基于O2/Ar比值估算海洋混合层群落净生产力的研究进展

群落净生产力(NCP)是海洋混合层中光合作用和群落呼吸作用的差值,代表了从表层海水向深层海洋输送的最大有机质量,是衡量生物活动对上层海洋碳循环影响的有效指标。海洋混合层的溶解氧浓度主要受物理过程和生物过程控制,而惰性气体氩(Ar)的分布主要受物理过程以及温度和盐度对溶解度的影响,由于O2和Ar具有相似的物理特性,因此氧氩比值(O2/Ar)消除了物理过程对海水中溶解氧的影响,其偏离平衡值的量(ΔO 2/Ar)可表征生物过饱和氧,并可据此估算群落净生产力。随着质谱技术的发展,连续走航测定O2/Ar比值技术得到广泛应用并可以获得高时空分辨率NCP分布,因此成为估算海洋混合层NCP的重要方法。本文介绍了基于O2/Ar比值法估算群落净生产力的原理,综述了用O2/Ar比值法估算海洋混合层中群落净生产力的研究进展,探讨了估算模型中存在的不足及解决办法,并对其未来发展方向做了展望。     

多功能变工况热泵干燥装置的设计分析

设计了可同时实现开式、闭式和半开式干燥介质循环,可在干燥过程中转换工艺、调节工况的热泵干燥装置,以热泵工质R134a为例进行了1匹热泵干燥装置的设计计算,就同一装置在变工况下的性能进行理论分析。结果表明,蒸发温度的提高可有效提高装置的性能及除湿能耗比,冷凝温度的降低可使装置的COP值升高,除湿能耗比下降。     

地源热泵土壤源换热器的施工技术

地源热泵（Ground Source Heat Pump，GSHP）作为最有发展潜力的热泵技术在各级政府的积极推窑下发壁迅速，但由于地源换热器施工安装成本高，技术的发展遇到了很大的阻力。探讨了土壤源换热器施工技术和土壤源换热器的热平衡问题，力图提高土源换热器施工技术，降低地源热泵成本，促进该技术的推广应用。     

Seasonal variations in pCO2 and its controlling factors in surface seawater of the northern East China Sea

Surface partial pressure of CO₂ (pCO₂), temperature, salinity, nutrients, and chlorophyll a were measured in the East China Sea (ECS; 31°30′–34°00′N to 124°00′–127°30′E) in August 2003 (summer), May 2004 (spring), October 2004 (early fall), and November 2005 (fall). The warm and saline Tsushima Warm Current was observed in the eastern part of the survey area during four cruises, and relatively low salinity waters due to outflow from the Changjiang (Yangtze River) were observed over the western part of the survey area. Surface pCO₂ ranged from 236 to 445 μatm in spring and summer, and from 326 to 517 μatm in fall. Large pCO₂ (values >400 μatm) occurred in the western part of the study area in spring and fall, and in the eastern part in summer. A positive linear correlation existed between surface pCO₂ and temperature in the eastern part of the study area, where the Tsushima Warm Current dominates; this correlation suggests that temperature is the major factor controlling surface pCO₂ distribution in that area. In the western part of the study area, however, the main controlling factor is different and seasonally complex. There is large transport in this region of Changjiang Diluted Water in summer, causing low salinity and low pCO₂ values. The relationship between surface pCO₂ and water stability suggests that the amount of mixing and/or upwelling of CO₂-rich water might be the important process controlling surface pCO₂ levels during spring and fall in this shallow region. Sea–air CO₂ flux, based on the application of a Wanninkhof [1992. Relationship between wind speed and gas exchange over the ocean. Journal of Geophysical Research 97, 7373–7382] formula for gas transfer velocity and a set of monthly averaged satellite wind data, were −5.04±1.59, −2.52±1.81, 1.71±2.87, and 0.39±0.18 mmol m⁻² d⁻¹ in spring, summer, early fall, and fall, respectively, in the northern ECS. The ocean in this study area is therefore a carbon sink in spring and summer, but a weak source or in equilibrium with the atmosphere in fall. If the winter flux value is assumed to have been the mean of autumnal and vernal values, then the northern ECS absorbs about 0.013 Pg C annually. That result suggests that the northern ECS is a net sink for atmospheric CO₂, a result consistent with previous studies.     

