95 research outputs found

    儿童利手形成的实验研究

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    &lt;正&gt; 利手的研究是神经心理学的一项重要课题,是探索大脑奥秘,揭示某些神经、精神疾病病因,研究大脑两半球机能不对称性的一条途径。本世纪二十年代以来,国外对这个问题做了大量研究,不少国家已经掌握了国人的利手分布数据。我国从1980年起,由中国科学院心理研究所组织全国十几个单位搞协作,开始对我国正常人的利手分布情况进行研究,现已取得了积极的成果。然而,中国人的利手是怎样形成的?它在个体发育过程中是个怎样的变化过程?这在我国尚未见到有人报道。因此,我们认为通过1~7岁儿童进行抓物实验,对探索国人利手形成规律是有意义的。</p

    Distribution Features and Speciation of Heavy Metals in Surface Sediments of Main Mangrove of China

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    利用ICP-MS分析了我国红树林主要分布区表层沉积物的As含量和形态,阐明As的分布及其形态特征.结果表明,表层沉积物中w(As)为3.14~19.16mg/g,平均值为8.14mg/g.表层沉积物中w(As)与w(Fe),w(Mn),pH,w(有机质),粉粒和黏粒所占比例呈显著或极显著正相关.表层沉积物中的As主要以残渣态存在,其次为有机质-硫化物结合态.在整个研究区域,As的5种形态在总量中的所占比例:可交换离子态为14.40%,碳酸盐结合态为1.41%,铁锰氧化物结合态为2.16%,有机质-硫化物结合态为30.40%,残渣态为50.65%.可交换离子态所占比例与w(有机质)和pH呈极显著正相关.有机质-硫化物结合态所占比例与盐度、黏粒和粉粒所占比例呈显著或极显著正相关.残渣态所占比例与盐度、粉粒和黏粒所占比例呈极显著正相关.Arsenic contents in surface sediments collected from mangrove were analyzed with a PE DRC-e ICP-MS,and the distribution and species of As were identified.The results showed that As content ranged from 3.14~19.16 mg/g,with an average content of 8.14 mg/g.As content correlated well and positively with the contents of Fe and Mn,pH,organic content,silt and clay.Residual As was the primary species,and organic and sulfide As were the secondary species in the surface sediments.Among five As species,the exchangeable As accounted for 14.40%,carbonate As accounted for 1.41%,Fe-Mn oxides As accounted for 2.16%,organic-sulphide As accounted for 30.40%,and residual As accounted for 50.65%.Exchangeable As positively correlated with organic content and pH significantly.Organic-sulfide As and residual As positively correlated with salinity,silt and clay significantly.国家自然科学基金项目(40676064,30530150

    单、双胎早产的高危因素及早产儿结局比较研究

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    目的探讨双胎早产与单胎早产高危因素的特点以及单、双胎早产儿的结局。方法回顾性分析广州医科大学附属第三医院2009年1月至2015年12月的单、双胎孕产妇与新生儿临床数据资料。结果研究期间在该院分娩的36 931例新生儿,双胎2080例,单胎34 851例,其中早产5877例,双胎早产1395例(双胎早产组),早产率为67.07%;单胎早产4482例(单胎早产组),单胎早产率为12.86%,总计早产发生率为15.91%,双胎早产率明显高于单胎,差异有统计学意义(P22~26岁组、>26~30岁组、>30~34岁组、>34~39岁组和>39岁组中,双胎早产率均明显高于单胎(单胎早产率对双胎早产率分别为:19.65%vs.64.86%、11.45%vs.70.85%、10.49%vs.68.16%、12.88%vs.65.41%、19.67%vs.64.51%、22.83%vs.68.42%,P均<0.05);单、双胎孕产妇不同孕周出生率比较,双胎在孕20~37周之间的出生率均高于单胎出生率;对早产的高危因素进行对比分析,双胎早产组中人工授精、体外受精-胚胎移植、羊水过多、胎膜早破、妊娠期糖尿病、妊娠期肝内胆汁淤积症的比例均明显高于单胎早产组,差异有统计学意义(1.79%vs.0.16%、1.79%vs.0.16%、2.79%vs.1.38%、32.48%vs.29.65%、19.50%vs.15.84%、2.22%vs.1.41%,P均<0.05);对新生儿的结局进行比较,单胎早产组中死胎、出生缺陷、新生儿呼吸窘迫综合征发生率均明显高于双胎早产组(8.68%vs.2.22%、11.20%vs.8.52%、15.35%vs.12.90%,P均<0.05),1 min、5 min、10 min Apgar评分双胎早产组明显高于单胎早产组,差异有统计学意义[(9.43±0.023)min vs.(9.06±0.026)min、(9.85±0.013)min vs.(9.69±0.016)min、(9.92±0.011)min vs.(9.81±0.014)min,P均<0.05]。结论双胎发生早产的风险显著高于单胎,与单胎早产相比,人工授精、体外受精-胚胎移植、羊水过多、胎膜早破、妊娠期糖尿病、妊娠期肝内胆汁淤积症等高危因素与双胎早产的关系更加密切,早产儿结局优于单胎早产组。国家重点研发计划(2016YFC1000405/2016YFC1000303);;国家自然科学基金(81571518

