查询词典 fertility ratio

Assulta was studied in the present paper. Based on the successful reciprocal crosses, sex ratio and fertility of the hybrids in larvae, pupae and adults were investigated. In addition, the physiological mechanisms and genetic basis of host plant ranges of H.

在此基础上，利用解剖和观察等方法对子一代幼虫、蛹和成虫的性别比例和可育性进行了较为系统的研究；并利用比较的方法对棉铃虫和烟青虫食性广度的生理机制和遗传基础进行了初步研究。

Soil fertility distribution, alkalic salt characteristic property, water ratio and the temperature change etc, that is farmland information main part is composed of a part, it is also basic meticulous agriculture decision analysis basis at the same time.

土壤的肥力分布、盐碱特性、含水率和温度变化等等，是农田信息的主要组成部分，同时它也是精细农业决策分析的根本依据。

The findings indicate that uxorilocal marriage helps to stabilize low fertility,alle- viate son preference,lower the sex ratio at birth,and improve female child survival and women's family and social status.

研究发现，招赘婚姻有利于稳定低生育率、降低男孩偏好和出生性别比、改善女孩和妇女的生活环境、缓解老龄化背景下没有儿子老人的养老困难。

Based on the facts of low soil fertility and unbalanced nutrient ratio in Ankou valley ,one soil sample was collected per 2 to 3 hm 2 according to the land use pattern and the relief determinant .

针对安口流域内土壤肥力水平低且养分比例失调的实际状况，按土地利用方式及地形部位每 2～ 3hm2 面积采集一个土壤样品，用常规分析方法测定了土壤有机质、有效氮、有效磷、有效钾、有效铜、有效锌等养分指标，编制了土壤养分丰缺对照表，对各测定项目进行了系统评价，并作了相应的推荐施肥建

In conclusion, these results suggested that (1) the ageing-associated decline in fertility of female KM mouse was due to a decrease in both quantity and quality of oocytes;(2) the ooplasm from young mice did not correct the meiotic errors of aged mice, and the ooplasm from aged mice did not induce abnormal segregation of meiotic chromosome of young mice, indicating that meiotic anomalies found in the oocytes of aged mice might be related to nucleus or chromosomes and relevant factors;(3) a critical nucleocytoplasmic ratio was essential for normal maturation and segregation of meiotic chromosomes of oocytes and development to 2-cell embryos.

本研究结果表明：（1）昆明白小鼠与衰老相关的生育力下降是其卵母细胞数量减少和质量下降的综合结果；（2）年轻小鼠卵母细胞细胞质不能纠正老龄小鼠GV的减数分裂错误，老龄小鼠卵母细胞细胞质也不诱导年轻小鼠的GV发生减数分裂错误，老龄小鼠卵母细胞减数分裂异常很可能与细胞核或染色体及其相关因素有关；（3）关键的核质比对卵母细胞正常的成熟、减数分裂染色体分离及2-细胞期胚的发育是绝对必需的。

Of the T〓 CaMVBT transgenic plants, the normally-growing plants showed two kinds of pollen fertility and seed-setting ratio under long-day condition. 62. 9% of which showed poorer pollen fertility, smaller, thinner seeds than those of untransformed regenerant control and that seeds were nonviable.

2自然启动子调控的rolB转基因农垦58S中，少数T〓代单株表现植株较矮小、茎杆细、叶片有卷曲或皱缩、生长势减弱、可育条件下败育等与CaMVBT转化的T〓代部分单株相似的表型。

Only nine isolates mating with tester produced ascospores with a fertility ratio 6.2%.

有9个菌株与标准菌株交配产生了子囊孢子，可育率为6.2%。

Within a short time span of just over 40 years China has developed from an insignificant to the world's largest and still fastest growing producer and user of chemical nitrogen fertilizer. Unfortunately China is now also the country with the most unbalanced nutrient ratio. If continued into the future, the grave nutrient imbalance that prevails at present threatens the fertility of China's soils that has been maintained so well over the centuries, thereby also threatening, sustainable agriculture.

仅40多年时间里中国就从世界上微不足道的氮肥使用国发展成为最大的、而且增长速度最快的氮肥生产和使用国，令人遗憾的是中国是世界氮、磷、钾使用最不平衡的国家，如果任凭这种趋势继续下去，将势必对数千年来我们祖先一直维持良好的地力造成威胁，由此也对农业持续发展带来威胁。

The results showed that 1518kg farmyard manure and 59.9kg chemical fertilizer, equal to 38kg N, P and K pure nutrient, were applied per unit area (667m2) of arable land,and that the nutrient ratio of farmyard manure and chemical fertilizer was 4.9∶5.1 (N∶P2O5∶K2O=1∶0.4∶0.62), and that the total complex grain output per year and the complex output value were 479.6kg and 804.47yuan per 667m2 respectively, and that the manure cost and the pure income from manuring were 148.25 yuan and 716.22 yuan per 667m2 respsctively, and that 12.6kg grain output could be gotten averagely from 1kg nutrient input The main factors affected the manuring effect were topography, cropping systems and crops kinds and manuring quantity from a peasant household as well effected the soil fertility significantly.

结果：平均每667m2耕地投入农家肥1 518 kg，化肥59.9 kg，折氮磷钾纯养分38 kg，农家肥与化肥养分比为4.9∶5.1，N∶P2O5∶K2O=1∶0.4∶0.62，全年粮食复合单产479.6 kg/667m2，复合产值864.47元，肥料成本148.25元/667m2，肥料纯收入716.22元，肥料产投比值5.9，投入1 kg养分产粮12.6 kg。影响投肥效应的主要因素为地势、耕制和作物。农户投肥数量对土壤肥力影响较大。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。