加勒比松幼林追肥试验研究

加勒比松1a生幼林氮磷钾不同配比的追肥试验表明，追肥后6a，肥效都极显著；其中以第2a的效果最显著，最大树高、胸径、材积分别比不追肥增加39．1％～52．6％、45．4％～109．3％和34．1％～405．6％；6a后肥效下降，但追肥仍比不追肥的树高、胸径、材积增长8．7％～20％、10．9％～17．9％、31．5％～54．7％。氮磷钾配合施用的效果最佳，施氮磷而缺钾有负效应。当氮磷钾相同配比（N30P30K30）时有特殊的低效应。     

混凝-吸附处理黄河水及对氯消毒中氯衰减的影响

选用2种无机高分子混凝剂聚合氯化铁(PFC)和聚合氯化铝(PAC)处理黄河水,考察了混凝剂的投加量对浊度、UV254、DOC和高锰酸盐指数的去除效果,并结合混凝出水的Zeta电位分析其混凝机制.选择粉末活性炭与混凝联用,研究了混凝剂和吸附剂投加量以及二者的投加顺序对有机物去除效果的影响,并对混凝吸附后出水进行加氯消毒,考察水中残余氯随时间的变化.结果表明,2种混凝剂均有较高的浊度去除率(﹥90%).PAC对UV254、高锰酸盐指数和DOC的去除率分别为29.2%、26.1%和27.9%;PFC对三者的去除率分别为32.3%、23.3%和32.9%.PAC在混凝过程中,电中和作用占主导地位;PFC在混凝过程中,吸附架桥和电中和同时发挥作用.混凝-吸附联用处理黄河水样时,有机物的去除率随混凝剂和吸附剂投加量的增加而升高.先混凝后吸附工艺对UV254和DOC的去除效果优于先吸附后混凝工艺.先使用PAC混凝后吸附对UV254和DOC的去除率分别为95.2%和99.9%;对于PFC,先混凝后吸附对UV254和DOC的去除率分别为90.1%和99.9%.但是先投加粉末活性炭能提高矾花的沉降性能,且处理出水在保持持续消毒效果方面优于前者.     

微量金属强化餐厨垃圾厌氧消化优化条件研究

采用L9(34)正交试验,研究了CoCl2·6H2O、FeCl2 ·4H2O及NiCl2·6H2O投加量对餐厨垃圾厌氧消化总固体(TS)、挥发性固体(VS)和COD减量及累积产气量的影响,确定了三因素的主次顺序及最优工艺条件.结果表明,当CoCl2·6H2O、FeCl2·4H2O及NiCl2·6H2O的投加量分别为0.1 mg/(L·d)、1 mg/(L·d)和0.4 mg/(L·d)时,餐厨垃圾厌氧消化减量及产气效果均最优.在此条件下,经过25 d单相厌氧消化,餐厨垃圾厌氧消化TS、VS、COD的去除率及累积产气量分别达到46.04％、61.02％、58.24％和27 433 mL/L,比不投加微量金属的处理分别高16.98％、28.12％、27.84％和48.63％.Co、Fe和Ni的投加量对餐厨垃圾厌氧消化TS、VS和COD去除率及累积产气量均有显著影响,其中Co的影响达到极显著水平;Co、Fe和Ni对餐厨垃圾厌氧消化减量及产气效率影响的主次顺序及显著性从大到小均为Co、Ni、Fe.     

Effect of ultra-micro powder Dendrobium officinale on the molecular diversity of intestinal bacteria in mice with spleen-deficiency constipation北大核心CSCD

