35 research outputs found

    近30年来职业教育与培训的国际比较研究进展

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    在经济全球化浪潮的推动下,出于政策制定和体系转换实践的需要,职业教育与培训日益受到关注,有关的国际比较也成为一个引人注目的研究领域,并且呈现出多学科和交叉研究的显著特征。本文从国际比较研究的推动力、对象和样本维度、关注的主要议题以及研究范式4个方面进行分析的同时,对近30年来该领域的研究进展作一些梳理与探讨也具有启示意义

    大数据多维度下的智慧交通

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    一、背景——城市交通现状如果想要出行便捷,汽车一定会是我们的首选工具,但是随着时间和科技的推移,如今的汽车却给人类带来了另一个大麻烦——耗费太多时间在堵车和等红绿灯上了。由于城镇化建设的不断推进和国民经济的快速发展,近年来大中型城市的机动车数量增幅巨大。城市拥堵、违规违章、事故频发、尾气排放日趋严重,这些看似无关痛痒的“城市病“,却成为文明城市进一步发展的阻碍。以北京

    交通事故因素分析与预防

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    城市的不断发展已经导致城市交通事故的频繁发生,能否对已发生事故做出正确的分析将直接影响到能否对未来类似事故的成功避免。本文提出了一种新的数据分析方法,其结合了数据挖掘领域中的多维关联规则技术和概率统计学中的多元线性回归模型,充分发挥两者的优点。在对大量交通事故记录的方法进行分析中,不仅找出交通事故的发生规律,并通过影响算子对其进行二次加工,从中得出直观的参数函数,使得交通管理人员或城市规划者能在交通管理中方便地运用这些函数,不但可以对交通事故的产生做定量的分析,还可以直观地获得改进建议

    Serosurveillance and the PCP-FMD

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    通过一次平衡法考察了pH、离子强度和溶剂介电常数对红壤吸附低分子量有机酸的影响。研究结果表明,随着溶液pH值的升高有机酸的吸附量降低,其中草酸和酒石酸的吸附量在pH3.5~5.0范围内随着pH值的升高而急剧下降,之后缓慢下降(pH5.0~7.0)。柠檬酸、酒石酸和苹果酸的吸附量在1~2mmol/L初始浓度范围内随着离子强度的增加没有明显变化,但在2~20mmol/L初始浓度范围内却随着离子强度的增加而增加。红壤对草酸、柠檬酸、酒石酸和苹果酸的吸附量均随着溶剂介电常数的减小而增加。当溶剂中含6%的乙醇时,草酸、柠檬酸、酒石酸和苹果酸的吸附量分别是对照(不含乙醇)的1.05、1.05、1.11和1.31倍

    ANALYSES ON LDH ISOENZYME AND PROTEIN FROM BOTH GUANGDONG STRAIN AND FUJIAN STRAIN OF ECHINOCHASMUS FUJIANENSIS

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    目的 探讨福建与广东两地福建棘隙吸虫生化特点。方法 用不连续聚丙烯酰胺凝胶电泳及薄层等电聚焦电泳等进行比较分析虫体乳酸脱氢酶 (LDH)同工酶和蛋白质。结果 福建与广东两地虫株都有 5种LDH同工酶 ,其中LDH1、LDH4 和LDH5的迁移率相同 ;蛋白质电泳都分离出 9条区带 ,其中有 7条带的等电点相同。但在LDH2 和LDH3 的迁移率 ,蛋白质区带的相对含量 ,同工酶的总活力与比活力 ,以及A和B亚基的含量等存在差异。结论 LDH同工酶与蛋白质的某些差异 ,可归因为基因型相似条件下所出现两地虫株生化遗传上差异Aim\ Inguired into the biochemical characteristrics of Echinochasmus fujianensis found in Fujian and Guangdong provinces. Methods\ Compared and analysed two strains by LDH isoenzyme eletrophoresis, discontinuous PAGE and thinlayer isoelectric equilibrium PAGE.Results\ Two strains both had five LDH isoenzyme, among them, LDH\-1、LDH\-4 and LDH\-5 had the same mobilities. There were nine bands in protein electrophoresis. Seven bands had the same isoelectric point.But there were differences in the mobilities of LDH\-2 and LDH\-3,the comparative amount of protein bands, total and specific activity of isoenzyme and the amount of A and B subunit. Conclusion Under the similar condition of genotypes, the differences of the biochemical inheritance can be contributed to the differences of LDH isoenzyme and protein.福建省科技计划基金资助项目!(No.98-Z-156);; 福建省“百千万人才”人选培养资金资助项

