Photosynthetic capacity of three common species of macroalgae and the application in coral aquarium

利用水下饱和脉冲调制叶绿素荧光仪(dIVIng-PAM)测定了珊瑚养殖水处理中3种常见大型海藻石莼(ulVA lACTuCA)、条浒苔(EnTErOMOrPHA ClATHrATA)和羽状蕨藻(CAulErPA MEXICAnA)光能转化效率(fV/fM),快速光曲线(rlC)相关参数和非光化学淬灭(nPQ)。结果表明:石莼和条浒苔的fV/fM分别为0.808±0.004和0.816±0.009,显著高于羽状蕨藻。最大相对电子传递速率rETrMAX(17.52±2.92和19.59±4.43μMOl E·M-2·S-1)、半饱和光强Ik(53.41±8.18和59.71±13.52μMOl PHOTOnS·M-2·S-1)也明显高于羽状蕨藻(rETrMAX和Ik分别为13.72±5.41μMOl E·M-2·S-1和32.67±14.06μMOl PHOTOnS·M-2·S-1),表明石莼和条浒苔有着比羽状蕨藻更高的光合能力和对强光的耐受能力,光保护能力更强;羽状蕨藻较高的rlC初始斜率α表明其在弱光下拥有更强的光捕获能力,弱光下光合效率更高;随光照的增强(0~373μMOl PHOTOnS·M-2·S-1),羽状蕨藻nPQ的增幅有限(0~0.2),最大值仅为条浒苔和石莼的38.1%和62.5%,表明这种藻类更容易受到强光的抑制。因此,在珊瑚养殖的水处理中,可以根据不同的光照选择适宜的藻种或藻种组合并根据光梯度进行布局,反之也可以根据藻种来选择合适的光源,以达到最佳的处理效率。This study investigated the difference of photosynthetic capacity in three macroalgae species( Ulva lactuca,Enteromorpha clathrata,and Caulerpa mexicana) commonly used for nutrient removal in coral aquariums.The photochemical efficiency( Fv/Fm),parameters relevant to rapid light curve( RLC) and non-photochemical quenching( NPQ) in the macroalgae were measured by underwater saturation pulse modulated chlorophyll fluorometer( Diving-PAM).The results showed that Fv/Fmwas 0.808 ± 0.004 for U.lactuca and 0.816 ± 0.009 for E.clathrata,which were higher than that for C.mexicana.Higher maximum relative electron transfer rates( rETRmax)( 17.52 ±2.92 and 19.59 ±4.43 μmol e·m- 2·s- 1) and half-starved value of light intensities( Ik)( 53.41 ±8.18 and 59.71 ±13.52 μmol photons·m- 2·s- 1) were observed in U.lactuca and E.clathrata than that in C.mexicana( 13.72 ± 5.41 μmol e·m- 2·s- 1for rETRmaxand 32.67 ± 14.06 μmol photons·m- 2·s- 1for Ik),indicating that U.lactuca and E.clathrata have stronger photosynthetic capacities,photo-protection capacities and tolerance to higher intense light than C.mexicana.A significantly lower RLC initial slope α in C.mexicana implied that this algal species has a higher photosynthetic capacity under weak light condition.With increasing the light intensity( 0- 373 μmol photons·m- 2·s- 1),however,C.mexicana had a limited increase of NPQ( 0- 0.2),the maximum of which was equivalent to 38.1% of that in U.lactuca and 62.5% of that in E.clathrata.These results indicate that the photosynthesis of E.clathrata may be more easily limited by intense light.Our study suggests that the selection of algal species for nutrient removal in a coral aquarium should be adapted to the light intensity.Single species or the combination of different species of macroalgae can be selected according to the illumination of the coral aquarium in order to maximize the efficiency of nutrient removal.国家海洋局第三海洋研究所基本科研业务项目(海三科2011033); 厦门海洋研究开发院共建项目; 海洋公益性行业科研项目(201105012)资

Concentration Protile of Etchant Measured by Microelectrode Technique in the Process of Chemical Micromachining

利用微圆盘电极技术,测定了KBr、L-胱氨酸和硫酸组成的刻蚀溶液体系中Pt电极表面电化学氧化产生的刻蚀剂Br2浓度分布,为约束刻蚀剂层技术(CELT)中刻蚀体系的选择和优化提供更直观的依据.GaAs表面CELT微加工实验证明了用微圆盘电极测得的表面刻蚀剂的浓度分布趋势与微加工实验所得到的结果一致.A carbon-disk microelectrode was used to investigate the surface concentration profile of etchant Br2, which was electrogenerated on the Pt working electrode. The steady state reducing currents of Br2 at different distances away from the Pt electode was measured. The concentration profile was estimated from the current-distance variation curves as a function of different sampling times. Experimentally determined concentration profiles are in good agreement with those estimated from the microetching results. The microelectrode technique has offered a good method to choose suitable etching solution for chemical micromachining.国家高新技术发展规划(863项目)(2002AA404170);; 福建省自然科学基金计划资助项目(E0520001

Concentration protile of etchant measured by microelectrode technique in the process of chemical micromachining

A carbon-disk microelectrode was used to investigate the surface concentration profile of etchant Br-2, which was electrogenerated on the Pt working electrode. The steady state reducing currents of Br-2 at different distances away from the Pt electode was measured. The concentration profile was estimated from the current-distance variation curves as a function of different sampling times. Experimentally determined concentration profiles are in good agreement with those estimated from the microetching results. The microelectrode technique has offered a good method to choose suitable etching solution for chemical micromachining

