17 resultados para Adams

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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虚拟样机技术是利用计算机分析软件,通过建立运动学、动力学模型来分析和评估系统的性能,从而为物理样机的设计和制造提供参数依据.本文简述了虚拟样机技术和动力学仿真软件ADAMS以及虚拟样机开发的流程;介绍了它在卡钳机构仿真分析中的应用。

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构造了基于非等距网格的迎风紧致格式,并将其与三阶精度的Adams半隐方法相结合,构造了求解不可压N-S方程高效算法。在数值模拟的基础上对二维槽道流动进行了分析,得到了Reynolds数从6 000到15 000的二维流动饱和态解(所谓"二维槽道湍流");定性及定量结果均与他人的数值计算结果吻合十分理想。对流场进行了统计分析,指出了"二维湍流"与三维湍流统计特性的区别。

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In this paper, an AC plasma arc reactorwithworkinggasofhydrogen is applied to destruct chemicalagents. The temperature attains 6000℃ in the arc area and over 2000℃ in the other space of the crucible. The Arsenic (As) contained chemical agent -Adams (DM) used in the experiment, was added into the plasmareactorwith the additives: Fe, CaO, and SiO_2, etc. Pyrolysis and destructionofchemicalagents occurs very quickly in the high-temperature reactor. Gaseous hydrogen was injected into the reactor to form a reductive environment, to reduce the formation of As_2O_3 etc. In the bottom of the crucible, the solid residues of toxicant and additives were melted and formed as vitrified slag. The off-gas was treated by a wet scrubber. The amounts of arsenic distributed in the off-gas, vitrified slag, waste water and solids (soot) were measured. The result shows DM is completely destructed in the plasmareactor. The Arsenic content in the off-gas, vitrified slag, waste water and soot are 0.052 mg/l, 3.0%, 10.44 mg/l, and 5.1% respectively, which will be disposed as the pollutant matters. The results show that the plasma technology is an environmentally friendly technology to destruct chemicals.

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通过直接数值模拟(DNS)研究槽道湍流的性质和机理。包含五个部分:1)湍流直接数值模拟的差分方法研究。2)求解不可压N-S方程的高效算法和不可压槽道湍流的直接数值模拟。3)可压缩槽道湍流的直接数值模拟和压缩性机理分析。4)“二维湍流”的机理分析。5)槽道湍流的标度律分析。1.针对壁湍流计算网格变化剧烈的特点,构造了基于非等距网格的的迎风紧致格式。该方法直接针对计算网格构造格式中的系数,克服了传统方法采用 Jacobian 变换因网格变化剧烈而带来的误差。针对湍流场的多尺度特性分析了差分格式的精度、网格尺度与数值模拟能分辨的最小尺度的关系,给出不同差分格式对计算网格步长的限制。同时分析了计算中混淆误差的来源和控制方法,指出了迎风型紧致格式能很好地控制混淆误差。2.将上述格式与三阶精度的Adams半隐格式相结合,构造了不可压槽道湍流直接数值模拟的高效算法。该算法利用基于交错网格的离散形式的压力Poisson方程求解压力项,避免了压力边界条件处理的困难。利用FFT对方程中的隐式部分进行解耦,解耦后的方程采用追赶法(LU分解法)求解,大大减少了计算量。为了检验该方法,进行了三维不可压槽道湍流的直接数值模拟,得到了Re=2800的充分发展不可压槽道湍流,并对该湍流场进行了统计分析。包括脉动速度偏斜因子在内的各阶统计量与实验结果及Kim等人的计算结果吻合十分理想,说明本方法是行之有效的。3.进行了三维充分发展的可压缩槽道湍流的直接数值模拟。得到了 Re=3300,Ma=0.8的充分发展可压槽道湍流的数据库。流场的统计特征(如等效平均速度分布,“半局部”尺度无量纲化的脉动速度均方根)和他人的数值计算结果吻合。得到了可压槽道湍流的各阶统计量,其中脉动速度的偏斜因子和平坦因子等高阶统计量尚未见其他文献报道。同时还分析了压缩性效应对壁湍流影响的机理,指出近壁处的压力-膨胀项将部分湍流脉动的动能转换成内能,使得可压湍流近壁速度条带结构更加平整。4.模拟了二维不可压槽道流动的饱和态(所谓“二维湍流”),分析了“二维槽道湍流”的非线性行为特征。分析了流场中的上抛-下扫和间歇现象,研究了“二维湍流”与三维湍流的区别。指出“二维湍流”反映了三维湍流的部分特征,同时指出了展向扰动对于湍流核心区发展的重要性。5.首次对可压缩槽道湍流及“二维槽道湍流”标度律进行了分析,得出了以下结论:a)槽道湍流中,在槽道中心线附近较宽的区域,存在标度律。b)该区域流场存在扩展自相似性(ESS)。c)在Mach数不是很高时,压缩性对标度指数影响不大。本文结果同SL标度律的理论值吻合较好,有效支持了该理论。对“二维槽道湍流”也有相似的结论,但与三维湍流不同的是,“二维槽道湍流”存在标度律的区域更宽,近壁处的标度指数比中心处有所升高。

