杉木干燥过程中的有机挥发物释放

采用小型干燥机干燥木材,在冰浴中用酸化的2,4-二硝基苯肼溶液和去离子水分别对尾气中醛类和有机酸、醇类采样,用活性炭管对萜烯类采样,采用高效液相色谱仪和气相色谱仪对有机挥发物进行分析.结果表明:杉木干燥释放的主要物质是甲醇、乙酸和甲酸,其次是乙醛、甲醛、丙烯醛/丙酮;萜烯类挥发物主要有α-蒎烯、D-柠檬烯、莰烯、β-蒎烯、β-水芹烯.杉木高温干燥释放的醛类和酸、醇类挥发物远高于常规干燥,高温和常规干燥中挥发物总量分别为91.7 g·m-3和29.9 g·m-3,但萜烯类挥发物总量差异很小.木材干燥终含水率对醛类和有机酸、醇类释放量影响较大,对萜烯类释放量影响较小.甲醛高温干燥时随含水率降低释放速率增大,其他物质在高温和常规干燥时的释放速率随含水率减少呈下降趋势.     

尾叶桉干燥过程中有机挥发物释放的研究

采用小型干燥机干燥木材,采用高效液相色谱仪和气相色谱仪对干燥过程中释放的有机挥发物进行分析。结果表明,尾叶桉干燥释放的主要物质是甲醇、乙酸,其次是甲酸、乙醛、甲醛、丙烯醛/丙酮,而萜烯类挥发物很少。尾叶桉高温干燥释放的挥发物比常规干燥明显增多,尾气中甲醇浓度超过标准限值。甲醛高温干燥时随含水率降低释放速率增大,其它物质在高温和常规干燥时的释放速率随含水率减少呈下降趋势。     

辐射松与杉木在高温干燥中萜烯类释放浓度研究

以40 mm厚的辐射松(Pinus radiata)和人工林杉木(Cunninghamia lanceolat)锯材为对象,研究高温干燥过程中干燥温度和锯材含水率对萜烯类产物释放浓度的影响,并与辐射松常规干燥中的萜烯类释放浓度作比较。高温和常规干燥过程中采抽气样次数均为5次,抽气速度为1.0 L/min,采样时间为30 min,采用Tenax管收集干燥过程中萜烯类产物,用气相色谱仪分析其成分及浓度。结果表明:高温干燥辐射松萜烯类释放浓度高于常规干燥辐射松与高温干燥人工林杉木,但萜烯类挥发物的组分有所差别。常规干燥辐射松锯材萜烯类释放浓度对环境是安全的,然而在高温干燥过程中,尤其在干燥中后期,当萜烯类挥发物浓度大于1.5 mg/m3时,对辐射松和人工林杉木释放萜烯类挥发物应采取回收措施,以确保对环境的安全。     

杨木热解过程中的有机挥发物释放

研究了杨木[populus tremula]在120～300℃温度范围内热解过程中释放的VOC成分与含量,采用热重红外联用仪分析了杨木的失重和热解速度,以及热解产物的官能团,在此基础上用热解气质联用仪对杨木热解过程中释放的VOC进行分析。结果表明:杨木在热解过程中释放的VOC主要为酚类,其次是酮类、酸类、醇类、醛类。该研究旨在为木材热改性过程中有机挥发物控制处理技术和排放标准提供理论基础。     

山楂和枣释放BVOCs组分生长季动态变化特征研究

【目的】探究北京地区经济林树种山楂和枣不同时期释放植物源挥发性有机物(BVOCs)组成成分的变化规律,以及两者释放有益BVOCs特征。【方法】采用动态顶空采集法收集释放的BVOCs,结合自动热脱附-气相色谱/质谱联用技术进行分析。【结果】在整个生长季从山楂叶中共检测出12类328种BVOCs,从枣叶中共检测出12类301种BVOCs,枣叶释放类别的数量与山楂叶相同,释放种类少于山楂叶,两树种均在9月释放类别最多;山楂叶和枣叶主要释放烷烃类、烯烃类和芳香烃类、酯类和醇类BVOCs;枣叶主要释放烷烃类、烯烃类、芳香烃类、酯类、醛类和醇类BVOCs,其中天然壬醛山楂叶和枣叶每月都有释放,但枣叶每月释放BVOCs的种类更加丰富;山楂是烯烃类夏季高释放量树种,枣是春季芳香烃高释放量树种;从山楂叶中共检测出烯烃类、芳香烃类、酯类、醛类、有机酸类、酮类、醇类和酰胺类8类43种有益成分,而枣叶不释放酮类,释放种类总数量比山楂叶多。【结论】两个树种释放烯烃类有益BVOCs在总有益BVOCs成分中占比最大,以释放对薄荷-1(7),3-二烯、α-蒎烯、罗汉柏烯、3-蒈烯、右旋萜二烯为主,夏季是山楂叶和枣叶释...     