专题:中国非正规经济(下)

李明欢以非正规雇佣为主要内涵的非正规经济之所以能够在跨国领域大行其道,根源之一在于全球化正如同由跨国资本把握方向盘的巨型“压路机“,力图突破一切不利于其扩张之国境边界,朝着政治和

1310nm FP TO-CAN偏心封装耦合效率的研究

文章应用ZEMAX软件模拟了管芯与光纤在不同偏移量下的耦合效率,并进行了实验验证。结果表明,6.5mm焦距的TO-CAN（晶体管外壳封装）与端面倾斜8°的光纤,在管芯偏移100μm时,耦合效率最大,模拟值为21.9%,实验值为21.32%;5.8mm焦距的TO-CAN与端面倾斜6°的光纤,在管芯偏移80μm时,耦合效率最大,模拟值为11.2%,实验值为10.42%;并且实验结果和仿真结果一致

Experimental study on competitive interaction among reef-building coral Turbinaria peltata,Rhizoclonium sp. and rabbitfish Siganus guttatus

本研究通过120 d的室内培养实验研究了盾形陀螺珊瑚(TurbInArIA PElTATA)、根枝藻(rHIzOClOnIuM SP.)和点斑篮子鱼(SIgAnuS guTTATuS)之间的相互作用关系.结果显示,高质量浓度的nO-3(5.00~10.00 Mg/dM3)刺激了丝状绿藻根枝藻在缸内的爆发式生长,在实验27 d时根枝藻在缸壁的面积覆盖率达到90.5%,藻丝长度为10~15 CM.在海藻的胁迫作用下,盾形陀螺珊瑚的PSⅡ最大光化学量子产量(f V/f M)均值逐渐从0.712降至0.626,降幅为10.7%~13.5%.放入4尾4~6 CM长的点斑篮子鱼后,实验缸壁根枝藻的面积覆盖率在2d内从90.5%下降至10.0%.但解除根枝藻胁迫后盾形陀螺珊瑚的f V/f M值并没有明显变化,与对照组的差异也不显著;随着海藻胁迫因子的消除,盾形陀螺珊瑚的f V/f M值逐渐升高,并在第120天时恢复至初始状态.本研究结果从珊瑚光合作用效率的角度验证了啃食者的存在确能缓解富营养化对造礁珊瑚的不利影响,为“下行控制假说“提供了新的证据.A 120 days experiment was conducted in the aquarium to study competitive interaction among reef-building coral Turbinaria peltata,green macroalgae Rhizoclonium sp.and rabbitfish Siganus guttatus.The results showed that high concentration of NO-3( 5.00 ~10.00mg/dm3) stimulated the explosive growth of filamentous Rhizoclonium sp.,which covered 90.5% of aquarium wall on the 27thday.The length of algal filament ranged from 10cm to 15cm.Some polyps of T.peltata were covered by algae or were continuously touched and squeezed by algal filament under the action of water flow.In the meantime,the mean F v / F m gradually declined from 0.712 to 0.626 under the stress.The addition of 4 rabbitfish sharply reduced the coverage of filamentous macroalgae from 90.5 % to 10.0 % level in 2 days,but the F v / F m of T.peltata didn't recover fast.However,as the stress on the algae disappeared,T.peltata F v / F m gradually returned back to initial state on day 120.The study verifies that the grazers indeed alleviate the negative effects of eutrophication on corals and it provides a new evidence for the "top-down control"of herbivores.国家海洋局第三海洋研究所基本科研业务费资助项目(海三科2011033); 国家海洋公益性行业科研专项资助项目(201105012); 厦门海洋研究开发院共建专项资助项

Chinese Revolution in the Socio-economic Perspective

自2004年起,本刊设立开放时代论坛,每年11月第一个周末定期举办,至今已逾十二届。开放时代论坛旨在邀集多领域学者,推进对前沿公共议题的跨学科讨论。自2015年起,本刊再设不定期的开放时代工作坊,旨在邀集某学科或某些相近学科的学者,对学科内与时势相接的重要学术问题作专门探讨。第一次开放时代工作坊于2015年1月13日至14日在中山大学举办,主题为“社会经济史视野下的中国革命“,我们希望从长时段、日常生活、地方社会的角度展现中国革命的复杂性、丰富性和延续性,以区别于惯行的党史研究。以下内容根据第一次开放时代工作坊录音整理而成,并经所有发言人审订。评论及讨论部分的小标题为编者所加。因篇幅所限,部分内容未能一并刊出

大连极紫外相干光源

先进光源的发展在前沿科学研究中发挥的作用越来越重要。近十年来,飞速发展的自由电子激光技术为科学家们提供了探索未知世界、发现新科学规律和实现技术变革的重要工具。建成的大连极紫外(EUV)相干光源的运行波段为50~150nm,单脉冲能量大于100μJ,且可提供10-12 s和10-13 s量级的超快激光脉冲,是我国第一台自由电子激光用户装置,并且是国际上唯一运行在极紫外波段的自由电子激光用户装置,在世界范围内为用户提供具有高峰值亮度和超短脉冲的极紫外激光。大连EUV相干光源是由国家自然科学基金委资助、由中国科学院大连化学物理研究所和上海应用物理研究所共同承担的重大科学仪器研制项目,目标是打造一个以先进极紫外光源为核心、主要用于能源基础科学研究的光子科学平台