用于太阳视频矢量磁象仪和视频多普勒仪的双折射滤光器的新双带方案

本文分析了用于太阳视频矢量磁象仪和视频多普勒仪的Ramsey双带方案的优缺点,提出了新的双带方案:将滤光器中次厚级放在最前部,以代替原Ramsey方案中最厚级放于最前部的结构。详细计算表明,新双带方案优于传统的单带方案,传统的单带方案优于Ramsey双带方案。在相同磁场条件下,它们的总体信噪比是0.963:～0.800:0.578。新方案可能对新的空间视频矢量磁象仪和新建的地面系统有重要价值,也可按此改进已有的地基视频矢量磁象仪系统。     

德意志联邦共和国的非城市化

非城市化的定义我们认为首先需要详细讨论非城市化的定义。贝里(Berry)提出一种相当确切的标准。他说:“1942年霍普·蒂斯代尔(Hope·Tisdale)曾经说过‘城市化人口集中的过程’。‘这种过程是人口较少集中向人口较大集中的运动’。……由此可见,从实质上说,非城市化过程是人口居住区缩小、人口密度减少和居住区的复杂性向单一性转化的过程。     

Stramonita haemastoma as a bioindicator for organotin contamination in coastal environments

Stramonita haemastoma was investigated as a suitable bioindicator of TBT and TPhT contamination in the tropical Atlantic Ocean by: 1. Imposex induction in healthy females after inoculation with TBT and TPhT in the laboratory; and 2. Determining incidence of imposex in S. haemastoma collected from areas with various levels of tributyltin (TBT) and triphenyltin (TPhT) and determining the concentrations of these chemical in its tissues and that of its prey, the mussell Perna pernas. Imposex intensities and organotin concentrations in tissues showed good correlation, indicating S. haemastoma as a reliable bioindicator of TBT and TPhT contamination in coastal waters. Body burden threshold of TBT and TPhT for imposex induction was estimated to be 10-20 ng g(-1).     

Mushroom production as an alternative for rural development in a forested mountainous area

Wild mushrooms are recognized as important non-wood forest products in mountainous ecosystems, but their real potential for generating rural economies has not been fully evaluated due to the difficulties in obtaining reliable productivity data, minimizing their true potential as contributor to rural economies. Mushroom yield models based on large data series from Pinus forest ecosystems in the region of Catalonia(Spain), combined with data from the Spanish National Forest Inventory allow us to estimate the potential mushroom productivity by forest ecosystems. The results of 24,500 tons/yr of mushrooms of which 16,300 tons are classified as edible and 7,900 tons are commonly marketed demonstrate the importance of mushroom productions in Catalonian pine forests, mostly located in mountainous areas where the development of agricultural activities is limited. Economic mushroom value is estimated at 48 million € for the edible mushroom and 32 million € for those corresponding to marketable yields, confirming the potential of this non-wood forest product. These production results and corresponding economic values provide a basis for the incorporation of wild mushrooms as significant non-wood forest products in the development of forest policies in mountainous areas.     

广西北部湾土壤地球化学基准值与背景值特征

文章统计了广西北部湾地区深层土壤地球化学基准值与表层土壤背景值,并且对表深层土壤元素含量特征进行对比研究。结果显示,大部分表层土壤元素对深层土壤有一定的继承性,少部分元素如Cd、N、P、Cl、S、有机碳等受表生迁移活动和人为活动因素影响又与深层土壤有所差异。     

Dissolved oxygen as an indicator of bioavailable dissolved organic carbon in groundwater

Concentrations of dissolved oxygen (DO) plotted vs. dissolved organic carbon (DOC) in groundwater samples taken from a coastal plain aquifer of South Carolina (SC) showed a statistically significant hyperbolic relationship. In contrast, DO-DOC plots of groundwater samples taken from the eastern San Joaquin Valley of California (CA) showed a random scatter. It was hypothesized that differences in the bioavailability of naturally occurring DOC might contribute to these observations. This hypothesis was examined by comparing nine different biochemical indicators of DOC bioavailability in groundwater sampled from these two systems. Concentrations of DOC, total hydrolysable neutral sugars (THNS), total hydrolysable amino acids (THAA), mole% glycine of THAA, initial bacterial cell counts, bacterial growth rates, and carbon dioxide production/consumption were greater in SC samples relative to CA samples. In contrast, the mole% glucose of THNS and the aromaticity (SUVA(254)) of DOC was greater in CA samples. Each of these indicator parameters were observed to change with depth in the SC system in a manner consistent with active biodegradation. These results are uniformly consistent with the hypothesis that the bioavailability of DOC is greater in SC relative to CA groundwater samples. This, in turn, suggests that the presence/absence of a hyperbolic DO-DOC relationship may be a qualitative indicator of relative DOC bioavailability in groundwater systems.     

红外相机CASCAM光学设计

介绍紫金山天文台研制的光学-近红外相机CASCAM（Chinese Academy of Science，CAMera)的光学系统设计．CASCAM相机以红外列阵HAWAII-1和光学CCD为探测器，配备国家天文台兴隆观测站2．16米和1．26米望远镜进行0．4—2．5μm波长范围的成像和偏振成像观测．相机的光学系统由F／9→F／6缩焦系统和Offner反射成像系统构成．优化设计结果表明，光学设计方案已满足天文观测的要求．CASCAM相机在设计上实现了光学-近红外很宽波段的消色差变焦，并在楔形分柬片、常温滤光片轮和折射式焦面摆动技术等方面进行了新的尝试．     

欧亚冰盖的消融

巴巴多斯和新几内亚的海平面变化表明：在过去的15000a中曾有过两次大规模的冰川融水流．同其它环境变化(如北大西洋深水环流)相比，这两次融水流形成的时间显然有助于我们进一步了解从未次冰期到问冰期的气候变迁及新仙女木事件．     

乙醇生产将导致2008年粮食价格继续升高

我们正在经历人类历史上巨大灾难。美国降低对石油的依赖度转而用粮食提炼原料用于汽车燃油的错误决策,已经引起了前所未有的全球范围粮食危机。