Characterization of spatial scaling relationships between vegetation pattern and topography at different directions in Gurbantunggut desert, China

Vegetation striped pattern is a common feature in semiarid and arid landscapes, which is seen as mosaics including vegetated and non-vegetated patches. Identifying scales of pattern in ecological systems and referring patterns to multi-scaled processes that create them are ongoing challenges. The aim of this paper is to study the vegetation patterns and their across-scale relationships between the vegetation and anisotropic topography (W-E and N-S) in 12 transects at Gurbantunggut desert. We used wavelet-based across-scale analysis for extracting information on scales of pattern for those transect data, evaluating their inherent structure, and inferring characteristics of the processes that imposed those patterns at across scales. The results show that, in W-E direction, the scales of vegetation pattern (C. ewersmanniana is at the scale 40 m, H. ammodendron, at 35 m) correspond to the dune ridge/dune valley sequences (appearing at distance of 40 m), and vegetation on mesoscale and large scale are significant cross-scale correlation with topography on mesoscale and large scale in all W-E transects. In N-S direction, there is an irregular pattern of vegetation along the N-S irregular topography, and no unified cross-scale relationships between topography and vegetation on different scales in different transects. Moreover, cross-scale correlation analysis between topography and vegetation provides further detail on hierarchical structure and specific scales in space that strongly influenced the larger patterns. Knowledge of the cross-scale relationships between topography and vegetation could lead to better understanding and management of biological resources in that region. (C) 2010 Elsevier B.V. All rights reserved

Additional file 1: of Millstone Exfoliation: a True Shear Exfoliation for Large-Size Few-Layer Graphene Oxide

Figure S1. SEM micrographs from MOG-30, MOG-60, MOG-90, and as-received graphite. Figure S2. TEM micrographs from MOG-30 and MOG-90. Figure S3. AFM micrographs from MOG-30 and MOG-90 (DOCX 2127 kb

Morphological Control over ZnO Nanostructures from Self-Emulsion Polymerization

Three different morphologies of ZnO nanostructures, such as nanospheres, nanorods, and nanoribbons, were controlled by tuning the ratio of the Zn²⁺ precursor to the 4VP monomer when polymerized in aqueous medium utilizing self-emulsion polymerization. The amphiphilic homopolymer (P4VP) acts as a template to form the ZnO/P4VP nanocomposite. The aspect ratio of the nanostructures is strongly dependent on the molar concentration of the Zn²⁺ precursor and becomes higher as its concentration increases. This results in different morphologies that are consistently repeatable. Pure ZnO was obtained from the ZnO/P4VP nanocomposites by calcination at 400 °C or by solvent washing. The calcination of the nanocomposties resulted in different morphologies, such as spherical, corolla shaped, and nanosheets. In addition, hexagonal nanoblocks, nanorods, and nanoribbons were observed when the polymer was removed from the nanocomposites by washing with chloroform. Removing polymer by solvent washing is a very easy, cost-effective method and has the potential for mass production of pure and highly crystalline ZnO nanostructures with known and controllable morphologies. The nanocomposites and pure ZnO nanostructures obtained after polymer removal were characterized by transmission electron microscopy, high resolution transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses, which confirmed the crystalline nature of the ZnO

Exploration of the Mechanism for Self-Emulsion Polymerization of Amphiphilic Vinylpyridine

A rare self-assembly behavior is observed in a hydrophilic monomer (4-vinylpyridine) (4VP) when polymerized in water with a hydrophilic initiator that results in the production of monodisperse polymeric nanoparticles in a single step. This behavior mimics the behavior obtained with the more commonly reported amphiphilic block copolymers. The synthesis and self-assembly of homopolymer nanoparticle from 4VP without the use of any cross-linker, stabilizing agent, surfactant, or polymeric emulsifier are described along with fundamental aspects of the mechanism of this polymerization. This facile and robust procedure enabled the production of highly monodisperse P4VP nanoparticle with a tunable size ranging from 80 to 445 nm. For the first time, we have investigated the growth mechanism of these polymeric nanoparticles to clarify the mechanism of polymeric nanoparticle formation. This work also provides direct visible evidence through transmission electron microscopy (TEM) images at the nanometer scale, which helps in obtaining a better understanding of the mechanism of self-assembly. The effect of temperature on the size of the polymeric nanoparticles was also examined along with the effect of initiator, monomer, and solvent concentrations. We therefore report a versatile and scalable process for the production of monodisperse polymeric nanoparticles, which we call self-emulsion polymerization (SEP)

新疆滴灌技术专利态势与分析/Analysis of Situation of Drip Irrigation Technology Patent in Xinjiang[J]

为了解新疆滴灌技术专利态势,探讨新疆滴灌技术的研发方向,采用国家知识产权局网站中国专利数据库作为专利数据源,检索并分析新疆滴灌专利数量的发展、专利发明人和申请人情况,IPC技术构成以及相关情况.其结果:①检索出新疆滴灌行业专利213件(其中发明专利70件、实用新型134件和外观设计9件).②2008年以来滴灌专利数量呈急剧增加趋势.③排在前3位的专利申请单位和个人为新疆天业(集团)有限公司、石河子大学及新疆生态与地理研究所.④技术构成显示研究的重点技术为A01G和B01D.⑤A01G与B01D及A01C技术研究关联较为紧密.结论:新疆滴灌技术的发展前景广阔,研究热点和方向集中在A01G和B01D之间.专利研发及创新能力的关键在于专业人才的引进和资金投入

Five nicotinic acetylcholine receptor subunits from the Morotoge shrimp, <i>Pandalopsis japonica</i>: cloning, tissue distribution, and functional expression in <i>Xenopus</i> oocytes

