发酵与焙烤对可可豆香气影响的GC-MS分析

采用顶空固相微萃取（HS-SPME）和气-质联用仪（GC-MS）分析未发酵豆、发酵豆和焙烤豆的香气成分,并采用主成分分析法对可可豆香气的影响进行分析。结果表明：未发酵豆、发酵豆和焙烤豆香气差异明显。从未发酵豆和发酵豆中分别鉴定出30和62种挥发性成分,主要为醇类、酮类、烯烃类和醛类,发酵后可可豆香气物质增多。在105、125、145 ℃下焙烤的未发酵豆和发酵豆分别鉴定出47、59、84和71、68、83种,主要为醇类、酯类、醛类、烯烃和吡嗪类,低温焙烤和高温焙烤的可可豆香气差异明显;酮类集中于未发酵低温焙烤区,酸类、酯类和醇类偏向于发酵低温焙烤区,呋喃类和吡嗪类等杂环类化合物指向高温焙烤区。这些香气成分的差异,形成不同处理可可豆之间的风味差异,可可豆香气成分的主成分分析可以作为可可豆不同处理潜在的评价方法。     

三峡工程运行后长江中游溶解气体过饱和演变研究

为了分析三峡工程运行后泄洪对长江中游溶解气体过饱和的影响,本文建立了长江中游溶解氧数学模型,对不同流量下长江中游的溶解氧过饱和演变进行了模拟预测。模拟结果表明,三峡和葛洲坝过坝水流的溶解氧饱和度在40000m3/s～50000m3/s和100000m3/s附近存在两个峰值,长江中游河道天然情况下溶解氧过饱和恢复速度较为缓慢,平均每100km降低5%,洞庭湖水的汇入能显著降低长江干流的溶解氧过饱和度。当三峡出库流量超过40000 m3/s时,其影响范围可达400km以上。本文讨论了溶解气体过饱和的不同指标间的关系,对气体过饱和可能造成的影响以及对长江中游鱼类目前的影响进行了阐述,认为通过三峡水库的调度减小出库高流量次数和历时是减缓下游溶解气体过饱和的有效手段。     

中缅油气管道国内段砂土液化处理措施

中缅油气管道国内段沿线存在不连续的长距离砂土液化地带,砂土液化是地下管道遭受地震破坏的主要原因之一.为增强管道抵抗土壤液化的能力,通过对砂土液化现象及其危害进行分析,结合油气管道沿线砂土液化特点,对管道敷设深度内有中等、严重砂土液化趋势的地段采取平衡压袋稳管方式进行液化处理.该处理措施具有经济、环保、便于施工、不影响管道主体工程安装和总体工期等特点,而且对于避免和减轻地震灾害,确保油气管道的安全运行具有重要意义,在类似管道工程建设中值得推广应用.(表2,图3,参4)     

加热炉管外积灰及减少积灰的措施

分析了输油管道直接式加热炉炉管积灰的形成、灰垢的种类和成分。认为灰垢就是燃料油燃烧后残留下来的不可燃部分Ｎａ、Ｋ、Ｖ、Ｍｇ等金属固体盐类和其它杂质，以及碳元素在燃烧不完全的情况下残留下的可燃组分的微粒。指出燃料灰分含量的高低、燃烧器雾化质量好坏、燃烧空气温度的高低及操作人员的技术水平的高低都是影响灰垢生成量的主要因素。分析了辐射室炉管外壁和对流炉管外壁的积灰规律。指出管外积灰增加了热阻，影响传热效     

Enhancement of photosynthesis and growth of tomato seedlings by forced ventilation within the canopy

A forced ventilation system that directs airflow upward or downward within a canopy was developed for plant culture in order to enhance photosynthesis and growth of the plant canopy. Tomato seedling canopies including the seedlings, growing medium, and a plastic tray were used for the experiments. In the upward and downward ventilation systems, air flows upward and downward, respectively, within the plant canopy; this is achieved by blowing and drawing air from holes (Ø 6 mm) made in plastic pipes positioned on the surface of the growing medium. A horizontal airflow system was used as a conventional system to compare the performance of the experimental ventilation systems. Using the upward and downward ventilation systems, the effects of air directions and air velocities on the CO₂ exchange rate of the tomato seedling canopy and the growth of the seedlings were compared with those observed using the conventional horizontal airflow system. The forced ventilation within the plant canopy enhanced the CO₂ exchange rate of the canopy and the dry masses of the seedlings by 1.4–1.5 and 1.2–1.3 times, respectively, as compared to the conventional horizontal airflow. When the leaf area index (LAI) increased from 1.2 to 2.4, there was only a 5% decrease in the CO₂ exchange rate per unit leaf area in the downward ventilation system, whereas there was a 20% decrease in the CO₂ exchange rate per leaf area in the horizontal airflow system. The coefficient of variation for the dry mass of the seedlings was higher in the downward system than in the other systems. These results demonstrate that forced ventilation within the canopy is an effective technique to enhance the gas exchange of the plant canopy and the consequent plant growth.     

