玉米浸泡液制备苏云金杆菌生物杀虫剂的影响因素研究

以玉米淀粉生产过程中的浸泡液为培养基,摇瓶发酵培养苏云金杆菌生物杀虫剂,通过一系列单因子试验,考察了不同培养条件(种子液的种龄、接种量、浸泡液的含固率、初始pH值、摇床转速、发酵温度及发酵时间)对苏云金杆菌在玉米浸泡液中的生长(菌数增长与芽孢形成)以及发酵液的生物毒效的影响.研究表明,在最佳摇瓶培养条件(种子液种龄10 h,接种量2%,浸泡液含固量3%,初始pH值7.0～7.5,摇床转速200 r/min,发酵温度30℃)下发酵48 h,活菌数和活芽孢数分别可达到7.9×108 CFU/mL和5.5×108 CFU/mL,毒力效价为698.0 IU/μL.本试验可为生物农药的工业化生产提供实用参数.     

用“条件”水分平衡法分析湖北省干旱的时空分布规律

从“条件”水分平衡角度和农业生产实际情况出发，提出了一个综合考虑水分盈亏和同期作物需水量的干旱指标，并用此指标分析了湖北省１９６１－１９９０年３０年来的主要干旱类型的时空分布规律及对农业生产的影响。     

Gas/particle partitioning of atmospheric PCDD/Fs in a satellite town in Eastern China

Gas/particle partitioning of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in ambient air was investigated in a satellite town in Eastern China from April 2007 to January 2008 comprehending large temperature variations (from 3 to 34 °C, daily average). Molecular weight, molecular structure and ambient temperatures are the three major factors that govern the gas/particle partitioning of atmospheric PCDD/Fs throughout the year. Generally, good agreements were obtained (except for winter) between measured particulate fractions and theoretical estimates of both the Junge–Pankow adsorption model and Harner Bidleman absorption model using different sets of subcooled liquid vapor pressure and octanol–air partition coefficient (K_oa), respectively. Models utilizing estimates, derived from gas chromatographic retention indices (GC-RIs), are more accurate than that of entropy-based. Moreover, during winter, the K_oa-based model using the GC-RIs approach performs better on lower chlorinated PCDD/Fs than that of -based. Furthermore, possible sources of mismatch between measured and predicted values in winter (3–7 °C) were discussed. Gas adsorption artifact was demonstrated to be of minor importance for the phenomena observed. On the other hand, large deviations of slopes (m_r) and intercepts (b_r) in logK_p vs. plots from theoretical values are observed in the literature data and these are found to be linearly correlated with ambient temperatures (P<0.001) in this study. This indicates that the non-equilibrium partitioning of PCDD/Fs in winter may be significantly influenced by the colder temperatures that may have slowed down the exchange between gaseous and particulate fractions.     

The study on the dechlorination of OCDD with Pd/C catalyst in ethanol-water solution under mild conditions

Dechlorination of octachlorodibenzo-p-dioxin (OCDD) was carried out in ethanol-water (v/v=1:1) solution of NaOH in the presence of Pd/C catalysts with the use of H(2). The substrate was dechlorinated with Pd/C under mild conditions (atmospheric pressure and <100 degrees C) to give a chlorine-free product, dibenzo-p-dioxin (DD), in high yields. After reaction of 3h at 50 degrees C, 95.9% OCDD was degraded to low dechlorinated congeners and the yield of DD was 77.4%. We have also studied the dechlorination selectivity of chlorine atoms on the different substituted positions and postulated the dechlorination pathway of OCDD. For OCDD, the 2-position has higher reactivity than 1-position, but the difference is very small. From the distribution statistics of the intermediates during the reaction, we postulate that the steric effect plays an important role during the reaction and affect the dechlorination pathway of OCDD.     

Extended alloparental care in the almost solitary bee Exoneurella eremophila (Hymenoptera: Apidae)

The possibility of extending brood care via the overlapping presence of relatively short lived adults could generate advantages that may have been among the selective forces at the origin of eusociality. In this paper we provide evidence for extended brood care through sib-rearing in the arid-zone allodapine bee, Exoneurella eremophila. Solitary females of the overwintered generation generally die before all their offspring have become independent. In a relatively high proportion of nests, a newly eclosed female invests in her siblings while producing her own offspring in the maternal nest. The sex ratio of the first offspring produced by the overwintered female is highly female biased, but the overall sex ratio of the brood is unbiased. This finding supports the prediction of Bull's 'insurance by protogyny' model of a female bias in the first-produced offspring as a strategy by the mother to ensure extended brood care.     

