台湾桤木林草复合模式根际与非根际氮特征

以台湾桤木+扁穗牛鞭草(模式A)和台湾桤木+自然杂草(模式B)两种模式为研究对象,研究并分析了两模式下台湾桤木、扁穗牛鞭草和自然杂草根际与非根际土的全氮、速效氮、铵态氮及其pH。结果表明:①两种模式下,根际养分均高于非根际养分,表现出明显的正根际效应和强烈的富集作用,在采样月根际土与非根际土间均有显著性差异,但在是从年平均来看并没有差异; ②A模式台湾桤木根际土(AAR)与B模式台湾桤木根际土(BAR),A模式草本根际土(AHR)与B模式草本根际土(BHR),A模式非根际土(AS)与B模式非根际土(BS)进行配对t检验,发现速效氮及铵态氮含量均没有显著性差异(p>0.05); 全氮含量在AAR与BAR、AS与BS之间没有显著性差异(p>0.05),但在AHR与BHR间有显著性差异(p<0.05); ③台湾桤木林内草本的变化对系统氮含量影响较小,只是扁穗牛鞭草改变了台湾桤木对全氮、速效氮和铵态氮的富集态势。     

台湾桤木与黑麦草复合模式细根和草根的 分解及养分动态

采用网袋法对台湾桤木与黑麦草复合模式下的细根和草根分解及养分释放进行了为期1年的研究。结果表明：直径0~1 mm、1~2 mm、0~2 mm台湾桤木细根、黑麦草草根、混合根(台湾桤木0~2 mm细根与草根质量比1∶1混合)的干质量残留率分别为39.47%、32.23%、37.11%、16.93%、24.05%,应用Olson指数方程模拟细根和草根的分解过程,拟合程度较好(p<0.01)。分解初期细根N、P、Ca的浓度存在上升趋势,K浓度则明显下降,Mg浓度变化平稳,草根和混合根N、K浓度变化趋势与细根的相同,其余的养分浓度与细根的浓度表现出不同规律。细根和草根分解过程中K、Mg、P的残留率与其干质量残留率变化相似,而N、Ca的残留率下降则较平缓;元素释放速率以K最快,其次为Mg、P、N,Ca最慢。混合处理的分解速率和N、P、K、Ca释放率介于单独分解的0~2 mm细根和草根相应释放率之间,而Mg释放率则大于单独分解的0~2 mm细根和草根的释放率。     

秦岭南坡油松和锐齿栎群落凋落叶碳释放及其与分解的关系

利用野外分解袋法分别对秦岭南坡油松和锐齿栎群落内凋落叶进行了为期24个月的分解试验.研究了凋落叶C释放过程及其与凋落叶分解过程中N、P释放和C/N、C/P比值变化的关系.研究结果表明:(1)油松群落凋落层(11265.58kg/hm2)C密度显著大于锐齿栎群落凋落层C密度(3047.31kg/hm2)(P<0.01),达到了3.7倍;(2)在凋落叶分解初期,2个群落凋落叶中碳含量均呈现先增加后下降的趋势,锐齿栎凋落叶C释放速率大于油松凋落叶C释放速率(P<0.01);(3)在两种群落类型凋落叶分解过程中,碳剩余百分率随时间变化规律符合Olson分解指数模型(R>0.81);(4)凋落叶C剩余百分率与凋落叶和N、P剩余百分率之间具有显著的二项式回归关系(锐齿栎凋落叶P剩余百分率除外),与凋落叶C/N、C/P呈显著的线性相关关系.凋落叶的C释放对凋落叶分解速率、养分元素的释放以及整个森林生态系统的物质循环过程产生显著的影响.     

