234 resultados para 205


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为了解青海省春小麦收割后田间堆放期间产量和品质的变化,选择近年育成的春小麦品种“高原205”(白粒,易穗发芽)、“高原115”(紫黑色小麦)、“高原448”(红粒)和“高原314”(白粒)以及曾为青海省主栽品种的“青春533”(红粒)为材料,收割后以农民常用的田间堆放方式进行堆放,每隔9d对其进行采样,测定产量、SDS沉淀值和降落数值的变化。结果表明,随着堆放时间的延长,收获产量逐步下降,平均产量从第1次采样(Od)时的504g/m^2减少到63d后的384g/m^2,收获产量平均值与取样时间直线回归F值为20.91,大于F0.01(6.90);SDS沉淀值变化较小,F值为0.90,小于F0.05(2.13);降落数值在取样时间点上差异极显著.F值等于46,72,大于F0.01(2.87)。高原205的降落数值一直呈现下降趋势,而高原448、高原115、高原314和青春533的变化是在O~18d间上升,然后下降。总体而言,田间堆放对收获产量和品质不利。

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Potentilla fruticosa scrub, Kobresia humilis meadow and Kobresia tibetica meadow are widely distributed on the Qinghai-Tibet Plateau. During the grass exuberance period from 3 July to 4September, based on close chamber-GC method, a study on CO2 emissions from different treatments was conducted in these meadows at Haibei research station, CAS. Results indicated that mean CO2emission rates from various treatments were 672.09+152.37 mgm-2h-1 for FC (grass treatment); 425.41+191.99 mgrn-2h-1 for FJ (grass exclusion treatment); 280.36+174.83 mgrn-2h-1 for FL (grass and roots exclusion treatment); 838.95+237.02 mgm-2h-1 for GG (scrub+grass treatment); 528.48+205.67 mgm-2h-1for GC (grass treatment); 268.97 ±99.72 mgm-2h-1 for GL (grass and roots exclusion treatment); and 659.20±94.83 mgm-2h-1 for LC (grass treatment), respectively (FC, FJ, FL, GG, GC, GL, LC were the Chinese abbreviation for various treatments). Furthermore, Kobresia humilis meadow, Potentilla fruticosa scrub meadow and Kobresia tibetica meadow differed greatly in average CO2 emission rate of soil-plant system, in the order of GG>FC>LC>GC. Moreover, in Kobresia humilis meadow,heterotrophic and autotrophic respiration accounted for 42% and 58% of the total respiration of soil-plant system respectively, whereas, in Potentilla fruticosa scrub meadow, heterotrophic and autotrophic respiration accounted for 32% and 68% of total system respiration from G-G; 49% and 51%from GC. In addition, root respiration from Kobresia humilis meadow approximated 145 mgCO2m-2h-1,contributed 34% to soil respiration. During the experiment period, Kobresia humilis meadow and Potentilla fruticosa scrub meadow had a net carbon fixation of 111.11 grn-2 and 243.89 grn-2,respectively. Results also showed that soil temperature was the main factor which influenced CO2 emission from alpine meadow ecosystem, significant correlations were found between soil temperature at 5 cm depth and CO2 emission from GG, GC, FC and FJ treatments. In addition, soil moisture may be the inhibitory factor of CO2 emission from Kobresia tibetica meadow, and more detailed analyses should be done in further research.