Sedimentary record of polycyclic aromatic hydrocarbons in a sediment core from a maar lake, Northeast China: evidence in historical atmospheric deposition

A maar lake is an excellent ecosystem to study the atmospheric deposition of pollutants, as its contaminants are primarily by atmospheric deposition. In this study, a sediment core from Sihailongwan Maar Lake, Northeast China, was collected and the historical atmospherically deposited polycyclic aromatic hydrocarbons (PAHs) were analyzed. The concentrations of TPAHs (the sum of the US EPA proposed 16 priority PAHs, excluding naphthalene and pyrene) ranged from 473.9 to 2289 ng g(-1) with a slow increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments. The input rate of TPAHs, especially that of PAH(9) (the sum of fluoranthene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(ah)anthrathene, and benzo(ghi)perylene), correlated well to the Chinese historical socioeconomic data. This indicates that sediment PAHs were mainly derived from human activities and PAH(9) can be regarded as a better indicator of the local socioeconomic development. Source identification suggested that PAHs were originated primarily from mixed sources (e.g., coal and biomass burning and petroleum combustion), except for perylene which was mostly of diagenetic origin. In addition, the down-core PAHs profile clearly illustrated that PAHs sources in Northeast China experienced a transformation from low- and moderate temperature to high-temperature combustion processes, especially after the late 1980s. Additionally, an ecological risk assessment using two redefined biological thresholds (TEQ(ERL) and TEQ(ERM)) indicated that most of the PAHs measured in the present sediment core would not cause an immediate toxic effect; only FLU and PHEN are a potential source of concern for biological impairment.     

Impact of socioeconomic development on ecosystem services and its conservation strategies: a case study of Shandong Province,China

Ecosystems and their components provide a lot of benefits for the welfare of human beings. Coupled with increasing socioeconomic development, most of the rapidly developing and transitional countries and regions have been experiencing dramatic land use changes. This has resulted in a large amount of forestland, grassland, and wetland being occupied as residential and industrial land or reclaimed for arable land, which in turn results in a sharp deterioration of ecosystem services around the world. Shandong Province, an economically powerful province of China, was chosen as a case study in order to capture the impact of socioeconomic development on ecosystem services. By way of the study, land uses and their changes were categorized between 1980 and 2006, and the ecosystem services capital and changes of 111 counties of Shandong Province in different phases were evaluated, as well as the total ecosystem services capital, followed by the zoning of ecosystem services function region of Shandong Province. We found that the counties in mountainous areas and wetlands, where generally the prefectural-level cities are located with a rapid socioeconomic development, experienced a successive deterioration of ecosystem services especially during the 2000s. Finally, three conservation strategies for managing and improving ecosystem services were proposed and discussed with the aim of achieving coordinate and sustainable development of the socioeconomy, environment, and ecosystems not only in Shandong Province but also in other provinces of China, as well as in other developing and transitional countries and regions.     

红枫湖水库水体富营养化及浮游植物群落结构特征

2008-2009年通过对红枫湖水库浮游植物及环境因子进行采样调查,并运用综合营养状态指数对红枫湖水库营养状态进行评价.研究结果显示,红枫湖水库浮游植物全年以蓝藻、绿藻为主的优势种群落,且在2008-2009年经常性局部发生蓝藻水华:冬、春季节主要是水华束丝藻(Aphanizomenon flos-aquae)的蓝藻水华;夏季主要是微囊藻属(Microcystis)蓝藻水华;秋季浮游植物主要是颗粒直链藻(Melosira)和小环藻属(Cyclotella)为主的硅藻类群,未出现水华现象.通过综合营养状态指数计算得红枫湖水库水体水质处于富营养化状态.     

Present status of recycling waste mobile phones in China: a review

A large number of waste mobile phones have already been generated and are being generated. Various countries around the world have all been positively exploring the way of recycling and reuse when facing such a large amount of waste mobile phones. In some countries, processing waste mobile phones has been forming a complete industrial chain, which can not only recycle waste mobile phones to reduce their negative influence on the environment but also turn waste into treasure to acquire economic benefits dramatically. However, the situation of recycling waste mobile phones in China is not going well. Waste mobile phones are not formally covered by existing regulations and policies for the waste electric and electronic equipment in China. In order to explore an appropriate system to recover waste mobile phones, the mobile phone production and the amount of waste mobile phones are introduced in this paper, and status of waste mobile phones recycling is described; then, the disposal technology of electronic waste that would be most likely to be used for processing of electronic waste in industrial applications in the near future is reviewed. Finally, rationalization proposals are put forward based on the current recovery status of waste mobile phones for the purpose of promoting the development of recycling waste mobile phones in developing countries with a special emphasis on China.     

Individual and combined inhibition of phenol and thiocyanate on microbial activity of partial nitritation

This study evaluated the individual and interactive effect of phenol and thiocyanate (SCN⁻) on partial nitritation (PN) activity using batch test and response surface methodology. The IC₅₀ of phenol and SCN⁻ on PN sludge were 5.6 and 351 mg L⁻¹, respectively. The PN sludge was insensitive to phenol and SCN⁻ at levels lower than 1.77 and 43.3 mg L⁻¹, respectively. A regression model equation was developed and validated to predict the relative specific respiration rate (RSRR) of PN sludge exposed to different phenol and SCN⁻ concentrations. In the range of independent variables, the most severe inhibition was observed with a valley value (17%) for RSRR, when the phenol and SCN⁻ concentrations were 4.08 and 198 mg L⁻¹, respectively. An isobole plot was used to judge the combined toxicity of phenol and SCN⁻, and the joint inhibitory effect was variable depending on the composition and concentration of the toxic components. Furthermore, the toxic compounds showed independent effects, which is the most common type of combined toxicity.