    Electrosynthesis of glyoxylic acid in a static bed reactor with cooled cathode

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    以过饱和草酸水溶液为阴极液,盐酸溶液为阳极液,在阴极冷却固定床电化学反应器内草酸电解合成乙醛酸。考察了电流密度、电极和电解液温度、阴极材料对合成乙醛酸时空产率和电流效率的影响。结果表明,阴极冷却固定床反应器是一种较理想的反应器,用石墨板作阳极,铅作阴极,电流密度为400.5A/m2,阴极空速u0=0.505m/s,电解温度为20℃左右时,电解1.5h,在阴极可得到质量分数为5.45%的乙醛酸溶液,平均时空产率可达0.12kg/dm3·h以上。Glyoxylic acid was produced by electroreduction of oxalic acid in the static bed reactor with cooled cathode. The cathodic and anodic electrolytes were super-saturated oxalic acid and hydrochloric acid aqueous solutions. The current efficiency and time-space yield of glyoxylic acid were studied under different current densities, temperatures of cathode and electrolyte,materials of cathode. The results indicated that the cooled cathode static bed reactor is an excellent reactor. The average space-time yield of glyoxylic acid is over 0.12 kg/dm~3·h and the concentration of glyoxylic acid can reach 5.45% after 1.5 h electrolysis with cathode of lead and anode of graphite board under conditions of temperature 20℃,superficial flow rate of 0.505 m/s and current density of 400.5 A/m~2 in the cooled cathode static bed reactor.福建省自然科学基金资助项目(F99029

    Preventive effect and mechanisms of 3,3-diindolylmethane on oxidative stress induced by hydrogen peroxide in HaCaT cells

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    目的:探究3,3'-二吲哚甲烷(dIM)对过氧化氢(H_2O_2)诱导人角质形成细胞(HACAT)氧化应激作用的预防效应及可能机制。方法:体外培养HACAT细胞,用H_2O_2建立氧化应激模型。采用CCk-8法检测不同浓度(1~20μMOl/l)dIM对HACAT细胞生长的抑制作用;流式细胞术检测dIM作用前后细胞内活性氧自由基(rOS)含量的变化;WESTErn blOT检测不同浓度dIM(0、5、10μMOl/l)对HACAT氧化应激相关蛋白核因子(nf-κb)和丝裂原活化蛋白激酶(MAPkS)磷酸化表达水平的影响。结果:成功建立了HACAT氧化应激模型。CCk-8法研究结果显示1-10μMOl/l dIM对HACAT细胞无明显毒性作用(P>0.05);流式细胞术检测结果表明10μMOl/l dIM预处理可有效预防由H_2O_2诱导的HACAT内rOS产生(P0.05).Flow cytometry results indicated that pretreatment with DIM(10 μmol/L) could inhibit the level of intracellular ROS(P<0.05).With increasing concentration of DIM,the levels of p-p38-MAPK,p-JNK and p-NF-κB were significantly depressed.CONCLUSION:DIM could protect HaCaT cells from H_2O_2-induced oxidative stress via suppressing production of ROS levels and down-regulating the expression of NF-κB and members of MAPKs.DIM might be used as an effective drug to treat or reduce oxidative stressmediated injury in skin cells.国家自然科学基金青年基金(81101562); 广东省科技计划项目(2012B060300005); 广东省自然科学基金(S2012010009633

