Warming Increased Nitrogen Availability and Tree Growth During the Last Five Decades as Revealed by Annual Ring Data of Pinus merkusii in Central Vietnam

The effects of climate change including warming on nitrogen (N) availability and growth of Pinus merkusii in central Vietnam were investigated using the relationship between climate variables (rainfall and temperature) and tree-ring parameters (ring width, density, basal area increment, and N concentration) for the last five decades. Rainfall was not correlated with any tree-ring parameters, indicating that water availability did not limit tree growth in the study site probably due to sufficient rainfall. Temperature was positively correlated with ring N concentration, basal area increment, and ring density, probably reflecting the positive effects of warming on soil N mineralization, net photosynthesis, and cell wall thickness, respectively. Therefore, this study suggested that global warming during the last five decades increased N availability and the increased N further helped warming-induced increases in the growth of P. merkusii in central Vietnam.     

Removal and Transformation of Pollutants in a Two-Line Denitrifying Phosphorus Removal Process Treating Low C/N Municipal Wastewater: Influence of Hydraulic Retention Time

A two-line denitrifying phosphorus removal process (2L-DPR) was established treating low C/N municipal wastewater efficiently in our previous studies, while hydraulic retention time (HRT) is one of the most important factors determining the substrate loading, contact time for biomass, and pollutants and further affect performance of the whole system. Removal and transformation mechanism of organic carbon (C), nitrogen (N), and phosphorus (P) were investigated together with mass balance under various HRTs (6, 9, and 18 h) in the established 2L-DPR process. The results showed that in anaerobic units, the concentration of the main storage products in activated sludge such as poly-hydroxyvalerate (PHV) and poly-hydroxybutyrate (PHB) at HRT of 9 h was higher than that under other HRTs. The highest TN and TP removal efficiency was also achieved under the HRT of 9 h with removal rates of 55.9% and 84.6% respectively. Increasing HRT from 6 to 9 h greatly enhanced TN removal in anoxic and aerobic units; however, HRTs had little influence on COD removal with effluent concentration of 48.6, 49.1, and 48.9 mg/L, respectively. HRT affected phosphorus up-taken in anoxic and aerobic units rather than on the release of phosphorus processes in anaerobic units.     

Synthesis and fungicidal activities of novel indene-substituted oxime ether strobilurins

Nineteen novel indene-substituted oxime ether strobilurins, which used an indene group to stabilize the ( E)-styryl group in SYP-Z071 (an unsaturated oxime strobilurin fungicide under development by the Shenyang Research Institute of Chemical Industry), were designed and synthesized. The biological assay results showed that all compounds possessed good or excellent fungicidal activities. It was found that most of the compounds showed higher fungicidal activities against Pyricularia oryzae, Phytophthora infestans, Erysiphe graminis, and Colletotrichum lagenarium than SYP-Z071 at the tested concentration. The biological assay results also indicated that most of the compounds exhibited higher in vivo fungicidal activities against cucumber Pseudoperonospora cubensis and C. lagenarium than the commercial fungicides trifloxystrobin and kresoxim-methyl at a concentration of 6.25 mg/L. Furthermore, it was found that alpha-(methoxyimino)- N-methylphenylacetamide oxime ethers 6m- s exhibited a broad spectrum and remarkably higher activities against all tested fungi. Especially, the 6-methylindene-substituted compound 6p was identified as the most promising candidate for further study.     

Kinetic modeling of formic acid pulping of bagasse

Organic solvent or organosolv pulping processes are alternatives to soda or kraft pulping to delignify lignocellulosic materials for the production of paper pulp. Formic acid, a typical organosolv system, has been presently examined under atmospheric pressure to pulp bagasse fibers. It was shown that efficient bagasse pulping was achieved when the formic acid concentration was limited to 90% (v/v). A statistical kinetic model based on the experimental results for the delignification of bagasse during formic acid pulping was developed that can be described as follows: D (delignification) = 0.747 x C(formicacid) (1.688) x (1 - e(-0.05171t)), an equation that can be used to predict the lignin content in formic acid during the pulping process. The delignification of bagasse by 90% formic acid was almost completed after approximately 80 min, while extended pulping did not improve the delignification but tended to degrade the carbohydrates in bagasse, especially the hemicelluloses, which were rapidly hydrolyzed at the onset of pulping.     

