有机质浸染砂水泥土的力学特性及本构关系

为研究海南省海湾地区分布的有机质浸染砂水泥土的力学特性,该文首先对有机质浸染砂水泥土和标准砂水泥土进行无侧限抗压强度对比试验(采用配合比均为熟石灰掺入比7.5%、水泥掺入比20%、水灰比0.45),定量分析养护龄期对其无侧限抗压强度及试样破坏形式的影响。然后对有机质浸染砂水泥土进行单轴抗压试验,获得了水泥土材料的应力-应变全过程曲线、刚度变化规律以及改进邓肯-张本构模型。结果表明:1)有机质浸染砂水泥土试样的破坏类型为塑性剪切破坏和脆性剪切破坏;2)有机质浸染砂水泥土抗压强度随着养护龄期的增加基本呈指数形式增长,但在养护龄期14 d后,增长速度逐渐降低并趋于稳定;3)随着养护龄期增长,水泥土刚度增加。在加载初期,水泥土切线模量随着轴向应变增加而增大,呈现刚度硬化现象;4)基于单轴抗压试验得到应力-应变全过程曲线,可分为2个阶段:塑性阶段、软化阶段;5)通过对应力-应变全曲线的描述,得到了修正的邓肯-张模型,确定模型参数后,与实测数据对比发现,该修正模型可以模拟有机质浸染砂水泥土的应力-应变关系。     

绿色屋顶降雨径流削减效果监测与过程模拟

选择平面、斜面、绿色、滞蓄4种不同形式屋顶,采用"液位计+三角堰"的径流测量方法,开展降雨径流对比监测。结果表明,相比平面与斜面屋顶平均径流系数(分别为0.68和0.84),绿色与滞蓄屋顶平均径流系数分别为0.41和0.43,均明显有所减小,并且数值相差不大,反映出相近的径流总量削减效应。比较分析绿色与滞蓄屋顶降雨径流过程,2类屋顶径流过程接近,产流后水流运动机制相似,均受上部积水水头作用影响,并以孔流(孔隙、孔口)形式出流,可以采用相似的水库概念模型进行简化模拟。根据土壤水饱和下渗理论,考虑到绿色屋顶基质层厚度有限,推导建立了描述绿色屋顶饱和产流后降雨径流过程的基本方程,并应用于模拟绿色屋顶降雨径流过程。结果表明,径流过程计算值与实测值间决定系数值为0.85、Nash-Sutcliffe效率系数值为0.84,初步验证了模型的合理性。研究成果有助于深入认识绿色屋顶对降雨径流的削减效应与出流机制。     

规模化奶牛场粪污全量贮存及肥料化还田工艺设计

为推进粪污全量贮存和肥料化还田模式在规模化奶牛场的应用，该研究以存栏500头规模奶牛场为例，分析了粪污收集量、贮存工艺与设施和粪肥还田等内容，提出了粪污贮存池设计容积和粪肥还田配套土地面积等参数。结果表明：奶牛粪污全量收集量为17.33 t/d，全量贮存设施分为舍内贮存池和舍外贮存囊2种。单个舍内贮存池尺寸为85 m×12 m×2 m（长×宽×深），粪污存储期9个月，所需贮存池数量为5个，总容积10 200 m3；舍外贮存囊占地尺寸为90 m×30 m（长×宽），深2.2 m，总容积5 615 m3。粪肥全部还田所需土地面积与种植作物类型和种植制度相关，种植作物为小麦、玉米、小麦+玉米和水稻（1年2熟）时，需配套土地分别为248.4、400.6、122.8和127.0 hm2。粪肥还田成本为10.37万元/a，全部还田可节省化肥22.8万元/a，年可产生经济效益12.43万元。     

Effects of different long-term cropping systems on phosphorus adsorption and desorption characteristics in red soils

Journal of Soils and Sediments - Phosphorus (P) fertilizer has been applied in regions with red soils to ensure high crop yield. However, the supply of bioavailable P for crop plants is...     