立式泵固有频率分析及隔振结构研究

本文应用自行开发的计算机程序,计算了几种立式泵的六个自由度的固有频率,数值计算的结果显示了立式泵的高度及其安装尺寸的变化与其固有频率之间的关系,并分析了不同安装尺寸的隔振效率。最后,为满足立式泵的隔振要求提出了新型的泵体机座设计。     

Nozzle Optimization for Water Jet Propulsion with A Positive Displacement Pump

In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.     

Myctophid feeding ecology and carbon transport along the northern Mid-Atlantic Ridge

Myctophids are among the most abundant fishes in the world׳s ocean and occupy a key position in marine pelagic food webs. Through their significant diel vertical migrations and metabolism they also have the potential to be a significant contributor to carbon export. We investigated the feeding ecology and contribution to organic carbon export by three myctophid species, Benthosema glaciale, Protomyctophum arcticum, and Hygophum hygomii, from a structurally and ecologically unique ecosystem- the Mid-Atlantic Ridge (MAR). Similar to the results of previous studies, the diet of these fishes was primarily copepods and euphausiids, however, gelatinous zooplankton was identified in the diet of B. glaciale for the first time. Ridge section and time of day were significant explanatory variables in the diet of B. glaciale as determined by canonical correspondence analysis, while depth was the only significant explanatory variable in the diet of P. arcticum. Daily consumption by MAR myctophids was less than 1% of dry body weight per day and resulted in the removal of less than 1% of zooplankton biomass daily. Although lower than previous estimates of carbon transport by myctophids and zooplankton in other areas, MAR myctophid active transport by diel vertical migration was equivalent to up to 8% of sinking particulate organic carbon in the North Atlantic. While highly abundant, myctophids do not impart significant predation pressure on MAR zooplankton, and play a modest role in the active transport of carbon from surface waters.     

山东省鲁北地区浅层地热能资源评价

鲁北地区于2001年已陆续开始应用热泵技术开发浅层地热能,但区内的浅层地热能资源评价工作却严重滞后,制约了区内浅层地热能资源的开发和合理利用。为促进鲁北地区浅层地热能的开发利用,省政府拿出专项资金,开展了鲁北地区浅层地热能的资源评价工作,前期在调查区域内开发利用现状和摸清地质条件的基础上,采用层次分析法,分别对地下水换热方式和地埋管换热方式进行了开发利用适宜性分区,采用热储体积法对该区的浅层地热容量进行了计算,得出鲁北地区浅层地热容量为29.386×1015kJ/℃;并根据适宜性分区结果,分别对地下水式和地埋管式地源热泵适宜区、较适宜区可利用换热量也进行了计算,得出地下水式地源热泵200m以浅可利用换热量为0.848 9×1010kW·h,地埋管式地源热泵200m以浅可利用换热量为6.526 1×1012kW·h。     

Evaluation of suitability area by ground source heat pump system in Baotou plain

According to the elements of hydrogeological conditions, lithology, stratigraphic thermal physical pa- rameters, construction technology and economic rational elements, the evaluation system of ground source heat pump （GSHP） were established in Baotou plain. The factor weights were determined by using analytic hierarchy process, and the comprehensive element method was selected to evaluate the region suitability of GSHP system. The results show that the suitable area is 559.63 km^2 for utilizing GSHP in the studied area, accounting for 62.58% of the total area; while the unsuitable area is 334.60 km2, accounting for 37.42%. The evaluating results can provide not only a scientific basis for development and utilization rationally of shallow geothermal heat in Baotou, but also offer an important reference to the other areas.     

Short and medium term dynamics of the carbon exchange between the Baltic Sea and the North Sea

A detailed analysis of the short and medium term dynamics of the carbon exchange between the Baltic Sea and the North Sea is presented. To quantify the carbon fluxes distinguishing the Baltic and North Sea water masses, the salinity-based End Members (EM) method was successfully applied. The results of 0.63±0.25×10¹² mol C year⁻¹ identify the Baltic Sea as a net source of carbon for the North Sea. Dissolved organic carbon (DOC) was found to contribute significantly (22%) to the bulk of exported carbon. The levels determined suggest the hydrology-dependence of the carbon fluxes in the Danish Straits, which stimulates the high variability of carbon fluxes at both interseasonal and interannual scales.