基于不同气候条件的中西太平洋鲣鱼渔场预报

根据1995—2014年中西太平洋鲣鱼围网捕捞生产统计数据,选取了产量最高的22个5°×5°的海区,结合尼诺指数划分不同的气候类型,以渔获量为指标,建立在不同气候条件下中西太平洋鲣鱼围网渔场的渔情预报模型。研究认为:在不同的气候条件下,鲣鱼产量有所波动,其中厄尔尼诺月份月总产量和月均产量最高,与拉尼娜月份产量接近,而正常年份产量最低;不同空间不同气候条件下的产量有较大差异,在130°E～145°E海域,北纬5°产量明显高于南纬5°产量,同时正常月份的产量最高;在145°E～165°E海域,拉尼娜月份产量最高;在165°E以东海域,拉尼娜月份产量最低;将渔获量与Nino 3. 4区的SSTA建立关系,结果显示两者有着很强的相关关系,均符合正态模型(P 0. 01)。模型验证的结果显示,3种气候条件下的预报结果与实际统计值间均存在显著相关关系(P 0. 01),模型有着较高的相关系数,拟合结果较好。针对中西太平洋不同空间位置的3种气候条件下鲣鱼渔获量波动规律进行研究,为预测渔场和相关预报工作提供了新的思路。     

萝卜根径发育候选基因的初步筛选

为了鉴定调控不同萝卜品种间根大小性状差异的关键基因,利用基于高通量测序的数字基因表达谱(DGE)技术,对2种根直径大小不同的圆球形萝卜‘扬州圆白’(直径大)和‘萨丁’(直径小)进行差异表达基因分析。测序共获得1 468个差异表达转录本。基于基因功能注释分析,共鉴定到参与细胞壁代谢相关的转录本28个,参与蔗糖代谢相关的转录本2个,参与激素合成与信号转导相关的转录本29个。利用RT-qPCR分析对6个细胞壁代谢相关基因的表达模式进行验证,其结果与测序结果基本一致。研究发现参与植物激素合成与激素信号转导相关基因(TIFYs、DELLA、 ERF2和 CYCD3)、蔗糖代谢相关基因( ATBETAFRUCT4和 HK3)和细胞壁代谢相关基因(XTHs、EXPs和COBs)可能是调控‘扬州圆白’和‘萨丁’萝卜根大小品种间差异的关键基因。     

纳米银胁迫下黄曲霉(Aspergillus flavus)TL-F3的氧化应激响应及其吸附能力

为研究纳米银(AgNPs)胁迫下黄曲霉(Aspergillus flavus TL-F3)的氧化应激变化及其对AgNPs的吸附能力,通过序批式试验,探究不同浓度AgNPs对A.flavus TL-F3生长、细胞形态、胞外聚合物(EPS)分泌、抗氧化系统和吸附能力的影响。研究发现,AgNPs可抑制A.flavus TL-F3生长,且抑制效果与浓度正相关。AgNPs可致A.flavus TL-F3菌丝发育不完全,表面破损。与不加AgNPs的对照组相比,当AgNPs的质量浓度为80 mg·L^-1时,胞外聚合物含量升至237.55 mg·g^-1,丙二醛含量、超氧化物歧化酶活性、还原性谷胱甘肽含量均显著(P<0.05)提高,而Na⁺K⁺-ATP酶活性显著(P<0.05)降低了50.37%。A.flavus TL-F3对AgNPs有一定的吸附能力,当AgNPs的质量浓度为1、30、50、80 mg·L^-1时,A.flavus TL-F3对AgNPs的吸附率可达68.54%以上。...     

毛竹林施肥研究进展

施肥是提高毛竹林经营效益的最有效手段之一。我国在毛竹林施肥研究方面,特别是在施肥量的计量、肥料种类以及施肥技术上取得了显著成就,但在生产实践中仍存在着盲目施肥、环境污染等问题。本文综述了毛竹林施肥研究的现状,分析了毛竹林施肥中存在的问题,并为毛竹林科学施肥提出了建议。     

纤维素酶对甜高梁秸秆发酵产酒率影响的研究

采用固态发酵法,进行了生产燃料乙醇的试验,同时尽量在相同条件下,研究了纤维素酶对甜高粱秸秆发酵产酒率的影响.实验分2组,第1组为空白试验:酵母菌接种量为0.2%,发酵温度28℃.第2组为对照试验:酵母菌接种量为0.2%,发酵温度28℃,纤维素酶0.8%,发酵时间为114 h.结果表明,第1组折算,甜高粱茎秆发酵产酒,体积分数为61%的乙醇得率为3.5 g/100 g;第2组折算,体积分数为61%的乙醇得率为6.56g/100g,比不加纤维素酶的乙醇得率提高了3.06%.     

大豆油贮藏期间质量指标变化规律的研究

为掌握我国市售大豆食用油的贮存期间品质变化及结果安全性分析和评价,本研究采用实验室贮藏抽样检测的方法对某成品包装大豆油的生物的、物理的、化学的变化状态进行了分析。其结果表明,农药残留、重金属、溶剂残留和黄曲霉毒素B1在成品包装大豆油的整个贮藏阶段均未检测到,而过氧化值（POV）值和酸值（AV）值随贮藏时间显著上升,在试验期中过氧化值虽呈增加趋势,但低于国家标准,但贮存至4个月时,酸值达到0．21mgKOH．g^-4超出GB1535—2003标准要求（0．2mgKOH．g^-1）。苯并（a）芘（BaP）含量随贮藏时间缓慢减少。