论高职英语教学中的文化导入

作为文化的一部分,语言与文化的关系是密不可分的。本文通过对我国高职英语教育目标及现状的分析,指出了在高职英语教学中进行文化导入的必要性及方法。     

Correcting sample selection in FARS data to estimate seatbelt use

Introduction

In this paper, we show that FARS data can be a comparable alternative to observational NOPUS data in estimating seat belt use in the United States once we correct for sample selection bias.

Results

Based on assumptions of independence for seatbelt choice, we establish a lower and upper bound for seatbelt usage rates, and find that once we correct for sample selection bias, the seatbelt usage estimates from the corrected FARS emerge at least as a comparable alternative to NOPUS estimates.

Impact on Industry

This implies that researchers can use corrected FARS to complement NOPUS, thus being able to utilize the rich cross-sectional details available in FARS data to analyze various relevant research questions.     

建设项目环境监理探讨

通过介绍建设项目环境监理的发展概况、依据以及突出问题,提出了逐步完善环境监理制度的几点建议：加强法律法规的制定;加强标准及技术规范建设;加强环境监理人才培养;统一资质管理,增加环境监理单位数量;拓宽环境监理工作范围。     

Public perception of river fish biodiversity in four European countries

Public support for biodiversity conservation is shaped by people's values and their knowledge, beliefs, and attitudes toward the environment. We conducted the first multinational representative survey of the general public's perceptions of river fish biodiversity in France, Germany, Norway, and Sweden. For the online survey, 1000 respondents per country were randomly selected from large panels following country-specific quotas set on age, gender, and educational level. Questions covered people's level of knowledge, beliefs, values, and attitudes toward river fish, environmental threats, and conservation measures. We found that the public had limited knowledge of freshwater fishes. Two non-native species, rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis), were widely perceived as native, whereas native Atlantic salmon (Salmo salar) was mostly classified as native in Scandinavia and largely as non-native in central Europe. These results suggest an extinction of experience paralleling the extirpation or decline of salmon stocks in countries such as Germany and France. Respondents thought pollution was the dominant threat to riverine fish biodiversity. In reality, habitat loss, dams, and the spread of non-native fishes are equally important. Despite limited biological knowledge, respondents from all countries held an overwhelmingly proecological worldview, supported conservation stocking, and appreciated native fishes, although only a minority interacted with them directly. Differences among the 4 countries related to several conservation issues. For example, threats to biodiversity stemming from aquaculture were perceived as more prevalent in Norway compared with the other 3 countries. Promoting fish conservation based on charismatic species and use values of fishes may work well in countries with a strong economic and cultural link to the freshwater environment, such as Norway. In countries where people rather abstractly care for nature, focusing conservation messaging on broader ecosystem traits and non-use values of fishes is likely to win more support.     

A methodology for calculating sample size to assess localized corrosion of process components

This paper proposes a methodology to estimate the required sample size to assess, with a specified precision, the localized corrosion of process components. The proposed methodology uses the extreme value and bootstrap methods. The results of estimated sample size ensure that the predicted maximum localized corrosion with the extreme value method is within an acceptable margin of error at a specified confidence level. Using the results of the proposed methodology, an equation is introduced to calculate sample size as a function of the acceptable margin of error, the population size, the standard deviation of corrosion data and the required confidence level. The probability of exceedance of critical limit of localized corrosion is also estimated. The methodology is explained through a case study of localized corrosion in process piping.     

半渗透膜采样技术在有机污染物监测中的作用

介绍了半透膜装置的组成和特点、半渗透膜采样技术的优点及其在有机污染物监测中的应用，指出该技术可用于研究有机污染物在空气、生物、水体中的分布和迁移规律，以及与有机污染物相关的生态毒理实验。     

