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51.
A 39-year-old woman (G4P1SAB2) was referred for amniocentesis for advanced maternal age. An interstitial deletion of the G-dark band 11 pi 2 was found in the fetus. Blood from the mother and her previous son was cultured and the same deletion was found in both. The absence of phenotypic effect in this family further confirms that G-dark euchromatic deletions are compatible with a normal phenotype, and underlines the importance of checking familial karyotypes even when apparently unbalanced structural rearrangements are found at prenatal diagnosis.  相似文献   
52.
Over the past decade, the emission standards and fuel standards in Beijing have been upgraded twice, and the vehicle structure has been improved by accelerating the elimination of 2.95 million old vehicles. Through the formulation and implementation of these policies, the emissions of carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOx), and fine particulate matter (PM2.5) in 2019 were 147.9, 25.3, 43.4, and 0.91 kton in Beijing, respectively. The emission factor method was adopted to better understand the emissions characteristics of primary air pollutants from combustion engine vehicles and to improve pollution control. In combination with the air quality improvement goals and the status of social and economic development during the 14th Five-Year Plan period in Beijing, different vehicle pollution control scenarios were established, and emissions reductions were projected. The results show that the emissions of four air pollutants (CO, VOCs, NOx, and PM2.5) from vehicles in Beijing decreased by an average of 68% in 2019, compared to their levels in 2009. The contribution of NOx emissions from diesel vehicles increased from 35% in 2009 to 56% in 2019, which indicated that clean and energy-saving diesel vehicle fleets should be further improved. Electric vehicle adoption could be an important measure to reduce pollutant emissions. With the further upgrading of vehicle structure and the adoption of electric vehicles, it is expected that the total emissions of the four vehicle pollutants can be reduced by 20%-41% by the end of the 14th Five-Year Plan period.  相似文献   
53.
在对历史环境问题进行梳理回顾的基础上,对新常态下作为典型资源型经济省份的山西省面临的环境保护形势进行了分析,并从实施绿色发展战略、改善环境质量、深化环境管理体制创新、加强环境监管、培育生态环保市场主体5个方面给出了基本的策略建议,以期为制定山西省"十三五"环境保护规划提供参考。  相似文献   
54.
随着我国经济发展进入新常态,"十三五"期间的环境保护工作也进入新阶段,为准确制定济南市"十三五"环境保护规划,文章对济南市经济总体发展情况,农业、工业和服务业发展情况,以及能源消费情况等方面进行了全面分析和预测,对"十三五"期间济南市环境保护工作面临的问题进行了识别,以期对济南市"十三五"环境保护所面临的形式做出全面准确的研判。  相似文献   
55.
Prenatal molecular genetic diagnosis for Noonan syndrome I is reported. Noonan syndrome was suspected because of large cystic hygroma colli, massive pleural effusion and ascites at 23 weeks of gestation and normal karyotype (46,XX). DNA was prepared from amnion cells and screened for mutations in the PTPN11 gene. In exon 8, a missense mutation (S285F) was found. Delivery was induced at 33 weeks of gestation because of silent cardiotocography (CTG). Despite immediate drainage of the hydrothorax, mechanical ventilation was insufficient and the child died 9 h after birth due to severe pulmonary hypoplasia. Pleural punctate was enriched for small lymphocytes and thus was characterized as chylus. Prenatal ultrasound findings in Noonan syndrome usually are unspecific and rarely lead to a diagnosis. However, with the combination of cystic hygroma, pleural effusion, ascites and normal karyotype Noonan syndrome should be considered and DNA testing for PTPN11 mutations may be appropriate. Malformations of lymphatic vessels and/or chylothorax in Noonan syndrome seem to be more frequent than usually anticipated. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
56.