This research aimed to study the effect of ultra-micro powder Dendrobium officinale on the molecular diversity of intestinal bacteria in mice with spleen-deficiency constipation, in order to provide scientific basis for ultra-micro D. officinale therapy. The mice with spleen-deficiency constipation in treatment groups were respectively given the traditional decoction of D. officinale and 50% dose ultra-micro powder D. officinale. The metagenome DNA of intestinal flora was extracted from intestinal contents. Then ARDRA analysis was made after PCR by universal primer of bacteria. The results showed that OTUs, Shannon index and Brillouin index were the same between the normal group and the 50% dose ultra-micro powder group, and between the model group and the traditional decoction group, but greater in the former two groups than the latter ones. The similarity coefficient (0.500 0) was bigger between the 50% dose ultra-micro powder group and the normal group than between the model group and the traditional decoction group, which was 0.181 8. Both cluster analysis and principal components analysis showed that the molecular diversity of intestinal microbiotia in mice of 50% dose ultra-micro powder group was the closest to that in the normal group. The results showed that the weakened molecular diversity of intestinal bacteria in mice with spleen-deficiency constipation can be regulated by the two kinds of D. officinale treatments to different extent. The efficacy of 50% dose ultra-micro powder D. officinale is better than the traditional decoction.     

Cloning and expression analysis of ScBAK1 gene and its alternative spliceosome in sugarcane北大核心CSCD

Alternative splicing (AS) is an important part of regulation of eukaryotic gene expression. BAK1 (Brassinosteroid insensitive1-associated receptor kinase 1) is a specific type of plant serine/threonine protein kinases, and can regulate growth and development and natural immunization. To reveal the responses of sugarcane BAK1 gene to the adverse environment, a ScBAK1 gene and its alternative spliceosome, termed ScBAK1 (GenBank accession number: KP032226) and ScBAK1 S1 (GenBank accession number: KP032227), were cloned from leaf cDNA of Yacheng 05-179 utilizing the methods of electronic cloning and RT-PCR. The open reading frame (ORF) length of ScBAK1/ScBAK1 S1 gene was 1 860bp/1 770bp, encoding 619/589 amino acids residues. The predicted molecular weight of the protein was 69.28 kDa/ 65.76 kDa. Both proteins were located in plasma membrane, estimated as acid, hydrophikic and secretive proteins. Random coil and alpha helix gave priority to extended strand in their secondary structure without beta turn. The most important protein function was cell envelope, secondly biosynthesis of amino acids and cofactors. Real-time quantitative PCR analysis revealed that the expression of sugarcane ScBAK1 S1 gene exhibited the reduced expression trend under smut fungus stress and various abiotic exogenous stresses, including SA, CuCl2, PEG, ABA, NaCl and JA, while the expression of ScBAK1 gene was induced by SA, CuCl2, PEG, NaCl and smut fungus stresses. The phenomenon showed that the absent sequences or amounts of ScBAK1 S1 gene plays a key role in the response of ScBAK1 to the stress of sugarcane smut fungus, osmotic stress and cell growth. The differential expression of ScBAK1 and ScBAK1 S1 lays a foundation for further research on the function of ScBAK1 gene under biotic and abiotic stress.     

云南兰坪县城滑坡地质特征及其成因分析

2000年9月兰坪县城发生特大型山体滑坡,造成重大经济损失,采取挡墙、抗滑桩等措施后,北部边坡局部基本稳定,南部依见明显新变形,2010~2013年尤甚。基于滑坡现状特征及区域地质环境条件分析,提出了以隐伏断裂(F2)为界将滑坡区重新分块,能够合理反映滑坡的变形破坏特征,并为类似滑坡地质勘察加强针对隐伏断裂的影响分析具有重要的借鉴意义。通过分析滑坡体地质及变形破坏特征,认为滑坡的成因主要受控于滑坡区发育的不利岩性条件及地质结构面,水~岩作用是导致岩体崩解破坏诱发滑坡的主要因素。     

Characteristics of soil fauna community in the decomposition of Deyeuxia arundinacea litters北大核心CSCD