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湟水流域位于青海省的东部,约处于北纬35°56′-37°38′,东径100°35′-103°05′。属于青藏高原和黄土高原的过滤地带,海拔1650-4394m,全区面积约16600km^2,属于大陆性气候和高原大陆性气候类型。本区共有野生种子植物83科、400属、1234种。分别占本区所属的青藏高原植物亚区唐古特地区总科数的92.22%、总属数的78.74%、总种数的54.00%。研究表明,湟水流域植物区系特征为:(1)在唐古特地区中种类相对较丰富;(2)温带成分占2.80%,以绝对优势确定了本区系为明显的温带性质(属于以北温带成分,特别是欧亚大陆温、寒地带典型成分为优势的,兼具温性,寒温和高寒类型的温带区系性南,或可称为在温带区第中的过渡区系所具有的“复合型”区系特征);(3)木本类型少,大多数种类为多年生草本植物,缺乏古老和原始类群,一些中国特有种衍生于其广布的亲缘种中,表明本区系具有年轻和衍生的性质;(4)我国西南高山区系和华北区系对该区系具有双重影响;(5)为青藏高原植物亚区唐古特植物地区同华北植物地区相互过渡的代表区系之一;(6)特有属和特有种少。在中国种子植物区系分区中,本区属于青藏高原植物亚区中的唐古特地区。

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根据3窝14只甘肃鼠兔幼子56天的生长发育资料初步分析了甘肃鼠兔的生长发育规律。依据逻辑斯蒂曲线的拐点 ,甘肃鼠兔的体重生长可划分为加速增长相 ( 0~205日龄 )和减速增长相 ( 205日龄以后 )。按照瞬时生长率曲线的拐点 ,体重增长过程可分为 3个时期 ,即缓慢生长期 ( 0~6 5日龄 )、快速生长期 ( 6 5~ 345日龄 )和渐进生长期 ( 345日龄以后 )。文章对使用逻辑斯蒂方程和其它“S”形曲线描述动物生长过程存在的一些问题进行了讨论 ,认为:如果只用1条“S”形曲线描述动物的整个生长过程,就有可能会因为成年期动物生长规律的变化而破坏模型参数的生物学意义 ,同时引起模型拟合精度的降低。为克服这一问题,作者建议:在使用“S”形曲线拟合动物生长模型时,生长过程的资料最好不要覆盖体重波动较大的成年阶段。

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目的:对红花岩黄芪化学成分进行研究。方法:用溶剂法、色谱法提取、分离红花岩黄芪化学成分,用波谱法鉴定其结构。结果:从红花岩黄芪中分离得到7 个化合物,碳三十醇(1) ,二十四碳酸( 2) ,5 ,7-二羟基-4′-甲氧基-6 ,8-二异戊烯基异黄酮(3) ,对香豆酸二十二酯( 4) ,豆甾醇( 5) , 5 ,7-二羟基-4 ,-甲氧基- 6-异戊烯基异黄酮( 6) ,咖啡酸二十四酯( 7) 。结论:化合物3 和4 为新天然产物,其它化合物均为首次从该植物中获得。

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设计了一种基于双目立体视觉的视觉里程计来实现移动机器人在非结构化环境下的自主定位导航.对图像序列中提取的环境特征进行跟踪和匹配获得特征序列,根据三维重建的不确定性,利用最小二乘法和极大似然法对移动机器人进行定位和运动估计.在MATLAB环境下的仿真实验结果表明,视觉里程计可精确估计机器人位置和运动状态,对运动过程中的测量误差进行补偿,减小了机器人在非结构化环境下长距离导航的定位和运动状态估计累积误差,验证了这种视觉自主定位导航控制方法的可行性和有效性。

