Maternal sex chromosome mosaicism diagnosed by amniocentesis and percutaneous umbilical cord sampling

We present a remarkable chain of events in which percutaneous umbilical cord sampling was performed in an attempt to clarify a situation of possible fetal sex chromosome mosaicism in an amniotic fluid culture and led to the discovery that the mother herself had a 45,X/46,XX/ 47.XXX chromosome constitution. This may have simply represented the chance concurrence of pseudo-mosaicism in the amniotic fluid culture of a woman with an abnormal sex chromosome constitution, but it is also possible that the 45,X colony was maternal in origin. Although clearly a most unusual circumstance, the possibility should be kept in mind when termination of a pregnancy is being considered because of apparent mosaicism in a prenatal diagnostic study.     

地面水水样预处理技术研究

研究了地面水中重金属元素Cu、Zn、Cd、Pb、Cr、Ni及Hg溶解态与悬浮态的分离技术;采用原子吸收光谱法定量测定上述元素,并比较了分离后两态重金属元素的浓度差异。实验结果,重金属元素大部分以悬浮态存在于水体中,溶解态的含量极微。采用最佳的过滤分离(滤膜和滤纸)和离心分离技术,能得到较好的分离效果,而澄清分离是不可取的,因其难以规范化。指出在地面水分析中,必须建立严谨和统一的地面水预处理技术,才能保证环境分析数据的准确性和可比性。     

区域PERE系统的通用自组织演化模型

分析了区域人口－经济－资源－环境系统的自组织过程，建立了区域ＰＥＲＥ系统的通用自组织演化模型，并把模型应用于山西省某市，预测了市未来的人口、经济和环境状况试图解决在区域ＰＥＲＥ系统中应用自组织理论时建模困难的问题。     

Annual nonmethane hydrocarbon trends in Beijing from 2000 to 2019

High loads of ground-level ozone have occurred with the implementation of the Air Pollution Prevention and Control Action Plan. However, the long temporal variation in precursor nonmethane hydrocarbons(NMHCs) has rarely been studied. In this study, we examined the evolution of NMHCs in Beijing based on ambient measurements from 2000 to 2019. The results indicated that the annual variation of ambient NMHCs during 2000 and 2019 could be divided into two stages. The mixing ratios of NMHCs rapidly r...     

Experimental investigation into the oxidation reactivity, morphology and graphitization of soot particles from diesel/n-octanol mixtures

Aiming to investigate the impacts of n-octanol addition on the oxidation reactivity, morphology and graphitization of diesel exhaust particles, soot samples were collected from a four-cylinder turbocharged diesel engine fueled with D100（neat diesel fuel）, DO15（85% diesel and 15% n-octanol, V/V） and DO30（70% diesel and 30% n-octanol, V/V）. All tests were conducted at two engine speeds of 1370 and 2150 r/min under a fixed torque of 125 N ·m. The soot properties were characterized by thermogravimet...     

己内酰胺生产废水的铁碳微电解深度处理与机理研究

采用铁碳微电解方法对己内酰胺生产废水进行深度处理,探讨了pH值、停留时间、铁碳质量比对处理效果的影响。在pH为4、停留时间为120 min、铁碳质量比为4的最佳处理条件下,COD去除率可达57.8%,色度去除率可达68.4%。微电解对己内酰胺废水的作用主要通过铁的絮凝作用,处理过程中的酸性条件、微电解的氧化还原和电场作用,从而提高其去除效率。     

铁屑对低浓度含铬地下水的处理研究

以某铬渣污染场地上抽提上来的低浓度含铬地下水作为实验研究对象。选用铁屑对含铬废水进行处理。通过静态试验考察了影响六价铬去除率的因素:pH、铁屑用量、反应时间,得到了较好的反应工艺参数。并在静态试验的基础上,用铁屑填充自制的反应柱研究了动态试验的效果。结果表明:六价铬的出水浓度低于0.05 mg/L,达到GB/T 14848-93《地下水质量标准》Ⅲ类排放标准。     

可吸入颗粒物对我市环境空气质量的影响及对策建议

近年来,随着城市化建设进程的加速和环境保护工作的深入开展,城市环境空气质量的污染类型已由SO2与PMIO混合型污染,逐步转变为以扬尘为主要污染物的可吸入颗粒物污染,通过对我市市区空气质量状况、可吸入颗粒物污染成因分析,提出控制或削减可吸入颗粒物污染的对策建议。