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Background and objectives: Pentobarbital and ketamine are commonly used in animal experiments, including studies on the effects of ageing on the central nervous system. The electroencephalogram is a sensitive measure of brain activity. The present study i

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Interferons (IFNs), consisting of three major subfamilies, type I, type II (gamma) and type III (lambda) IFN, activate vertebrate antiviral defences once bound to their receptors. The three IFN subfamilies bind to different receptors, IFNAR1 and IFNAR2 for type I IFNs, IFN gamma R1 and IFN gamma R2 for type II IFN, and IL-28R1 and IL-10R2 for type III IFNs. In fish, although many types I and II IFN genes have been cloned, little is known about their receptors. In this report, two putative IFN-gamma receptor chains were identified and sequenced in rainbow trout (Oncorhynchus mykiss), and found to have many common characteristics with mammalian type II IFN receptor family members. The presented gene synteny analysis, phylogenetic tree analysis and ligand binding analysis all suggest that these molecules are the authentic IFN gamma Rs in fish. They are widely expressed in tissues, with IFN gamma R1 typically more highly expressed than IFN gamma R2. Using the trout RTG-2 cell line it was possible to show that the individual chains could be differentially modulated, with rIFN-gamma and rIL-1 beta down regulating IFN gamma R1 expression but up regulating IFN gamma R2 expression. Overexpression of the two receptor chains in RTG-2 cells revealed that the level of IFN gamma R2 transcript was crucial for responsiveness to rIFN-gamma, in terms of inducing gamma IP expression. Transfection experiments showed that the two putative receptors specifically bound to rIFN-gamma. These findings are discussed in the context of how the IFN gamma R may bind IFN-gamma in fish and the importance of the individual receptor chains to signal transduction. (c) 2009 Elsevier Ltd. All rights reserved.

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Vertical cavity surface emitting lasers operating in the 1.3- and 1.5-mu m wavelength ranges are highly attractive for telecommunications applications. However, they are far less well-developed than devices operating at shorter wavelengths. Pulsed electrically-injected lasing at 1.5 mu m, at temperatures up to 240 K, is demonstrated in a vertical-cavity surface-emitting laser with one epitaxial and one dielectric reflector. This is an encouraging result in the development of practical sources for optical fiber communications systems.