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摘 要 随着全球市场竞争更加激烈,上层计划管理系统(MRPII/ERP)受市场影响越来越大,计划的适应性问题愈来愈突出,明显感到计划跟不上变化。因此,解决生产计划的适应性以及增加底层生产过程的信息流动,提高计划的实时性和灵活性,已经成为一个重要的研究课题。制造执行系统(MES),作为上层计划和底层控制的桥梁,能够通过传递信息,使得从订单下达到产品完成的整个生产过程进行优化。依赖准确的数据对工厂活动进行指导、启动、响应和报告。车间级计划与调度管理系统是整个(MES)系统的核心技术,是现代生产管理的关键问题之一。 本文结合陕西法士特齿轮有限公司装配制造执行系统的研究和开发,对装配生产线多品种变批量调度问题进行了深入的研究,给出了不同类型产品装配调度算法,及面向装配制造企业调度优化模型和变批量调度问题的算法。以先进的MES管理理念为依托,设计和开发齿轮装配线制造执行系统。并通过仿真软件对装配生产线进行仿真,进行初步资源优化。这些研究具有重要的理论意义和实用价值。 首先,本文阐述了MES产生及发展,分析了制造执行系统研究现状,并对装配制造车间计划调度优化问题研究。提出面向装配制造系统生产调度模型,给出了变批量生产调度问题的启发式算法。 其次,提出了装配制造执行系统功能模型。结合装配生产线的特点,针对装配车间管理,设计符合企业生产线运作与管理的制造执行系统,分析该系统的总体结构模型,并具体阐述了计划和调度模块设计的具体步骤,以及对一些问题的处理方法。并设计实现了齿轮MES的核心功能。 最后,讨论了计算机仿真技术在制造企业车间中的应用发展,以eM-Plant为平台,开发了装配生产线数字化仿真系统,并对装配车间生产线的资源优化设计作了分析,提出适合实际生产的策略。

