Early Cambrian phosphatized blastula- and gastrula-stage animal fossils from southern Shaanxi

Marine invertebrate animal embryos and their early developmental products are of great significance to the study of taxonomy and phylogeny of early animals. A great number of phosphatized globular fossils were collected fromthe early Cambrian Kuanchuanpu Member (upper Dengying Formation), southern Shaanxi, and a nearly complete develo-pmental sequence—from a fertilized egg, via blastodisc formation, blastula development, blastodisc enlargement toward gastrulae, to tissue differentiation—can be discerned in this collection. This discovery provides unmatchable material for studies on the origin, taxonomy, radiation, and ontogeny of early metazoans.     

Early Oligocene anatexis in the Yardoi gneiss dome, southern Tibet and geological implications

The Yardoi gneiss dome is located to the easternmost of the North Himalayan Gneiss Dome (NHGD), southern Tibet. It consists of metapelite, garnet amphibolite, granite and leucogranite, and is a key subject to constrain the formation and tectonic evolution of NHGD. SHRIMP zircon U/Pb data on the leucogranite yield an age of 35.3±1.1 Ma, which is substantially older than that of the similar leucogranites to the west. Sr and Nd isotope systematics indicate that this leucogranite was derived from partial melting of the mixed garnet amphibolite and metapelite. Our data suggest that (1) during the early stage of Himalayan magmatism, amphibolite dehydration melting overwhelmed that of the metapelite; and (2) such a melting at middle-lower crust might be a major factor that initiated the movement along the Southern Tibetan Detachment System (STDS). Supported by National Natural Science Foundation of China (Grant No. 40673027), the Outlay Research Fund of Chinese Academy of Geological Sciences (Grant No. 20071120101125), and the Hundred Talent Program of Chinese Academy of Sciences     

Sponge fossil assemblage from the Early Cambrian Hetang Formation in southern Anhui

Abundant well-preserved large articulated sponge fossils and isolated spicules have been reported from the Early Cambrian Hetang Formation, southern Anhui Province. This unique epifaunal fossil assemblage dominated by articulated sponge fossils is called the Xidi Sponge Fauna. The sponge fauna lived in a quiet oxygenic environment below the storm wave base. Bloom of phytoplankton and rapid sedimentation rate resulted in the deposition of the black shales. Sufficient food supply, lack of other competitors, abundant ecological niches, and demand for oxygen during early Cambrian were in favor of the diversification and evolution of large sponges in the Early Cambrian.     

具有层间窜流的三层油藏非牛顿幂率流试井模型

在前人工作的基础上,建立了3种外边界条件下的三层油藏非牛顿流渗流模型,对模型进行了求解;绘制了3种外边界条件下的典型渗流曲线,从渗流机理和渗流过程对曲线形态进行了深入分析.研究结果不仅可用于试井解释,也有助于人们更清楚地认识和评价油藏,为油藏制定合理工作制度提供科学的依据.     

斗争与融合：契约华工与秘鲁华人社会的形成

19世纪中后期,大量华人劳工以“苦力贸易”的形式来到秘鲁,这种劳动力的跨国迁移,有两种驱动力量,一种是“拉力”,即秘鲁国内的劳动力不能满足经济发展的需求;另一种是“推力”,即当时中国经历了太平天国战乱,民生凋敝、大量贫农被拐骗到秘鲁。在秘鲁务工时,华工遭到残酷虐待和压榨,这激起了他们的反抗。在坚持不懈的斗争中,华工赢得了自己在秘鲁社会平等的地位,秘鲁华人社会由此形成,华人并由此成为当地的强势族群。     

Plant crop remains from the outer burial pit of the Han Yangling Mausoleum and their significance to Early Western Han agriculture

A large amount of carbonized plant remains were discovered in one of the outer burial pits of the Han Yangling Mausoleum, which was built more than 2000 years ago for the Jing Emperor, Liu, Qi (188―141 cal a BC), the fourth emperor of the Western Han Dynasty. The remains are identified by phytolith analysis and macrofossil morphological features. Seeds from foxtail millet (Setaria italica), broomcorn millet (Panicum miliaceum), rice (Oryza sativa) and chenopod (possible Chenopodium giganteum) are identified...     

农村人力资源开发与农业现代化

人力资源是进行社会生产最基本最重要的资源。在知识经济时代，人力资源在经济增长中越来越起到决定性的作用。我国农村人力资源丰富，但人力资源素质低下，人力资本含量不足，严重制约了农业的发展，延缓了农业现代化的进程。因此，农民素质的提高和农村人力资源的开发是实现我国农业现代化的关键。     

Primitive agriculture in a social amoeba

Agriculture has been a large part of the ecological success of humans. A handful of animals, notably the fungus-growing ants, termites and ambrosia beetles, have advanced agriculture that involves dispersal and seeding of food propagules, cultivation of the crop and sustainable harvesting. More primitive examples, which could be called husbandry because they involve fewer adaptations, include marine snails farming intertidal fungi and damselfish farming algae. Recent work has shown that microorganisms are surprisingly like animals in having sophisticated behaviours such as cooperation, communication and recognition, as well as many kinds of symbiosis. Here we show that the social amoeba Dictyostelium discoideum has a primitive farming symbiosis that includes dispersal and prudent harvesting of the crop. About one-third of wild-collected clones engage in husbandry of bacteria. Instead of consuming all bacteria in their patch, they stop feeding early and incorporate bacteria into their fruiting bodies. They then carry bacteria during spore dispersal and can seed a new food crop, which is a major advantage if edible bacteria are lacking at the new site. However, if they arrive at sites already containing appropriate bacteria, the costs of early feeding cessation are not compensated for, which may account for the dichotomous nature of this farming symbiosis. The striking convergent evolution between bacterial husbandry in social amoebas and fungus farming in social insects makes sense because multigenerational benefits of farming go to already established kin groups.     