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本文研究了典型有毒赤潮藻——亚历山大藻(Alexandrium)对海湾扇贝(Argopecten irradians Lamarck)、文蛤(Meretrix meretrix Linnaeus)和太平洋牡蛎(Ostrea gigas Thunberg)受精卵孵化的影响和致毒机制以及对蒙古裸腹溞(Moina mongolica Daday)生命活动的影响。此外,还针对我国赤潮发生特点,模拟研究了我国东海大规模赤潮对菲律宾蛤仔(Ruditapes philippinarum (Adams et Reeve))受精卵孵化和蒙古裸腹溞种群数量的影响。 结果发现:8株产PSP毒素的亚历山大藻:塔玛亚历山大藻( ATHK, AT5-1, AT5-3, ATCI02, ATCI03),链状亚历山大藻, A. lusitanicum、微小亚历山大藻和2株不产PSP毒素的相关亚历山藻(AC-1, AS-1)对海湾扇贝受精卵的孵化均有显著抑制作用,说明在亚历山大藻属中,这种抑制作用具有一定的普遍性,并与PSP毒素的产生无直接关系,表明存在非PSP毒素的其它毒性物质。一种PSP标准毒素STX也没有这种抑制作用,进一步证明该抑制作用与PSP毒素不直接相关。 相关亚历山大藻AC-1对海湾扇贝、文蛤和太平洋牡蛎受精卵孵化的有显著的毒害作用,其藻液、重悬液、去藻液和内容物均显著影响受精卵的孵化。相关亚历山大藻AC-1对海湾扇贝、文蛤和太平洋牡蛎担轮幼虫细胞的超微结构有显著破坏作用,破坏膜结构和胞内结构,影响细胞内的功能器官如溶酶体的稳定性,使卵黄颗粒萎缩变形;对文蛤和太平洋牡蛎的受精卵显示出极强的毒害作用: 3000cells•ml-1时,使二者胚胎完全溶掉消失;在2000cells•ml-1的藻液中培养2h后,担轮幼虫的外膜发生溶解,整个幼体呈葡萄串样。相关亚历山大藻AC-1产生的这种毒性物质可能对贝类胚胎细胞的结构和功能有影响。 亚历山大藻对蒙古裸腹溞的毒性效应与不同藻种/藻株密切有关:塔玛亚历山大藻(AT-6, ATCI02)、链状亚历山大藻、A. lusitanicum和微小亚历山大藻不影响蒙古裸腹溞的存活,而塔玛亚历山大藻(ATHK、ATCI03和AT5-1)和相关亚历山大藻(AC-1, AS-1)有显著影响。蒙古裸腹溞能摄食塔玛亚历山大藻(AT-6, ATHK, ATCI02, ATCI03, AT5-1),链状亚历山大藻, A. lusitanicum和微小亚历山大藻,很少或基本不摄食相关亚历山大藻。亚历山大藻影响蒙古裸腹溞的RNA/DNA比值和蛋白质含量以及Na+,K+-ATP酶活性。相关亚历山大藻AC-1对蒙古裸腹溞的存活有极强的毒性作用,藻液、重悬液、内容物和碎片均有显著影响;即使与3×106cells•ml-1小球藻混合,10和50cells•ml-1的相关亚历山大藻AC-1仍能使蒙古裸腹溞的产幼数和存活时间显著下降。亚历山大藻对蒙古裸腹溞生命活动的影响不仅与PSP毒素有关,还与非PSP毒素有关;蒙古裸腹溞可能也是研究有害藻急性和慢性毒性的一种理想生物。 应用菲律宾蛤仔胚胎和蒙古裸腹溞评价我国东海特大规模赤潮对海洋生物资源的潜在危害时发现:单种链状亚历山大藻对菲律宾蛤仔受精卵的孵化和蒙古裸腹溞的种群增长均有显著不利影响;单种东海原甲藻(1~10×104cells•ml-1)对菲律宾蛤仔受精卵的孵化没有影响;较低密度的东海原甲藻能维持蒙古裸腹溞(2~5×104cells•ml-1)的种群增长;较高密度的东海原甲藻对蒙古裸腹溞(10×104cells•ml-1)种群有显著的抑制作用。两种藻以赤潮密度混合后,适当密度的东海原甲藻能在一定程度上减轻链状亚历山大藻对菲律宾蛤仔受精卵和蒙古裸腹溞的毒性。可见,东海连年爆发的大规模赤潮不仅对浮游生态系统有不利影响,若同时爆发亚历山大藻赤潮,则对海洋浮游生态系统和贝类资源的恢复产生更加不利的影响。