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Surface pollen assemblages and their relationhips with the modern vegetation and climate provide a foundation for investigating palaeo-environment conditions by fossil pollen analysis. A promising trend of palynology is to link pollen data more closely with ecology. In this study, I summarized the characteristics of surface pollen assemblages and their quantitative relation with the vegetation and climate of the typical ecological regions in northern China, based on surface pollen analysis of 205 sites and investigating of modern vegetation and climate. The primary conclusions are as follows:The differences in surface pollen assemblages for different vegetation regions are obvious. In the forest communities, the arboreal pollen percentages are more than 30%, herbs less than 50% and shrubs less than 10%; total pollen concentrations are more than 106 grains/g. In the steppe communities, arboreal pollen percentages are generally less than 5%; herb pollen percentages are more than 90%, and Artemisia and Chenopodiaceae are dominant in the pollen assemblages; total pollen concentrations range from 103 to 106 grains/g. In the desert communities, arboreal pollen percentages are less than 5%. Although Chenopodiaceae and Artemisia still dominate the pollen assemblages, Ephedra, Tamaricaceae and Nitraria are also significant important in the pollen assemblages; total pollen concentrations are mostly less than 104grains/g. In the sub-alpine or high and cold meadow communities, arboreal pollen percentages are less than 30%. and Cyperaceae is one of the most significant-taxa in the pollen assemblages. In the shrub communities, the pollen assemblages are consistent with the zonal vegetation; shrub pollen percentages are mostly less than 20%, except for Artemisia and Hippophae rhamnoides communities.There are obvious trends for the pollen percentage ratios of Artemisia to Chenopodiaceae (A/C), Pinus to Artemisia (P/A) and arbor to non-arbor (AP/NAP) in the different ecological regions. In the temperate deciduous broad-leaved forest region, the P/A ratios are generally higher than 0.1, the A/C ratios higher than 2 and the AP/NAP ratios higher than 0.3. In the temperate steppe regions, the P/A ratios are generally less than 0.1, the A/C ratios higher than 1 and the AP/NAP ratios less than 0.1. In the temperate desert regions, the P/A ratios are generally less than 0.1, the A/C ratios less than 1, and the AP/NAP ratios less than 0.1.The study on the representation and indication of pollen to vegetation shows that Pinus, Artemisia, Betula, Chenopodiaceae, Ephedra, Selaginella sinensis etc. are over-representative in the pollen assemblages and can only indicate the regional vegetation. Some pollen types, such as Quercus, Carpinus, Picea, Abies, Elaeagus, Larix, Salix, Pterocelis, Juglans, Ulmus, Gleditsia, Cotinus, Oleaceae, Spiraea, Corylus, Ostryopsis, Vites, Tetraena, Caragana, Tamaricaceae, Zygophyllum, Nitraria, Cyperaceae, Sanguisorba etc. are under-representative in the pollen assemblages, and can indicate the plant communities well. Populus, Rosaceae, Saxifranaceae, Gramineae, Leguminosae, Compositae, Caprifoliaceae etc. can not be used as significant indicators to the plants.The study on the relation of pollen percentages with plant covers shows that Pinus pollen percentages are more than 30% where pine trees exist in the surrounding region. The Picea+Abies pollen percentages are higher than 20% where the Picea+Abies trees are dominant in the communities, but less than 5% where the parent plants are sparse or absent. Larix pollen percentages vary from 5% to 20% where the Larix trees are dominant in the communities, but less than 5% where the parent plants are sparse or absent. Betula pollen percentages are higher than 40% where the Betula trees are dominant in the communities" but less than 5% where the parent plants are sparse or absent. Quercus pollen percentages are higher than 10% where the Quercus trees are dominant in the communities, but less than 1% where the parent plants sparse or absent. Carpinus pollen percentages vary from 5% to 15% where the Carpinus trees are dominant in the communities, but less than 1% where the parent plants are sparse or absent. Populus pollen percentages are about 0-5% at pure Populus communities, but cannot be recorded easily where the Populus plants mixed with other trees in the communities. Juglans pollen accounts for 25% to 35% in the forest of Juglans mandshurica, but less than 1% where the parent plants are sparse or absent. Pterocelis pollen percentages are less than 15% where the Pterocelis trees are dominant in the communities, but cannot be recorded easily where the parent plants are sparse or absent. Ulmus pollen percentages are more than 8% at Ulmus communities, but less than 1% where the Ulmus plants mixed with other trees in the communities. Vitex pollen percentages increase along with increasing of parent plant covers, but the maximum values are less than 10 %. Caragana pollen percentages are less than 20 % where the Caragana plant are dominant in the communities, and cannot be recorded easily where the parent plants are sparse or absent. Spiraea pollen percentages are less than 16 % where the Spiraea plant are dominant in the communities, and cannot be recorded easily where the parent plants are sparse or absent.The study on the relation of surface pollen assemblages with the modern climate shows that, in the axis 1 of DCA, surface samples scores have significant correlation with the average annual precipitations, and the highest determination coefficient (R2) is 0.8 for the fitting result of the third degree polynomial functions. In the axis 2 of DCA, the samples scores have significant correlation with the average annual temperatures, average July temperatures and average January temperatures, and the determination coefficient falls in 0.13-0.29 for the fitting result of the third degree polynomial functions with the highest determination coefficient for the average July temperature.The sensitivity of the different pollen taxa to climate change shows that some pollen taxa such as Pinus, Quercus, Carpinus, Juglans, Spiraea, Oleaceae, Gramineae, Tamariaceae and Ephedra are only sensitive to the change in precipitation.

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1分散元素成矿研究概况。分散元素通常是指镉、镓、锗、铟、硒、碲、铊和铼等8种元素。由于它们在地壳中的平均含量低(一般为10^-9~10^-6级),不易形成独立矿物,难以发生有意义的富集。大百科全书云:“分散元素不形成独立矿床,它们以伴生元素方式存于其他元素的矿床内”。因此,长期以来,分散元素多被作为其他矿床的伴生组分,并侧重于含量和赋存状态两方面研究。

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遵义牛蹄塘组黑色岩系发现的多水硫磷铝石主要产出在Ni-Mo多金属层的微裂隙中,偶尔在多金属层下部的黑色粉砂岩中以脉体形式产出。该矿物结构不稳定,结构中一部分水分子很容易失去,在X射线衍射鉴定时其特征谱线变化较大;在自然条件下存放一定时间后,样品具有稳定的X射线衍射特征。此外,对这些样品进行了红外光谱、热重和差热分析、TEM观测、化学分析和晶胞参数计算,与纤磷铝石进行了对比和讨论。

