22 research outputs found

    干出和紫外辐射对坛紫菜光合作用的影响

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    以坛紫菜叶状体为材料,研究了干出和阳光紫外辐射(uVr)对其光合作用的影响.长时间干出和阳光uVr不能进一步诱导藻体合成紫外吸收物质,而且uVr对干出藻体的叶绿素A和类胡萝卜素合成有抑制作用.uVr显著抑制干出状态下藻体光系统II(PSII)的有效光化学效率和藻体的光合固碳速率,而且对光合活性的抑制作用随失水率的增大而增强.国家自然科学基金重点资助项目(批准号:90411018

    丹江口水库鲤肠道寄生蠕虫群落结构与季节动态

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    2004年2月到2005年11月在丹江口水库库区206尾鲤(Cyprinus carpio)肠道中检获蠕虫11种,其中复殖吸虫3种,线虫5种,棘头虫2种,绦虫1种。总体感染率为45.63%,平均感染丰度为4.23±12.65,平均感染强度为9.29±17.48,其中饭岛盾腹吸虫(Aspidogaster ijimai)的总感染率(25.24%)和平均感染丰度(1.76±6.46)最大,瓣睾鲫吸虫(Carassatrema lamellorchis)的感染强度(25.00±46.68)最大。除部分平均感染丰度较低的线虫如鲤带巾线虫(Cucullanus cyprini)外,其他蠕虫的分布类型均为聚集分布,蠕虫群落多样性指数为4.63,均匀度指数为0.60,对群落多样性的季节动态分析表明,各季节群落多样性和均匀度波动较大,并无明显变化规律。每尾鲤感染蠕虫种数多在1—4种之间,所有感染的11种蠕虫中优势种为饭岛盾腹吸虫;次优势种为日本侧殖吸虫(Asymphylodora japonica)、中华许氏绦虫(Khawia sinensis)、瓣睾棘吸虫和鲤长棘吻虫(Rhadinarhynchus cyprini);非优势种为对盲囊线虫(Contracaecum sp.)、鲤带巾线虫、鲤杆咽吸虫(Rhabdochona cyprini)、黄颡刺盖线虫(Spinitectus gigi)、毛细线虫(Capillaria sp.)和木村小棘吻虫(Micracanthorhynchina motomurai)。在种间协调关系方面,鲤杆咽线虫和瓣睾鲫吸虫、鲤长棘吻虫和饭岛盾腹吸虫、对盲囊线虫和木村小棘吻虫、鲤长棘吻虫和木村小棘吻虫之间分别存在显著正关联。对优势种和次优势种蠕虫中种群的季节动态分析表明,鲤寄生蠕虫各组分的感染率和平均感染丰度存在显著的季节差异,在秋、冬季节的感染水平普遍比较高,而到春夏则急剧下降,但中华许氏绦虫无显著季节变化

    Principle demonstration of the phase locking based on the electro-optic modulator for Taiji space gravitational wave detection pathfinder mission

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    Weak-light phase locking is a key technology for Taiji space gravitational wave detection and its pathfinder mission. Previously, the phase locking was achieved by a complicated technique, which controls the frequency of the laser via a piezo-electric actuator (kHz range or more) and a temperature actuator (sub-Hz range). We propose an easy phase-locking strategy, which is based on the electro-optic modulator (EOM). Compared with the traditional way, this strategy only needs to modulate the driven voltage of the EOM, and the frequency bandwidth can cover all ranges. An experiment is also established to prove the feasibility of the method. The results show that the noises are &lt;80 mu rad/Hz(1/2) in frequencies from 0.2 to 1 Hz, and the thermal drift is the main noise source in our recent system. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)</p

    阳光紫外辐射对褐藻羊栖菜生长和光合作用的影响

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    为探讨经济褐藻羊栖菜对阳光紫外辐射变化的响应,我们在全波段阳光辐射(280--700nm),去除UV—B辐射(320--700nm)以及光合有效辐射PAR(400--700nm)3种辐射条件下对其进行培养,测定了其光合作用与生长的变化。羊栖菜的生长是通过每两天测量一次藻体的湿重来测定的,光合放氧是用Clark型氧电极测定的,为了测定藻体叶绿素a和紫外吸收物质的含量,从250nm到750nm对羊栖菜的甲醇提取液进行扫描,叶绿素。的浓度用Porra的公式计算,紫外吸收物质的计算是根据Dunlap的方法先计算紫外吸收物质和叶绿素。的比率,然后乘以每单位藻体叶绿素a的含量。结果表明,当藻体接收较多的日辐射量时有较高的相对生长速率,当滤除UVR后,较高的太阳辐射也导致了较高的光合放氧。然而太阳紫外辐射能够抑制藻体的光合放氧和生长速率,降低叶绿素a的浓度,并且这种抑制作用随着辐射水平的升高而增强。此外,阳光紫外辐射也诱导产生了一定量的紫外吸收物质,但并不足以抵抗紫外辐射对藻体的伤害作用

