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981.
Lena Wartosch Karen Schindler Melina Schuh Jennifer R. Gruhn Eva R. Hoffmann Rajiv C. McCoy Jinchuan Xing 《黑龙江环境通报》2021,41(5):620-630
The gain or loss of a chromosome—or aneuploidy—acts as one of the major triggers for infertility and pregnancy loss in humans. These chromosomal abnormalities affect more than 40% of eggs in women at both ends of the age spectrum, that is, young girls as well as women of advancing maternal age. Recent studies in human oocytes and embryos using genomics, cytogenetics, and in silico modeling all provide new insight into the rates and potential genetic and cellular factors associated with aneuploidy at varying stages of development. Here, we review recent studies that are shedding light on potential molecular mechanisms of chromosome missegregation in oocytes and embryos across the entire female reproductive life span. 相似文献
982.
云南省清洁发展机制项目潜力调研 总被引:1,自引:0,他引:1
清洁发展机制(CDM)的实施能使区域经济获得生态环境保护与经济发展“双赢”。云南尚有很大的CDM项目潜力。结合项目背景和国内外发展状况,通过调查数据整理和案例研究,对促进云南省CDM项目实施提出对策建议。 相似文献
983.
采用原子吸收分光光度计测定经过连续浸提的土样中镁的化学性能。结果表明,重庆市植烟土样中水溶态、可交换态、碳酸盐结合态、有机结合态、残留态镁的含量分别为0.01、0.59、0.15、0.6、0.63cmol/kg,各形态所占的百分比分别为0.5%,29.7%,7.5%,30.3%,32%,均低于0.8—1.6cmol/kg的正常水平。植烟土壤对镁的最大吸附量为1.25mg/g,吸附作用较好,故适量施加镁肥将会促进烟叶质量的提高。 相似文献
985.
986.
987.
Ecological city is the advanced mode of harmonious development of city. Constant improvement is being made in the development of ecological city. However, building ecological city is an enormous project that calls for a huge amount of capital. The government fund is far from adequate. This paper probes into the fund issue and discusses in detail the mechanism of investment and financing in building ecological city from various aspects such as diversification of the investment subjects and the modes of financing. 相似文献
988.
雁荡山是一座白垩纪复活破火山,经断裂切割抬升而成为典型性的破火山立体模型。它向人们展示了破火山内部的各种地质要素和各类岩石的相互关系,提供了破火山喷发产物与中央侵入体有直接联系的证据。涵盖了流纹质岩浆火山爆发、喷溢、侵出、侵入等的完整过程,堪称流纹质火山岩类的天然博物馆。雁荡山不仅显现了白垩纪时期亚洲大陆边缘复活型破火山形成与演化的地质过程,而且是古太平洋伊泽奈奇(lzanaqi)板块向亚洲大陆俯冲、壳幔深部作用的一种地表标志性展示。雁荡山破火山的奇特景观代表着东亚亚热带滨海山岳地质生态模式、奇特优秀的自然景观、具普遍意义的杰出科学价值和浓厚的民族山水文化,三者交融在一起,构成了雁荡山所特有的世界上独一无二的、兼符自然与文化双重标准的自然遗产。 相似文献
989.
1 IntroductionThispaperreportsstudiesofthemercurycontentsaswellastheirdistributionincoalsfrom 12maincoalminesintheNortheastofChinaandtheeastofInnerMongolia .Thecoal burningproductsaredividedintothreeparts:bottomash ,flyashindustcollectorandthepartescaping… 相似文献
990.
Agro-residue is one of the important biomass resources in China and its efficient utilization is crucial for providing bio-energy, releasing risk of environmental pollution, and enhancing rural incomes. Densification is one of the important utilization routes of agro-residues. The objective of this paper is to explore the development of agro-residue densified fuel in China based on energetics analysis. The energetical property and energy potential of main agro-residues in China were firstly analyzed and then the development of agro-residue densified fuel in every region was evaluated based on energetics analysis. The results show that the main agro-residues in China are good feedstocks as densified fuel and they constitute enormous energy potential for developing densified fuel. However, the situation of every region should be considered for the development of agro-residue densified fuel. The primary energy embodied per unit of useful energy indicates that most of the regions in China are suitable for developing agro-residue densified fuel as it is energetically advantageous compared with coal, whereas only about 25% of regions near coal production locations are not suitable as they are less energetically advantageous. 相似文献