71 research outputs found

    非离子态氨对转“全鱼”生长激素基因鲤鱼的急性毒性和慢性毒性

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    在自然水体和人工水体中氨氮对鱼类是有毒的.利用静水更新式生物测试研究了非离子态氨对转基因鲤鱼和对照鱼的96h急性毒性实验和21d慢性毒性实验.通过96h非离子态氨急性毒性实验发现,转基因鲤鱼的非离子态氨氮24,48,72和96h半数致死浓度(LC50)(2.64,2.44,2.28和2.16mg/L)分别比对照鲤鱼相应的24,48,72和96h半数致死浓度(LC50)(2.70,2.64,2.52和2.33mg/L)略低,没有显著性差异;但在不同非离子态氨氮(3.86,3.29和2.09mg/L)胁迫下

    Preliminary Study of Spatial Design in Zhu-gan-cuo Dwelling in Zhangzhou

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    “竹竿厝“是一种主要分布在我国东南地区工商业较发达城镇,与商业店铺相结合的民居形式。本文首先对“竹竿厝“的平面布局、结构形式及发展变迁三个方面依次进行介绍,进而从建筑学和城市学的角度分析“竹竿厝“的空间组织特征及城市发展的贡献。最终在漳州固有的红砖文化氛围中探寻独特的“竹竿厝“街巷空间。Zhu-gan-cuo is a type of traditional dwelling that combines with shops and distributes in commercial district of southern cities.The paper first introduces it by analyzing its plan layout, structure form,and development.Then discusses the characteristic of Zhu-gan-cuo’s spatial organization and the significance from the point of architecture and urban.Finally, it comes back to Zhangzhou, a place with Red brick culture to experience the special space of Zhu-gan-cuo area

    凹多边形区域覆盖无人机航迹规划方法

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    覆盖航迹规划技术对于提高无人机的目标搜索能力和正确完成任务能力具有重要的意义。针对凹多边形区域形状,本文提出一种无人机覆盖算法,该算法旨在协助无人机自主完成无遗漏地覆盖搜索给定区域。首先,描述了如何选取无人机的飞行方向;其次,给出了如何将凹多边形转变为凸多边形的流程,并详细说明无人机覆盖区域的过程;最后,通过仿真示例验证了算法的有效性与正确性。国家自然科学基金项目(61673327);;航空科学基金项目(20160168001

    Studies on chemical constituents in ethanolic extract from Acanthus ilicifolius as a pharmaceutic mangrove

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    目的探讨老鼠簕的化学成分。方法将老鼠簕全株粉碎后,用95%乙醇浸提3次,合并浓缩,浸膏的石油醚部位经反复硅胶柱层析分离,结合波谱学数据鉴定化合物结构。结果从石油醚部位分离得到8个化合物,分别为β-谷甾醇(Ⅰ)、豆甾醇(Ⅱ)、正十六烷酸(Ⅲ)、正二十八烷酸(Ⅳ)、4,22-二烯-3-酮豆甾烷(stig-masta-4,22-dien-3-one)(Ⅴ)、4-烯-3-酮豆甾烷(stigmast-4-en-3-one)(Ⅵ)、5,22-二烯-7-酮-3β-羟基豆甾烷(3β-hydroxystigmasta-5,22-dien-7-one)(Ⅶ)、2-唑啉酮(2-benzoxazolinone)(Ⅷ)。结论其中Ⅴ,Ⅵ,Ⅶ为首次从该植物中分离得到。Objective To study the chemical constituents of Acanthus ilicifolius.Methods The air-dried and powdered plant material was extracted with 95% ethanol.Silica gel and Sephadex LH-20 column chromotography were used in the isolation from the ethanol extracts of the whole plant,the compounds were determined on the basis of various modern spectroscopic analyses and physical constants.Results Eight compounds were isolated from the petroleum ether soluble portion,identified as β-sitosterol(Ⅰ),stigmasterol(Ⅱ),n-hexadecane acid(Ⅲ),n-octacosanic acid(Ⅳ),stigmasta-4,22-dien-3-one(Ⅴ),stigmasta-4-en-3-one(Ⅵ),3β-hydroxystigmasta-5,22-dien-7-one(Ⅶ) and 2-benzoxazolinone(Ⅷ).Conclusion CompoundⅤ,Ⅵ,Ⅶ were obtained from the genus for the first time.国家自然科学基金(30671646);; 福建省科技计划资助项目(2003Y036

    粘液性嚢胞腺腫の悪性化との鑑別に苦慮した膵未分化癌の1例

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    症例は70歳代の女性.7年前に膵尾部単純性嚢胞と診断され,経過観察中であった.4ヶ月持続する発熱と心窩部痛の精査を目的として入院した.入院時のCTでは多発肝腫瘍を認め,嚢胞内には結節病変を,嚢胞周囲には出血・感染を示唆する所見を認めた.以上より,嚢胞性病変が癌化して転移・浸潤をきたし,嚢胞周囲に膿瘍を形成したものと考えて対症的に治療したが,第15病日に死亡した.剖検所見から嚢胞の癌化は否定され,嚢胞に近接して発生した膵未分化癌と,肝転移,肺転移等の多臓器転移,腹膜播種と診断された

