Analysis of winter thermal comfort conditions: street scenarios using ENVI-met model

Environmental Science and Pollution Research - Rapid migration to cities and the increasing demand for housing negatively affect living areas. Furthermore, uncontrolled population growth,...     

我国自然生态系统氮沉降临界负荷评估

过量的氮沉降引起了一系列环境问题并导致生物多样性损失,因此评估当前生态系统氮沉降临界负荷对区域氮管理及其污染控制至关重要.利用稳态质量平衡法估算了当前我国自然生态系统的氮沉降临界负荷,并与氮沉降数据对比,获取了我国超过氮沉降临界负荷的生态系统空间分布情况.结果表明,6%的地区氮沉降临界负荷大于56 kg·(hm²·a)^-1,67%的地区氮沉降临界负荷在14～56 kg·(hm²·a)^-1之间,27%的地区氮沉降临界负荷小于14 kg·(hm²·a)^-1.氮沉降临界负荷较高的区域主要分布在青藏高原东部、内蒙古东北部和南部部分地区.氮沉降临界负荷较低的区域主要分布在青藏高原西部、西北地区和东南部分地区.氮沉降超过临界负荷的区域约占我国的21%,主要分布在东南和东北部分地区.东北、西北和青藏高原地区超临界负荷值普遍低于14 kg·(hm²·a)^-1.因此,未来这些超过氮沉降临界负荷地区的氮素管理和控制更为值得关注.     

高温气冷堆陶瓷堆内构件热老化试验平台开发

目的 开发一种试验平台模拟高温气冷堆正常工况、氧化腐蚀工况和事故工况试验条件,研究陶瓷堆内构件的氧化腐蚀行为和长期服役热老化规律。方法 通过分析高温气冷堆陶瓷堆内构件服役环境特征,确定试验平台开发技术要求,其主要部件包括氧气流量控制器、氦气流量控制器、储气罐、反应气流量控制器、气体预热器、高温反应炉、气体循环泵、氦气纯化器、纯水罐、蠕动泵、真空泵、排气冷肼、在线气相色谱仪、在线露点仪等。结果 该试验平台可精确控制在冷却剂氦气中混入微量的O2、H2O杂质,研究反应时间、温度等因素的影响,还可模拟高温堆正常工况和蒸汽发生器传热管破裂进水事故工况条件,开展长达3 000 h以上的连续热老化试验。结论 该试验平台具有高精度、大尺寸、耐高温、耐长周期试验等优异特性,可模拟复杂多样的工况条件,开展热老化试验研究。     

综放支承压力峰值位置的理论及回归分析

鉴于综放支承压力峰值位置对工作面安全生产影响的重要性,对支承压力峰值位置的确定进行了研究分析。其中煤体硬度、煤层厚度及工作面推进速度为支承压力峰值位置的主要影响因素。采用相似模拟实验及理论分析方法研究各因素对支承压力峰值位置的影响规律及其函数关系。最后应用回归分析方法得到了支承压力峰值位置确定的经验公式,并将其进行了实际应用。结果表明:上述3个影响因素对支承压力峰值位置的影响均为非线性的;支承压力峰值位置与煤体硬度近似地满足反比关系;支承压力峰值位置与开采煤层厚度、工作面推进速度满足指数函数关系;通过对这3个因素的回归分析,可以确定支承压力的峰值位置。     

Evaluation of a fetus at risk for dihydropteridine reductase deficiency by direct mutation analysis using denaturing gradient gel electrophoresis

