中国工业行业技能偏向型技术变化的实证检验

近年来,我国工业行业技能劳动力的需求快速增加,技能供需矛盾日益突出。虽然有文献认为技能偏向型技术变化是其中的重要原因,但是对技能偏向型技术变化存在性的规范检验几乎一片空白。本文基于经典文献提供的实证方法,以工业全行业和大中型行业为实证对象,规范检验20世纪90年代以来我国工业技术进步的技能偏向性。首先,对技能劳动力就业份额变化进行分解的结果表明,我国工业就业结构技能升级的主导因素是细分行业内而不是细分行业之间技能劳动力就业份额的变化。其次,基于我国工业经济的特性,计量检验了技术进步、对外开放和资本-技能互补性等因素对工业就业结构技能升级的影响,揭示了技术进步与技能劳动力就业份额之间显著的正相关关系。这两方面的结果验证了20世纪90年代以来我国工业行业的技能偏向型技术变化,并为技能劳动力短缺提供了基于需求角度的解释。     

冬季不同生境下菹草的水质净化效果研究

在室外通过人工构建静态模拟生态系统,研究冬季不同底质、水深、水质条件下,菹草对水体营养盐的吸收净化效果。结果表明,在不同水深或水质污染程度的相应组实验中,添加土壤改良剂的各组实验的TN、TP、NO3--N、高锰酸盐指数去除率均高于相应的未添加组,而NH4+-N去除情况相反;添加土壤改良剂有助于菹草对水体营养盐的综合去除,菹草在水深较深且营养盐负荷较高的水体中对营养盐的去除效果更好;水深35cm比水深25cm更适宜菹草的生长;菹草在实验设计的水质条件下能正常生长和对水质进行高效净化,适合在冬季运用于一般河道的水体修复。     

Strategies for applying gray water effluent on ornamental sunflower crops

Environmental Science and Pollution Research - In a context of scarcity of good quality water, reuse is a mandatory practice to increase water availability, thus allowing the exploitation of more...     

澳门城市小流域地表径流污染特征分析

在澳门半岛选取土地利用为公园绿地和商住混合的2个分流制城市小流域.于2005-08～2005-11借助自动采样器进行流域出口5场降雨地表径流水质水量监测.结果表明,商住混合分流制小流域TN、TP、COD多场降雨平均浓度值分别超出国家地表水环境V类标准4倍以上.公园绿地小流域TN、TP均超出V类水标准2倍多.从降雨-径流过程污染物浓度历时变化看,2个小流域TN和TP呈现一定的初始冲刷现象.TSS与TN、TP的判定系数R²都在0.95以上,地表径流中水土流失与总氮总磷输出显     

泥河湾盆地于家沟遗址AMS-14C年代学研究及其考古学意义

于家沟遗址作为泥河湾盆地中唯一具有新旧石器工业过渡的典型遗址,为研究东亚旧石器向新石器时代过渡提供了理想的场所。本文通过于家沟遗址剖面沉积物(厚约550 cm)的加速器质谱法(AMS-~(14)C)年代测定,确定了于家沟剖面的年代跨度为16.19?—?2.43 ka BP,其中旧石器向新石器时代的转化时限为9.35 ka BP。该遗址中发现的最早陶器经同层位地层推测,其年代为13.60 ka BP,是目前中国北方发现的最早陶器。陶器的使用可能改善了古人类的生活条件;大量细石器反映出泥河湾盆地中采猎经济高度繁荣。因此,在晚更新世末期气候开始变暖的背景下陶器和细石器的出现一定程度推动了中国北方旧石器时代向新石器时代的转变。     

Turbidimetric determination of chloride in different types of water using a single sequential injection analysis system

A sequential injection analysis system for the turbidimetric determination of chloride in different types of water is proposed. The determination is based on the reaction of chloride with silver ions and the subsequent measurement of the turbidity caused by silver chloride precipitation. In this method, the use of toxic reagents, such as mercury thiocyanate, commonly employed in most spectrophotometric techniques for chloride determination, is avoided. The main feature of the developed system is the use of a single configuration to carry out the determination over a wide concentration range (2-400 mg L(-1)) by changing only the aspirated sample volume. This characteristic allows the determination of chloride in ground, surface and wastewaters using the same manifold. In addition, a considerable saving of precipitating reagent is achieved due to non-continuous consumption. The results obtained with the developed system were statistically indistinguishable from those of the potentiometric titration reference method. Relative standard deviations for ten consecutive injections were lower than 3.7%, with a sampling frequency of between 55 and 57 determinations per hour.     

