Seasonal and annual variation of CO2 flux above a broad-leaved Korean pine mixed forest

Long-term measurement of carbon metabolism of old-growth forests is critical to predict their behaviors and to reduce the uncertainties of carbon accounting under changing climate. Eddy covariance technology was applied to investigate the long-term carbon exchange over a 200 year-old Chinese broad-leaved Korean pine mixed forest in the Changbai Mountains (128°28′E and 42°24′N, Jilin Province, P. R. China) since August 2002. On the data obtained with open-path eddy covariance system and CO₂ profile measurement system from Jan. 2003 to Dec. 2004, this paper reports (i) annual and seasonal variation of F _NEE, F _GPP and R _E; (ii) regulation of environmental factors on phase and amplitude of ecosystem CO₂ uptake and release Corrections due to storage and friction velocity were applied to the eddy carbon flux.

L_AI and soil temperature determined the seasonal and annual dynamics of F_GPP and R_E separately. V_PD and air temperature regulated ecosystem photosynthesis at finer scales in growing seasons. Water condition at the root zone exerted a significant influence on ecosystem maintenance carbon metabolism of this forest in winter.

The forest was a net sink of atmospheric CO₂ and sequestered −449 g C·m⁻² during the study period; −278 and −171 gC·m⁻² for 2003 and 2004 respectively. F _GPP and F _RE over 2003 and 2004 were −1332, −1294 g C·m⁻². and 1054, 1124 g C·m⁻² respectively. This study shows that old-growth forest can be a strong net carbon sink of atmospheric CO₂.

There was significant seasonal and annual variation in carbon metabolism. In winter, there was weak photosynthesis while the ecosystem emitted CO₂. Carbon exchanges were active in spring and fall but contributed little to carbon sequestration on an annual scale. The summer is the most significant season as far as ecosystem carbon balance is concerned. The 90 days of summer contributed 66.9, 68.9% of F _GPP, and 60.4, 62.1% of R _E of the entire year.

     

Major features of warm and cold eddies south of the Nansei Islands

As regards the eddies occurring in the origination region of the Kuroshio (west of 130° E), the earliest informations were reported by R. Shigematsu (1932) and K. Koenuma (1936) respectively. From the data observed in the twenties, they pointed out that there was a warm eddy located to the right side of the Kuroshio in the Luzon Strait. Using the data obtained from the fourties through the sixties, Nitani further convinced the existence of the warm eddy. During the latest two decades, observations of the area south of the Nansei Islands on board of R/V Chofu Maru (1965, '66, '67) and Hakuho Maru (1974, '75) also revealed the existence of warm and cold eddies, but few works on "eddies" are reported, so far as we know.     

Decoupling of stalagmite-derived Asian summer monsoon records from North Atlantic temperature change during marine oxygen isotope stage 5d

The Asian monsoon is an important component of the global climate system. Seasonal variations in wind, rainfall, and temperature associated with the Asian monsoon systems affect a vast expanse of tropical and subtropical Asia. Speleothem-derived summer monsoon variation in East Asia was previously found to be closely associated with millennial-scale change in temperature in the North Atlantic region between 75 and 10 ka. New evidence recovered from East Asia, however, suggests that the teleconnection between summer monsoon in East Asia and temperature change in the North Atlantic region may have significantly reduced during 120 to ~ 110 ka, a period directly after the full last interglaciation and corresponding roughly to marine oxygen isotope stage 5d. This reduction may be due to the low ice volume in the North Hemisphere at that time, which makes the millennial-scale change in temperature in the North Atlantic region less effective in influencing the Asian summer monsoon. This is important for investigating the mechanisms controlling the Asian summer monsoon and the paleoclimatic teleconnection between East Asia and the North Atlantic region, and for predicting monsoon-associated precipitation in East Asia under a global-warming trend.     

