17 research outputs found

    Controlled release method for herbicides in rhizosphere to prevent aggression of Spartina alterniflora in intertidal zone

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    为防除滨海滩涂互花米草入侵,探讨根际土壤缓释除草剂的新方法。该研究采用扩散法研究了蛭石、PE膜和合成壳聚糖膜3种缓释材料的根际缓释除草剂的性能,同时,采用根部浸泡试验验证根际施药防除互花米草的效果。结果表明,3种缓释材料的缓释性能差异显著,蛭石对草甘膦控释能力较弱,初始释放农药量最大,释放迅速,适合淤泥质潮滩;PE膜则表现出较强的控释能力,释放量较小,但整个过程释放量较稳定,适合沙质和近根际水体;壳聚糖膜介于两者之间。根部浸泡试验表明,0.25~1.00g/l草甘膦、0.09~0.23g/l百草枯、0.28~2.30g/l草铵膦根部浸泡2~6d即可显现毒杀互花米草效果,通过饱和土壤一维溶质渗滤模型计算,在点源释放模式下,除草际根部释放点间有效除草间距为50~60CM。研究证明了根际缓释除草剂防除互花米草具有可行性。To guard effectively against the ecological aggression of the smooth cord-grass Spartina alterniflora growing in intertidal zone,a new method was considered to apply herbicides in rhizosphere soil with controlled release techniques.Three types of controlled release materials,vermiculite particles,polyethylene(PE) and chitin membrane,were tested on their herbicide-releasing characteristics,meanwhile,three herbicides,including glyphosate,parauat and basta,were evaluated on the effects of killing the smooth cord-grass.The results show that the controlled herbicide-releasing ability of vermiculite particles is weaker than the other two materials,and its initial releasing quantity is bigger,so it can be used for the muddy beach.On the contrary,that of PE was stronger,and therefore it is suitable for a sandy beach.Furthermore,that of chitin membrane is between the vermiculite particles and PE membrane.The three herbicides,glyphosate,paraquat and basta,can kill the grass effectively after 2-6 days of cultivation in 0.25-1.00 0.09-0.23 and 0.28-2.30 g/L solutions,respectively.One dimensional model for solute infiltration in saturated soil was used to modulate the herbicide migration,and the modulation result suggested that the distant between any two herbicide-releasing points should be set at less than 50-60 cm in field weeding practice.The experiment proved it is feasible in practice to guard against the ecological aggression of smooth cord-grass by controlled release of herbicides in rhizosphere.国家海洋公益性行业科研专项经费项目(200905009)资

    HPLC and MALDI-Tof-MS Analysis of Hydrolysates of Xylan

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    利用HPlC结合MAldI-TOf-MS对1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生化后山毛榉木聚糖水解产物进行分析,检测到了难以获得标准品对照的木聚糖水解产物。结果表明,稀硫酸水解山毛榉木聚糖的主要水解产物有木糖和4-O-甲基葡萄糖醛酸-木糖(b2),以及少量4-O-甲基葡萄糖醛酸(b1)。内切重组木聚糖酶An Xyn10C水解山毛榉木聚糖产生木糖、木二糖和4-O-甲基葡萄糖醛酸-木三糖(b3),而内切重组木聚糖酶HO Xyn11A水解山毛榉木聚糖主要产生木糖、木二糖、木三糖、4-O-甲基葡萄糖醛酸-木四糖(b4)和4-O-甲基葡萄糖醛酸-木五糖(b5)。基于PMP柱前衍生化的HPlC结合MAldI-TOf-MS方法能高效地分析复杂的木聚糖水解产物。The hydrolysis end products of beechwood xylan,which were released by sulfuric acid or enzymes and then labeled at their reducing ends with 1-phenyl-3-methyl-5-pyrazolone( PMP) derivatization,were analyzed by HPLC assisted with MALDITof-MS.Some of the hydrolysates,which were lack of related commercial available standard substances,were determined.It was found that the xylose and 4-O-methyl-glucuronic acid-xylose( B2) were the main products with minor amounts of 4-Omethylglucuronic acid( B1) in the hydrolysates of beechwood xylan by sulfuric acid.Recombinant endo-β-1,4-xylanase An Xyn10 C released xylose,xylobiose,and 4-O-methyl-glucuronic acid-xylotriose( B3) as the main hydrolysates from beechwood xylan,whereas recombinant endo-β-1,4-xylanase Ho Xyn11 A released xylose,xylobiose,xylotriose,4-O-methyl-glucuronic acidxylotetrose( B4) and-xylopentaose( B5),and aldohexaouronic acid.These results revealed that HPLC assisted with MALDITof-MS based on PMP derivatization was a very useful and robust method for the determination of products in hydrolysis of xylan.国家自然科学基金资助项目(31170067); 厦门市海洋经济发展专项资金项目(14GZP59HJ29); 福建省海洋高新产业发展专项项目(闽海洋高新[2014]25号