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新疆霍什布拉克铅锌矿床的矿体和含矿地层的产状一致,主矿体的矿石具有条带状、纹层状构造,矿石中大量发育霉球状、管状和环带状生物结构,显示出层控、热水沉积成因的特点。含矿地层和矿石样品的主量元素PER图解显示含矿碳酸盐岩以含石膏的灰岩为主,围岩的白云岩化微弱,矿化与硅化关系密切。矿石、含矿碳酸盐岩和页岩、粉砂质灰岩和泥质粉砂岩等碎屑岩具有各自鲜明的微量元素分布特征,上层矿体矿石中较强的富集过渡族元素Ti、V、Cr、Mn、Co、Ni、非活动性元素Zr、Hf及大离子亲石元素Sr和Pb,亏损活动性元素Na、K、Rb、Ba和非活动性元素Nb、Th。其围岩重结晶泥晶灰岩富集Ti、Mn、Ni、Sr和Pb,亏损Na、K、V、Fe、Rb、Ba、Zr、Hf、Nb和Th。下层矿体的围岩页岩和泥质、粉砂质灰岩样品的微量元素分布在平均上地壳线附近,部分样品较明显的富集Ti、V、Cr、Mn、Co、Ni、Rb、Y、Zr和Hf,亏损Na、Fe、Sr、Nb。上层矿体矿石和下层矿体围岩中的部分碎屑岩富集强亲岩浆元素Cr、Co、Ni,且上层矿体矿石的稀土元素分布模式具有强的正Eu异常,部分下层矿体围岩具有较明显的正Eu异常。地质和地球化学特征显示该矿床属于热水沉积矿床中的SEDEX型矿床.

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白秧坪铜钴多金属矿床产于下白垩统景星组陆相红色碎屑岩中,呈似层状、脉状分布于断裂带内,蚀变 分带明显。研究表明:在原生矿石中钴主要赋存于独立矿物.辉砷钴矿中,同时钴可以类质同象赋存于砷黝铜 矿及少量含钴黄铁矿中:在氧化矿石中,以钴华存在于矿石的表面。辉砷钴矿的成分和Co/Ni比值揭示钴的成 矿作用与基性.超基性岩浆有关。矿床褪色蚀变岩、碳酸盐化蚀变岩矿石和正常岩石具有类似的稀土元素配分 模式。即富集轻稀土而重稀土相对亏损、铈异常不明显而铕异常显著,但稀土元素总量、分异程度存在明显的 差异。这可能与流体中带入稀土元素的方式、带入稀土的矿物类型和流体性质的差异等因素造成,反映成矿物 质来源存在差异。相对正常岩石的微量元素含量,元素CIl、co、As、 、Bi、Ag等在褪色蚀变岩、碳酸盐化蚀变岩 和矿石中均相对富集,但在在褪色蚀变岩以亲石元素富集最明显,而在碳酸盐化蚀变岩和矿石中以显著富集 亲硫元素(成矿元素)为主特征,表明在蚀变过程中,赋矿围岩本身没有为成矿作用提供主成矿元素,主成矿元 素源自幔源的基性岩浆。由此认为钴的成矿作用可能主要与喜马拉雅期幔源的基性岩浆活动有关。