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从1949年以来经过近五十年的发展,超低温保存种质细胞技术已经趋于成熟,特别是在家畜推广良种化的过程中发挥重要作用。对海洋动物种质细胞保存研究的范围主要集中在鲑鳟鱼类和牡蛎等少数几种海洋生物上。本研究结合“国家自然科学基金”研究项目,进行了三种贝类和两种鱼类精子的超低温保存实验,得到了它们在液氮(-196 ℃)条件下的适宜保存条件。栉孔扇贝(Chlamys farreri)冻精解冻后复苏比例、受精率和孵化率最高可达到49.39%、42.06%和12.15睦栉孔扇贝精子超低温保存时发生冷冻伤害的温度范围在-30 ℃~-60 ℃;其低温保存的最适降温速率为20 ℃/min;使用抗冻剂二甲基亚砜(DMSO)的最适浓度为5 ℃,其保存效果优于甘油;样品保存的最佳体积为0.6ml~1ml;解冻精子的最适水温为35 ℃,50 ℃次之,20 ℃最差;用自然海水激活解冻后精子的效果好于低盐度溶液;在0 ℃进行预处理平衡时间不宜太长;在抗冻液中加入蛋黄对保存效果没有改善,并且会对冻精的孵化率有抑制作用;用20 ℃/min和5%DMSO冷冻精子,液氮中保存栉孔扇贝精子55天后其复苏比例达到42.17%。超低温保存紫贻贝(Mytilus galloprovincialis Lamarck)精子,解冻后其复苏比例、受精率和孵化率最高可达到41.63%、69.52%和54.74%。保存紫贻贝精子最适降温速率为5 ℃/min,发生冻伤的温度范围是-20 ℃~-60 ℃;使用抗冻剂DMSO的保存效果好于甘油,且使用抗冻剂DMSO的最适浓度为15%;利用自然海水激活冻精效果好于低盐度或高pH值的溶液;样品体积(在0.2~1ml之间)对保存效果没有影响;采用15%DMSO和5 ℃/min的降温速率处理精子,液氮中保存90天后复苏比例仍达到41.8%。保存菲律宾蛤仔(Ruditapes philippinarum (Adams and Reeve))精子的最适降温速率为5 ℃/min,发生冻伤的温度范围是-30 ℃~-60 ℃;抗冻剂DMSO的保存效果好于甘油,也用DMSO与甘油混合使用,使用抗冻剂DMSO的最适浓度为10%;利用自然海水激活冻精效果好于低盐度或高pH的溶液;样品体积(在0.2%~1.6ml之间)对保存效果有显著影响。冷冻保存后精子复苏比例、受精率和孵化率最高达到40.84%、68.87%和47.17%;以最适降温速率和抗冻剂浓度处理精子,并在液氮中保存36天后冻精复苏比例仍可以达到38.54%。黑鲷(Sparus macrocephalus)精子经过超低温保存后复苏率、存活率最高可以达到61.37%和61.4。保存黑鲷精子时发生冷冻伤害的温度范围是-20 ℃~-60 ℃,适宜的降温速率为20 ℃/min;使用抗冻剂DMSO的适宜浓度为20%;样品体积对保存效果有相关性;利用自然海水激活冻精效果好于低盐度或高pH值的溶液;使用20%DMSO和20 ℃/min降温速率处理,在液氮中保存黑鲷精子66天后解冻,其复苏率和存活率分别为59.81%和58.45%。在液氮中保存真鲷(Pagrosomus major)精子时发生冷冻伤害的温域为-30 ℃~-60 ℃,适宜的降温速率为20 ℃/min;使用抗冻剂DMSO的适宜浓度为20%;采用低盐度或高pH值的溶液激活冻精的效果不如自然海水。真鲷冻精的复苏率和存活率最高可达到50.73%和62.5;以20 ℃/min和20%DMSO处理真鲷精子,保存在液氮中46天后冻精复苏率和存活率为50.63%和61.02%。通过对多种贝类和鱼类精子的超低温保存实验,不仅获得超低温保存基本条件,并且通过显微镜观察结合前人的研究,对产生冻伤的原因和保护的机理提出了一个模式。