    Distribution of Mercury in Surficial Sediments from Main Mangrove Wetlans of China

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    作者简介: 丁振华(1966~ ) , 男, 博士, 教授, 主要研究方向为污染生 态学, E-mail : dzh@ xmu. edu. cn[中文文摘]通过对我国主要红树林区表层沉积物中总汞含量和环境因素的测定,研究了红树林湿地沉积物中汞的分布规律和影响因子之间的关系.结果表明,我国红树林湿地沉积物中总汞的含量范围是2.3~903.6 ng.g-1,平均值为(197±137.6)ng.g-1,福建洛阳桥[(467.5±68.8)ng.g-1]、浮宫[(438.2±147.0)ng.g-1]、鹅湾[(264.3±89.2)ng.g-1]、姚家屿[(125.4±27.1)ng.g-1],海南三亚[(164.8±143.9)ng.g-1]、东寨港[(314.1±335.7)ng.g-1],广东深圳[(179.9±7.7)ng.g-1]等7个红树林区的汞含量均显著高于当地土壤背景值,汞污染严重;而福建云霄[(63.3±43.9)ng.g-1]、广东高桥[(178.6±127.0)ng.g-1]、广西大冠沙[(26.1±18.8)ng.g-1]、山口[(73.8±21.1)ng.g-1]、北仑河口[(117.8±51.4)ng.g-1]、钦州湾[(147.5±107.6)ng.g-1]等红树林区汞含量接近于背景值,基本无污染.红树林湿地中汞含量的差异是众多环境因素和人类活动相互交叉影响的结果.红树林湿地中,pH值、粒度、有机质、Fe/Hg、Mn/Hg与总汞含量显著相关.其中,黏粒和Fe/Hg是影响沉积物中汞含量最显著的因素.环境因素对总汞含量的综合影响作用,可以用线性回归方程表示.[英文文摘]Surficial sediment samples were collected from main mangrove wetlands of China, mercury, pH, salinity, organic matters, grain size, Fe/Hg , Mn/Hg were analyzed. Mercury content ranges from 2.3 to 903.6 ng.g- 1, with a average of ( 197±137.6) ng.g- 1. Compared with local background level, serious Hg pollution with high Hg content was found in 7 areas, including Luoyangqiao [ ( 467.5 ±68.8)ng.g- 1] , Fugong [ ( 438.2 ± 147. 0) ng.g- 1 ] , Ewan [ ( 264.3 ± 89.2) ng.g- 1 ] , Yaojiayu [ ( 125.4 ± 27.1) ng.g- 1 ] , Fujian Province;Sanya [ ( 164. 8 ±143.9) ng.g- 1 ] , Dongzhaigang [ ( 314.1 ±335. 7) ng.g- 1 ] , Hainan Province, Shenzhen [ ( 179.9 ±7. 7) ng.g- 1 ] ,Guangdong Province. Hg content was similar with background value in the other 6 areas, including Yunxiao [ ( 63.3 ±43.9) ng.g- 1 ] , Fujian Province; Gaoqiao [ ( 178. 6 ± 127.0) ng.g- 1 ] , Guangdong Province; Daguansha [ ( 26.1 ±18.8) ng.g- 1 ] , Shankou [ ( 73.8±21.1)ng.g- 1 ] , Beilun estuary [ ( 117.8 ±51. 4) ng.g- 1 ] , Qinzhou Bay [ ( 147.5 ±107. 6) ng.g- 1] , Guangxi Autonomous Region. Discrepancy of total Hg concentrations in mangrove wetlands is due to many environmental factors and human activities. Parameters such as grain size, pH,organic matter, Fe/Hg, Mn/Hg are significantly correlated with total Hg respectively. Clay and Fe/Hg are obvious factors influencing total Hg concentration. Impact of environmental factors on mercury can be showed by regression equation.国家自然科学基金项目(40676064,30530150);厦门大学创新团队项

    Distribution of Hg in Mangrove Plants and Correlation with Hg Speciation in Sediments

