206 research outputs found
超越“福利国家”
本文采用社会科学研究中比较分析的研究方法,从对西方“福利国家”的危机分析入手,对当代西方“福利国家”的危机及其社会保障制度改革进行评述,并力求从其改革的成就及存在的问题中寻求对我国建立适应社会主义市场经济体制的社会保障制度的启示。全文由四个部分组成: 第一部分阐述西方“福利国家”的形成、演变及其危机的产生。西方发达国家从19世纪末开始通过立法确定并扩大了政府的社会保障职能,从而建立了现代社会保障制度。并于20世纪中期建成了“福利国家”。这一制度安排充分发挥了作为资源配置方式之一的政府在再分配领域的作用,极大地促进了经济的发展和社会的稳定。但随着20世纪70年代“石油”危机的来临,西方“福利国...学位:管理学硕士院系专业:法学院政治学与行政学系_行政管理学号:19980601
厌氧条件在不同Fe( II) 浓度测定方法中必要性的比较研究
厌氧是目前Fe(II)测定方法中常选择的处理方式,但是不可避免会给实验操作带来不便。为了方便、准确地测定铁还原体系中的Fe(II)浓度,对比研究了厌氧条件对草酸—草酸铵和盐酸两种典型浸提方法测定Fe(II)浓度的影响。结果表明:对于草酸—草酸铵浸提法,厌氧条件是必须的,以防止提取液中的Fe(II)被氧化,而且样品浸提1 h 便可用于Fe(II)的测定;然而对于盐酸浸提法,厌氧条件却并不是必须的,对Fe(II)浓度测定基本不产生影响。因此,为简化实验操作或在没有厌氧条件的情况,可利用盐酸浸提法测定铁还原体系中Fe(II)浓度
Iron and manganese oxides enhance electron output efficiency of Clostridium pasteurianum
[Background] Fermentative dissimilatory metal-reducing bacteria, which are capable of reducing metallic oxides, get energy from fermentation. Little is known about how metallic oxides affect electron output efficiency of fermentative dissimilatory metal-reducing microorganisms. [Objective] This study was conducted to explore the influence of iron and manganese oxides (Fe_2O_3/MNO_2) on electron output efficiency. [Methods] Different concentrations of Fe_2O_3/MNO_2 were added into fermented system containing glucose and inoculated 5% C. pasteurianum. Electrochemical activity of C. pasteurianum was detected. The concentrations of Fe(Ⅱ) and Mn(Ⅱ) were measured by ferrozine spectrophotometry and formaldoxime method. Fermentation substrate and metabolites of C. pasteurianum were detected by gas chromatography and high performance liquid chromatography. Lastly, we calculated the electron output efficiency. [Results] The current density peaked with the value of about 0.93 mA/m~2. The concentrations of Fe(Ⅱ) and Mn(Ⅱ) gradually accumulated. The consumption of glucose was increased by 9.4%/7.7%, Meanwhile, acetate production was increased by 37.5%/25.0%, and butyrate production was increased by 22.7%/6.8%. Additionally, hydrogen production was increased by 21.6%/9.8%, and the total electron output efficiency was increased by 24.27%/10.82%, respectively. The pH values between experimental group and control are no significant difference. [Conclusion] This study shows that iron and manganese oxides can improve the electron output efficiency of C. pasteurianum by increasing glucose consumption and buffering pH value. The results provide evidence for revealing the effects of multivalent metal oxides on the electron output of fermentative dissimilatory metal-reducing bacteria, and further expand our understanding of the interaction mechanism between multivalent metal oxides and fermentative dissimilatory metal-reducing bacteria.</p
银鲫两个蛋白合成相关基因全长cDNA的克隆及其特征分析
通过构建雌核发育银鲫心跳期SMARTcDNA质粒文库并从文库中随机挑选克隆测序 ,克隆得到银鲫翻译起始因子 3亚单位 2 (GTIF3 S2 )和翻译延伸因子 1亚单位α(GEF 1α)基因全长cDNA。银鲫翻译起始因子 3亚单位 2基因cDNA全长 12 80bp ,开放阅读框位于 117— 10 91bp之间 ,编码 32 5个氨基酸。其推断的氨基酸序列存在三个WD结构域。该基因在鱼类中为首次报道。银鲫翻译延伸因子 1亚单位alpha基因cDNA全长 1784bp ,开放阅读框位于82— 14 6
哌啶阳离子功能化侧链型阴离子交换膜的制备
燃料电池因其能量转化率高、污染小等特点,成为当前的研究热点.然而,作为关键部件的阴离子交换膜仍然存在离子电导率低、耐碱性能差等缺点,这限制了燃料电池的发展.利用威廉姆森成醚反应在聚醚酮主链接枝哌啶鎓盐,成功制备了侧链型阴离子交换膜.设计的哌啶鎓盐通过长柔性亚甲基与主链相连,使膜内形成有利于高效离子传输的微相分离结构,PEKCQA-1.0膜在80℃的电导率高达72.7mS/cm.此外,哌啶阳离子基团离主链较远,减弱了对主链的吸电子作用;同时,环型结构的哌啶阳离子具有一定的空间位阻,减少了OH~-对阳离子基团的攻击,使膜表现出优异的耐碱性能.PEK-CQA-0.8膜在60℃下1mol/L KOH水溶液中浸泡360h后,离子电导率仅下降了8.8%,有望应用于碱性燃料电池.国家自然科学基金面上项目(21376194,21576226
