海岱地区史前时期稻作农业的产生、发展和扩散

地处黄淮下游的海岱地区,新石器时代偏早时期是以种植粟类作物为主的旱作农业区。随着与南方地区文化交流的增强,至迟在北辛文化时期稻作已传入海岱地区,然后循着东、西两路由南向北不断地扩散和发展。到龙山文化时期,海岱地区的南部和东部沿海一带,已经形成了一定规模的稻作农业经济。以东部沿海地区为基点,稻作农业还渡海传播和扩散到了辽东半岛和朝鲜半岛地区,并进一步向日本列岛扩散和发展。     

稻水蝇生物学特性研究

对稻水蝇生物学特性进行研究表明 ,该虫成虫多食性 ,两性生殖 ,雌雄性比为 1,具较强趋光性 ,羽化高峰在每天 7∶30～ 10∶0 0之间 ,羽化过程平均 7 2分钟。各代成虫羽化 1 5～ 3小时后即行交尾 ,一天内集中出现 2次高峰 ,一生交尾平均 6 37次。雌虫交尾 1～ 2天后即产卵 ,田间多产在稻田边埂处漂浮物上 ,亦产于稻株近水面叶鞘、叶片及茎秆部位。产卵对稻株叶色无明显趋性。产卵一天内出现 2次高峰。雌虫一生产卵 74～ 153粒 ,多在 12 0粒左右 ,产卵后 5～ 14天内死亡 ,卵量 (x ,粒 )与寿命 ( y ,天 )间具以下线形关系 :y =- 0 1195x 2 2 52 2 6(r =0 9897 )。幼虫四龄 ,水生 ,喜盐碱。孵出过程平均 10分钟。孵出后即下潜蛀入萌发稻种内取食 ,二龄后叮咬水稻幼根 ,亦见咬食水稻叶片。老熟幼虫以第 9～ 11节伪足形成环状结构把蛹体固定于稻根或茎叶上化蛹     

Converting observed likelihood to levels of significance for transformation models

Inference for a scalar parameter in the pressence of nuisance parameters requires high dimensional integrations of the joint density of the pivotal quantities. Recent development in asymptotic methods provides accurate approximations for significance levels and thus confidence intervals for a scalar component parameter. In this paper, a simple, efficient and accurate numerical procedure is first developed for the location model and is then extended to the location-scale model and the linear regression model. This numerical procedure only requires a fine tabulation of the parameter and the observed log likelihood function, which can be either the full, marginal or conditional observed log likelihood function, as input and output is the corresponding significance function. Numerical results showed that this approximation is not only simple but also very accurate. It outperformed the usual approximations such as the signed likelihood ratio statistic, the maximum likelihood estimate and the score statistic.