    阳光紫外辐射对褐藻羊栖菜生长和光合作用的影响

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    为探讨经济褐藻羊栖菜对阳光紫外辐射变化的响应,我们在全波段阳光辐射(280&mdash;700nm),去除UV-B辐射(320&mdash;700nm)以及光合有效辐射PAR(400&mdash;700nm)3种辐射条件下对其进行培养,测定了其光合作用与生长的变化。羊栖菜的生长是通过每两天测量一次藻体的湿重来测定的,光合放氧是用Clark型氧电极测定的,为了测定藻体叶绿素a和紫外吸收物质的含量,从250nm到750nm对羊栖菜的甲醇提取液进行扫描,叶绿素a的浓度用Porra的公式计算,紫外吸收物质的计算是根据Dunlap的方法先计算紫外吸

    阳光紫外辐射对褐藻羊栖菜生长和光合作用的影响

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    为探讨经济褐藻羊栖菜对阳光紫外辐射变化的响应,我们在全波段阳光辐射(280--700nm),去除UV—B辐射(320--700nm)以及光合有效辐射PAR(400--700nm)3种辐射条件下对其进行培养,测定了其光合作用与生长的变化。羊栖菜的生长是通过每两天测量一次藻体的湿重来测定的,光合放氧是用Clark型氧电极测定的,为了测定藻体叶绿素a和紫外吸收物质的含量,从250nm到750nm对羊栖菜的甲醇提取液进行扫描,叶绿素。的浓度用Porra的公式计算,紫外吸收物质的计算是根据Dunlap的方法先计算紫外吸收物质和叶绿素。的比率,然后乘以每单位藻体叶绿素a的含量。结果表明,当藻体接收较多的日辐射量时有较高的相对生长速率,当滤除UVR后,较高的太阳辐射也导致了较高的光合放氧。然而太阳紫外辐射能够抑制藻体的光合放氧和生长速率,降低叶绿素a的浓度,并且这种抑制作用随着辐射水平的升高而增强。此外,阳光紫外辐射也诱导产生了一定量的紫外吸收物质,但并不足以抵抗紫外辐射对藻体的伤害作用

    EFFECTS of SOLAR ULTRAVIOLET RADIATION ON GROWTH AND PHOTOSYNTHESIS of HIZIKIA FUSIFORMIS

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    为探讨经济褐藻羊栖菜对阳光紫外辐射变化的响应,我们在全波段阳光辐射(280—700nM),去除uV-b辐射(320—700nM)以及光合有效辐射PAr(400—700nM)3种辐射条件下对其进行培养,测定了其光合作用与生长的变化。羊栖菜的生长是通过每两天测量一次藻体的湿重来测定的,光合放氧是用ClArk型氧电极测定的,为了测定藻体叶绿素A和紫外吸收物质的含量,从250nM到750nM对羊栖菜的甲醇提取液进行扫描,叶绿素A的浓度用POrrA的公式计算,紫外吸收物质的计算是根据dunlAP的方法先计算紫外吸收物质和叶绿素A的比率,然后乘以每单位藻体叶绿素A的含量。结果表明,当藻体接收较多的日辐射量时有较高的相对生长速率,当滤除uVr后,较高的太阳辐射也导致了较高的光合放氧。然而太阳紫外辐射能够抑制藻体的光合放氧和生长速率,降低叶绿素A的浓度,并且这种抑制作用随着辐射水平的升高而增强。此外,阳光紫外辐射也诱导产生了一定量的紫外吸收物质,但并不足以抵抗紫外辐射对藻体的伤害作用。Effects of solar ultraviolet radiation(UVR) on the growth and photosynthesis of the economic brown alga Hizikia fusiformis were investigated while exposed to full spectrum solar radiation(280—700 nm),solar radiation depleted of UV-B(320—700 nm) and solar radiation deprived of total UVR(400—700 nm) in order to understand its responses to changes in solar UVR.The growth of H.fusiformis was determined by weighting the fresh algae every two days and the photosynthetic oxygen evolution was assayed by a Clark-type oxygen electrode.To determine the contents of chlorophyll a and UV-absorbing compounds(UVAC),methanol extracts from H.fusiformis were scanned from 250 to 750 nm.The concentration of chlorophyll a was calculated using the equation of Porra and the contents of UVAC per fresh mass were estimated by determining the ratio of UVAC to chlorophyll a according to Dunlap et al and multiplying the ratio of chlorophyll a content to fresh weight of the sample used.It was found that the relative growth rate was higher when algae received more daily doses and higher levels of solar irradiances depleted of UVR also led to higher photosynthetic oxygen evolution.However,solar UVR could inhibit the photosynthetic oxygen evolution and growth rate and decrease the content of chlorophyll a of H.fusiformis and higher levels of solar UVR irradiances or doses led to higher inhibitory effects.Although ultraviolet-absorbing compounds were induced by solar ultraviolet radiation,they could not fully counteract the damage to H.fusiformis induced by UVR.“863”项目(2006AA10A416);基金委项目(90411018)资

