不同砧木嫁接艾思油栗对树体叶幕形成及早期产量的影响

用豫罗红栗做砧木嫁接板栗新品种艾思油栗,叶幕形成快,早期产量高.采用丁字形芽接或枝接,第2年就有产量,4年产量合计为每株7.8kg和17.2kg.按3 m×4 m株行距计算,折合产量可达6 585kg/hm2和14 340kg/hm2,超出豫南地区板栗平均单产的6倍以上.     

论方东美美学的方法和问题

方东美的美学方法和他所回答的种种问题在逻辑上是一致的.他是从人文途径建构了一个"既超越又内在"形上学方法,并以此反对西方二元对峙的方法.他的美学和哲学是浑为一体的,是步了"天人合一"的理路.他把人、自然、宇宙的统一看作是生命情调以美学化方式的一种渲泄.方东美美学的方法还可以称作是"全体的直透"法.由于把宇宙、人皆看作是有生命的"情理集团",他对美的解释是庄子所谓的"大美",是"原天地之美而达万物之理".同时,他主张这个天地之美寄于生命,形于创造.总之,方东美的美学思想既承续了中国传统体用不二的路数,又借鉴了西方柏格森、怀特海许多有益的因子,构成了一个独具特色的当代中国美学的思想体系.     

宋代的双季稻

宋代虽然有早稻和晚稻的名称 ,却并不是现代意义上的双季稻 ,但这并不能否定宋代有双季稻的存在。宋代存在再生、间作和连作三种形式的双季稻。再生稻 ,又名再熟稻、稻孙、二稻、传稻、孕稻、魏撩、再撩、再生禾、女禾等 ,分布于两浙、淮南、江南、福建和湖北等地。间作稻 ,又名寄生 ,主要分布在浙东一带。连作稻 ,在宋代虽然没有专门的名称 ,但却出现了许多连作稻的品种 ,如江苏的乌口稻、浙江的乌和第二遍、江西的黄穋禾、福建的和献台、岭南的月禾等等。另外 ,在宋代的稻品种中 ,还发现了有些品种既当早稻又充晚稻的现象 ,也应是双季连作的结果。宋代的连作双季稻分布虽广 ,但由于品种不佳、产量不高、季节和劳动力的矛盾、放牧的需要、肥水条件的限制、投入产出率低等等原因 ,双季稻总的种植面积并不大 ,在粮食生产中的作用如同凤毛麟角。宋代的双季稻大多都是在原有的品种基础上发展起来的 ,与当时引进的早熟而耐旱的品种占城稻关系不大。     

贵州早二叠世玄武岩喷发环境及其古海洋效应研究

二叠纪是中国南方火山活动较为强烈的时期之一,此时贵州省境内形成了大面积的玄武岩。文章通过岩石学、地球化学、大地构造学研究论证了早二叠世玄武岩喷发时为大陆裂谷环境,从宏观、微观岩石学特征确定了分布区东部的早二叠世玄武岩为海底喷发的产物,并详细研究了它对古海洋沉积学、古海洋地球化学的影响。     

Possible developmental mechanisms underlying the origin of the crown lineages of arthropods

The extraordinarily preserved, diverse arthropod fauna from the Lower Cambrian Maotianshan shale, central Yunnan (southwest China), represents different evolutionary stages stepping from stem lineages towards crown arthropods (also called euarthropods), which makes this fauna extremely significant for discussion of the origin and early diversification of the arthropods. Anatomical analyses of the Maotianshan shale arthropods strongly indicate that     

Caffeine as a psychomotor stimulant: mechanism of action

The popularity of caffeine as a psychoactive drug is due to its stimulant properties, which depend on its ability to reduce adenosine transmission in the brain. Adenosine A₁ and A_2A receptors are expressed in the basal ganglia, a group of structures involved in various aspects of motor control. Caffeine acts as an antagonist to both types of receptors. Increasing evidence indicates that the psychomotor stimulant effect of caffeine is generated by affecting a particular group of projection neurons located in the striatum, the main receiving area of the basal ganglia. These cells express high levels of adenosine A_2A receptors, which are involved in various intracellular processes, including the expression of immediate early genes and regulation of the dopamine- and cyclic AMP-regulated 32-kDa phosphoprotein DARPP-32. The present review focuses on the effects of caffeine on striatal signal transduction and on their involvement in caffeine-mediated motor stimulation.Received 8 July 2003; received after revision 7 September 2003; accepted 6 October 2003     