不同水性高分子异氰酸酯胶对人工林木材胶合性能的影响

采用同一类型的高分子化合物、填料和乳胶按不同配比组成2种主剂,然后与贮存期不等的交联剂组成不同的水性高分子异氰酸酯胶黏剂(API),用来黏接杉木、杨木、巨桉、尾巨桉、柠檬桉和窿缘桉等6种人工林木材试样以研究 API主剂特征和交联剂贮存时间对人工林木材胶合性能的影响。试验结果表明:1)API主剂特征显著影响6种人工林木材的胶合性能。2)随着交联剂贮存期的增长,人工林试材的胶合性能有降低趋势,但胶合杉木、杨树、巨桉和尾巨桉4 种人工林木材时仍能达到标准要求。     

松材室干过程中VOCs释放规律研究

木材干燥排放的尾气因含有对环境有害的VOCs而备受关注。以企业实际运行的木材干燥过程为研究对象,采样研究了松材在室干过程中VOCs的释放规律,包括VOCs采样方式、采样时间以及采样点对VOCs释放的影响。结果表明:松材在室干过程中释放醛类及萜烯类等化合物25种,其中甲醛与乙醛浓度高于国标规定的污染物排放浓度限值,苯与丙烯醛浓度低于排放限值;采样40 min测得的VOCs释放量高于采样20 min;不同采样点的VOCs释放量有差别;采样方式对VOCs释放无明显影响。总有机挥发物释放量呈先升高,后降低,再升高的趋势,在含水率为30%左右达到最大。     

大气候室测定家具中甲醛及其他VOC的释放量

采用30m(3)大气候室测定家具中释放的甲醛和其他有机挥发物,并用气相色谱仪和液相色谱仪等分析.结果表明:家具中释放的甲醛和总有机挥发物(TVOC),超过相关标准限量;TVOC中二甲苯、乙酸丁酯和正十一烷相对较多;甲醛为总醛类挥发物的88%.基材甲醛释放量为E2级时,通过贴面并涂饰处理,仍不能阻止甲醛的释放.     

马尾松的综合作用

马尾松(Pinus massoniana Lamb)是一种人人皆知的速生快长适应性极强的造林绿化先锋树种。在广西各地,马尾松举目可见,在利用上给人们印象最深的是可采割松脂和利用木材。其实,马尾松全身都是宝,它的叶、花、果、皮和树根都可利用,并与人类生活息息相关。叶——马尾松针叶,通过光合作用吸收 CO_2放出 O_2,释放萜烯类挥发物。每公斤松针叶含胡罗卜素291.87毫克,叶绿素1840毫克,含蛋白质12.2%、粗脂肪13.5%、维生素16.2%、钙0.84%、磷     

侧柏春季挥发物浓度日变化规律及其影响因子研究

采用动态顶空吸附采集法对侧柏春季释放的挥发物(Volatile Organic Compounds,VOCs)进行采集,同时利用Li-cor6400便携式光合系统测定仪测定其主要光合生理指标,分析了侧柏春季挥发物的主要成分、日变化规律及其影响因子.结果表明:(1)侧柏挥发物成分包括9类106种,主要挥发物成分是萜烯类化...     

Simultaneous determination of Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography

A new method of simultaneous determining Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography was developed. The experiment condition was studied and the results show that the optimum base solution is that the residue got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1.0 mol/L ammonia-ammonium chloride, 5.0 mL 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL with water. Under the condition of this base solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution, Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) in synthetic samples were determined with relative errors 0.4–9.4% and relative standard deviations 0.8%-12.2%. Under this experiment condition, one fold of Pb(II), Cr(VI) and Mo(VI) do not interfere with the determination for Cu(II). This method has been used to the simultaneous determination of the amount of the six cations in the samples of soil and Beiqi Tea. The relative standard deviations were 0. l%-2.1% and recoveries were 93.5%-99.0 %.     

