北阡遗址人和动物骨的C，N稳定同位素分析     

王芬  宋艳波  李宝硕  樊榕  靳桂云  苑世领 《中国科学:地球科学》2013,(12):2029-2036

青岛市即墨北阡遗址先后经过三次考古发掘,出土大量大汶口文化和周代两个时期的人和动物骨资料,对其进行碳和氮稳定同位素分析可望复原先民的食物结构,探讨动物、植物驯养情况．分析结果表明：大汶口文化和周代先民的食物结构中粮食作物以C4类食物为主,肉类更多为海洋贝类和家畜;家猪的驯养则以C3植物为主,并受先民生活方式的影响．研究推测,尽管北阡遗址地处海岸线附近,海洋渔业更多依赖贝类而不是海洋鱼类．总体而言,大汶口时期先民的食物资源包括粟类作物（C4植物）、贝类海洋食物和家畜,体现为农耕、驯养和渔业为主,而狩猎为辅的生活方式;周代与之相比,驯养和海洋渔业等肉食资源更丰富,生活条件有了显著提高．  相似文献   

生物技术公司遭控诉：保护知识产权还是垄断？     

《海洋世界》2008,(7):8-8

粮食危机来了!不久前，世界各国领导人聚首罗马，共同商讨食物紧缺这个大问题，生物技术公司也开始推销它们的新技术以解决危机。然而，一项调查结果却将生物技术公司推上审判台。这项调查发现，有9家生物技术公司在全世界至少申请了532项专利，其中包括植物的55个基因，这些基因使植物可以抵抗炎热、干旱以及洪涝灾害。如果这些专利最终获得许可，生物公司将掌握世界范围内食物供应的主动权。  相似文献   

北极熊遥望雪雁蛋     

《海洋世界》2009,(1):7-7

随着全球气候的变化，北极变暖，春天的破冰时间提前。北极熊为了生存，必须寻找其他的食物来源。过去，人类曾发现北极熊吞食棉凫（棉鸭）蛋和黑雁蛋。最近，有研究者通过计算得出结论：未来雪雁蛋可以作为食物，缓解北极熊的生存压力。北极熊和雪雁在加拿大的哈德逊湾“相遇”。在那里，北极熊每年通常会有4～5个月待在陆地上。由于气候变暖，每年的破冰时间平均提前0．72天，  相似文献   

复印综合     

《青海国土经略》2009,(6):45-45

由于复印机的静电作用、空气中产生臭氧，这种物质使人头痛、头晕、咳嗽等。预防的办法是：复印机要避免日光直射，室内空气要经常流通；经常与复印机打交道的人，要适当增加含维生素E的食物。  相似文献   

Effects of Calanoid Copepod Schmackeriapoplesia as a Live Food on the Growth,Survival and Fatty Acid Composition of Larvae and Juveniles of Japanese Flounder,Paralichthys olivaceus     

LIU Guangxing  XU Donghui 《青岛海洋大学学报(英文版)》2009,(4):359-365

Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for cul- turing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs （DHA, EPA and ARA） in S. po- plesia was significantly higher than that in the other two live foods （P〈O.O1）. Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods （S. poplesia） had significantly higher growth rate than those fed with the other two organisms （P〈0.01）. The survival of the flounder larvae fed with copepods was significantly higher than that of the others （P〈0.01）, and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia （P〈0.05）. The contents of three types of HUFAs （DHA, EPA and ARA） and the ratio of DHA/EPA in larval and juve- nile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet orArtemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.  相似文献   

能吃还挑食,要质量还是要数量?     

魏博逊 《海洋世界》2013,(2):48-53

种类不同,吃的也不同海洋中,生活着大量的大型海洋动物。与陆地不同,大型海洋动物的食谱基本都是以肉为主。这自然有它的道理:在冰冷的海水中,越是大型的海洋动物,消耗的能量也就越大。没有高能量食物的支持,这些动物只能因为能量耗尽而  相似文献   

Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus     

Guangxing Liu  Donghui Xu 《中国海洋大学学报(英文版)》2009,8(4):359-365

Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods (P<0.01). Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods (S. poplesia) had significantly higher growth rate than those fed with the other two organisms (P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others (P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia (P<0.05). The contents of three types of HUFAs (DHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.  相似文献   

国外耕地保护的常用手段     

陈美球 《河南国土资源》2008,(8)

保护耕地是当今世界实现可持续发展战略目标的一个共同关注的热点。纵观世界各国耕地保护的动因，可以归纳为四个方面：一是食物安全。二是耕地为社会提供的公共自然福利功能。除了生产农产品外，耕地还给人类提供各种各样的非生产性功能，如农田耕作传统文化、开放空间、农村独特景观、生物栖息、空气与地下水的净化，这些功能具有强烈的外部性，为社会公众共同享受，且不能通过市场规律调节，人们对这种公共自然福利的需求，  相似文献   

陆地霸主黑犀牛     

桑雪 《发现．图形科普》2000,(4):18-25

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海洋浮游细菌的生态学研究   总被引：23，自引：2，他引：23  

肖天 《地球科学进展》2001,16(1):60-64

海洋浮游细菌在海洋生态系统中的重要作用随着对其生物量和生产力的深入研究而得到了充分肯定。以浮游细菌为核心的微食物环研究的开展，也显示出微食物环在海洋生态系统动力学过程中有不可替代的作用，是主食物链的重要补充，特别是在贫营养的大洋生态系统中。在不同水 层和特殊环境中对海洋浮游细菌的研究结果表明其研究潜力巨大。就国内在这方面的研究现状和需进一步研究的内容进行了阐述。  相似文献