Immediate prenatal diagnosis of Zellweger syndrome by direct measurement of very long chain fatty acids in chorionic villus cells

We report a gas chromatographic-mass spectrometric method which allows the very long chain fatty acids content of trophoblastic tissue to be directly measured in samples collected by biopsy between 8 and 11 weeks of gestation. This method has been successfully applied to the detection of fetal Zellweger syndrome in two pregnant women who had previously delivered affected infants. In one of them, increased concentrations of C26:0 (0.254 versus 0.108±0.035 μ/mg proteins) and C24:0 (1.32 versus 0.815±0.325 μ/mg proteins) in trophoblast indicated that the fetus had Zellweger syndrome, a diagnosis confirmed by pathological findings after abortion. In the second case, the pregnancy was allowed to proceed, on the basis of normal concentrations of very long chain fatty acids in trophoblastic tissue, and its outcome was actually a healthy newborn.     

水污染造成的环境经济损失分析

立足于我国水资源现状，对造成水污染损失的主要影响因素进行分析。探讨适合于我国国情的水污染损失的计算方法。以南方某市为例，计算该市水污染损失，得到了一些有益的结论．给政府部门提供了一个较为准确的损失数据。通过政府的干预或经济法律手段，加大水资源保护管理工作的力度。     

环境污染事故风险预测评估模式研究

从环境风险到环境污染事故演变的一般规律入手,提出了环境污染事故风险预测评估模式,为环境污染事故风险评估、预防与应急响应提供科学手段。环境污染事故风险预测评估模式的提出,一方面丰富和发展了环境安全与应急响应理论;另一方面,对公共安全、企业安全管理与应急响应等工作具有一定指导意义。     

基于遗传算法进行EMI滤波器电感的设计

通过电感的高频特性及其对共模插入损耗的影响分析,采用遗传算法和Ngspice仿真库设计出电感的选择方案,最后通过电路仿真和实验同时验证方案的有效性。该方案避免了对EMI滤波器高频段的复杂建模,降低了电感选择的难度,对电感元件的选择具有一定的指导意义。     

中─高级变质相中水热流体的形成与作用

固体地壳中流体是普遍存在的，中—高级变质相中的矿物并非只发生晶体塑性变形，溶解和溶移作用在非糜棱岩化岩石中占主导地位，因为高温高压环境下存在的水热流体，在变质变形作用中起着至关重要的作用。在周围分布有网络状进进剪切带的递进缩短带中，与应交梯度有直接关系的单个矿物的位错密度梯度在其晶体边缘形成，产生了化学位梯度，从而使矿物边缘发生溶解。变形分解作用是产生这一过程的动力，并为流体汇聚形成水热循环系统提供了空间。     

净化铁锰氨生物滤池内氨氮转化途径

为考察净化铁锰氨生物滤池内NH₄+-N的转化途径,利用氮素计量关系和沿程试验研究了净化铁锰氨生物滤池内产生TN_loss(氮损失)的原因和NH₄+-N转化途径. 结果表明,净化铁锰氨生物滤池内DO消耗异常,TN_loss不守恒,当进水ρ(NH₄+-N)平均值分别为1.262、2.296、3.111 mg/L时,NLR(氮损失率)分别能达到7.89%、12.91%、17.73%. 利用硝化反应和CANON(全程自养脱氮)方程式计算得出理论TN_loss和TDOC(理论耗氧量),与实际TN_loss和ADOC(实际耗氧量)的差值分别小于±0.030、±0.10 mg/L,各阶段NH₄+-N 通过CANON途径转化的比例分别为48.58%、60.77%、68.10%,硝化反应和CANON途径共同参与了NH₄+-N转化. 沿程试验结果表明,整个试验阶段,NO₂--N在滤层中均有积累,并在滤层厚度为10~18 cm内出现NO₂--N和NH₄+-N共存的现象,进一步证明CANON途径是净化铁锰氨生物滤池内产生TN_loss的原因.      