    静止和充气培养条件下短期紫外辐射对钝顶螺旋藻光化学效率的影响

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    为了研究短期太阳紫外辐射对钝顶螺旋藻的影响,作者将静止和充气培养的藻体,暴露在全波长太阳辐射PAB(PAR+UVA+UVB),去除UVB辐射PA(PAR+UVA)及切断所有紫外辐射的光合有效辐射P(PAR)三种光处理条件下,测定了其光化学效率的变化。结果表明,紫外辐射(UVP)及光合有效辐射(PAR)均能导致钝顶螺旋藻的光化学效率降低,表现出了明显的光抑制,但是,UVR可导致更大程度的光抑制。充气培养条件下,与早晨(07:00)初始值相比,PAR导致了11%~20%的光抑制,而UVR(PAB-P)所产生

    Effects of solar UVR on the growth and photosynthetic electron transfer rate in artificially raised young seedlings of Hizikia fusiformis

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    为探讨经济褐藻羊栖菜人工幼苗对阳光紫外辐射变化的响应,在全波段阳光辐射省(PAb,280~700nM)、去除uV-b辐射(PA,320~700nM)和光合有效辐射PAr(P,400~700nM)三种辐射处理及不同辐射水平下培养羊栖菜幼苗,并测定了其生长与光合作用的变化。结果表明,无论在紫外辐射(uVr)存在情况下(PA,PAb)还是滤除uVr(PAr)时,高辐射水平条件下(55%),羊栖菜幼苗都具有较高的生长速率,而低辐射水平下羊栖菜的生长速率较低。在不同辐射处理之间,随着辐射水平的增高,uVr的抑制效应逐渐突显。uVr降低羊栖菜幼苗的光合电子传递速率。Effects of solar ultraviolet radiation (UVR) on the growth and photosynthesis of artificially raised young seedlings of Hizikia fusiformis were investigated while exposed to full spectrum solar radiation (PAB,280-700 nm),solar radiation depleted of UV-B (PA,320-700 nm) and solar radiation deprived of total UVR (P,400-700 nm) in order to understand its responses to changes in solar UVR.It was found that the young seedlings showed higher relative growth rate at 55% of solar irradiance level,regardless of the treatments with UVR (PA,PAB) or without UVR (PAR).Lower solar irradiance level resulted in low relative growth rate.Among the different treatments,the inhibitory effects on growth were increased with the enhancement of solar irradiance level.In addition,photosynthetic electron transfer rate of young seedlings was significantly suppressed by UVR.国家高技术计划海洋“863”项目(No.2006AA10A416);国家自然科学基金重点项目(No.90411018)资

    Ni_2P/SBA-15耦合BmimBF_4催化加氢脱氮的新过程

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    通过改性固体催化剂,耦合离子液体进行催化反应,实现了在温和条件下催化加氢脱氮性能的提高。采用助剂Mo对Ni2P/SBA-15催化剂进行改性,并用XRD、BET、XPS对催化剂结构进行表征。以吡啶为含氮模型化合物,将固体催化剂耦合BmimBF4在温和的条件下进行加氢脱氮活性评价。结果表明,低温时的脱氮过程主要以离子液体萃取为主;随着温度的升高,耦合加氢脱氮效果表现显著,且改性后的5%Mo-25%Ni2P/SBA-15催化剂耦合离子液体在150℃、3 MPa的条件下评价脱氮率最高,达到了80.1%。离子液体4次加氢循环之后,其加氢性能没有明显的下降。离子液体的参与使得催化加氢脱氮反应在温和的条件下得以实现,这为催化加氢在低温低压条件下提供了新的理论和工艺
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