    SURVEY OF MIXED INFECTIONS OF FISH-BORNE TREMATODES IN PINYUAN COUNTY AND DNA(RAPD)ANALYSIS

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    目的 调查广东省平远县棘隙吸虫及其他鱼源性吸虫混合感染情况。方法 对鱼类宿主取鱼鳃和鱼肉等组织 ,镜检囊蚴 ;用水洗过筛沉淀法粪检虫卵 ,部分虫卵阳性动物解剖检查。采用DNA -RAPD技术 ,比较福建棘隙吸虫广东株与福建株。结果 查出华支睾吸虫 (Clonorchissinensis)、东方次睾吸虫 (Metorchisorientalis)、福建棘隙吸虫 (Echinochasmusfujianensis)、日本棘隙吸虫 (E japonicus)、抱茎棘隙吸虫 (E perfoliatus)和钩棘单睾吸虫 (Haplorchispumilio) 6种。第二中间宿主为麦穗鱼等 11种 ,感染率 48 3% (182 / 377) ,有 92 4%的阳性鱼混合感染 2种以上吸虫囊蚴。保虫宿主狗、猫感染率 79 2 % (19/ 2 4) ,每只阳性动物均有 2种以上吸虫混合感染。 15个引物在福建棘隙吸虫广东株与福建株两者共获DNA片段 185个 ,共享度 (F) =0 984,遗传距离 (D) =0 0 16。结论 当地为人兽共患的多种鱼源性吸虫混合感染区。形态学观察和分子生物学检测结果相印证 ,福建棘隙吸虫广东株与福建棘隙吸虫福建株为同一虫种。Aim To seek the possible existence of mixed infections of Echinochasmus fujianensis and other fish-borne tremtodes in Pinyuan county,Guangdong.Methods Metacercariae of trematodes were detected from gills,muscles and some other tissues of freshwater fish and examintd under microscopy Sedimentation pocedures were used to observe parasite ova in stool Adult worms were obtained from definitive animal hosts upon dissection Experimental animal infection were performed from metacercariae of E fujianensis strains in Fujian and Guangdong,and it's DNA analysis Random amplified Polymorphic DNA(RAPD).Results Six species of trematodes were found,including Clonorchis sinensis,Metorchis orientalis,E fujanensis, E japonicus,E perfoliatus and Haplorchis pumilio Eleven species of freshwater fish comprising Pseudorasbora parve were identified as the second intermediate hosts,with an average positive rate of 48 33%(182/377) The overall mixed infection animal were contracted with 2 or more species Dogs and cats were detected to be reservoir hosts,the total infection rate being 79 2%(19/24).92 4% of infecded fish were contracted with 2 or 6 speies of the metacercariae of trematodes 185 DNA fragments were obtained by 15 primers,F=0 894 and D=0 016 between E fujianensis Guandong and Fujian strain Conclusion There are six species of fish-borne trematodes which may cause infections in human and animal in the regions E fujianensis Guangdong stain and Fujian strain are the same species福建省科技计划基金!资助项目 (No 98-Z - 1 56);; 福建省“百千万人才”人选培养资

    Gender Disparities Between Income and Rate of Return to Education of Migrant Workers