35 kV变压器油色谱异常事件分析

对一起35 kV变压器油色谱异常的检查与处理进行了介绍。一台35 kV变压器返厂大修投运后2年内,在周期性油色谱试验中发现该变压器本体油样中含有超量乙炔。对该变压器进行吊罩检查,发现变压器高压C相的调压线圈抽头引线与线圈抽头连接部位螺栓未完全紧固。对引线接头进行了处理,处理后油色谱试验合格,对故障原因进行了分析,保障了电网设备的安全稳定运行。     

Development and Application of Cotton InDel Markers Based on High Throughput Sequencing

[Objective] Dimorphic InDel markers can be used for cotton variety identification and purity detection, to improve the accuracy and efficiency of cotton seed testing, and to play a role in molecular breeding of cotton. [Method] Based on the whole genome sequencing of 121 cotton varieties from different sources, the InDel markers with high polymorphism were developed according to polymorphism information content(PIC) and were applied in the genetic distance analysis and cluster analysis by using 66 cotton varieties in China. [Result] Totally 10 967 InDel were identified based on the next generation sequencing data of 121 cotton varieties. Among the 85 pairs of InDel primers synthesized, 64 were selected including 35 from At group and 29 from Dt group. The minimum average allelic frequency(MAF) of At and Dt chromosomes were 0.45 and 0.32, respectively, while the PIC were 0.49 and 0.40, respectively. The genetic distances of the 66 cotton varieties ranged from 0.04 to 0.65 centimorgan (cM), with an average of 0.39 cM. The two varieties with the largest genetic distance were Simian 3 and CCRI 36, and the two varieties with the smallest genetic distance were Xumian 18 and Xuza 3. [Conclusion] The 64 cotton dimorphic InDel markers can effectively reveal the relationships among varieties based on the genetic distance, and distinguish cotton varieties from different sources, which has certain theoretical significance and application value.     

凡纳滨对虾养殖体系中群体感应淬灭菌的筛选、安全性评估及发酵条件优化

从凡纳滨对虾(Litopenaeus vannamai)养殖体系中筛选得到具有群体感应淬灭(Quorum quenching, QQ)活性的潜在功能菌，并对菌株进行16S rDNA鉴定、安全性评估及发酵条件优化。采用根癌农杆菌(Agrobacterium tumefaciens) A136液体X-gal法进行活性菌株筛选，发现2株细菌(BDZ5和W1B)的发酵液对信号分子己酰基高丝氨酸内酯(C6-HSL)具有显著的降解作用，但经沸水浴处理后均丧失降解活性。经16S rDNA基因序列分析，菌株BDZ5和W1B分别被鉴定为芽孢杆菌属(Bacillus)和科贝特氏菌属(Cobetia)。安全性评估结果显示，菌株BDZ5和W1B均无溶血性，且对多数抗生素具有敏感性，注射2株活性菌未提高凡纳滨对虾死亡率，且对凡纳滨对虾血清免疫酶活性无显著影响。单因素条件优化结果显示，在起始pH为7.0、盐度为20、0.0005%的MnCl2条件下培养48 h后，菌株BDZ5达到最大生长量；在起始pH为6.0、盐度为40、0.05%的CaCl2条件下培养48 h，菌株W1B达到最大生长量。2株菌的最适信号分子C6-HSL降解条件与其生长条件有所不同，在起始pH为7.5、盐度为30、0.0005%的MnCl2条件下培养48 h，2株活性菌对信号分子C6-HSL的降解率达到最大值。研究表明，菌株BDZ5和W1B可作为益生菌应用于水产养殖，为基于QQ角度防治对虾细菌性病害提供优良菌种。     

Expression and functional characterization of glutamine synthetase from giant freshwater prawn (Macrobrachium rosenbergii) under osmotic stress

The freshwater prawn, Macrobrachium rosenbergii naturally lives in the freshwater, though it migrates to the brackish water environment during spawning that claimed to be resistant on a broad range of saline fluxes. However, little is known about the osmoregulatory patterns and the effect of an enzyme glutamine synthetase (GS) in M. rosenbergii under stress. Here, we described the identification and functional characterization of GS from M. rosenbergii (Mr‐GS) at molecular and protein levels. The identified Mr‐GS was comprised of 361 amino acids that phylogenetically shared the highest identity with other crustaceans and predicted to contain Gln‐synt_C and Gln‐synt_N domains at the respective terminal regions. Tissue distribution analysis in M. rosenbergii revealed that the Mr‐GS was highly expressed in muscle, and commonly existed in other examined tissues in the following order gills > heart > stomach > brain > haemolymph. Whereas, the mRNA of Mr‐GS was significantly up‐regulated in the muscle and gill tissues following challenges with either hyper (0 → 13‰), or hypo (13 → 0‰) osmotic stress at 3, 6 and 12 hr. Furthermore, the level of Glutamine concentration was positively correlated with the GS mRNA and protein expression patterns in hyper‐osmotic stress, whereas in hypo‐osmotic stress a slight decrease in the gills and maintained a level in the muscle tissues at 3, 6 and 12 hr post‐treatments. Our findings suggest that Mr‐GS potentially exhibited the osmoregulation responses in the gill and muscle tissues of M. rosenbergii throughout the time of osmotic stress, which will benefit for future study on osmoregulation.