7 research outputs found

    分泌AFP的胃肝样腺癌(光镜、电镜和免疫组化观察)

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    分泌AfP的胃肝样腺癌(光镜、电镜和免疫组化观察)江显毅1杨善民2张思宇1方庆全1关键词胃癌;肝癌细胞样分化;电镜;免疫组化1.厦门市第一医院(厦门361003)2.厦门大学抗癌研究中心自1982年PrATH[1]等首次在卵巢的卵黄囊肿瘤发现肝癌细胞..

    分泌AFP的胃肝样腺癌1例─附光镜、电镜和免疫组化观察

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    分泌AfP的胃肝样腺癌1例─附光镜、电镜和免疫组化观察江显毅,杨善民,张思宇,方庆全(厦门市第一医院病理科3610032厦门大学抗癌研究中心)自1982年PrATH[1]等首次在卵巢的卵黄囊肿瘤发现肝癌细胞样细胞特3征以来,在胃、肺、子宫内膜、结肠和..

    An Information Hiding Algorithm Against the Cropping Attack

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    提出了一种基于拉丁方阵的抗剪切信息隐藏算法,通过载体图像隐藏容量和秘密信息的大小确定隐藏秘密信息的备份数,根据备份数确定隐藏信息的拉丁方阵模板,对秘密信息进行分组和编号,通过拉丁方阵模板按对应的编号,将秘密信息嵌入到载体图像中,实现信息隐藏.实验结果表明该算法能够实现大容量隐藏并且能够抵抗大面积的剪切攻击,具有较好的应用价值. This paper proposes an anti--cropping steganography scheme based on Latin square. At first, the amount of secret copies is obtained by the cover image's hiding capacity and the length of the secret message. According to the amount of copies, a Latin square is confirmed as the template for hiding secret message. The secret message is divided into groups and each group is numbered. Then the secret groups are embedded into the cover image with the corresponding element in the Latin square. Experimental results indicate that the proposed scheme can achieve high capacity, and can be against the cropping attack. It has significant practical value for information security.国家自然基金(61363034,61300109);广西自然科学基金(2011GXNSFD018026,2012GXNSFBA053166,0832104);广西科学研究与技术开发计划项目(10123005--8);重庆市教委科技项目(KJ121310);涪陵区科技计划项目(FLKJ,2012ABA1056);广西信息科学实验中心项目(20130204

    An Information Hiding Method Based on JPEG Images

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    本文提出一种JPEG图像的信息隐藏算法,根据给定阈值确定隐藏信息的低频DCT系数,对这些低频系数进行编号分组,得到载体信息。将秘密信息每2位分为一组,每组秘密信息转换为十进制数,用这个数确定隐藏到载体中某组系数的位置。根据嵌入方式,对秘密信息进行预处理得到嵌入数据,通过与3的模数修改隐藏信息的低频DCT系数实现信息隐藏。实验结果表明,本文算法有较好的视觉效果。This paper proposes a steganography scheme based on JPEG images. According to a given threshold, the low frequency coefficients are chosen to hide data. Then these low frequency coefficients are divided into groups to get the carrier. Two bits of secret message are taken as a group from the secret information,and converted into a decimal number. This number will be used to determine the hiding po- sition of the coefficients group. According to the hiding scheme,the secret message is preprocessed to get the hidden data,and the low frequency coefficients of the hiding position is modified by model 3 to hide the secret data. Experimental results indicate that the proposed scheme achieves better image quality of stego-images.国家自然科学基金资助项目(61363034,61300109); 广西自然科学基金资助项目(2011GXNSFD018026,2012GXNSFBA053166,0832104); 广西科学研究与技术开发计划项目(10123005-8); 重庆市教委研究项目(KJ121310); 涪陵区科技计划项目(FLKJ2012ABA1056); 广西信息科学实验中心项目(20130204

    Feeding habit of Erisphex potti from Changjiang Estuary and adjacent sea in spring

