Litter- and ecosystem-driven decomposition under elevated CO2 and enhanced N deposition in a Sphagnum peatland

Peatlands represent massive global C pools and sinks. Carbon accumulation depends on the ratio between net primary production and decomposition, both of which can change under projected increases of atmospheric CO₂ and N deposition. The decomposition of litter is influenced by 1) the quality of the litter, and 2) the microenvironmental conditions in which the litter decomposes. This study aims at experimentally testing the effects of these two drivers in the context of global change. We studied the in situ litter decomposition from three common peatland species (Eriophorum vaginatum, Polytrichum strictum and Sphagnum fallax) collected after one year of litter production under pre-treatment conditions (elevated CO₂: 560 ppm or enhanced N: 3 g m⁻² y⁻¹ NH₄NO₃) and decomposed the following year under treatment conditions (same as pre-treatment). By considering the cross-effects between pre-treatments and treatments, we distinguished between the effects on mass loss of 1) the pre-treatment-induced litter quality and 2) the treatment conditions under which the litters were decomposing. The combination between CO₂ pre-treatment and CO₂ treatment reduced Polytrichum decomposition by −24% and this can be explained by litter quality-driven decomposition changes brought by the pre-treatment. CO₂ pre-treatment reduced Eriophorum litter quality, although this was not sufficient to predict decomposition. The N addition pre-treatment reduced the decomposition of Eriophorum, due to enhanced lignin and soluble phenols concentrations in the initial litter, and reduced litter-driven losses of starch and enhanced litter-driven losses of soluble phenols. While decomposition indices based on initial litter quality provide a broad explanation of quantitative and qualitative decomposition, they can only be taken as first approximations. Indeed, the microbial ATP activity, the litter N loss and resulting litter quality, were strongly altered irrespective of the compounds' initial concentration and by means of processes that occurred independently of the initial litter-qualitative changes. The experimental design was valuable to assess litter- and ecosystem-driven decomposition pathways simultaneously or independently. The ability to separate these two drivers makes it possible to attest the presence of litter-qualitative changes even without any litter biochemical determinations, and shows the screening potential of this approach for future experiments dealing with multiple plant species.     

萘胺类化合物缓解家蚕氟中毒的效果

用氟敏指数和过氧化氢酶活性为指标 ,测定萘胺类化合物 (CRL)和增效剂的解毒效果。其结果为CRL和增效剂有良好的解毒效果。NaF、NaF +CRL、NaF +CRL +增效剂 3种处理的氟敏指数依次递减 ,而过氧化氢酶活性的大小依次为NaF处理区 >NaF +CRL处理区 >NaF +CRL +增效剂处理区 >对照。     

绵羊中草药饲料添加剂预试初报

为了帮助我国北方旱区或半干旱区绵羊度过草枯严寒的漫长冬、春季，开发研制一种能够提高现有草料利用率的绵羊中草药饲料添加剂。根据中兽医药学的辨证施治理论，采用小鼠日粮添加倍量秸秆粉和不同中草药复方的方法，在120只小鼠上进行了增重率和重料比的中草药复方的筛选研究。结果表明，以益气养血和消食健胃为主的两个中草药复方能够较好地改善小鼠的增重率和重料比。     

金银花和红银花挥发性成分的顶空固相微萃取#br# 气质联用检测与比较

 采用顶空固相微萃取气质联用（SPME–GC–MS）的方法检测红银花与金银花新鲜花蕾和 干花蕾的挥发性成分。4 种花蕾样品共鉴定出67 种挥发性物质,其中新鲜红银花与金银花分别检测出48 种和46 种,经烘干处理的干红银花与金银花分别检测出34 种和37 种。[3.2.1.0（1,5）]三环辛烷、β– 芳樟醇、5–甲基–2–己醇和以及十六烷是4 种样品共有的成分。其中红银花挥发性成分主要以烃类、 醇酮类为主,β–芳樟醇含量显著高于金银花;样品在由新鲜到烘干这一过程中,烃类和酯类挥发性物质 含量降低,醛类和醇酮类挥发性物质显著增加。     