沙棘果实生长期间维生素含量变化研究

本文对乌鞘岭地区天然分布的中国沙棘和西藏沙棘果实生长与成熟期间维生素C,PP,E等含量的动态变化进行了系统的调查和分析测定。结果表明:V_C主要存在于果肉中,且随果实发育而增加,果实变色期(花后107—110天)达到最高值,随后急速下降。但完熟后果肉中V_C减少时种子内V_C却有所增加。中国沙棘V_C水平远较西藏沙棘为高(5倍以上)。果实发育前期果肉中V_(PP)含量很高,以后逐渐下降,完熟期中国沙棘果实内V_(PP)再度升高,其变化与呼吸速率的变化表现出相同的消长规律。V_E主要存在于种子里,总趋势是随成熟而增加。种子变色期V_E上升至第一高峰值,随后下降,果实完熟后达到第二高峰值。西藏沙棘V_E含量高于中国沙棘。本文对不同维生素可能起的生理作用也进行了讨论。     

Soil Carbon and Nitrogen Stocks Under Plantations in Gambo District,Southern Ethiopia

The effect of six plantation species in comparison to natural forest (NF) on soil organic carbon (SOC) and total nitrogen (TN) stocks, depth-wise distribution, biomass carbon (C), and N was investigated on plantations and cultivated lands on an Andic paleudalf soil in Southern Ethiopia. The SOC, N, and bulk density were determined from samples taken in 4 replicates from 10-, 20-, 40-, 60-, and 100-cm depth under each site. Similarly, the biomass C and N of the plantation species and understory vegetation were also determined. The SOC and N were concentrated in the 0- to 10-cm depth and decreased progressively to the 1-m depth. Next to the NF, Juniperous procera accrued higher SOC and N in all depths than the corresponding plantations. No evidence of significant difference on SOC and N distribution among plantations was observed below the 10-cm depth with minor exceptions. The plantations accrue from 133.62 to 213.73 Mg ha^–1 or 59.1 to 94.5% SOC, 230.4 to 497.3 Mg ha^–1 or 6.9 to 14.9% TBC and 420.37 to 672.80 Mg ha^–1 or 12.5 to 20% total C-pool of that under the NF. The N stock under Juniperous procera was the highest, while the lowest was under Eucalyptus globulus and Cupressus lusitanica. We suggest that SOC and N sequestration can be enhanced through mixed cropping and because the performance of the native species Juniperous procera is encouraging, it should be planted to restock its habitat.     

Model estimates of net primary productivity,evapotranspiration, and water use efficiency in the terrestrial ecosystems of the southern United States during 1895–2007

The effects of global change on ecosystem productivity and water resources in the southern United States (SUS), a traditionally ‘water-rich’ region and the ‘timber basket’ of the country, are not well quantified. We carried out several simulation experiments to quantify ecosystem net primary productivity (NPP), evapotranspiration (ET) and water use efficiency (WUE) (i.e., NPP/ET) in the SUS by employing an integrated process-based ecosystem model (Dynamic Land Ecosystem Model, DLEM). The results indicated that the average ET in the SUS was 710 mm during 1895–2007. As a whole, the annual ET increased and decreased slightly during the first and second half of the study period, respectively. The mean regional total NPP was 1.18 Pg C/yr (525.2 g C/m²/yr) during 1895–2007. NPP increased consistently from 1895 to 2007 with a rate of 2.5 Tg C/yr or 1.10 g C/m²/yr, representing a 27% increase. The average WUE was about 0.71 g C/kg H₂O and increased about 25% from 1895 to 2007. The rather stable ET might explain the resulting increase in WUE. The average WUE of different biomes followed an order of: forest (0.93 g C/kg H₂O) > wetland (0.75 g C/kg H₂O) > grassland (0.58 g C/kg H₂O) > cropland (0.54 g C/kg H₂O) > shrubland (0.45 g C/kg H₂O). WUE of cropland increased the fastest (by 30%), followed by shrubland (17%) and grassland (9%), while WUE of forest and wetland changed little from the period of 1895–1950 to the period of 1951–2007. NPP, ET and WUE showed substantial inter-annual and spatial variability, which was induced by the non-uniform distribution patterns and change rates of environmental factors across the SUS. We concluded that an accurate projection of the regional impact of climate change on carbon and water resources must consider the spatial variability of ecosystem water use efficiency across biomes as well as the interactions among all stresses, especially land-use and land-cover change and climate.     