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    采用碳氮稳定同位素技术和聚类分析法对春季长江口及其邻近海域虻(Erisphex potti)的饵料组成、摄食随体长的变化进行研究,结果表明:(1)虻的食物由大于900μm的浮游动物、细螯虾(Leptochela gracilis)、太平洋褶柔鱼(Todarodes pacificus)、双喙耳乌贼(Sepiola birostrata)、火枪乌贼(Loligo beka)、日本枪乌贼(Loligojaponica)、脊腹褐虾(Crangon affinis)和仔稚鱼组成,优势饵料为浮游动物,其重量贡献率为69%~75%。(2)虻的食物组成及摄食量在体长为60mm时发生较大变化,脊腹褐虾、仔稚鱼及软体动物等饵料对体长大于60 mm的虻的贡献率增大,增幅为1%~12%。In order to assess the relative trophic importance of the spotted velvetfish in Changjiang Estuary and adjacent sea in summer,carbon(δ~(13)C) and nitrogen(δ~(15)N) stable isotope ratios were determined in spotted velvetfish and its potential food sources.Based on an organism's stable isotope ratios are an integration of the isotopic signatures of food sources that have been assimilated through time.The δ~(13)C and δ~(15)N values showed that the spotted velvetfish's food sources were composed of plankton >900 μm,Leptochela gracilis,common squid,Lantern cuttlefish,Beka squid, Common Japanese squid,larvae and juvenile and Japanese sand shrimp.plankton >900 μm was the most important food source,accounting for 69%-75% of the total food by weight.Food proportion of the spotted velvetfish varied among different classes of sizes.Cluster analysis dived the body lengths of the spotted velvetfish into two groups according to stable isotope ratios,>60 mm and 900 μm was 68%-87% to 75%-88% for the > 60 mm to 900 μm was the most important prey,while others were eaten occasionally by the spotted velvetfish.If the production of plankton >900 μm decrease in some cases,the spotted velvetfish would increase the other food proportion,sharing the large size food with other organisms,which would decrease the production of high trophic level organisms or shorten the length of food chain.国家自然科学基金重大项目(30490233);; 国家自然科学基金面上项目(30570293

    小流域生态经济系统模式研究

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    本研究系吉林省科技攻关项目,是吉林省生态建设的重要内容之一,该项目以东北低山丘陵区吉林省东辽县黑牛河流域为重点,运用水土保持学、恢复生态学及经济学理论,系统地研究该区小流域生态经济系统建设、诊断、模式与优化结构及可持续发展评价。分析诊断指标体系建立及系统健康诊断,生态经济系统优化模式与结构(生态经济和环境整治措施与配置优化),东北低山丘陵区特殊地形水土保持措施及其配置和可持续发展评价指标体系与评价方法是限制该区生态环境建设的关键,也是解决该问题的主要支撑技术。在15.32cm平方公里的黑牛河流域通过全面的综合调查,系统分析,建立健康诊断指标体系,进行病理诊断,开展水保措施与配置和结构优化试验示范,建设实体模型。同时开展可持续发展评价指标体系研究,进行可持续发展评价,检验建设成果。该项目由吉林省水土保持研究主持,中科院教育部水土保持与生态环境研究中心与北京林业大学水土保持学院为协作单位,研究直接切入吉林省生态省建设项目,增强了研究的针对性,缩短了试验示范推广周期;由科教、生产单位科技人员组成联合攻关专题组,具有优势互补,中尺度区域性研究和试验示范互为支撑的特点;在黑牛河试验示范区成功地探索了快速、高效、持续开展生态经济系统建设的科技支撑作用,黑牛河小流域经过治理后,每年农、林、牧、副、渔和工业经济效益比治理前增加了699.36万元/年;近几年,该项成果在吉林省各区的小流域治理中得到广泛应用,应用面积为5972平方公里,其生态经济系统建设规划、植被建设布局及配置模式等在吉林省生态建设中发挥了重要指导作用,创经济效益17916万元。取得显著生态、经济和社会效益

    中国西部山区典型流域综合治理技术与示范

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    该成果针对我国西部水土流失的现状和特点,对小流域综合治理进行了系统的理论研究。在理论研究方面,将流域景观生态学与生态系统管理引入到流域治理研究中,提出流域生态系统综合诊断方法,开发出流域治理决策支持系统,对流域水沙运移规律和侵蚀产沙模型进行了系统研究,充实了流域综合治理的理论基础,对流域水土流失治理和管理提供了重要的技术支撑。选择三个具有不同地质地貌特征的典型流域,综合流域水土流失和管理存在的实际问题的诊断,将研究的流域综合治理技术用于生产实践,突破了地域对理论技术的限制等难点,拓展了理论的适用空间,对我国西部山区流域生态环境的整治改善提供了直观的、可操作的范例
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