大连市人口老龄化及其对策探讨

随着全国人口老龄化的加重,大连市的这一问题也越发突出,本文详细分析了大连市人口老龄化的发展趋势,及由此给大连社会经济发展可能带来的影响,并提出了一些探讨性的对策与建议,旨在使大连市老年人口得以合理发展,促进社会经济的良性运行。     

农艺措施对水稻群体特征的影响

载插密度、施肥方法等农艺措施因影响群体特征而影响水稻产量。密度增大,群体茎蘖峰值提前,落差增大,品种分蘖力、群体分蘖力、分蘖效率皆降低;群体LAI增加,但群体势容比却下降,粒充实度也随之下降。施肥方法改变,上述诸项指标也随之呈规律性改变,但其显著性因品种而异。     

重庆城镇化水平与西部开发的探讨

对西部经济增长点的选择,是西部开发的前提,城镇是区域的核心,是生产力、科技力量集中的地域,城镇建设可以带动区域经济的发展,从人口、社会、经济指标3个方面分析重庆市的城镇化水平,试图揭示城镇建设也是西部开发的经济增长点之一。     

内蒙古人口发展过程的分析及预测

应用定性分析与定量研究相结合的方法, 对内蒙古人口发展过程进行分析,探讨了人口急剧增长的原因,在研究人口结构的基础上,建立了人口发展的预测模型,并提出控制人口过快增长的对策和人口理想发展的设想.     

320国道贵州昌明至景阳段及其邻近地区的古银杏调查--贵州古银杏种质资源调查资料Ⅳ

同已有的调查相反,本文涉及的调查区域较大,含1线3点15个自然村和3个县的地域。着重研究银杏的区域地理分布特点。但其调查研究的方法和内容是相同的。包括快速踏查、目测、实测、记录、绘图及摄影等。对一些“多代同株”的银杏大树、则快中有慢、粗中有细。经6次进出终于掌握了较丰富的第一手资料,取得三大系列数据：“320国道贵阳昌明至景阳段及其邻近地区银杏调查总表”、“320国道调研地区的银杏种群物候型成分表”及“320国道研究区村落及银杏分布示意图”等。调查研究结果表明：调查地区内至今还存在着一个树龄极大已处于濒死木阶段的古银杏群体。该群体至少出现于2000－3000年以前的西州（原始农业初期）至三国时代,远远早于已知的银杏始种于宋的历史。因此,该古银杏群体应该是野生的。进一步分析表明：其他小于该古树群的大量个体,应大部为该古银杏群的查接后裔。凭借自然繁殖的能力和人民群众的习俗爱护,野生或半野生地生长,发育和延袭至今。根据已发表和即将发表的资料得知：320国道贵州昌明至景阳地区的古银杏群,应属贵州野根分布中心南缘古银杏群的一个残存部分。该残存部分以近村落、链珠状分布式集中分布于山谷盆地边缘,或呈斑点状或独株分布。其诸多特征表明,它同园艺学人工栽培银杏无缘。此外,本文还报导了“瓮城新寨性变枝银杏”和“瓮城老察古银杏雄树群”等资料。     

龙岩市学龄人口变动对教育发展的影响及对策

以龙岩市2000-2010年教育适龄人口变动数据为依据,从构建龙岩市终身教育体系出发,剖析龙岩市教育发展现状和问题,测算2010-2020年教育适龄人口和各教育层次在校生人数变化趋势,分析教育适龄人口变动对教育发展的影响,为龙岩市建立合理的教育结构,科学制定龙岩市教育发展战略、教育政策等提供参考。提出龙岩市教育发展要遵循全局性、针对性、超前性、效率性等教育科学决策的原则,及时调整不同层级、不同结构适龄人口教育发展思路等对策。     

Description and ecology of a new species of sun spider (Arachnida: Solifugae) from the Brazilian Cerrado

