Mangroves Distribution Pattern along the River and the Adapted Mechanism to Salt Water and Fresh Water Rotation

为什么真红树植物只生长在盐生环境中？目前有两种假说来解释这一现象。其一，真红树植物是生态需盐；其二，真红树植物是生理需盐。目前大多数学者都认同前一种假说，认为真红树植物的生长不需要盐。支持这一假说的主要证据是：在一些河流红树植物可以沿河深入分布到离入海口很远的地方，这些地方的河水往往是淡水而真红树植物在这里生长良好。为了验证这一假说我们对有类似现象的黄竹江进行了详细的调查研究。本研究调查了黄竹江红树植物的沿河分布格局，跟踪了河流水体盐度日变化和季节变化，测定了不同地点真红树植物桐花树（Aegicerascorniculatum）叶片的光合特性和主要无机渗透调节物质（Na、K、Ca、Cl）的季节...Why are the true mangroves only living in salinity habitat? There are two hypotheses to answer this question. The first one, true mangroves are facultative halophytes. The second one, true mangroves are obligate halophytes. The first one was widely accepted now. The most important evidence was that many true mangroves penetrate considerable distances upstream along river banks where water is perm...学位：理学硕士院系专业：生命科学学院生物学系_植物学学号：2012005130197

Response of Photosynthetic Apparatus to Different Irradiance in Flag Leaves of High-Yielding Winter Wheat PH01-35 Grown under Low Light Conditions

为了解弱光下生长的小麦叶片在不同光强下PS II和光合电子传递链的工作状态,解释其突然转入强光下时发生光抑制和光破坏的原因,以PH01-35为材料,采用大田人工遮光的方法,测定了小麦旗叶叶绿素含量、光合特性参数及快速光曲线。弱光处理15 d后,旗叶叶绿素含量明显上升,净光合速率、光补偿点、光饱和点、表观量子效率、羧化效率均出现不同程度的下降。与250μMOl M-2 S-1的弱光适应3 H相比,1 200μMOl M-2 S-1的强光适应3 H后,弱光下生长叶片的快速光曲线初始斜率下降幅度较大,曲线下降部分的斜率、最大相对电子传递速率、半饱和光强的上升幅度均小于自然光下生长的叶片,光能利用能力较低,其非光化学猝灭系数nPQ也明显低于自然光下生长的叶片,为自然光下生长叶片的87.5%。弱光下生长的小麦叶片光能吸收能力增强,但较低的光能利用能力和过剩光能耗散能力是其转入自然强光后易发生光抑制甚至光破坏的主要原因。To further explain the mechanism of photoinhibition and light damage in wheat(Triticum aestivum L.) leaves when it was suddenly transferred from low light to high light conditions,the responses of photosynthetic apparatus in shaded leaves of the high-yielding winter wheat line,PH01-35,were examined using chlorophyll fluorescence and gas exchange techniques.After 15-day shading,the chlorophyll content increased greatly,but the net photosynthetic rate(Pn),light compensation point(LCP),light saturation point(LSP),apparent quantum yield(AQY),and carboxylation efficiency(CE) all decreased.Compared with leaves grown in full sunlight,the initial slope(α),decline slope(β),maximum relative electron transport rate(rETRmax),and minimum saturating irradiance(Ek) of rapid light curves in leaves grown in low light were lower when the plant was transferred from low light intensity of 250 μmol m-2 s-1 to high light intensity of 1 200 μmol m-2 s-1.Non photochemical quenching(NPQ) in leaves grown in low light was significantly lower than that in leaves grown in full sunlight,indicating that the ability of light use and thermal energy dissipation was limited in leaves grown in low light.The wheat leaves grown in low light were more suscepti-ble to photoinhibition due to low CO2 assimilation and photoprotective ability,such as xanthophylls cycle-dependent dissipation of excessive energy,despite the better energy absorbability in low light conditions.山东省农业良种工程重大课题(鲁农良种字[2006]6号)资

Study on the New Type Fe_3O_4 composite Anode

制备超细Fe3O4颗粒,然后与还原铁粉混合烧结制成Fe3O4-Fe复合阳极,分别进行析氯电位、循环伏安和强化电解寿命等实验测试,优化该复合阳极的最佳烧结温度和最佳Fe含量,为实用型Fe3O4-Fe复合阳极的制作提供了可行性依据.An ultrafine powder of magnetite has been prepared, and used to prepare the composite anode of Fe_(3)O_(4)-Fe by sintering method. The voltage of chlorine evolution、polarization curves、service life and mass loss, and the optimum sintering temperature and the weight ratio of the sintered powder have been investigated. All results showed that the method of preparing the practical Fe_(3)O_(4)-Fe composite uniform anode is feasible.作者联系地址：中国科学院福建物质结构研究所,中国科学院福建物质结构研究所,福州市煤气公司,中国科学院福建物质结构研究所,中国科学院福建物质结构研究所,中国科学院福建物质结构研究所,中国科学院福建物质结构研究所 福建厦门361012 ,福建厦门361012 ,福建福州350002 ,福建厦门361012 ,福建厦门361012 ,福建厦门361012 ,福建厦门361012Author's Address: 1, FANLie-peng~1, WANG Mao-hua~2, GUOQi-long~1, HONGYan-ping~1, HUANGChang-hui~1, WU Jia-lin~1 1.Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Xiamen 361012,China,2. Fuzhou Gas Company, Fuzhou 350002, Chin