    Robust Flight Control System Design for BTT Missile

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    飞行控制系统设计是倾斜转弯( B T T )控制型导弹的-项关键技术.B T T 导弹转弯和 机动时需绕其速度矢量快速滚转,因而会导致较强的俯仰与偏航通道耦合,给飞行控制系统设计 带来困难.本文对BTT 导弹飞行控制系统进行设计,内回路采用蕴匝砸控制方法以抑制系统不确 定性;外回路采用混合灵敏度H∞鲁棒控制方法以抑制外部干扰和消除模型不确定带来的影响. 仿真验证表明,所设计的BTT 导弹飞行控制系统满足控制性能要求,目标拦截性能优于基于经典 控制方法设计的BTT 导弹飞行控制系统性能.Flight control system design is a key technique for bank-to-turn (BTT) missile. Because BTT missile needs to spin around its velocity vector rapidly when it makes a turn or maneuver,this will result in stronger coupling between pitch and yaw channels and bring difficulty for the flight control system design. In this paper,a flight control system design is performed for BTT missile,in which,LQR control method is employed in the inner loop to suppress system uncertainty,and the mixed sensitivity 匀肄 control method is used in the outer loop to suppress outside disturbance and eliminate the effect caused by model uncertainty. Simulation results demonstrate that the designed BTT flight control system satisfies the control performance requirements, a n d has better target interception performances c o m p a r e d to the flight control system designed with classic control method.国家自然科学基金项目(61673327)曰航空科学基金项目(20140168001;20160168001

    Upwind Compact Schemes for Hamilton-Jacobi Equations

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    基于Hamilton-Jaeobi(H-J)方程和双曲型守恒律之间的关系,将三阶和五阶迎风紧致格式推广应用于求解H-J方程,建立了高精度的H-J方程求解方法.给出了一维和二维典型数值算例的计算结果,其中包括一个平面激波作用下的Richtmyer-Meshkov界面不稳定性问题.数值试验表明,在解的光滑区域该方法具有高精度,而在导数不连续的不光滑区域也获得了比较好的分辨效果.相比于同阶精度的WENO格式,本方法具有更小的数值耗散,从而有利于多尺度复杂流动的模拟中H-J方程的求解

    Studies on Curing Shrinkage of Liquid Optical Clear Adhesive

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    紫外光固化的液态光学胶固化过程中出现的体积收缩现象,严重影响其黏接强度和产品外观.系统研究了液态光学胶预聚物的种类、活性稀释剂的种类和用量、光引发剂的用量、光固化的类型等诸多因素对固化收缩率的影响.研究发现,以聚乙二醇二丙烯酸酯作为预聚物可明显降低固化收缩率.当添加的活性稀释剂官能度相同时,胶黏剂的固化收缩率随活性稀释剂相对分子质量的增加而减小;当活性稀释剂相对分子质量相近时,官能度增加,固化收缩率随之增大.而光引发剂的用量则对固化收缩率无明显影响.阳离子型胶黏剂的固化收缩率比自由基型的小,但硬度和黏接强度较低;而混杂型的固化收缩率则介于二者之间.The volume shrinkage during UV-curing of liquid optical clear adhesives(LOCA)had a serious effect on the adhesive strength and appearance of the product.In this paper,the effect of different factors,including types of active diluents,amounts of active diluents and photo-initiators,and UV-curing types,on the volume shrinkage for LOCA was systematically investigated.Based on the experiment,polyethylene glycol diacrylate as the prepolymer could significantly reduce the shrinkage.With the same functionality of the added active diluents,the shrinkage decreased when the molecular weights of the active diluents increased.When the molecular weights of active diluents were similar,the shrinkage increased with the increase of the functionality.The amount of photo-initiators had no significant effect on shrinkage.The shrinkage of cationic adhesives was smaller than that of radical adhesives,but the hardness and adhesion strength were relatively lower.The shrinkage of hybrid adhesives was in between in general

    豚尾猴(Macaca nemestrina)等灵长类动物反转学习的比较研究

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    &lt;正&gt; 不同种类猿猴脑高级机能的比较生理心理研究的资料很少,并且意见不完全一致。和(1997)曾报道黑猩猩较阿拉伯狒有较大的推断能力。Shell和Riopelle(1958)报道阔鼻猴蜘蛛猴(Ateles geoffroyi),卷尾猴(Cebus albifrons)</p

    豚尾猴(Macaca nemestrina)等灵长类动物反转学习的比较研究

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    不同种类猿猴脑高级机能的比较生理心理研究的资料很少,并且意见不完全一致。和(1997)曾报道黑猩猩较阿拉伯狒有较大的推断能力。Shell和Riopelle(1958)报道阔鼻猴蜘蛛猴(Ateles geoffroyi),卷尾猴(Cebus albifrons
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