不溶性胞壁结合酚类物质在棉花对枯萎病抗性中的作用

分析了枯萎病菌侵染后棉花叶片和根茎部组织中不溶性胞壁结合酚类物质 (胞壁结合的简单酚、复杂酚聚合物及黄酮醇 )含量的变化。结果表明 ,抗病品种棉苗中不溶性胞壁结合酚类物质含量高于感病品种 ,同一品种内根茎部组织中含量较高 ;氟乐灵播前土壤处理可诱发棉苗产生对枯萎病的诱导抗性 ,同时也促进了棉苗组织中不溶性胞壁结合酚类物质的积累 ;枯萎病菌侵染后棉苗组织中不溶性胞壁结合酚类物质含量明显增加 ,抗病品种棉苗和经氟乐灵处理的棉苗受侵后不溶性胞壁结合酚类物质含量的增加分别大于感病品种棉苗和未经氟乐灵处理棉苗中的增加水平。这些结果说明 ,不溶性胞壁结合酚类物质在棉花对枯萎病的抗性及由氟乐灵诱发的诱导抗性中起作用     

Control of Volatile Organic Compounds Pollution Caused by Building and Decoration Materials

The importance of indoor air quality and the effect of volatile organic compounds(VOC) on human health are discussed in this paper,TVOC as a measurement for evaluation of VOC and the VOC pollution control methods and technology for indoor air are also presented.     

低分子量有机酸对不同合成磷源的释磷效应

采用化学浸提方法,研究了5种低分子量有机酸(草酸、柠檬酸、酒石酸、苹果酸、乙酸)对不同合成磷源的释磷效应。结果表明:供试有机酸(低浓度乙酸除外)均能促进不同合成磷源(DCP、OCP、FA、Fe-P、A l-P)中磷素的释放;其释磷效果与有机酸的种类和浓度有关,强弱顺序依次为柠檬酸、草酸、酒石酸、苹果酸、乙酸,有机酸浓度越高其释磷效果越好;有机酸与氟磷灰石(FA)反应后,溶液pH值升高。低浓度条件下pH值变化较大,而高浓度条件下pH值变化较小。     

热脱附-气相色谱质谱法测定挥发性有机化合物的研究

运用自动热脱附仪和气相色谱/质谱联用技术,通过对木制品中释放的多种挥发性有机物(VOCs)进行测试,得到较优的测试处理条件.研究发现,该方法的重现性和稳定性较好;较低的采样流速,可有效的降低苯在Tenax TA吸附管中的穿透行为.     

固液反应球磨制备Al-Cu-Co三元金属间化合物

利用固液反应球磨技术制备了Al-Cu-Co三元合金．分别采用Co球球磨Al-33．2％Cu(此文中的百分比为质量分数)，Al-54％Cu(A12Cu)和Al-70％Cu(A1QJ)二元合金熔体，在923K和973K球磨Al-33．2％Cu熔体12h后生成Al65Co15Cu20粉末；在923K和1023K球磨24h后生成Al69Co25Cu6粉末，在893K和993K分别球磨Al-54％Cu(A12Cu)合金熔体12h和24h后均生成Al65Co15Cu2n粉末；在1123K球磨Al-70％Cu合金熔体24h后生成Al65Co15Cu20粉末．采用Al-Cu-Co固液反应球磨得到的金属间化合物粉末为纳米粒子．同时，对Al-Cu-Co三元合金相形成的规律进行了研究，对固液反应球磨机理进行了探讨．在固液反应球磨过程中，三元合金产物的元素摩尔比接近于二元母合金中的元素摩尔比；三元合金产物成分中固相第三组元的成分含量与二元母合金熔体成分有很大关系；提高反应球磨温度、延长球磨时间有利于三元合金产物的形成；延长球磨时间，形成的三元合金产物中磨球的成分增加；反应球磨温度超出二元母合金熔点越高，球磨反应越容易进行．     

番茄、黄瓜的风味物质及研究

本文对番茄和黄瓜风味品质的研究进行简要的综述。主要从这两种蔬菜的特征风味化合物，芳香物质的主要形成途径，挥发性物质与其它品质性状的关系，风味品质的研究方法，以及形成过程中的重要酶之一脂氧合酶的研究现状等方面进行评述。