上海市郊区大气细颗粒和超细颗粒物中元素粒径分布研究

用同步辐射X荧光光谱分析了上海市郊区大气细颗粒和超细颗粒物（0.028 7～2.40 μm）中元素粒径分布、质量中值粒径、元素相关性和不同粒径颗粒物中的富集因子.Ca、Ti主要分布于粒径>2 μm的颗粒物中,它们之间的相关系数达0.933,富集因子在0.1～3.2之间,且与粒径无明显关联,主要来自土壤扬尘等自然来源.V、Cr、Mn、Ni、Zn、Cu、Pb、Cl、S等元素主要分布在0.1～1.0 μm颗粒物中,质量中值粒径在0.56～0.94 μm之间.V、Cr、Ni、Cu、Zn、Pb显著富集,且富集程度随粒径减小而增大.其中Pb在超细颗粒物（<0.1 μm）中的富集因子达2 023.7～2 244.2,远大于在细颗粒和 PM_2.5中的富集程度.这些元素主要来自燃油、燃煤、冶金和机动车尾气等人为污染.Fe在>0.2 μm颗粒物中分布较均匀,质量中值粒径1.3 μm.除了局部污染源,远距离传输对该地区大气颗粒物污染有不可忽略的影响.     

环境试验箱围护结构传热研究

通过对环境试验箱围护结构由高温降至低温时的非稳态传热过程建立物理模型和数学模型,并使用有限容积法及TDMA进行围护结构传热数值计算来分析3种不同降温工况下的围护结构的传热特性,提出了围护结构质量系数概念,用以简化计算其降温时的耗冷量.     

Using empirical models of species colonization under multiple threatening processes to identify complementary threat‐mitigation strategies

Approaches to prioritize conservation actions are gaining popularity. However, limited empirical evidence exists on which species might benefit most from threat mitigation and on what combination of threats, if mitigated simultaneously, would result in the best outcomes for biodiversity. We devised a way to prioritize threat mitigation at a regional scale with empirical evidence based on predicted changes to population dynamics—information that is lacking in most threat‐management prioritization frameworks that rely on expert elicitation. We used dynamic occupancy models to investigate the effects of multiple threats (tree cover, grazing, and presence of an hyperaggressive competitor, the Noisy Miner (Manorina melanocephala) on bird‐population dynamics in an endangered woodland community in southeastern Australia. The 3 threatening processes had different effects on different species. We used predicted patch‐colonization probabilities to estimate the benefit to each species of removing one or more threats. We then determined the complementary set of threat‐mitigation strategies that maximized colonization of all species while ensuring that redundant actions with little benefit were avoided. The single action that resulted in the highest colonization was increasing tree cover, which increased patch colonization by 5% and 11% on average across all species and for declining species, respectively. Combining Noisy Miner control with increasing tree cover increased species colonization by 10% and 19% on average for all species and for declining species respectively, and was a higher priority than changing grazing regimes. Guidance for prioritizing threat mitigation is critical in the face of cumulative threatening processes. By incorporating population dynamics in prioritization of threat management, our approach helps ensure funding is not wasted on ineffective management programs that target the wrong threats or species.     

单光子/光电子在线质谱实时分析聚氯乙烯热分解/燃烧产物

实验室研制了低能光电子磁场增强电离(MEPEI)和单光子电离(SPI)复合电离源,该电离源具有电离化合物范围宽、碎片离子少、质谱图简单等优点,结合飞行时间质谱(TOF-MS)实现了聚氯乙烯(PVC)热分解/燃烧产物的在线分析.针对不同的目标化合物,MEPEI/SPI复合电离源通过调节电离区电场强度,可以快速在SPI和SPI-MEPEI之间切换.PVC热分解/燃烧产物中电离能大于光子能量(10.60 eV)的HCl和CO2(12.74 eV、13.77 eV)利用MEPEI模式电离;而烯烃、二氯乙烯、苯系物、氯苯、苯乙烯、茚满及萘系物等可通过SPI-MEPEI复合模式电离.通过实时监测PVC主要燃烧产物的信号强度随温度的变化趋势可推断出,PVC燃烧产物主要是通过两种机制生成:①250～370℃时,PVC发生脱氯及分子内环化反应,产生大量的HCl、苯和萘;②380～510℃时,PVC发生分子间交联反应,生成烷基芳烃,如甲苯和二甲苯/乙苯等.实验结果表明,SPI/SPI-MEPEI复合离子源TOF-MS分析速度快,应用范围广,在在线分析中具有广泛的应用前景.