中国森林凋落物分解速率的空间格局及 主控因子:基于最优线性混合模型

基于与中国森林生态系统凋落物的分解速率有关的国内外文献资料,共收集覆盖热带、亚热带与温带3大气候区的569个分解速率记录,在此基础上建立了最优线性混合模型,分析了环境因子、凋落物基质质量和自身物理特征对凋落物分解速率的影响,揭示了影响凋落物分解的主控环境因子和空间格局差异.结果表明:分解速率随温度、降水、初始N、K质量分数的增加而增加,随海拔、纬度、分解时间、初始C质量分数、w(C)/w(N)、w(木质素)/w(N)、w(C)/w(P)的增加而减小;天然林和人工林凋落物分解速率无显著差异,阔叶林分解快于针叶林,针阔混交林与针叶林分解无显著差异,凋落物枝的分解速率显著低于其他组分;在全国大的空间尺度上,环境因素很重要,它们能够解释森林凋落物分解速率85%的变异,其中网孔、分解时间和海拔是森林凋落物分解的主控因子,而网孔和温度、网孔和海拔、海拔和分解时间分别为阔叶林、针叶林和针阔混交林的分解速率的主控因子.反演的中国森林凋落物的分解速率存在较大的空间异质性,其值大多为0.2~2.0.     

人工湿地3种植物凋落物分解及其对水位降低的响应

为了解人工湿地种植的3种植物凋落物分解特征,采用网袋法,通过1 a的凋落物分解实验,研究了人工湿地3种植物(美人蕉、狭叶香蒲和梭鱼草)凋落物储量、凋落物分解动态及其对水位降低的响应.结果表明：美人蕉、狭叶香蒲和梭鱼草3种植物凋落物储量分别为1 887.83、1 073.25、2 358.86 g·m－2;分解1 a后,3种凋落物年分解率各自为63.5%、46.5%、61.1%,且它们之间存在差异显著(p<0.05).通过Olson 经典指数模型拟合的3种凋落物分解方程,表明了美人蕉凋落物分解速率最高(k＝0.063),其次为梭鱼草(k＝0.047),最小为狭叶香蒲(k＝0.032);湿地植物立枯期间,模拟3种植物美人蕉、狭叶香蒲、梭鱼草的枯落物(叶)在立枯期间的分解速率比枯落物死亡后放置地表的分解速率各自减少6.9%、8.6%和6.9%.人工湿地岸带,水位降低,美人蕉、狭叶香蒲、梭鱼草3种植物凋落物的分解速率分别较水淹条件下增加了33.8%、42.5%和69.6%.这些结果表明气候变暖,可能降低湿地岸带水位,进而增强湿地碳释放.     

黔中喀斯特地区典型次生林内凋落叶化学计量特征

为了研究退化喀斯特森林养分循环特征,以黔中喀斯特常绿落叶阔叶次生林内的10个优势种凋落叶为对象,开展化学计量学特征研究。研究结果表明:凋落叶中C、N、P元素与凋落叶的质量比分别为(497.88±12.97)mg/g、(12.19±0.54)mg/g和(0.89±0.05)mg/g。m(C)∶m(N)、m(C)∶m(P)和m(N)∶m(P)值分别为43.17±2.07、620.03±42.33和14.60±0.81。不同生活型树种凋落叶中C和P元素与凋落叶的质量比及m(C)∶m(P)均表现为常绿树种大于落叶树种(P0.05)。凋落叶中N、P与凋落叶的质量比呈正相关。同其他研究结果相比,喀斯特地区树种凋落叶中C、N、P元素与凋落叶的质量比具有地域差异。黔中次生森林凋落叶中C、N、P与凋落叶的质量比普遍较高,凋落叶的分解速率较快,N、P元素成比例矿化释放,但是矿质养分和凋落叶的分解不受有机物与凋落叶质量比的影响。     

不同林龄油松针叶凋落物初期分解特性比较

应用凋落袋法,研究了北京山区24、32、40年生油松(Pinus tabulaeformis)人工林针叶凋落物初始化学组成、分解速率以及养分释放过程。结果表明:凋落物初始基质无机养分含量、灰分、粗蛋白、C/N在3个林龄之间差异性明显(p<0.05)。凋落物失重率季节动态变化表现为双峰型,且季节变化明显。随着林龄的增大,针叶凋落物年平均分解速率、分解系数k值逐渐增大。通过重复测量设计的方差分析可知,随着分解时间的延长,失重率、N剩余百分率在不同林龄间均有显著性差异,而P、K、Ca、Mg元素的积累释放受林龄影响不明显(p<0.05)。     