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燕山期(205~65Ma)山东地区地壳活动强烈,构造体系已由古亚洲构造域完全转化为滨太平洋构造域,构造活动导源于太平洋板块对欧亚板块的俯冲。由于太平洋板块对欧亚板块的俯冲(NW向),鲁东地区岩石圈发生了快速拆沉减薄作用.同时鲁东地区也可能会出现地l漫柱的活动;另外,在太平洋板块俯冲作用影响下,炎区庐断裂(山东称沂沐断裂)带发生了大型左行走滑剪切和拉张活动。以上构造因素加上早白至世末一晚白至世期间燕山造山带的垮塌,都可能为山东地区中生代地壳拉张提供了动力条件。山东地区中生代(燕山期)基性脉岩特别发育,这些慢源基性岩脉充填张性裂隙,是大陆地壳拉张的标志;另外,山东地区也存在大量拉张背景下的燕山期火山岩和碱性岩。但关于它们的年代学和系统的地球化学研究还比较薄弱,且对其成因和形成的构造环境,仍存在着争议。本论文主要从同位素年代学、岩石化学、地球化学和Sr-Nd-Pb同位素方面对山东地区燕山期基性脉岩、火山岩和碱性超基性脉岩进行了系统研究。同时,考虑到鲁东地区煌斑岩中金含量普遍较高,且燕山期又是山东金矿的主成矿期,论文中对煌斑岩与金成矿之间的关系也作了一定的研究。通过研究,得出以下主要认识:1、火山岩为一套以钙碱性安山岩为主,含少量拉斑玄武岩和英安岩。成因上为富集地慢部分熔融作用的结果,但在成岩过程中也可能存在单斜辉石、斜长石、橄榄石和Ti-Fe氧化物等矿物的分离结晶作用。碱性超基性脉岩岩性上为单一的橄榄辉石岩,为富集地慢源低度(3.4%)部分熔融作用的产物,岩浆演化过程经历了以橄榄石为主的分馏作用。基性脉岩主要包括辉长岩、辉绿岩(主要分布在鲁西地区)和煌斑岩(以斜闪煌斑岩为主,同时含部分拉辉煌斑岩和角闪煌斑岩)(主要分布在鲁东地区),都为富集岩石圈地慢部分熔融的产物。三类岩石在侵位结晶过程都不存在明显的地壳混染。2、火山岩、碱性超基性脉岩和基性脉岩(除少数外)都形成于大陆板内拉张环境。3、富集地慢源区(EMI)的产生是俯冲并熔融的扬子下地壳物质进入华北岩石圈地慢并与之相互交代作用形成的。4、研究区中生代基性脉岩K-Ar年龄分布范围为72.2±1.70Ma~204.2±5.4Ma,且基本上在90~140Ma之间变化。综合碱性超基性脉岩和已知的青山组的火山岩、基性脉岩年龄数据,认为山东地区中生代地壳拉张至少存在四次:即约80Ma、100Ma、120Ma和 140Ma。但鲁东地区在地壳拉张方面可能存在着与鲁西地区不同的制约因素:即鲁东地区存在拆沉作用和可能存在地慢柱的影响,而鲁西地区可能受到了郊庐断裂的左行走滑剪切和拉张活动的影响。5、胶北地区煌斑岩为钙碱性系列,且金含量普遍较高(平均28ppb),该研究对胶北地区的找矿勘探工作具有一定意义。

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The catalytic performance of Ir-based catalysts was investigated for the reduction of NO under lean-burn conditions over binderless Ir/ZSM-5 monoliths, which were prepared by a vapor phase transport (VPT) technique. The catalytic activity was found to be dependent not only on the Ir content, but also on the ZSM-5 loading of the monolith. With the decreasing of the Ir content or the increasing of the ZSM-5 loading of the monolith, NO conversion increased. When the ZSM-5 loading on the cordierite monolith was raised up to ca. 11% and the metal Ir content was about 5 g/l, the NO conversion reached its maximum value of 73% at 533 K and SV of 20 000 h(-1). Furthermore, both the presence of 10% water vapor in the feed gas and the variation of space velocity of the reaction gases have little effect on the NO conversion. A comparative test between Ir/ZSM-5 and Cu/ZSM-5, as well as the variation of the feed gas compositions, revealed that Ir/ZSM-5 is very active for the reduction of NO by CO under lean conditions, although it is a poor catalyst for the C3H8-SCR process. This unique property of Ir/ZSM-5 makes it superior to the traditional three-way catalyst (TWC) for NO reduction under lean conditions. (C) 2001 Elsevier Science B.V. All rights reserved.