分光光度法测定海洋河弧菌510脂多糖

本文研究了直接测定海洋河弧菌 (vibrio fluvailis) 5 10脂多糖的分光光度法。利用 1,9-二甲基亚甲蓝 (DMB) ,在适当条件下同脂多糖发生染色反应 ,在 5 5 0 nm波长下 ,反应体系的吸光值同脂多糖含量呈线性相关。相关系数为 0 .9993,最低检出限为 10 μg/m L,相对标准偏差为 1.6 2 ,平均回收率为 (10 5± 2 .18) %。     

均匀层浅海声场与海底反射损失的关系

海底对浅海声传播的影响很大。海底有复杂的多层结构。在计算声场时如果把多层海底的影响都考虑进去,就会使计算复杂化,得不出一个清晰的物理图象。因此,在计算中往往使用海底反射损失系数来代替多层海底的模型。但海底反射损失与角度有复杂的依赖关系。为了计算方便,提出过不少简化模型。已经使用的模型有反射损失与角度无关、与角度一次方成正比;后来又提出反射损失在某一临界角之下与角度一次方成正比,在临界角之上与角度无关的三参数模型,克服了远场与近场衔接的问题[1,2]。但这些模型不一定在所有情况下都能反映海底反射损失与角度的关系的主要特征。本文提出一个近似方法,可以计算海底反射损失按任意规律随角度单调上升的情况下的声场。     

Relationship between biogeochemical features of biogenic elements and flocculation in the Changjiang Estuary

ＲｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｂｉｏｇｅｏｃｈｅｍｉｃａｌｆｅａｔｕｒｅｓｏｆｂｉｏｇｅｎｉｃｅｌｅｍｅｎｔｓａｎｄｆｌｏｃｃｕｌａｔｉｏｎｉｎｔｈｅＣｈａｎｇｊｉａｎｇＥｓｔｕａｒｙ￥ＬｉｎＹｉ＇ａｎ；ＴａｎｇＲｅｎｙｏｕ；ＬｉＹａｎ；Ｄｏ...     

海湾扇贝肝素样多糖分离方法的研究

于1992年1月-1993年2月，对从海湾扇贝中提取获得的糖胺聚糖（GAG）用乙醇和溴化十六烷基三甲铵（CTAB）分级分离，并对所得制品用琼脂糖凝胶电泳和高效液相色谱验证，以研究一种简便、快速的分离提纯方法。结果表明，扇贝GAG水溶液在乙醇量60％时分离获得的级分，其GAG－GTAB给合物再用2.0 mol/LNaCl溶液解离得到的主要级分，琼脂糖凝胶电泳和高效液相色谱均显示出单一区带，红外光谱类似干肝素的。证明这一提纯过程是一简便、快速的分离提纯方法。     

Modelling nitrogen and phosphorus cycles and dissolved oxygen in the Zhujiang Estuary Ⅰ. Model development

wrmcrloxHuman activities related to the population growth and developrnent of industry and rnwhci-pality have led to the incrouing hadings of various POllutants into estudries during the past fewdecades. These increasing edlutant lOadings have caused declined estuallne hedth which can bemereured by a vdriety of indices. In order to obtain solutions to environrnent problerns, re-sources manageTnnt apencies are supporting a holistic approach to envirorirnental management.An effcient strategy t…     

海藻硫酸多糖911对小鼠脾淋巴细胞增殖反应及对细胞产生IL—2作用的影响

本文以~3H—TdR掺入法观察911对小鼠脾淋巴细胞增殖反应的影响并用CTLL细胞检测了其对IL—2的作用。体外实验结果表明,911对小鼠脾淋巴细胞增殖反应有明显的增强作用,以0.5μg/ml的浓度效果最为明显,相对增殖指数RPI可达200％;体内实验则以5mg/kg体重ip,连续7d效果最好,相对增殖指数RPI可达176％;911用药组小鼠IL—2的产生量均高于对照组,以5mg/kg和10mg/kg效果最好。以上实验证明,这一多糖是一种有希望的新免疫调节药物。     

《海藻遗传学》书评

海藻遗传学是研究海藻遗传和变异的遗传学分支，是海藻种质改良的理论基础。第一部藻类遗传学专著《The Genetics of Algae》是1976年出版的，主编是美国藻类学家R．A．Lewin先生，此后没有这方面的专著出版。这本由中国海洋大学张学成教授、中国科学院海洋研究所秦松研究员、上海水产大学马家海教授、江苏省海洋水产研究所许璞研究员等编著的《海藻遗传学》是我国在该领域的首部专著，