台湾地貌学发展历史及方向

在台湾,一般认为地貌学是地理学的分支。尽管许多地理学家和工程学家在这一领域作出很大贡献,但仍然是地貌学家作了大量的工作。在各个综合大学及师范大学的地理系,地貌学被作为一个必不可少的独立课程来进行教学。台湾现已有20个职业地貌学家,他们中的大多数正在一些高等院校,中学和研究所从事教学和科研工作。一、战前时期的研究从十九世纪到1946年这一时期,台湾才开始地形学的研究。但这方面的工作主要是由外国学者做的。这一阶段前期,研究工作主要围绕对台湾岛主要地形特征的勘探和形态描述。这时常常强调了陆地表面起伏和自然地理的描述,却忽视了对这两方面的起源及其发展历史的原因的探讨。     

南海北部1987～1988年颗粒物质和硅藻通量的季节性变化:季风气候与 El Nino的响应

南海北部1987年9月～1988年10月沉积物捕获器中颗粒物质和硅藻通量的季节性变化受到季风气候的控制.颗粒物质与硅藻在东北和西南季风盛行期增加,在季风转变期减少.浅层和深层的颗粒总通量、蛋白石通量、碳酸钙通量、蛋白石/颗粒总通量比值、碳酸钙/颗粒总通量比值、有机碳/磷的比值以及浅层硅藻Thalassionema nitzschioides、Coscinodiscus excentricus、Coscinodiscus nodulifer、Nitzschia marina和Rhizosolenia bergonii的通量在东北季风期间明显地增加了,这些变化可能与1987年～1988年发生的EINino事件相关.     

融冰期北极楚科奇海陆架中心区硅限制与来源补充

相对氮亏损(N:P约为7,小于16)的太平洋入流水携带的营养盐是支撑北冰洋上层生态系统的重要物质基础。海冰消退,光限制消失,楚科奇海陆架存在强烈的营养盐消耗与利用,广泛认为其表现为氮限制,因此该区域重点关注氮元素循环,对于硅元素的相关研究较少。本文基于2016年中国第七次北极科学考察和中国-俄罗斯首次联合北极科学考察两个同步进行的航次调查结果,全面展示了融冰期整个楚科奇海陆架区的营养盐分布格局。结果显示,硝酸盐和亚硝酸盐表层基本耗尽;硅酸盐表现为中心低,周围高,陆架中心区是强烈的硅限制区域,受到硅和氮的共同限制。沿着太平洋入流方向,S01、R01、LV77-01站位30 m以深硅酸盐浓度高于太平洋入流水端员,说明沉积物孔隙水向底层水释放硅酸盐,因此在浅水陆架区孔隙水可作为上层海洋硅酸盐的潜在来源。本研究结合文献数据计算得到楚科奇海陆架沉积物-水界面硅酸盐年通量为630.78 mmol·m^-2·a^-1,总量为3.75×10¹¹ mol·a^-1,是太平洋入流水所携带硅酸盐年通量的一半(6.59×10¹¹ mol·a^-1),表明沉积物孔隙水也是楚科奇海陆架硅酸盐的重要来源。     

河流-河口-近海连续体碳循环研究进展

河流-河口-近海连续体(简称连续体)是连接陆地和大洋的过渡地带,也是目前全球碳收支估算的薄弱环节.这个复杂的海陆交互生态系统不仅可以通过光合作用、溶解作用吸收大气中的CO2,陆地和流域光合作用或化学风化作用固定的碳也可以被横向输送到陆架和大洋中.本文以国际上著名的切萨皮克湾以及长江-长江口-东海等为例,综述了连续体碳循...     

南海水柱微体生物壳体中氨基酸、氨基糖与糖类物质的检出及意义

对１９９４－１９９５年南海中部时间系列沉积物捕获器收集的微体生物壳体进行了氨基酸与糖类分析,结果表明,微体生物壳体中含有的氨基酸与糖类物质大致与颗粒物全样相当,其氨基酸与糖类组成基本保持了活体浮游生物的特征,而与颗粒物全样的有所不同,推测氨基酸与糖类物质一是作为壳体本身的组成部分存在于壳体中,二是被包裹在有孔虫房室及放射虫、硅藻壳体纹饰或筛孔中,因而可以很好保存,上述结果表明生物南体本身也是有机质从海洋表层向下输送的良好载体,而且生物体内氨基酸与糖类组成的原生信息可以很好地保存于壳体内,这对于利用壳体中的生物标志物来追索原生的有机物来源,演化及其它环境矍有重要意义。     

Jupiter: Aerosol Chemistry in the Polar Atmosphere

Aromatic compounds have been considered a likely candidate for enhanced aerosol formation in the polar region of Jupiter. We develop a new chemical model for aromatic compounds in the Jovian auroral thermosphere/ionosphere. The model is based on a previous model for hydrocarbon chemistry in the Jovian atmosphere and is constrained by observations from Voyager, Galileo, and the Infrared Space Observatory. Precipitation of energetic electrons provides the major energy source for the production of benzene and other heavier aromatic hydrocarbons. The maximum mixing ratio of benzene in the polar model is 2x10-9, a value that can be compared with the observed value of 2+2-1x10-9 in the north polar auroral region. Sufficient quantities of the higher ring species are produced so that their saturated vapor pressures are exceeded. Condensation of these molecules is expected to lead to aerosol formation.     