<div><p>The nicotinic acetylcholine receptor (nAChR) is a member of the ligand-gated ion channel (LGIC) family and is composed of five subunits arranged around a central pore. Expressed sequence tag screening and traditional cloning strategies revealed five full-length cDNAs encoding nAChR subunit homologs (Pajα3, Pajα10, Pajα11, Pajα12, and Pajβ1) in the Morotoge shrimp, <i>Pandalopsis japonica</i>. The nAChR subunits exhibited common structural characteristics, including a signal peptide sequence, a large N-terminal extracellular domain with conserved motifs for ligand binding (loops A–F), and a transmembrane (TM) domain with four hydrophobic TM motifs (TM1–TM4). Based on the conserved GEK motifs located just before TM2, all five nAChR subunits from <i>P. japonica</i> appear to be cation-selective ion channels. Among the five subunits, Pajα3 and Pajβ1 clustered together with insect core groups, whereas Pajα10, Pajα11, and Pajα12 were classified as a divergent group. Three distinct transcripts were identified in Pajα3, presumably due to alternative splicing between TM3 and TM4, which may be involved in channel formation with other subunits. All five nAChR subunits were expressed predominantly in neuronal tissues, including the brain, sinus gland/X-organ complex, thoracic ganglia, and abdominal ganglia, with no significant differences in subunit expression levels among the neuronal tissues. The five shrimp nAChR subunits could not be functionally expressed in <i>Xenopus</i> oocytes, but coexpression of Pajβ1 and rat α4 subunit (Rα4) formed functional channels responding to acetylcholine. Functional expression of vertebrate α subunit (Rα4) with invertebrate β1 subunit (Pajβ1) will expand our knowledge regarding the structural characteristics and molecular gating mechanism of invertebrate nAChRs.</p></div

盐角草改良新疆盐渍化棉田效果初报/The Preliminary Study of Recovery Effects on Cotton Field by Salicornia europaea L.in Xinjiang[J]

在种植盐角草改良过后的次生盐渍化棉田进行了棉花的对比种植试验,结果表明,生物改良能够明显提高棉田土壤有机质含量.改良后土壤的电导值显著降低,Na+,Cl-,SO42-等主要盐害离子均显著降低.生物改良次生盐渍化棉田能够促进棉花出苗,提高子棉产量

气候变化对蒙古扁桃适宜分布范围和空间格局的影响/Impact of climate change on suitable distribution range and spatial pattern in Amygdalus mongolica[J]

为模拟、预测气候变化对孑遗、濒危植物蒙占扁桃(Amygdalus mongolica)潜在分布的影响,利用最大熵(MAXENT)模型模拟、预测、对比、分析、揭示蒙占扁桃在最大冰期(CCSM及M1ROC模型)、历力史气候(1961-1990年)及未来气候(2020年、2050年和2080年,政府间气候变化专 门委员会排放情景特别报告的A2A情景)条件下的适宜分布范围和空间格局的变化.结果表明:(1)蒙占扁桃在历史气候条件下的潜在分布区集中在蒙古的南戈壁省及东戈壁省,我国内蒙古巴彦淖尔市、阿拉善左旗、鄂尔多斯市、锡林郭勒盟西部,河西走廊中部及东部,宁夏北部及陕西北部,以及河北北部的部分地区;(2)与历史气候条件下的潜在分布相比,蒙古扁桃在最大冰期CCSM气候情景下的分布经历了明显的、大范围的向南迁移和范围缩小;(3)未来A2A气候情景下,其潜在分布范围表现出在2020年明显扩大,在2050年减小,到2080年又略有增大的趋势.分布格局表现出不断向我国河北及内蒙古东部,蒙古东部、北部及西部大幅度扩散、迁移的趋势

流域生态需水概念及估算方法评述[J]

生态需水的量化是流域水权分配的重要依据.在综合分析已有生态需水研究的基础上,(1)对造成生态需水相关概念混淆的原因进行了分析,并进一步明确了生态需水的概念内涵；(2)提出了干旱区内陆河流域河道内、外生态需水项,并着重介绍了河道内基础流量需水和河道外植被需水量的估算方法和方法适用条件；(3)提出当前生态需水研究需要重点考虑尺度转换、差异化水量、水量交叉和评价体系等4方面问题

膜下滴灌和淹灌两种栽培模式下水稻光合生理特性的研究/Photosynthetic Characteristics of Rice Under Drip Irrigation with Plastic Film Mulching and Continuous Flooding[J]

以粳稻品系 T-04和 T-43为试材,通过盆栽控水试验,比较了在膜下滴灌和淹灌两种栽培模式下乳熟期叶片的光合色素含量、光合特性、叶绿素荧光参数和渗透调节物质含量的差异,分析了两种栽培模式下的水分利用效率和产量构成因素。结果表明,在膜下滴灌栽培模式下,2个水稻品系的水分利用效率显著高于淹灌,叶绿素 a、叶绿素 b、类胡萝卜素含量均降低；最大净光合速率、胞间 CO 2浓度、气孔导度、蒸腾速率显著降低,表明光合速率下降受叶绿素含量和气孔的双重影响；表观量子效率、羧化效率、ΦPSI 、电子传递速率、F v/F m 均显著降低,说明光合色素含量降低导致 PSⅡ反应中心捕光能力减弱和光化学转化效率降低,从而使叶片光合速率降低；可溶性糖、可溶性蛋白均显著低于淹灌栽培；丙二醛、脯氨酸含量高于淹灌栽培,说明滴灌栽培水稻植株的膜脂过氧化加剧,细胞膜系统受到一定程度的破坏,通过主动积累渗透调节物质,适应干旱胁迫。膜下滴灌栽培水稻单位面积有效穗数和结实率显著降低,导致最终减产