Drought responses of six ornamental herbaceous perennials

Although low water use landscaping is becoming common in arid regions, little is known about drought tolerance and drought responses of many ornamental plants, especially herbaceous perennials. Drought responses were assessed for six herbaceous ornamental landscape perennials in a 38 l pot-in-pot system in northern Utah over a 2-year period. The first year was an establishment period. During the second year, drought responses were evaluated for established Echinacea purpurea (L.) Moench, Gaillardia aristata Pursh, Lavandula angustifolia P. Mill., Leucanthemum × superbum (J.W. Ingram) Berg. ex Kent, ‘Alaska’, Penstemon barbatus Roth var. praecox nanus rondo, and Penstemon × mexicali Mitch. ‘Red Rocks’. Plants were irrigated at frequencies of 1 (control), 2, or 4 weeks between June and September, simulating well-watered conditions, moderate drought, or severe drought. Osmotic potential (Ψ_s), gas exchange, visual quality, leaf area, and dry weight were assessed. In a confined root zone, P. barbatus showed the greatest tolerance to all levels of drought, avoiding desiccation by increasing root:shoot ratio and decreasing stomatal conductance as water became limiting. L. angustifolia and P. × mexicali showed tolerance to moderate drought conditions, but died after exposure to the first episode of severe drought. Neither G. aristata nor L. superbum were able to regulate shoot water loss effectively. Instead, both species displayed drought avoidance mechanisms, dying back when water was limiting and showing new growth after they were watered. Compared to control plants, G. aristata shoot dry weight was reduced by 50% and 84%, and L. superbum shoot dry weight was reduced by 47% and 99% for the 2- and 4-week irrigation intervals, respectively. Root dry weights were affected similarly for both species. E. purpurea exhibited poor visual quality at all irrigation intervals, in particular wilting severely in both drought treatments, but regaining turgor when watered again. P. barbatus is recommended for ornamental landscapes that receive little or no supplemental irrigation, while E. purpurea is not recommended for low water landscapes because of low visual quality under even mild drought.     

Sap flow in papaya plants: Laboratory calibrations and relationships with gas exchanges under field conditions

In papaya plants a study to quantify the water flow through the trunk is important for to promote a good water management in commercial orchard. The objective was to study the relationship between water flow through the trunk and temperature measurements determined by probes inserted in the papaya plant stem in laboratory. In addition, was possible to study the relationship between sap flow and instantaneous gas exchange in field conditions. We constructed an instrument that maintained a stable water flux through a 0.30 m stem section with a constant pressure, simulating the xylem sap flow through the stem. Water flux was adjusted by varying pressure of water in the stem section. The mathematical model used to fit the relation between K (Granier heat coefficient) values and sap flow density was the exponential model: u = 0.5511 × K^1.9104. Field studies was conducted in a commercial orchard located in North of the State of Rio de Janeiro, with 12 plants in October 2002, and eight plants in January 2003. We verified that instantaneous transpiration, measured by a portable system of gas exchange (porometry), presented a good (R² = 0.75) positive relationship with xylem sap flow. Estimates of papaya sap flow can be obtained by scaling portable photosynthesis system measurements with exposed leaves, however the relationship is non-linear in higher instantaneous transpiration rates. The causes of the non-linear relationship in higher transpiration are discussed. In addition, was possible to obtain a good (R² = 0.76) relationship between net photosynthesis rate and xylem sap flow in papaya field-grown.     

气相色谱-电子捕获检测器测定电子废弃物处理场地底泥中的四溴双酚-A

通过优化分析仪器的条件设置，建立了使用气相色谱-电子捕获检测器技术分析四溴双酚-A（TBBP—A）的仪器分析方法。样品采用正己烷索氏提取、硅胶柱分离纯化、外标法定量，结果表明，测定方法在测量范围内具有良好的线性关系，测定的平均回收率为86．8％，检出限为5．0ng／ml，相对标准偏差为3．26％～8．77％：     

现代物业小区车辆智能化综合管理系统

给出了一种现代物业小区车辆智能化综合管理系统，由物业管理中心的中央计算机和下层的各个小区服务器构成多级控制的网络化管理系统，怪实现进出车辆的登记识别、计时计费、等多种功能，并提出了一种能有效识别车辆特征的方法。     

年产3万m^3中密度纤维板生产线气力输送系统的设计

通过对年产3万m~3中密度纤维板生产线铺装成型工段气力输送系统的设计,以及在设计中注意管网平衡计算、合理选择系统的技术参数及输送装置,实现干纤维的回收及输送,保证中密度纤维板生产线的正常生产.