Toxicity identification evaluation (TIE) of pore water of contaminated marine sediments collected from Hong Kong waters

Marine sediment can function both as a source and as a sink of marine chemical contaminants. The toxicity of contaminated marine sediment can be assessed by toxic evaluation of its pore water, the inter-particle water of sediment, because toxicants in the pore water may be bioavailable to marine organisms. In this study, the toxicity identification evaluation (TIE) was performed to identify the major toxicants in the pore water of marine sediment collected in Hong Kong waters. In Phase 1 TIE, the suspected toxicants were characterized as anions or organic compounds that are either oxidizable or filterable in alkaline medium. In Phase 2 TIE, the suspected toxicants were identified as sulfide (S²⁻) based on the reduction of toxicity due to lowering of sulfide concentrations by experimental manipulations. The mass balance and spiking analyses in Phase 3 confirmed that S²⁻ was one of the major toxicants and that some non-toxic unknown compounds measured by LC–MS, which was removed by C18 solid phase extraction, enhanced the toxicity of S²⁻ in the pore water samples.     

2012年楚科奇海及其邻近海域浮游植物现存量和初级生产力粒级结构研究

通过2012年夏季第五次北极科学考察期间在楚科奇海及其邻近海域现场调查所获得的数据分析研究了海域的粒度分级叶绿素a浓度和初级生产力。结果表明,叶绿素a浓度和初级生产力的高值均出现在楚科奇海陆架区,并且远高于深海区。去程时调查海域水层平均叶绿素a浓度的变化范围为0.32~15.66mg/m3,平均(2.77±3.96)mg/m3,高值区出现在南部邻近白令海峡海域、北部阿拉斯加巴罗近岸和冰缘区;初级生产力的范围为50.11~943.28mg/(m2d),高值出现在冰缘水华区。返程时水层平均叶绿素a浓度的变化范围为0.07~1.52mg/m3,平均(0.41±0.40)mg/m3,高值仍出现在陆架区,但比去程时低了一个数量级;初级生产力的分布范围为12.31~41.35mg/(m2d),高值出现在陆架区。浮游植物粒度分级测定结果表明,在生物量较低的深海区,叶绿素a浓度和初级生产力的粒级结构以微微型浮游生物(Pico级份)占优势(其贡献率分别为46.1%和56.9%),小型(Net级份)和微型(Nano级份)对总叶绿素a浓度的贡献差异极小,分别为26.6%和27.3%,对总初级生产力的贡献分别为23.8%和19.3%;而在生物量较高的水深小于200m的陆架区,Net级份叶绿素a浓度所占百分比最高,Pico级份次之,Nano级份最低,分别为59.8%、27.9%和12.3%,初级生产力的粒级结构中叶绿素a浓度所占百分比由高到低同样是Net、Pico和Nano,所占百分比分别为60.6%,32.2%和7.2%。     

2017年春季长江口-东海连续体pCO2的空间分布特征及其控制因素

厘清河口-陆架连续体的碳源/汇机制是认识海洋在"碳中和"中作用的重要基础.本研究基于2017年春季长江口-东海的走航CO2分压(pCO2)及温、盐等资料,分区域阐述春季长江口-东海连续体pCO2的空间分布格局,半定量解析水团分配、有机质生产及降解等过程对pCO2的控制作用.结果表明:水团来源是决定春季长江口-东海连续体...     

Removal and biodegradation of nonylphenol by different Chlorella species

All four Chlorella species, including one commercially available species, Chlorella vulgaris and three local isolates, Chlorella sp. (1 uoai), Chlorella sp. (2f5aia) and Chlorellaminiata (WW1), had a rapid and high ability to remove nonylphenol (NP). Among these species, C. vulgaris had the highest NP removal (nearly all NP was removed from the medium) and degradation abilities (more than 80% of NP was degraded) after 168 h, followed by WW1 and 1 uoai; 2f5aia had the lowest NP degradation ability. The NP removal by C. vulgaris was less affected by growth conditions, but its biodegradation efficiency was significantly increased by temperature and light intensity, suggesting that the biodegradation ability was positively related to photosynthetic and metabolic activities. These results indicated that C. vulgaris was the most suitable species for effective removal and biodegradation of NP, especially under 25 °C with light illumination and initial biomass between 0.5 and 1.0 mg chlorophyll l(-1).