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    为了解红树植物对汞的富集能力和影响因素,对我国几种主要的红树植物的汞含量、沉积物总汞含量和形态进行了研究.结果表明,几种主要红树植物的总汞含量范围为817.5~3 197.6 ng/g,具有明显的种间差异和器官差异.秋茄汞含量为(1 579.4±1 326.8)ng/g,桐花树为(2 115.1±1 892.3)ng/g,白骨壤为(2 159.3±1 678.7)ng/g,木榄为(2 566.5±821.6)ng/g,海漆为(2 104.3±1 661.8)ng/g,无瓣海桑为(3 197.6±2 782.8)ng/g,老鼠簕为817.5±632.3 ng/g,红海榄为(1 801.8±1 255.4)ng/g.各种红树植物对汞的吸收能力的顺序为:无瓣海桑>木榄>白骨壤>桐花树>海漆>红海榄>秋茄>老鼠簕.我国主要红树林地区表层沉积物的汞形态主要为易挥发态,其次为硫化物及有机结合态或可交换离子态,少量为碳酸盐结合态和铁锰氧化物结合态,残渣态少量甚至没有.只有深圳红树林沉积物中的汞以残渣态为主,其次为硫化物及有机物结合态.无瓣海桑的茎和叶,海漆叶的汞含量与易挥发态汞、可交换态汞具有显著正相关关系,而大多数红树植物的茎汞和叶汞含量与沉积物的总汞含量、不同形态汞之间并没有明显的相关性.红树植物富集的汞来源多样,且这些不同来源的汞在植物体内可能是能够迁移的.Plant is an important role in biogeochemical cycle of Hg.The aim of this study is to ascertain Hg accumulation in several kinds of mangrove plants,and to discuss relationship among Hg concentrations in mangrove plants and different Hg speciation in sediments.Contents of total mercury(THg) in mangrove plants and sediments were determined.Hg speciation was determined with a modified Tessier's method.Contents of THg of the mangrove plants were in the range of 817.5-3 197.6 ng /g.In detail,Hg concentration was(1 579.4 ± 1 326.8) ng /g in Kandelia candel,(2 115.1 ± 1 892.3) ng /g in Aegiceras corniculatum,(2 159.3 ± 1 678.7) ng /g in Avicennia marina,(2 566.5 ± 821.6) ng /g in Bruguiera gymnorrhiza,(2 104.3 ± 1 661.8) ng /g in Excoecaria agallocha,(3 197.6 ± 2 782.8) ng /g in Sonneratia apetala,(817.5 ± 632.3) ng /g in Acanthus ilicifolius,(1 801.8 ± 1 255.4) ng /g in Rhizophora.stylosa,respectively.There are obvious interspecific variation,and organic variation in THg contents of mangrove plants,which is closely related to environment and physiological characteristics of mangrove plants.Enrichment of THg in mangrove plants was inhomogeneous,following the order of Sonneratia apetala > Bruguiera gymnorrhiza > Avicennia marina > Aegiceras corniculatum > Excoecaria agallocha > Rhizophora stylosa > Kandelia candel > Acanthus ilicifolius.Mercury exists mainly in volatile form in most mangrove wetlands,but mainly in the form of residue in sediments from Shenzhen mangrove wetlands.Significantly positive correlations were found among Hg concentrations in leaves and stems of Sonneratia apetala and volatile Hg,exchangeable Hg of sediments.Significantly positive correlations were also found among Hg concentrations in leaves of Excoecaria agallocha and volatile Hg,exchangeable Hg of sediments.But,there is no significant correlation between Hg concentrations of most mangrove plants and different Hg speciation in sediments.It showed that plants assimilate Hg from different sources,such as water,sediment and air,and that Hg assimilated by plants could transfer among different plant organics.国家自然科学基金项目(40676064;30530150

    Speciation,bioaccumulation and transportation of mercury in sediments of mangrove wetlands of China