A new species of solifuge from São Paulo State, south-eastern Brazil, is described, together with its phenology, habitat use, activity pattern and the effect of fire on the population. Mummucia coaraciandu n. sp. differs from other Mummuciidae in cheliceral dentition and pleurite coloration. Over a one-year period, 649 individuals of M. coaraciandu were captured in 72 pitfall traps distributed in three Cerrado physiognomies: borders of gallery forest (N=53), campo sujo (N=561) and campo cerrado (N=35). The species is diurnal and showed two peaks of surface activity during the year: the highest peak occurred in the cold–dry season (June to July) and the smaller peak in the middle of the warm–wet season (December to February). The number of individuals per trap was negatively correlated with the mean monthly temperature, but showed no correlation with the monthly precipitation. The sex ratio was male-biased (7:1) and the number of males trapped was positively correlated with the number of reproductive females. More individuals were trapped in burned areas when compared with unburned areas 1 month after the fire. This difference between the two areas was not observed 1 month before and 3–4 months after the passage of the fire (when the vegetation had recovered). Mummucia coaraciandu is the second solifuge described from the Brazilian Cerrado and its ecology is very similar to that of Mummucia mauryi from Caatinga vegetation.     

Population structure of Tachypleus tridentatus (Chelicerata: Merostomata) at a nursery beach in Puerto Princesa City,Palawan, Philippines

This study aimed to determine the population structure of juvenile Tachypleus tridentatus, one of two species of horseshoe crabs found in Palawan, at Aventura Beach, Puerto Princesa City, Palawan. Surveys to assess the population in terms of size, density, size‐frequency, age structure, sex ratio and distribution were conducted from June to October 2002. The habitat was mapped and physical/chemical parameters taken to further describe it. The position of population members was plotted on the map. Individuals were measured, marked, sexed and released. Prosoma width was measured for living individuals and exuviae. Postembryonic stages were identified based on histograms with different interval size. The normal distribution of the animals per instar stage was tested with the Kolmogorov–Smirnov test. After the 5‐month survey a total of 125 juveniles was recorded and 40% of them were recaptured. Population size was estimated to be 150 individuals. Seven postembryonic stages were identified based on their prosoma width. Male: female ratio was 1:1.8 and the age of the first five postembryonic stages ranged from 5.4 months to 17.6 months. The population density was 1.47 individuals per?100?m². The majority of the animals of all postembryonic stages were found between 0 and 50?m from the mean high tide level. Further studies on the population structure of T. tridentatus with regards to the adult population are seen as a necessity.     

Population dynamics and reproduction of the hermit crab Calcinus gaimardii (Anomura: Diogenidae) at Inhaca Island,southern Mozambique

The population dynamics and reproduction of Calcinus gaimardii were studied at Inhaca Island, southern Mozambique. Crabs were sampled monthly from January to December 2003 in order to assess abundance, size distribution, sex ratio, reproduction and juvenile recruitment. Calcinus gaimardii is sexually dimorphic in relation to size, with males reaching larger size than females. Sex ratios were female‐biased during most months of the study period. Females were more abundant in the intermediate size classes while males outnumbered females in the largest ones. Reproduction took place year‐round with peaks of breeding activity between August and October. Likewise, juvenile recruitment was continuous for both sexes with high intensity in winter (May and June). Egg number increased with female size.     

成功制作离体心脏灌注模型要点和经验

目的探讨并总结制作Langendorff离体心脏灌注模型的要点及成功经验。方法通过16只健康SD大鼠（体质量200～400 g）,以HTK液作为心脏停搏液建立标准的Langendorff离体心脏灌注模型,将此模型与持续K-H液心肌灌注、持续心脏搏动组大鼠的同一时段的心肌酶学及血流动力学指标进行对比,使用SPSS 11.5作统计学重复测量资料的方差分析。结果 1例因操作不熟练致提取心脏时间延长,1例因灌注管插入深度过深导致主动脉瓣毁损,1例因室温过低,1例因灌注管管径过大无法插入而导致实验失败,其余12例在应用了室内加热器、不同管径灌注针、自制球囊测压管及加快操作速度后均获得实验成功。所制模型心肌酶学及血流动力学各指标与持续心脏搏动组无明显差异（P〉0.05）。结论掌握制作要点及注意事项后,Langendorff离体心脏灌注模型可顺利快速地成功制备。