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Ninteen species of subfamilies Imbricariinae and Cylindromitrinae, family Mitridae, are recorded from the China's seas. Of which, one genus and six species are recorded for the first time from China's seas, i.e., genus Ziba Adams H and Adams A, Cancilla (Cancilla) carnicolor, Ziba duplilirata, Z. insculpta, Neocancilla circula, Scabricola (Scabricola) desetangsii, Scabricola (Swainsonia) ocellata ocellata.

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The morphology and infraciliature of two ectoparasitic ciliates, Trichodina caecellae n. sp. and T. ruditapicis Xu, Song & Warren, 2000, parasitising the gills of marine molluscs from the Shandong coast of the Yellow Sea, China, were investigated following wet silver nitrate and protargol impregnation. T. caecellae was found on the small marine sand clam Caecella chinensis Deshayes and is distinguished mainly by the acute triangle-like blade, the very delicate central part and the needle-shaped ray. T. ruditapicis was studied based on four populations from three clams: two populations from Ruditapes philippinarum (Adams) and one each from Saxidomus purpuratus (Sowerby) and Solen grandis Dunker. All four populations fell within the range of morphometry and agreed closely in the overall appearance of the adhesive disc. However, variability was found in the denticle structure, especially in populations from different host clams. Our observations suggest that denticle morphology may be more or less variable between and within populations, and that such minor differences should not be overestimated. It should be emphasised that, except for the denticle morphology, the bright granules or circles in the centre of the adhesive disc represent another important feature facilitating the identification of this trichodinid species.

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The composition of the leaf oils from seven populations of J. sabina L., one population of Juniperus sabina var. arenaria (E. H. Wilson) Farjon were examined for their geographic variation. In addition, the leaf oils of J. chinensis L. and J. davurica Pall. were compared to J. sabina. Juniperus sabina var. arenarla, the sand loving juniper, oil was found to be very similar to that of J. davurica, Mongolia, and J. sabina, on sand dunes in Mongolia. This suggests that J. sabina var. arenaria might be conspecific with J. davurica. Farjon's move (2001) of J. sabina var. arenaria out of J. chinensis is supported. Considerable differentiation was found in populations of J. sabina from the Iberian peninsula. Cedrol, citronellol, safrole, trans-sabinyl acetate, terpinen-4-ol and beta-thujone were found to be polymorphic in several populations.

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该文对中国科学院沈阳自动化所研制的水陆两栖蛇形机器人的水下蜿蜒运动进行受力分析并用ADAMS做了动力学仿真。从关节角函数的幅值、频率和体内形成波的个数三个方面对蛇形机器人前进速度的影响进行了仿真,得出以下结论:存在一个最优关节角函数幅值,使得蛇形机器人前进速度达到最大;增加频率和在满足形成蛇形曲线的体内形成波个数的情况下减少形成波的个数会使机器人前进的速度增加。

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月球探测车在崎岖不平的月面上行走时,其动态性能的优劣直接影响到车载各种科学仪器设备的正常工作。针对某一六轮摇杆转向架式月球车,利用ADAMS软件建立了其刚柔耦合多体系统动力学模型,并进行了模态分析。结果表明,月球车前六阶固有频率在5.79~19.11Hz之间,模态比较密集,结构比较柔软。该结果可为月球车结构动态设计及振动控制提供依据和参考。

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本文介绍了使用ADAMS软件包在机器人虚拟样机制造中,进行动力学分析的方法及ADAMS动力学分析软件与COSMOS有限元分析软件相结合,在机器人本体(SIASUN-RH6型)设计与研制过程中的应用。