松材线虫侵染对马尾松苯丙烷类代谢的影响

1.5年生马尾松植株接种松材线虫后,苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)的活性水平均高于对照,活性高峰通常出现在症状表现前夕,并在植株发病后下降.叶内PAL和POD活性高峰的出现晚于茎,与叶部病害发展一致.茎中酚类物质的含量随着线虫侵染时间的延长逐渐增加,至发病时达到高峰.酚类物质含量的变化与PAL、POD、PPO 3种酶活性的变化趋势基本一致.松材线虫的侵染明显影响寄主植物的苯丙烷类代谢,由此可知,松材线虫病的发生发展与松材线虫诱导感病寄主苯丙烷类代谢的异常变化有关.     

运用Cytb 和12s rRNA 基因鉴别梅花鹿(Cervus nippon)和马鹿(Cervus elaphus)的研究

本研究介绍了运用细胞色素b基因和12s核糖体RNA基因部分序列的系统学和核甘酸距离分析来鉴别降解的梅花鹿和马鹿样品。采用PCR和直接测序技术获得了8份嫌疑样品402bp细胞色素b基因序列,并与来自GenBank数据库27份同源的细胞色素b基因序列进行比对。3份嫌疑样品与梅花鹿的核甘酸距离值相同(0.026±0.006),小于梅花鹿与东部马鹿间最小的核甘酸距离值(0.036)。并且梅花鹿和马鹿的系统学分析表明这些样品与梅花鹿聚为一枝,因此可以推测它们来源于梅花鹿。同样的方法得出另3份嫌疑样品来源于马鹿。该结果被387bp12s核糖体RNA基因序列的系统学和核甘酸距离分析进一步证实。该方法是有效的,花费的时间少,能帮助减少同类野生动物案件的发生。图2表1参13。     

两种卵蜂在舞毒蛾卵上的寄生动态

北京地区大蛾卵跳小蜂和舞毒蛾卵平腹小蜂在舞毒蛾卵上一年可以分别完成４－５代和２—３代。两种卵蜂对舞毒蛾的寄生率因采集时期不同而有差异，以８月采集的卵块寄生率最高。７月中旬至８月中旬采集的卵中大蛾卵跳小蜂的寄生率为２．２６—４．１８％。７月中下旬采集的，舞毒蛾卵平腹小蜂的寄生率为０．６４—０．６６％。大蛾卵跳小蜂当年羽化的占９９．３％，次年羽化的占０．７％。舞毒蛾卵平腹小蜂当年羽化的占８１．０％，次年羽化的为１９．０％。为保护两种卵蜂，人工采摘卵块除治舞毒蛾的最好时期是９月下旬至次年３月下旬。     

GIS在生态土地分类中的作用

This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province. Foundation item: This paper was supported by Chinese Academy of Sciences “100 people” project and the Open Research Station of Changbai Mountain Forest Ecosystem. Biography: XIAO Bao-ying (1974-), female, postgraduate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. China Responsible editor: Zhu Hong     

MF—97三聚氰胺—甲醛树脂对中密度纤维板（MDF）耐湿性能影响初探

本文着重介绍了用ＭＦ－９７三聚氰胺－甲醛树脂制备准耐水级ＭＤＦ的结果。     

在生态土地分类中的作用(英文)

本文描述了研究区吉林省东部山区的地文景观特点和自然植被状况,阐述了生态土地分类的定义、基本特点及发展。根据研究区的地形图和卫片结合试点的劲松林场480个样点植被现状的调查数据,探讨了基于坡度、坡向、植被和海拔的四个分类因素下的5类和15类生态土地类型图。生态分类系统是确定、描述和绘制生态系统类型图的方法。本文研究是生态分类系统在吉林省东部针阔混交林区试验应用的一部分。图5表1参14。