黄红壤上烟草对钾的反应及种烟后土壤钾的变化

黄红壤上烟草对钾的反应及种烟后土壤钾的变化马友华，李道林，陈邦本，方明（安徽农业大学土化系，合肥２３００３６）（南京农业大学资环系）我国南方亚热带的红壤是我国植烟面积较大的土类，适用于种植各种类型的烟草［１］。烟草是喜钾作物，近年来我国南方在烟草种植...     

A roadmap for the conservation of freshwater mussels in Europe

Europe has a long history of human pressure on freshwater ecosystems. As pressure continues to grow and new threats emerge, there is an urgent need for conservation of freshwater biodiversity and its ecosystem services. However, whilst some taxonomic groups, mainly vertebrates, have received a disproportionate amount of attention and funds, other groups remain largely off the public and scientific radar. Freshwater mussels (Bivalvia, Unionida) are an alarming example of this conservation bias and here we point out six conceptual areas that need immediate and long-term attention: knowledge, threats, socioeconomics, conservation, governance and education. The proposed roadmap aims to advance research, policy and education by identifying the most pressing priorities for the short- and long-term conservation of freshwater mussels across Europe.     

Electricity generation from cattle dung using microbial fuel cell technology during anaerobic acidogenesis and the development of microbial populations

A microbial fuel cell (MFC) was constructed to investigate the possible generation of electricity using cattle dung as a substrate. After 30 days of operation, stable electricity was generated, and the maximum volumetric power density was 0.220 W/m(3). The total chemical oxygen demand (TCOD) removal and coulombic efficiency (CE) of the MFC reached 73.9±1.8% and 2.79±0.6%, respectively, after 120 days of operation. Acetate was the main metabolite in the anolyte, and other volatile fatty acids (VFAs) (propionate and butyrate) were present in minor amounts. The PCR-DGGE analysis indicated that the following five groups of microbes were present: Proteobacteria, Bacteroides, Chloroflexi, Actinobacteria and Firmicutes. Proteobacteria and Firmicutes were the dominant phyla in the sample; specifically, 36.3% and 24.2% of the sequences obtained were Proteobacteria and Firmicutes, respectively. Clostridium sp., Pseudomonas luteola and Ochrobactrum pseudogrignonense were the most dominant groups during the electricity generation process. The diversity of archaea dramatically decreased after 20 days of operation. The detected archaea were hydrogenotrophic methanogens, and the Methanobacterium genus disappeared during the periods of stable electricity generation via acidogenesis.     

Preparation and Properties of Thermoplastic Starch/Montmorillonite Nanocomposite Using N-(2-Hydroxyethyl)formamide as a New Additive

N-(2-Hydroxyethyl)formamide (HF) was synthesized efficiently and used as a new additive to prepare thermoplastic starch/montmorillonite nanocomposite (TPS/MMT). Here, HF acted as both plasticizer for TPS and swelling agent for MMT. The hydrogen bond interaction among HF, starch and MMT was proven by Fourier-transform infrared (FT-IR) spectroscopy. By scanning electron microscope (SEM), starch granules were completely disrupted. Atomic force microscopy demonstrated that partially exfoliated TPS/MMT nanocomposite was formed. The crystallinity of corn starch, MMT, HF-plasticized TPS (HTPS) and TPS/MMT nanocomposite was characterized by X-ray diffraction (XRD). Thermal stability of HTPS and TPS/MMT was determined by thermogravimetric analysis (TGA). The water resistance of TPS/MMT nanocomposite increased compared with that of pure HTPS. Tensile strengths of TPS/MMT nanocomposites were higher than those of HTPS, but just the reverse for elongations at break.     

A double‐edged sword: The moderating role of conscientiousness in the relationships between work stressors,psychological strain,and job performance

Although conscientiousness was commonly viewed as a type of personal resource to help individuals reduce strain or mitigate the impacts of stressors, empirical research demonstrated mixed results. Based on the personal resource allocation perspective, we posited that rather than functioning as personal resource per se, conscientiousness may act as a key factor influencing how individuals allocate their personal resources. The current study examined the moderating roles of conscientiousness in the relationships that work stressors (i.e., challenge stressors and hindrance stressors) have with employee psychological strain and job performance by using multi‐source, time‐lagged data collected from 250 employees working at two companies. The results showed that both challenge stressors and hindrance stressors were positively related to psychological strain. Conscientiousness moderated the relationships between both stressors and psychological strain, such that the positive relationships were stronger for individuals with high conscientiousness. Conscientiousness also moderated the relationship between challenge stressors and performance, such that the relationship was positive for individuals with high conscientiousness but negative for those with low conscientiousness. Altogether, the findings suggest that conscientiousness acts as a double‐edged sword that both promotes performance and exacerbates the stress reaction of employees when they are confronted with stressful situations. Copyright © 2014 John Wiley & Sons, Ltd.     

便携式空调系统研究

在炎热环境中,便携式空调系统可以对人的身体进行冷热调节,创造一种微气候环境。根据Natick士兵中心研究结果:只要提供300 W制冷量就能满足一个人的热负荷需求。北京工业大学研制了微型蒸汽压缩制冷系统作为便携式空调的冷源,微型制冷系统的制冷量为300 W,重量为2．85 kg,几何尺寸为270 mm×260 mm×120 mm。采用强化传热措施及轻质材料来减小微型制冷系统的重量及体积。     

合并财务报表的合并理论与合并范围分析

《合并财务报表》会计准则的发布，使企业集团合并财务报表的编制更加规范。本文主要分析了该准则的合并理论和合并范围，指出合并理论应侧重实体理论，合并范围应强调实质性控制。     

应用化学质量平衡模型解析烟台市污染源的排放贡献率

根据烟台地区污染排放特点,应用化学质量平衡模型（CMB8）进行污染源解析分析,得出每个污染源对于受体地区颗粒物体样本的排放贡献率。最终的模型结果显示,建筑尘和居民烯煤锅炉排放,海洋尘和冶炼厂排放对于大气环境污染也有一定的贡献,以上分析可以为城市污染源治理提供一定的依据。     

Decomposition of phorate in aqueous solution by ozonation

Phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate) dissolved in aqueous solution was almost completely decomposed by ozonation to form various species within 10 minutes of reaction time for the experimental conditions examined in this research. The generation rate of sulfate was found to be fairly independent of solution pH value. However, the formation of phosphate and carbonate was more favorable for alkaline solutions where hydroxyl free radical is the primary oxidative species. The reaction rates increased with initial gaseous ozone concentrations, indicating the reaction was mass transfer-controlled within the experimental range of this research. Combining the analytical results by various instruments, including gas chromatograph equipped with an electron ionization detector (GC-EID), high performance liquid chromatography (HPLC), ion chromatography (IC), and total organic carbon (TOC), the temporal sequence of phorate ozonation was proposed in this study. The oxidation of sulfur atoms on the phosphorus-sulfur double bond or carbon-sulfur-carbon bond by ozonation was found to occur at first to form sulfate and various intermediates.