唐初统治集团的重农思想表现及其发展农业的措施

以李渊、李世民父子为首的唐初统治集团的重农思想主要表现在：“抚民以静”的无为而治思想,“民为邦本”的民本思想,“农为邦本”的“农本思想,和“偃武修”、“去奢从约”的思想。在这些重农思想的指导下,唐初统治集团在发展农业方面采取了栽汰冗员,择善任人;推行均田制,奖励垦荒;实行租庸调法;增殖人口,解决劳动力严重不足问题;兴修水利,防治水旱灾害等一系列开明、进步的措施。从而为以后的社会发展奠定了基础。     

Lower Cambrian small shelly faunas from Zhejiang (China)and their biostratigraphical implications

Despite a long history of research on the Early Cambrian in China most available data on small skeletal fossils concern fossil associations of the shallow carbonate platform. Information on skeletal fossils from marginal shelf environments of the Yangtze Platform is scanty, which may reflect the rarity of fossils in deeper sedimentary environments but is also due to limitation of carbonate distribution and outcrops, difficulties in fossil extraction, and a general research focus on the Precambrian-Cambrian boundary beds on the carbonate platform. Here we present a documentation of Meishucunian to Qiongzhusian small skeletal fossils from the lower Hetang Formation and the chert unit at its base from the Jiangshan region, Zhejiang Province, representing a relatively deep shelf environment compared to the inner shelf region. The earliest association (Meishucunian) from the chert unit underlying the Hetang Formation is mainly characterized by the occurrence of Protohertzina anabarica, P. unguliformis, Fengzuella zhejiangensis, and Kaiyangites novilis, which differs somewhat in composition from SSF-associations of typical inner shelf deposits. The enigmatic skeletal fossil Fengzuella zhejiangensis, which exhibits an unusual secretional growth mode previously unrecognized from the Early Cambrian, is described in detail. A younger (Qiongzhusian) fossil association contains numerous arthropod remains, such as disarticulated spines of arthropods (Jiangshanodus- and Kijacus-type), which have previously been considered as conodont-like fossils, and bradoriid valves.     

Change in the sedimentary environment of Wanquan River Estuary,Hainan Island,China

Pb geochronology and sediment core profiles of organic carbon, total sulfur and organic carbon isotope (d 13C) values were used to reconstruct the local environ-mental history of the Shamei Lagoon, located in the Wan-quan River Estuary, eastern Hainan Island, China. Totalsulfur and d 13C values decreased upwards in the top 30 cm of a sediment core that spanned the last 200 years of deposi-tion. Total sulfur concentration and d 13C values respectively decreased upward from 1.92% to 0.36%, and -20.63?to -23.64? The C/S ratio in the 19th century and earlier was relatively stable in the range of 0.47—0.80, and there was a positive correlation between organic carbon and total sulfur. Since around 1900 AD, the C/S ratio increased rapidly to a maximum of 3.94, but no simple correlation was found be-tween organic carbon and total sulfur during this more re-cent period. These results indicated that before 1800 AD, the lagoon had a fully marine character, and the location of to-day抯 Wanquan River Estuary was an open embayment.From 1800 to 1900, the salinity of Shamei Lagoon decreased noticeably. The amount of seawater which could enter thelagoon decreased gradually as the Yudai spit grew. Today,seawater scarcely affects the lagoon; it is essentially a fresh-water basin.     

咏物诗与初唐诗歌建设

初唐咏物诗不能被简单地视为南朝遗绪,它有力地促成了初唐诗歌声律的成熟,而风骨的产生也是以咏物诗为标志的,从这个意义上来说,咏物诗对盛唐诗歌高潮的到来起到了先导的作用。