目的 针对发动机钛合金部件在热盐环境与工作载荷下的寿命衰减问题,开展TC11钛合金热盐腐蚀疲劳与应力腐蚀试验,研究腐蚀环境下TC11的高温寿命衰减规律与失效机理。方法 利用喷盐法制备TC11钛合金试验件,研究不同温度与应力水平对TC11腐蚀疲劳以及应力腐蚀的影响规律。利用SEM等观测手段,开展腐蚀疲劳以及应力腐蚀试样断口与表面的形貌分析,分析腐蚀环境下的失效机理。结果 热盐腐蚀环境导致TC11的寿命显著降低,对比450 ℃下无腐蚀寿命,腐蚀疲劳寿命下降了2个数量级,应力腐蚀寿命下降到不足1%,且分散性较大。观察腐蚀疲劳和应力腐蚀的试样可以发现,表面有明显的腐蚀坑,腐蚀坑底发现裂纹。结论 热盐环境下,TC11腐蚀疲劳寿命和应力腐蚀寿命都会明显下降。由于腐蚀导致钛合金试样表面产生许多腐蚀坑,在腐蚀坑局部形成近似缺口,缺口部位的应力集中是导致腐蚀疲劳寿命衰减的重要因素。腐蚀疲劳的寿命低于Kt=1的无腐蚀疲劳寿命,但是要大于Kt=3的无腐蚀疲劳寿命。  相似文献   
57.
Wayne Groszko  R. M. Moore 《Chemosphere》1998,36(15):3083-3092
An equilibrator for sampling the partial pressures of halomethanes in seawater was designed and built, incorporating semipermeable membrane tubing to carry the gas phase. The equilibrator was tested for its ability to equilibrate chloromethane, bromomethane, iodomethane, and CFC-11. The residence time required for these halomethanes to equilibrate in the tubing (30 to 60 s) was determined experimentally. In a laboratory test, concentrations calculated from equilibrator measurements and based on published solubility values were found to differ by 6% to 16% from concentrations measured with a purge-and-trap apparatus, but uncertainties in the solubility values are likely to contribute significantly to the differences. In a comparison at sea, no significant difference was found between the semipermeable membrane equilibrator and another, more conventional equilibrator, except a 1.3% difference for CFC-11. This study demonstrates the feasibility of using semipermeable membranes in this and related applications.  相似文献   
58.
吴兵  庄雨适 《环境与发展》2020,(1):242-243,245
"十四五"是在打赢污染防治攻坚战、全面建成小康社会的基础上,加快实现2035年基本建成美丽中国"吉林样板"的关键五年。研究报告在对吉林省"十三五"生态环境保护成效及存在的主要问题、"十四五"生态环境保护面临的机遇和挑战进行分析的基础上,提出了"十四五"全省生态环境保护的总体思路与目标及主要任务。  相似文献   
59.
“十四五”推动绿色消费和生活方式的政策研究   总被引:1,自引:1,他引:0  
当前,中国消费规模持续快速扩张,居民消费已从温饱向小康转型升级,消费对中国经济增长的贡献率快速提升,成为驱动经济增长的重要引擎。前期研究表明,消费领域的绿色转型有助于引导和倒逼生产的绿色化,促进形成绿色生产生活方式,带动公众积极践行绿色理念,改善社会绿色转型的治理体系,将对中国整体绿色转型和高质量发展发挥决定性作用。在此基础上,本文研究提出了中国“十四五”时期推动绿色消费的总体目标、指标体系和重点领域,认为中国政府应将绿色消费放在更加突出的战略位置,通过“十四五”规划全面推动相关实践,按照供给侧与需求侧共同发力、激励约束并举、政府企业消费者共建共治共享的原则,构建绿色消费政策体系,并针对建筑、汽车、电力、物流等重点行业提出了具体的政策建议。  相似文献   
60.
国家“十四五”环境经济政策改革路线图   总被引:6,自引:6,他引:0  
"十三五"时期环境经济政策对建立我国生态文明建设长效机制发挥了重要作用,"十四五"时期需要通过进一步深化环境经济政策改革与创新以适应新时代生态文明建设需要。本文研究提出了我国"十四五"时期环境经济政策改革思路、框架与重点,认为我国"十四五"时期环境经济政策改革要深入贯彻习近平生态文明思想,系统考虑政策改革创新面临的新形势和新要求,推进建立"两山"转化和环境质量达标的长效激励机制,突出环境质量持续改善激励、突出经济过程全链条调控,突出政策手段的系统优化与协同增效,突出政策执行能力保障。继续推进生态环境财政制度改革,深化绿色价格税费机制创新,推进建立多元化、市场化生态补偿制度,健全生态环境权益交易机制,完善绿色金融体系,并同步推进完善生态环境价值核算、环境信息公开和信用体系、资源环境名录、政策绩效评估等政策实施配套能力建设,构建全面支撑生态文明建设的环境经济政策体系,推进环境治理体系和治理能力现代化。  相似文献   
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