车集矿井下水处理及利用

根据车集矿井下水的水质特性，采用混凝沉淀和过滤的方法对矿井不处理，并根据矿井水同用水水质要求供给不同水质的水，在尽可能提高矿井水的利用率的前提下尽量减少水处理的成本。     

臭氧催化氧化-BAF深度处理抗生素废水效能及微生物群落结构分析

采用臭氧催化氧化-曝气生物滤池（BAF）组合工艺对抗生素废水二级生化处理出水进行深度处理，考察了组合工艺对废水污染物的去除效果，通过三维荧光光谱结合平行因子法（EEMs-PARAFAC）分析了废水中有机物的荧光变化特征，并利用Illumina MiSeq高通量测序技术对BAF中微生物菌群结构的变化进行研究.结果表明，在最佳运行条件下，抗生素废水COD平均值由232 mg·L^-1降至46 mg·L^-1，NH₄⁺-N平均浓度由12 mg·L^-1降至4.1 mg·L^-1，出水水质可稳定达到《发酵类制药工业水污染物排放标准》（GB21903-2008）.EEMs-PARAFAC从废水中解析出3类荧光组分，主要可归为腐殖酸（胡敏酸）、富里酸及其混合物，经组合工艺处理后荧光强度大幅下降甚至消失.Illumina MiSeq测序显示，污泥经抗生素废水驯化后微生物丰富度和均匀度明显降低，Proteobacteria（变形杆菌门）、Chloroflexi（绿屈挠菌门）和Firmicutes（厚壁菌门）是优势菌门，其中，Thiothrix（发硫菌属）、Thermomonas、Pseudoxanthomonas（假黄单胞菌属）和JG30_KF_CM45是降解抗生素类污染物的主要菌属.     

东北地区近50年来霾天气气候特征

利用东北地区194个地面气象观测站的1961~2013年观测资料,对东北地区霾日及不同等级霾日的空间分布特征和时间演变规律进行分析.结果表明:东北地区霾日空间分布差异显著,辽宁中部和黑龙江中北部霾日相对较多,年平均霾日超过50d,吉林西部地区霾日最少,年平均霾日不超过2d,不同等级的霾日日数空间分布与总霾日日数基本一致;东北地区霾日主要集中在冬季,占全年霾日57.9%,秋季次之,春季最少;1961~2103年东北地区平均霾日呈显著增加趋势(2.9d/10a),其中1981~2000年时段增加最为显著,轻微霾日、轻度霾日、中度霾日和重度霾日均呈增加趋势,但轻度霾日、中度霾日和重度霾日21世纪以来较80年代略有减少.     

Zinc accumulation in Solanum nigrum is enhanced by different arbuscular mycorrhizal fungi

Solanum nigrum was found to proliferate in sediments with high levels of metal pollution. The effect of Zn on plant growth and tissue metal accumulation was assessed. The response of the plant to the inoculation with four different isolates of arbuscular mycorrhizal fungi (AMF) (Glomus sp. BEG140, Glomus claroideum, Glomus mosseae and Glomus intraradices) was studied. While the isolates of AMF did not have a significant (P<0.05) influence on mycorrhizal colonisation, increasing Zn concentration to high levels (500 and 1000 mgkg(-1)) induced significant (P<0.05) decrease of the AMF colonisation. In general, the presence of AMF did not affect the growth and biomass of S. nigrum individuals. However, the level of metal in the matrix affected S. nigrum growth; plants grown at 100 mgkg(-1) had significantly (P<0.05) lower leaf, stem, root and total biomass than control ones and plants growing at 500 and 1000 mgkg(-1) had the significantly (P<0.05) lowest biomass. Plants inoculated with the AMF G. claroideum and G. intraradices presented significantly (P<0.05) higher Zn accumulation in all plant tissues. In general, the stem tissues had the higher Zn content while the leaves registered the lowest values, which indicate a high translocation of the metal. AMF inoculation had no significant (P<0.05) influence on the metal translocation within the plant. This study suggests that inoculation with the AMF G. claroideum or G. intraradices, can enhance the Zn accumulation in the tissues of S. nigrum, not affecting the plant translocation capacities.