Translocation of threatened plants as a conservation measure in China

We assessed the current status of plant conservation translocation efforts in China, a topic poorly reported in recent scientific literature. We identified 222 conservation translocation cases involving 154 species, of these 87 were Chinese endemic species and 101 (78%) were listed as threatened on the Chinese Species Red List. We categorized the life form of each species and, when possible, determined for each case the translocation type, propagule source, propagule type, and survival and reproductive parameters. A surprisingly large proportion (26%) of the conservation translocations in China were conservation introductions, largely implemented in response to large‐scale habitat destruction caused by the Three‐Gorge Dam and another hydropower project. Documentation and management of the translocations varied greatly. Less than half the cases had plant survival records. Statistical analyses showed that survival percentages were significantly correlated with plant life form and the type of planting materials. Thirty percent of the cases had records on whether or not individuals flowered or fruited. Results of information theoretic model selection indicated that plant life form, translocation type, propagule type, propagule source, and time since planting significantly influenced the likelihood of flowering and fruiting on the project level. We suggest that the scientific‐based application of species conservation translocations should be promoted as part of a commitment to species recovery management. In addition, we recommend that the common practice of within and out of range introductions in nature reserves to be regulated more carefully due to its potential ecological risks. We recommend the establishment of a national office and database to coordinate conservation translocations in China. Our review effort is timely considering the need for a comprehensive national guideline for the newly announced nation‐wide conservation program on species with extremely small populations, which is expected to stimulate conservation translocations for many species in the near future.     

Species-specific tuning increases robustness to sampling bias in models of species distributions: An implementation with Maxent

Various methods exist to model a species’ niche and geographic distribution using environmental data for the study region and occurrence localities documenting the species’ presence (typically from museums and herbaria). In presence-only modelling, geographic sampling bias and small sample sizes represent challenges for many species. Overfitting to the bias and/or noise characteristic of such datasets can seriously compromise model generality and transferability, which are critical to many current applications - including studies of invasive species, the effects of climatic change, and niche evolution. Even when transferability is not necessary, applications to many areas, including conservation biology, macroecology, and zoonotic diseases, require models that are not overfit. We evaluated these issues using a maximum entropy approach (Maxent) for the shrew Cryptotis meridensis, which is endemic to the Cordillera de Mérida in Venezuela. To simulate strong sampling bias, we divided localities into two datasets: those from a portion of the species’ range that has seen high sampling effort (for model calibration) and those from other areas of the species’ range, where less sampling has occurred (for model evaluation). Before modelling, we assessed the climatic values of localities in the two datasets to determine whether any environmental bias accompanies the geographic bias. Then, to identify optimal levels of model complexity (and minimize overfitting), we made models and tuned model settings, comparing performance with that achieved using default settings. We randomly selected localities for model calibration (sets of 5, 10, 15, and 20 localities) and varied the level of model complexity considered (linear versus both linear and quadratic features) and two aspects of the strength of protection against overfitting (regularization). Environmental bias indeed corresponded to the geographic bias between datasets, with differences in median and observed range (minima and/or maxima) for some variables. Model performance varied greatly according to the level of regularization. Intermediate regularization consistently led to the best models, with decreased performance at low and generally at high regularization. Optimal levels of regularization differed between sample-size-dependent and sample-size-independent approaches, but both reached similar levels of maximal performance. In several cases, the optimal regularization value was different from (usually higher than) the default one. Models calibrated with both linear and quadratic features outperformed those made with just linear features. Results were remarkably consistent across the examined sample sizes. Models made with few and biased localities achieved high predictive ability when appropriate regularization was employed and optimal model complexity was identified. Species-specific tuning of model settings can have great benefits over the use of default settings.     

固定污染源NMHC-CEMS样品传输管线加热的必要性问题探究

针对非甲烷总烃在线监测系统（NMHC-CEMS）样品传输管线在不同伴热温度下对辛烷的吸附作用,以及管线自身的挥发情况开展研究。试验表明：在室温条件下,低、中、高质量浓度的辛烷标气在不锈钢传输管线中均有较为明显的吸附残留,在≥90 ℃的伴热条件下,辛烷在传输管内残留量对测定结果基本无影响,残留量明显低于1%,说明对样品进行加热传输是保证NMHC-CEMS测定结果准确性的必要措施。PTFE和PFA材质伴热管线在高温伴热下挥发明显,而不锈钢伴热管线更适用于NMHC-CEMS样品的传输。