硅酸盐细菌在工农业生产中的应用及其作用机理(英文)

硅酸盐细菌在农业生产中具有潜在的应用前景。这种特殊的芽胞杆菌 ,可产生十分丰富的胞外多糖 ,目前人们正利用它制成细菌肥料 ,以便从土壤矿物中释放出可溶性钾、磷和硅等元素 ,以满足作物生长的需要。在冶金工业上 ,硅酸盐细菌主要被应用于细菌淋滤和改进某些矿物材料的特性等方面 ,实践表明 ,该类细菌对低品位矿物的开发以及回收利用某些有用金属具有良好的前景。本文报道了有关这一领域的国内外研究与应用现状 ,作者特别强调采用矿物学与微生物学相结合的研究方法和手段来解决诸如细菌与矿物相互作用的问题。     

农业外来有害生物入侵现状及防控对策

外来有害生物的入侵对农业生产安全、生态环境、人类健康和社会构成了严重影响．报道了我国目前外来有害生物入侵现状,并提出了防控对策．     

农药7322系列的电子结构和构效关系以及与农药7323的比较

对７３２２系列农药应用ＭＯＰＡＣ程序包ＭＡ１方法进行量子化学计算,讨论它们的电子结构特征和结构活性关系,并对此系列进行比较,为探讨并开发该类化合物的药物性能及对家蚕微粒子病的作用机理和药物分子结构设计提供指导。     

论土壤环境污染和农业清洁生产

论述了实行清洁生产和保护土壤生态环境的重要性，分析了土壤环境污染的主要途径及严重性。从保护农业环境的要求出发，提出了加强管理、科学施肥、推广无公害农药、采用可降解地膜及加强对“三废”及城市垃圾和空气、酸雨污染治理等保护农业生态环境的措施，并分析了清洁生产的可行性。     

黄土原区土地结构与农业开发

利用TM卫片解译与野外调查相结合、路线考察与典型样地相结合、资料分析与专题访问相结合的方法,对洛川原土地资源进行了全面系统的调查分析;提出了土地资源系列制图的理论;阐述了土地结构与农业综合开发的意见。     

油菜在我国西部农业中的地位和发展前景

我国西部是油菜的原产地，作物生长期内的气候特点，同春油菜的生物学特性恰相适应。春油菜作为冷凉气候区的优势作物，对西部多发的霜冻、冰雹等自然灾害有减避功能，其自我肥田固土效能和产品的工业开发增值潜势大于其它作物。菜籽油是最佳佐膳油和后备燃料油，菜籽饼是优质蛋白类饲料源，市场广阔。在西部开发中加大油菜生产比重和产品的高科技开发力度，可取得以农业发展促加工业发展的双重效果。在我国东部适粮西部适油的大生态格局中，是种植业结构调整的优化选择。     

多点地质统计学在秘鲁D油田地质建模中的应用

应用多点地质统计学和相控建模相结合的方法,以秘鲁D油田V层为例进行了地质条件约束下的地质建模研究。首先根据地质概念模型建立训练图像,然后应用多点地质统计学Snesim算法模拟沉积微相,最后在沉积微相控制下进行储层参数模拟。研究结果表明：多点地质统计学方法不仅忠实于井点数据,而且可以在使用的训练图像中加入地质概念,从而对随机模型进行地质约束;V层沉积微相随机模拟较好地再现了沉积微相的空间结构,其孔隙度模拟实现与相应沉积微相模型吻合较好,且沉积微相对储层参数的空间分布具有较大影响;多点地质统计学方法和相控建模的建模原则有助于从地质的角度对模型进行约束,促进概念模型向定量模型的转化,从而建立合理的反映地下实际情况的三维模型。     

聚合物反胶团萃取中的亲油作用和氢键作用

为探索聚合物反胶团萃取亲水溶质的机理以及聚合物与溶质的相互作用，在比较了聚合物胶团萃取和聚合物反胶团萃取的特性基础上，利用热力学分析、红外光谱分析和紫外光谱分析，研究了聚合物反胶团萃取的作用机制，指出并实验验证了聚合物与溶质之间存在着亲油作用和氢键作用。研究结果表明，亲油作用在聚合物反胶团萃取过程中起主导作用。当聚合物与溶质存在氢键作用时，氢键作用对萃取效果有明显的影响。氢键作用较弱时，溶质的萃取受亲油作用支配     

中国观光旅游开发规划研究

观光农业是旅游业和农业相互交融的新兴产业，我国观光农业的开发已形成一定的规模，但也存在不少问题，中国的观光农业还需进一步开发，在开发中需注重项目的合理布局，强调观光农业项目创意和专题旅游设计，强化旅游促销。