    御寒暖胃膏穴位贴敷对胃癌前病变大鼠胃黏膜的影响

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    目的:研究御寒暖胃膏贴敷胃经穴对慢性萎缩性胃炎癌前病变大鼠胃黏膜的影响,探讨御寒暖胃膏贴敷胃经穴对慢性萎缩性胃炎癌前病变大鼠胃黏膜损伤修复的作用机制。方法:大鼠随机分为正常组、模型组、御寒暖胃膏贴敷胃经穴组、御寒暖胃膏贴敷对照点组、药物对照组,采用综合干预方法复制慢性萎缩性胃炎癌前病变大鼠模型,肉眼下观察大鼠胃黏膜损伤指数,光镜下观察胃黏膜组织的病理变化,彩色多普勒观察胃黏膜的血流量。结果:与模型组比较,御寒暖胃膏贴敷胃经穴组和药物对照组大鼠胃黏膜损伤指数值均显著降低(P0.05),胃黏膜组织的病理损伤未得到明显修复,胃黏膜血流量未见显著升高(P>0.05)。结论:御寒暖胃膏贴敷胃经穴可以促进慢性萎缩性胃炎癌前病变大鼠胃黏膜损伤的修复,增加胃黏膜的血流量,并且存在经脉-脏腑特异相关性。深圳市科技研发资金项目(JCYJ20130401105615482

    A Review of Person- environment Fit in Organization Settings

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    在综述人-环境匹配(Person-environment fit,PE)的概念、结构、测量、已有研究发现和所面临的问题等基础上,提出了从PE匹配多维模型的有效化,预测、中介和调节机制,边界条件和动态过程,测量工具和研究方法改进,文化和地域差异,以及人—群体匹配(Person-group fit,PG)、人—上级匹配(Person-supervisor fit,PS)等几个方面着手探讨探讨在我国开展该类研究的可能性

    用于细菌生物膜感染治疗的Pickering乳液制备

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    人体常见的持续性感染疾病通常与细菌生物膜有关。使抗菌药物高效渗透到细菌生物膜内部并杀伤细菌是治疗细菌生物膜感染的关键。本研究构建了一种具有强渗透性和杀菌性的Pickering乳液。该Pickering乳液以天然抗菌剂丁香油为油相内核,以稳定吸附在油水界面的正电壳聚糖纳米颗粒(CS-NPs)为外壳,通过与负电胞外基质的静电相互作用,实现对细菌生物膜的强渗透。制备的壳聚糖纳米颗粒平均粒径为590.30±3.90 nm,多分散性指数PDI为0.125±0.003,平均电势为15.60±0.40 m V。Pickering乳液平均粒径为2312±53 nm,多分散性指数PDI为0.137±0.013,平均电势为26.45±0.55 m V。细菌生物膜渗透实验与杀菌性能实验表明,该Pickering乳液对细菌生物膜有较强的渗透能力,并能有效地杀伤细菌。该Pickering乳液有望用于治疗人体与细菌生物膜相关的持续性感染

    An investigation on social psychological characteristics of Hunan populace during the period of SARS

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    通过问卷调查 ,首先对湖南民众在非典时期的社会心理状况进行描述分析 ,随后对不同年龄、文化程度、职业类型的民众的社会心理特征进行了比较研究 ,并在此基础上为战胜非典的舆论导向和领导决策提供了相应的心理学依据和对

    用于刚性机械手结构拓扑优化的叠加方法

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    针对考虑动态载荷条件的刚性机器手连杆的拓扑优化问题,提出了一种类似于等效静载荷技术的综合拓扑叠加方法。该方法是将对应于不同角度位置的单个最佳拓扑叠加,以便在所有角度位置都有较好的综合效果;然后,进行归一化和再惩罚,以获得所需的体积分数。此外,利用图像处理技术进行后处理,可以降低应力值和几何复杂度。通过理论仿真,对该方法所得综合拓扑的性能进行了评估,并以3自由度工业机械手刚性连杆为例进行了验证。结果表明,体积分数降低30%的情况下可将关节转矩降低24.9%,同时,具有更好的挠度和应力值。与任何一种单个优化拓扑相比,综合拓扑的挠度和应力值降低了10%~25%

    Development of Analytical Chemistry and It's Teaching Reform

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    结合分析化学的发展,对当前分析化学教学中存在的问题进行了分析,提出了理工融合新体系分析化学课程体系、教学内容及教学方法改革的初步方案.Abstract:The development of analytical chemistry was summarized .The problems in present education of analytical chemistry were discussed .The reform measures of course system 、teaching content and teaching method of analytical chemistry were studied

    Optimization of ultrafiltration technology for purification of nucleotide

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    从膜通量、蛋白去除率、核苷酸收率、膜污染和膜清洗等方面考察了5种不同型号的Ultra-floTM超滤膜过滤RNA酶解液的效果。实验表明3#(MWCO30 kD,CA)Ultra-floTM超滤膜同时具有高收率(96.4%)、高蛋白去除率(81.3%)、高膜通量(65.6L.m-2.h-1)、易清洗(水通量恢复99%)的优点,不仅可以替代通常使用的中空纤维膜,且通量大、污染小、易清洗,使该过程得到优化。The filt ration performances of enzymatic RNA degradation liquid wit h five different Ult ra2flo TM ult ra2 filt ration membranes have been st udied by comparing flux , protein rejection , nucleotide yield , membrane foul2 ing and membrane cleaning. The result s show t hat 3 # Ult ra2flo TM ult rafilt ration membrane (MWCO 30kD) was t he optimum , having a high nucleotide yield (96. 4 %) , high protein rejection (81. 3 %) , high flux (65. 6L ·m- 1 ·h - 1 ) , high recovery ratio of water flux (99 %) . This characteristic of high flux , low fouling and easy cleaning leads us to conclude t hat 3 # Ult ra2flo TM ult rafilt ration membrane was a good candidate for replacing t he com2 monly used hollow fiber membrane to achieve an optimized filt ration of enzymatic RNA degradation liquid.福建省科技重点资助项目(2000-I-015);福建省青年科技人才创新资助项目(2001J065)
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