Data processing method of time-of-flight 3D imaging camera
飞行时间法三维成像摄像机测量结果存在中心点偏移、距离歧义性和混合像素等问题,且易受曝光时间和主动光源影响.为提高测量结果的有效性和准确性,对测量数据进行了如下处理:对摄像机进行校正,减小了球面距离到三维坐标转换过程中引入的误差;采用2个不同光源调制频率交替进行测量,根据2次测量结果差值消除距离歧义性;过度曝光时测量幅值随曝光时间增大而减小,据此提出了一种基于感兴趣区域的快速自动曝光控制方法;边界混合像素以单点或单线形式出现,根据某像素邻域内各像素位置分布情况判定该像素是否为混合像素;由测量幅值判定噪声大小,根据对主动光源成像时测量幅值很大、偏移值很小的特点辨别主动光源.实验结果表明:以上方法能有效提高数据可靠性和准确性.Measurement results of time-of-flight 3D imaging camera have problems of center offset,range ambiguity and mixed-pixel,and they are sensitive to exposure time and vulnerable to active light source.The measurement data were processed to improve the effectiveness and accuracy of measurement results.The camera was calibrated so that the error was decreased thanks to the transformation from spherical distances to Cartesian coordinates.The ambiguity was eliminated according to the difference between two measurements taken with two different light modulation frequencies alternately.The amplitude decreases with increasing exposure time due to excessive exposure,accordingly,a rapid auto-exposure control method based on region of interest was proposed.Boundary mixed pixels are in form of a single point or a single line,accordingly,the location distribution of each pixel in its neighborhood was a used to determine whether the pixel was a mixed pixel.Noise was determined according to the amplitude,meanwhile,the active light source was identified according to the characteristics that the amplitude was very small and the offset was very big when the active light source was measured.The experimental results showed that the data reliability and accuracy were improved with the above methods.国家自然科学基金重点资助项目(60534070);国家自然科学基金资助项目(60302013
The Role of Microorganisms in the Geochemical Iron Cycle
铁元素虽然只在地壳含量中位列第4,但却是地球上分布最广的变价金属元素之一,微生物介导的铁循环及其与生源要素碳、氮、氧和硫等耦合的氧化还原反应是微生物地球化学循环的重要驱动力.由于铁循环过程中氧化态三价铁Fe(Ⅲ)在环境p H条件下大多以不溶状态存在,因而由其参与的地球化学循环进程通常较为缓慢.研究表明,微生物在铁元素的地球化学循环过程中起着举足轻重的作用,并在该过程中参与矿物的生成与转化.近年来的最新研究发现,参与地球化学铁循环的微生物之间,微生物与矿物之间,以及矿物介导的微生物之间存在着多样的相互作用,而含铁矿物介导的微生物胞外电子传递机制是其中最受瞩目的研究热点.本文综述了微生物介导的地球..
“动物酵素营养液”在家禽饲养上应用效果
用2 862羽肉鸡与4 000羽蛋鸡进行试验,探讨“京福龙“动物酵素对肉鸡生长和蛋鸡产蛋情况的影响。结果表明与对照组相比,饲喂添加“京福龙“动物酵素的肉鸡出栏重平均每只较对照组增长9.45%,料肉比降低0.21,死亡率降低2.2%,蛋重的平均增长率较对照组增长1%,产蛋率增加了5.0%,死亡率降低6%,可见“京福龙“动物酵素能降低家禽的疾病发生情况和促进肉鸡生长、蛋鸡的产蛋率
茵蒲灌肠液联合美沙拉秦肠溶片治疗轻中度溃疡性结肠炎的临床效果
目的观察茵蒲灌肠液联合美沙拉秦肠溶片治疗轻中度溃疡性结肠炎(UC)的临床效果。方法选取2016年1月—2017年12月轻中度UC患者60例,按治疗方法不同分为对照组和观察组,每组30例。对照组给予美沙拉秦肠溶片,观察组在对照组基础上给予茵蒲灌肠液保留灌肠。比较2组治疗后的临床症状、结肠镜下黏膜改变、不良反应情况以及总体疗效。结果治疗后,观察组的临床症状缓解率、结肠镜下黏膜修复有效率以及总体疗效有效率高于对照组(P0.05)。结论茵蒲灌肠液联合美沙拉秦肠溶片对轻中度UC的临床症状缓解、结肠镜下黏膜修复程度均具有较好的效果,且不增加不良反应的发生率。福建中医药大学校管课题(XB2016066
双重实时PCR快速同时检测霍乱弧菌和副溶血弧菌
目的建立改良分子信标双重实时PCR同时检测霍乱弧菌和副溶血弧菌的快速方法,应用于霍乱监测、副溶血弧菌食物中毒的快速诊断和海产品检验。方法根据GenBank公布的霍乱弧菌肠毒素基因A亚单位(ctxA)和副溶血弧菌的耐热直接溶血毒素基因(TDH)的保守序列,分别设计引物和改良分子信标探针,以10种细菌作对照,建立双重实时PCR改良分子信标检测体系,应用于副溶血弧菌食物中毒快速诊断和霍乱监测。结果改良分子信标双重实时PCR反应体系DNA灵敏度为102.4~166.6fgμl,菌液灵敏度为32~64CFUml或3~6CFUPCR反应体系,无交叉反应。此反应体系同时检测40株副溶血弧菌和50株霍乱弧菌,均出现特异的荧光信号,两种细菌检测互不干扰。对3起细菌性食物中毒共48份样品和100份海产品进行检测,9份副溶血弧菌实时PCR阳性,其中7份副溶血弧菌细菌培养阳性,其余样品都为阴性。从样品处理到检测结果仅需1天时间。结论改良分子信标双重实时PCR检测体系快速、灵敏度高、特异性强,可用于霍乱和副溶血弧菌食物中毒的快速诊断,为食源性疾病的分子流行病学调查提供新的检测手段
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