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    基于2008年全国外来务工人员的调查数据,本文对该群体的收入与教育回报率的性别差异进行实证分析,并在分样本回归中引入z检验通过总样本和分样本回归,本文得出以下三个结论:第一,男性和女性在工资收入方面存在显著的性别差异,受教育年限、工作经验、婚姻状况、务工所在地等对外来务工人员的收入均有显著影响;第二,不论是总样本回归还是分样本回归,不论是以受教育年限还是以教育层次回归,男性和女性的教育回报率差异均不显著,说明性别间的收入差异不是由教育带来的;第三,从受教育层次看,外来务工人员的回报率不是线性递增的,每提高一个教育层次,男性和女性的教育回报率都将大大增加。This paper empirically examines the gender differences in income,and rate of return to education of migrant workers and is based on national survey data of migrant workers performed in 2008.A Z-test is included in separate regressions for samples.There are three findings in this paper.First,there is a significant income disparity between men and women.Additionally,years of education,work experience,marital status,and work location significantly affect the income of migrant workers.Second,there is no significant correlation between gender and the rate of return to education in total and separate regression samples.Using years of education and education levels as explanatory variables to regress indicates that the income gap between female and male migrant workers is not related to education.Third,the rate of return to education among migrant workers increases nonlinearly as workers obtain higher levels of education

    红壤中低分子量有机酸的吸附动力学

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    低分子量有机酸在土壤中广泛存在尤其是在根际土壤中,其主要来源于动植物残体的分解、微生物的代谢、植物根系的分泌和土壤中有机物的转化等。由于羧基的强络合作用,低分子量有机酸一旦进入土壤将很快被土壤吸附,影响土壤的表面电荷性质和动电性质,进而影响其在土壤中的作用。关于

    红壤中低分子量有机酸的吸附特征

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    应用平衡法研究了红壤对草酸、柠檬酸、酒石酸和苹果酸的吸附行为。结果表明:红壤对有机酸的吸附量随着有机酸平衡溶液浓度的增加而增加,有机酸种类不同,吸附量也不同。有机酸在红壤中的吸附行为均可以很好地用Langmuir、Freundlich和Temkim方程描述,其中以Langmuir方程的拟合效果最好。红壤对有机酸均具有较高的吸附率,在0.5~20mmolL-1初始浓度范围内,草酸、柠檬酸、酒石酸和苹果酸的吸附率最大分别可达89.2%、77.5%、67.4%和47.1%。红壤对柠檬酸、酒石酸和苹果酸的吸附率均随着有机酸初始浓度的增加先急剧下降(〈5mmolL-1),之后缓慢下降至趋于平稳;草酸的吸附率则随着初始浓度的增加而增加,在3mmolL-1左右时达到最大,随后降低至趋于平稳

    红壤主要土壤组分对低分子量有机酸吸附的研究

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    通过一次平衡法研究了双氧水去除有机质、添加1%腐殖酸和DCB法(连二亚硫酸钠-柠檬酸钠-碳酸氢钠)去除游离氧化铁、铝对红黏土发育的红壤吸附草酸、柠檬酸、酒石酸和苹果酸的影响。结果表明,去除有机质后,由于受溶液pH、表面吸附点位变化、土壤结构变化、表面基团活性变化、草酸根生成等多种因素的影响,红壤对低分子量有机酸的吸附量虽略有增加,但增加并不明显。添加腐殖酸培养一个月后,由于受土壤表面电荷变化、吸附点位覆盖、氧化铁活性改变、基团质子化等因素的影响,红壤对低分子量有机酸的吸附量虽有轻微的减少,但减少也不明显。去除占土壤总量3.79%的游离氧化铁、铝后,土壤表面正电荷将会显著减少,而导致红壤对低分子量有机酸的吸附量显著减少,其减少程度因有机酸种类而异,与原土对有机酸的最大吸附量(Sm)大小顺序相反
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