杨-桤混交林及其凋落物对土壤氮矿化的影响

【目的】研究含氮量中等的立地条件下杨-桤混交林相比于杨树纯林能否增加土壤养分,分析桤木是否为合适的固氮树种,探讨桤木与杨树营造混交林以缓解人工林连栽带来的土地肥力衰退问题。【方法】以苏北地区杨树人工纯林以及杨-桤(1∶1)混交林为研究对象,采用尼龙网袋法观察两种林分下凋落叶质量分解以及养分释放的过程,比较两种凋落物处理(去除凋落物与保留凋落物)对土壤全氮以及碱解氮含量的影响。采用树脂芯田间原位培养法,研究杨-桤混交林与杨树纯林两种林分在两种凋落物处理下,林地土壤氮年净矿化量的变化。【结果】营造杨-桤混交林显著提高了林地土壤全氮和碱解氮含量。杨树纯林凋落物分解时需从周围土壤中吸收更多氮素,且分解速率较慢。杨-桤混交林凋落物分解更快进入氮释放状态,因此去除凋落物后混交林土壤碱解氮显著减少。保留凋落物处理下,杨-桤混交林中每公顷土壤氮年净氨化量显著高于杨树纯林中的,去除凋落物后两者差异不显著。【结论】研究发现,桤木是杨树较合适的伴生树种,营造杨-桤混交林可以起到增加土壤全氮和碱解氮含量的作用,有助于缓解杨树纯林连栽带来的地力下降问题。混交林凋落物分解速率与氮素释放速率更快,有利于人工林生态系统氮循环。保留凋落物处理下,混交林中每公顷土壤氮年净氨化量显著高于杨树纯林的,而每公顷土壤氮年净硝化量没有显著差异,表明混交林凋落物分解释放的氮素主要促进土壤氨化过程,对土壤硝化过程影响较弱。     

中国陆地生态系统叶凋落物分解的格局及控制因素

分析我国大空间尺度下气候对叶凋落物分解的调控机制,可以为预测中国生物地球循环对未来气候变化的响应提供理论基础和数据支持。针对我国大空间尺度下叶凋落物的分解建立数据库,中国叶凋落物平均分解速率为0. 726y-1,其中阔叶草本针叶。分解速率与年均温、年均降水、凋落物N、P和K含量正相关,而与凋落物C、纤维素和木质素含量负相关。本研究证明气候可以直接影响凋落物分解,但是并不支持气候通过凋落物性质而间接影响凋落物分解这一观点。年均降水和凋落物养分含量解释了全部叶凋落物分解速率85. 4%的变异,而年均降水和凋落物纤维素含量解释了阔叶凋落物分解速率84%的变异。这些结果表明,大空间尺度下,气候和凋落物性质直接影响着中国陆地叶凋落物分解,且气候比凋落物性质更重要。     

外来植物薇甘菊对本地植物凋落物分解的影响

 外来植物薇甘菊（Mikania micrantha HBK.）已入侵华南许多地区,并造成严重危害。探讨了外来植物薇甘菊凋落物对4种本地植物大叶榕（Ficus virens）、潺槁树（Litsea glutinosa）、樟树（Cinnamomum camphora）和台湾相思（Acacia confusa）凋落物分解的影响。凋落物分解采用网袋法,将薇甘菊凋落物分别与本地植物凋落物按3个比例混合,3个比例为,m（薇甘菊）∶m（本地植物） = M₁（1∶4）,M₂（1∶1）和M₃（4∶1）。分解60 d后,测定凋落物的分解速率与养分释放。结果表明,薇甘菊与本地植物凋落物混合比例为M₁时,凋落物分解速率变慢,但在M₃时,凋落物的分解速率变快。与单独本地凋落物养分释放相比,薇甘菊凋落物混入后C释放有所下降,而N素释放量有所提高,这种N释放量的增加可能会对薇甘菊的入侵产生正反馈作用。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.