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    为了认识红树林表层沉积物中Hg的生物地球化学行为,采用改进的TESSIEr连续浸取法,对我国主要红树林沉积物中Hg的形态特征进行了研究,并讨论了Hg的生物可利用性和迁移性。结果表明:(1)我国红树林沉积物中的Hg绝大部分以易挥发态为主,具有较高的生物可利用性,易挥发态Hg向大气Hg的转化是红树林湿地中汞迁移的主要方式。只有深圳红树林沉积物中的Hg以残渣态为主,次为可交换离子态和碳酸盐结合态,沉积物中Hg主要通过不可溶的固体颗粒物形式迁移,其生物可利用性较低。(2)总Hg与易挥发态Hg呈极显著正相关(r=0.967,P<0.01),碳酸盐结合态Hg与铁锰氧化物结合态Hg之间存在极显著正相关(r=0.871,P<0.01),有机结合态Hg分别与碳酸盐结合态Hg、铁锰氧化物结合态Hg存在极显著相关(r1=0.618,P1<0.01;r2=0.686,P2<0.01);有机质与总Hg存在显著正相关(r=0.526,P<0.05)。In order to understanding biogeochemical behavior,speciation of mercury in the mangrove sediments from 9 main mangrove wetlands of China were determined with modified Tiesser's method.It shown:(1) Two situations were found.One is that mercury exists mainly in volatile form in most mangrove wetlands.That volatile mercury turns into atmospheric mercury is the main transport form for most mangrove wetlands.The mangrove wetlands are the source of global mercury pollution.The mercury in sediments of mangrove wetlands can be bio-accumulated easily.Another situation is that mercury exists mainly in the form of residue which is hard to bio-accumulate,typically in Shenzhen mangrove wetlands.The mercury transports in the form of insoluble particle.(2) Significant positive correlation was found between volatile Hg and total Hg(r=0.967,p<0.01).Carbonate-bound Hg is strongly correlated with Fe-Mn oxide-bound Hg(r=0.871,p<0.01),and organic matter is significantly correlated with total Hg(r=0.526,p<0.05).Organic-bound Hg is significant correlated with carbonates-bound Hg and Fe-Mn oxide bound mercury(r1=0.618,p1<0.01;r2=0.686,p2<0.01).国家自然科学基金项目(40676064;30530150);东华理工大学核资源与环境教育部重点实验室开放基金(070717

    Vapor-liquid-equilibrium and volume expansion calculations of CO_2/acetone,CO_2/ethanol and CO_2/ethanol/water at high pressure by using t-mPR equation of state

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    作者简介:蒋茂星(1983-),女,助教,主要研究方向:超临界流体技术 通信联系人:李军,教授,主要研究方向:超临界流体技术,[email protected][中文文摘]采用t-mPR状态方程(EoS)对CO2/丙酮、CO2/乙醇二元体系和CO2/乙醇/水三元体系的高压汽液平衡(VLE)、液相体积膨胀率进行计算,并与文献报道的实验数据,以及采用PR EoS得到的结果进行比较。结果表明,与PR EoS相比较,t-mPR EoS可以对上述二元体系的VLE取得较好的关联效果,对三元体系取得较好的预测效果。基于VLE的计算,进一步对上述体系的液相体积膨胀率进行预测。与PREoS相比较,t-mPREoS对二元体系的预测结果的精度有所提高,对三元体系在7.8MPa左右有最大体积膨胀率,模型预测较好。[英文文摘]The vapor-liquid equilibirum (VLE) and volume expansion of the liquid phases for the CO2/acetone and CO2/ethanol binary systems and the CO2/ethanol/water ternary system have been investigated using the t-mPR equation of state (t-mPR EoS). Calcualted results have been compared with published experimental data and those obtained from the PR equation of state (PR EoS). The correlations for the published VLE data of the above binary systems and the prediction for the ternary system showed that both the t-mPR EoS and the PR EoS can provide fairly good VLE calculations, but t-mPR EoS gives slightly better results. The volume expansion prediction for the above systems and the comparison with the published data showed that the t-mPR EoS gives better results to PR-EoS for the binary systems and provides more reasonable results around 7.8 MPa (there exists a maximum volume expansion) for the ternay system.高等学校博士学科点专项科研基金资助项目(20100121110009

    起源于伊比利亚半岛的高贵与勇气之花——百里香

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    百里香是唇形科(Labiatae)百里香属(Thymus)植物的统称,其属名源于希腊语thymos(上香、供奉之意)。该属植物为多年生小灌木或半灌木,因其植株在花期具有强烈芳香气味而得名。在希腊神话中,百里香是斯巴达王后海伦的泪滴,为战死的爱人特洛伊王子而流。伤心的泪水增加了战士们继续战斗的勇气,后来百里
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