高土壤水分入渗性能,其中生物炭改良措施显著提高了掺加层含水量,河沙改良措施显著提高了土壤掺沙层以下土壤含水率;不同改良处理下,河沙改良措施相较于生物炭改良措施更有利于盐碱化土壤脱盐,处理S3的平均脱盐率比掺生物炭处理提高14.5%~27.7%,脱盐区深度、达标脱盐区深度均超过了0~50 cm作物根系密度较大的土层.根据河沙和生物炭在室内一维垂直积水入渗试验结果,土壤表层掺沙可有效改良黄河三角洲地区盐碱化土壤的水盐分布,为作物生长提供良好的环境.     

新疆全面建设小康社会的重点与难点分析

中央新疆工作会议明确提出2020年实现全面建设小康社会的奋斗目标,但从目前的实现进程看,到2020年仅能实现目标的79%,实现全面建设小康社会的任务十分艰巨。当前城乡居民收入水平较低、城乡居民收入差距不断拉大、区域经济发展不平衡日益凸显、文化教育投入亟需加大、生态环境保护任务艰巨等问题十分突出,距离实现全面小康目标还有相当长的距离,解决以上问题是新疆全面建设小康社会的重点,也是难点。     

How does the Hedley sequential phosphorus fractionation reflect impacts of land use and management on soil phosphorus: A review

The Hedley sequential‐phosphorus (P)‐fractionation method has been used in many countries to study the effects of land‐use and management systems on soil P. Many data sets have been obtained but collectively never have been considered or to goal topic reviewed. Therefore, the objectives of this review were to compile and systematically evaluate these data. The data generated over many years were grouped into temperate, and subtropical and tropical soils of different land use and duration of soil‐management studies. In natural ecosystems, vegetation types and composition and percent of vegetation covers substantially affected all P fractions with pronounced impacts on the labile and moderately labile P. In short‐term studies (≤ 10 y), changes in the labile and moderately labile inorganic P (P_i) fractions were detected when more P (e.g., by factor 5) was applied than commonly recommended for agricultural crops. However, without P application the changes in all P fractions were subtle in temperate soils, but declines were significant in labile and moderately labile P in subtropical and tropical soils. In both temperate and tropical climates, medium (10–25 y) and long‐term (>25 y) cultivation without P application depleted all P fractions, whereas most of P fractions increased with continuous P application, regardless of the amount and source of P. Synthesis of data resulted in multiple‐regression functions which described differences in labile and moderately labile P fractions as function of differences in amount of P application and duration of the experiments. Moreover, the correlation analysis also showed strong association among most of the P fractions. Current limitations in data interpretation of Hedley fractionation can be overcome by the application of ³¹P nuclear–magnetic resonance (NMR) and X‐ray absorption near‐edge fine‐structure (XANES) spectroscopy.     

中厚球壳的轴对称变形分析

针对工程中常见的δ／Ｒ＝１／６￣１／１０的壳体，采用中厚壳的基本假定，整理和指导了基本方程，得出了在球壳轴对称变形的特定情形下，薄壳理论的全部公式与结论均适用于中厚壳的结论，从而为这种情况下薄壳理论的研究成果开辟了新的应用范围。     

Transformation and recovery of fertilizer phosphorus applied to five Quebec Humaquepts

Abstract

Improving phosphorus (P) fertilizer efficiency while minimizing environmental impacts requires better understanding of the dynamics of applied P in soils. This study assessed the fate of fertilizer P applied in Quebec Humaquepts. A pot experiment with five textural Humaquepts, each receiving 0 (P0), 10 (P10), 20 (P20) and 40 (P40) mg P kg^?1 soil was conducted under barley (Hordeum vulgare L.)-soybean (Glycine max L.) rotations. A modified Hedley procedure was used for soil P fractionation. The clayey soils reached a plateau of dry matter at less P applied than the coarser-textured soils. Plant P uptake, soil labile inorganic P (resin-P?+?NaHCO₃-P_i) and moderately labile inorganic P (NaOH-P_i) increased proportionally with P rate. The coarser-textured soils had lower contents of labile and moderately labile P_i, but a larger increase in labile P_i than the finer-textured soils after receiving P additions. The applied P was retained primarily as soil labile P_i, accounting for 43–69% of total soil recovery of applied P, compared to 20–30% recovered as moderately labile P_i, and 7–29% assumed to be sparingly soluble P (HCl-P?+?H₂SO₄-P). The labile P_i recovery of applied P was linearly depressed with clay content, compared to a quadratic relation for the moderately labile P_i recovery. The results suggest the importance of accounting for soil texture along with soil P adsorption capacity when assessing the efficiency of applied P, P accumulation in soils and subsequently P nutrient management.     

一株中度嗜盐菌的分离鉴定及其强化高盐有机废水处理的研究

为探索中度嗜盐菌在高盐有机工业废水处理中的应用,解决高盐有机工业废水处理这一难题,从山东省威海市路道口盐场晒盐池盐水中分离一株嗜盐菌株YS - 1,通过对该菌株进行原子力显微镜观察、生理生化测定,全细胞脂肪酸分析、16S rDNA序列同源性分析发现YS - 1菌株16S rD NA序列与Halomonas sp.(AB167061)的亲缘关系最为接近,结合上述其他各项结果确定该菌株为盐单胞菌属(Halomonas sp.),属中度嗜盐菌;在SBR反应器中对该菌株进行强化高盐有机废水处理试验,结果表明,含盐12%,CODCr=1 494 mg/L的高盐模拟有机废水,经72 h C ODCr去除率为90.0%,120 h 的CODCr去除率为98.1%,该菌株具有强化高盐有机废水处理的功能,通过分离筛选嗜盐菌强化高盐有机工业废水处理具有可行性.     

科学适度发展南方丘陵山地农机化

对南方丘陵山区农业机械化发展现状进行分析,探究南方丘陵山地在发展农机化过程中面临的困难和存在的问题,然后提出相应的政策建议.作者认为南方丘陵山地特殊的自然资源条件,无法像北方平原地区那样全面推行作物全程机械化,应该分地区、分作物、分环节,因地制宜、科学适度的发展农业机械化.     

微咸水对生物炭作用下盐碱土水盐运移特征影响

为了合理利用微咸水资源并结合生物炭改良剂,在节水基础上探究施用生物炭微咸水矿化度对盐碱土水盐运移规律影响.以黄三角中度盐碱土为研究对象,在室内进行一维垂直入渗试验,包括对照共设置8个处理:CK,W1,W2,W3,C1,W1C,W2C,W3C.结果表明:相同入渗时间下,累积入渗量和湿润锋运移深度随微咸水矿化度增加先增加后降低;低矿化度条件下,掺生物炭的土壤入渗性能优于未掺生物炭的,提升幅度2.16%~8.54%,且处理W2C效果最优,W1C略小于W2C,Kostiakov模型能够更好地描述微咸水矿化度对生物炭作用下盐碱土的土壤水分入渗过程.相同土壤条件下,各处理0~20 cm土层土壤含水率随着微咸水矿化度增加先增加后降低,掺生物炭的土壤含水率比未掺生物炭高2.53%~3.95%,且处理W2C增幅显著,W1C略小于W2C.各处理的土壤含盐量随着微咸水矿化度增加而增加,生物炭处理的脱盐效果略小于未掺生物炭的,其中2 g/L微咸水处理的脱盐效果最优,脱盐率高达47.4%.综合考虑,对黄河三角洲地区中度盐碱土,建议掺加生物炭并采用2 g/L微咸水进行灌溉.