This study aimed to understand the soil fauna characteristics during the litter decomposition process of perennial herb Deyeuxia arundinacea. The litters were put in 6-, 30-, and 260-mesh litterbags to investigate their mass loss and the dynamics of soil faunal community during Aug. 2013 to Jul. 2014. Faster decomposition rate of Deyeuxia arundinacea in different meshes was found in the early period than in mid- and end-periods. Among different mesh sizes, 6-mesh had the fastest decomposition rate, followed by 30-mesh and 260-mesh. A total of 2218 individuals of soil fauna were obtained in different meshes, with 958, 737 and 523 individuals in 30-, 260- and 6-mesh respectively. Oribatida and Poduridae were the dominant groups, accounting for 73.22% of total individuals. The soil animal individual and group densities shared a very similar trend among the decomposition bags of three aperture sizes, all with obvious characteristics of seasonal dynamic distribution. During the 12 months of decomposition, the density of soil animal groups did not show significant difference between the 6 mesh and 260 mesh decomposition bags except for May. Correlation analysis showed that the group density was highly significantly correlated with average monthly temperature and rainfall, and the individual density significantly correlated with the average monthly temperature. The results indicated that the structure and diversity of soil fauna community of Deyeuxia arundinacea are influenced by hydrothermal conditions. The findings help in understanding the effect of soil fauna to perennial herb litter decomposition.     

Controlling bacterial leaf blight of rice and enhancing the plant growth with endophytic and rhizobacterial Bacillus strains

This study was conducted to assess efficacy of biological control against bacterial leaf blight (BLB) of rice produced by Xanthomonas oryzae pv. oryzae. Five endophytic strains (A1, A2, A3, A13 and A15) and two rhizospherial Bacilli (D29 and H8) were tested for their antagonistic activities against BLB in vitro and in vivo. All seven strains showed high potential of antagonistic activity against X. oryzae pv. oryzae and three phytopathogenic fungi in vitro. Test of 16SrRNA gene sequence were assigned isolates A1, A3 and A13 as Bacillus amyloliquefaciens while isolates A2 and A15 as B. methylotrophicus and B. subtilis, respectively. In greenhouse, four strains of displayed 50.29%–57.86% inhibition rate against the pathogen and significantly increased plant fresh weight from 50.03% to 73.11% and dry weight from 64.11% to 86.65% in treated rice plants. In addition, these strains demonstrated strong capability to produce indole-3-acetic acid, siderophores, solubilizing phosphate and also colonize roots. Real-time quantitative polymerase chain reaction revealed that expression of defense-related genes including OsAOS2, OsJMT1, OsNPR1 and OsPR1b were significantly up-regulated in leaves of D29-exposed rice plants, suggesting that treatment of rice with D29 suppressed BLB through systemic activation of the plant defense system. Therefore, data suggest that Bacillus isolates A13, A15, D29 and H8 support effective antagonistic activity against BLB under greenhouse conditions in addition to their potential to promote growth of rice plants.     

Changes in nitrogen budget and potential risk to the environment over 20 years(1990–2010) in the agroecosystems of the Haihe Basin,China

The nitrogen balance can serve as an indicator of the risk to the environment of nitrogen loss from agricultural land. To investigate the temporal and spatial changes in agricultural nitrogen application and its potential threat to the environment of the Haihe Basin in China, we used a database of county-level agricultural statistics to calculate agricultural nitrogen input, output,surplus intensity, and use efficiency. Chemical fertilizer nitrogen input increased by 51.7% from1990 to 2000 and by 37.2% from 2000 to 2010, concomitant with increasing crop yields.Simultaneously, the nitrogen surplus intensity increased by 53.5% from 1990 to 2000 and by16.5% from 2000 to 2010, presenting a continuously increased environmental risk. Nitrogen use efficiency decreased from 0.46 in 1990 to 0.42 in 2000 and remained constant at 0.42 in 2010,partly due to fertilizer composition and type improvement. This level indicates that more than half of nitrogen inputs are lost in agroecosystems. Our results suggest that although the improvement in fertilizer composition and types has partially offset the decrease in nitrogen use efficiency, the environmental risk has still increased gradually over the past 20 years, along with the increase in crop yields and nitrogen application. It is important to achieve a better nitrogen balance through more effective management to significantly reduce the environmental risk,decrease nitrogen surplus intensity, and increase nitrogen use efficiency without sacrificing crop yields.