Dihydropteridine reductase (DHPR) is an enzyme involved in the recycling of tetrahydrobiopterin (BH₄), which is an obligate co-factor of the aromatic amino acid hydroxylases. DHPR deficiency is a rare, autosomal recessive disorder caused by mutations in the QDPR gene. DHPR-deficient patients are diagnosed by a lack of response to a low phenylalanine diet and by severe neurological symptoms. Final diagnosis is made by measurements of neurotransmitters and pterin metabolites in cerebrospinal fluid (CSF) and urine, in addition to DHPR enzyme activity, which can be assessed in whole red blood cells. Treatment of DHPR deficiency can be difficult and the outcome is not always satisfying, even if all treatment strategies are followed. Therefore prenatal diagnosis is of great importance in affected families. Prenatal diagnosis is possible by measuring DHPR activity in different cell types but this is time consuming. More than 25 different mutations have to date been identified in the QDPR gene and direct identification of a mutation in a fetus would be easy and rapid. We have developed a method based on denaturing gradient gel electrophoresis (DGGE) for the analysis of the QDPR gene. The method is useful for rapid and simultaneous scanning of all exons and flanking intronic sequences of the QDPR gene. We describe the first prenatal diagnosis conducted using this method. Copyright © 2001 John Wiley & Sons, Ltd.     

Real-Time PCR Detection of Norovirus in Mussels Collected from the Bosphorus in Istanbul,Turkey

Norovirus (NoV) is recognised as one of the most common causes of foodborne infections, and shellfish are a well-documented source of this virus. The presence of NoV in shellfish has not previously been investigated in Turkey, and hence the aim of this study was to determine the frequency of human NoV genogroups I and II in mussels collected from the Bosphorus, Istanbul, Turkey. A total of 320 mussels representing 110 samples originating along the Bosphorus coast were collected from fish distributors. RNA was extracted using the RNeasy Mini Kit and real-time RT–PCR performed using primers specific for NoV genogroup I and II. Amongst the 110 samples, 5 (4.5%) were found to be positive for NoV genogroup II by SYBR Green assay; no genogroup I was detected. A positive signal was obtained by SYBR Green for NoV Genogroup II in mussels collected in October, November and December 2008, and February and July 2009. Only four out of five SYBR Green positive samples could be confirmed by the use of a NoV GII probe-based real-time RT–PCR. The average count and SD of Enterobactericaeae, E. coli and sulphide reductase anaerobic bacteria in PCR positive mussels were 3.56 log ± 0.96 log, 2.32 log ± 0.77 log and 1.70 log ± 0.56 log, respectively. This study shows that NoV Genogroup II is present in mussels collected from the Bosphorus, Istanbul, and may constitute a risk to human health.     

Enhancing employees' duty orientation and moral potency: Dual mechanisms linking ethical psychological climate to ethically focused proactive behaviors

Based on social cognitive theory (SCT), we develop and test a model that links ethical psychological climate to ethically focused proactive behavior (i.e., ethical voice and ethical taking charge) via two distinct mechanisms (i.e., duty orientation and moral potency). Results from multi-wave field studies conducted in the United States, Turkey, France, Vietnam, and India demonstrate that an ethical psychological climate indirectly influences employees' ethical voice and ethical taking charge behaviors through the dual mechanisms of duty orientation and moral potency. Additionally, we find that individuals' moral attentiveness strengthened these mediating processes. Together, these findings suggest that ethical psychological climate is an important antecedent of ethically focused proactive behavior by stimulating individuals' sense of duty and enhancing their moral potency, particularly when employees are already highly attuned to moral issues.     

Health risk assessment of soil trace elements using the Sequential Gaussian Simulation approach

Environmental Science and Pollution Research - In this study, the performance of the Sequential Gaussian Simulation (SGS) approach was studied with the aim of accurately determining local health...     

Evaluation of ecological risk,source, and spatial distribution of some heavy metals in marine sediments in the Middle and Eastern Black Sea region,Turkey

Environmental Science and Pollution Research - In the present study, the concentration levels of heavy metals such as Mn, Fe, Ni, Cu, Zn, Cr, and Pb in sediment samples collected from 16 sampling...     

确保地表建筑物安全矸石充填开采原料配比及充填量的确定

为确定某矿的矸石充填开采过程中最优充填材料配比和最佳的矸石充填量。设计了一种新型的矸石压缩模具,应用该模具和YE-200A液压试验机对十种不同粒径配比的矸石进行压缩试验,得出均匀配比的矸石为最优充填配比。采用最小二乘法拟合的数学模型,确定了均匀配比矸石充填材料与压力的变化规律。最后推出了均匀配比的矸石充填高度与采厚、顶板允许下沉量及顶板压力的函数关系。