超高速切削现象的理论分析

运用金属学知识和摩擦磨损原理对超高速切削的干现象作了理论分析,结果表明,切削力较普通切削小的原因是切削力更集中地作用于切削层金属,位错易于运动、剪切变形更昂扬 及前后刀面摩擦阻力减小的结果,切削热和切削温度的固有特性与切削过程的剪切变形和前后刀面的摩擦挤压人艇特点相关;高的表面质量有赖于积梢瘤和鳞刺的消失,但后刀面与加工表面的摩擦挤压引起的隆起残留量的减少也起着重要的作用。     

马面鲀卵巢在不同贮藏温度下磷脂成分的变化

在20℃、4℃、-10℃、-20℃四种温度下贮藏马面鲀卵巢，对其中磷脂含量的变化进行了测定，并利用薄层层析分析测定了不同温度下贮存3d后马面鲀卵巢中磷脂各组分的相对百分比。结果表明：马面鲀卵巢中磷脂的损失率随贮藏温度的上升而增加；在不同温度下贮藏3d，磷脂各组分的相对百分比都发生了变化；随贮藏温度的升高磷脂酰胆碱的降解速度大大加快，所占的百分比快速下降，而溶血磷脂酰胆碱的比例有不同程度的增加。相对而言，-20℃下贮藏数天，磷脂的含量及组分的变化较小。     

浅析发动机冷却系统

一、现代发动机冷却系统的特点 传统冷却系统的作用是可靠地保护发动机,而还应具有改善燃料经济性和降低排放的作用。为此,现代冷却系统要综合考虑下面的因素：发动机内部的摩擦损失;冷却系统水泵的功率;燃烧边界条件,如燃烧室温度、充量密度、充量温度。     

Influence of Seawater Temperature on Phytoplankton Growth in Jiaozhou Bay, China

The phytoplankton reproduction capacity (PRC), as a new concept regarding chlorophyll-a and primary production (PP) is described. PRC is different from PP, carbon assimilation number (CAN) or photosynthetic rate ( P^B ) . PRC quantifies phytoplankton growth with a special consideration of the effect of seawater temperature. Observation data in Jiaozhou Bay, Qingdao, China, collected from May 1991 to February 1994 were used to analyze the horizontal distribution and seasonal variation of the PRC in Jiaozhou Bay in order to determine the characteristics, dynamic cycles and trends of phytoplankton growth in Jiaozhou Bay; and to develop a corresponding dynamic model of seawater temperature vs. PRC. Simulation curves showed that seawater temperature has a dual function of limiting and enhancing PRC. PRC‘s periodicity and fluctuation are similar to those of the seawater temperature. Nutrient silicon in Jiaozhou Bay satisfies phytoplankton growth from June 7 to November 3. When nutrients N, P and Si satisfy the phytoplankton growth and solar irradiation is sufficient, the PRC would reflect the influence of seawater temperature on phytoplankton growth. Moreover, the result quantitatively explains the scenario of one-peak or two-peak phytoplankton reproduction in Jiaozhou Bay, and also quantitatively elucidates the internal mechanism of the one- or two-peak phytoplankton reproduction in the global marine areas.     

卫星红外遥感技术在我国环保领域中的应用与发展分析

本文较为系统地分析了卫星红外遥感技术在我国秸秆焚烧、沙尘、气溶胶、颗粒物、灰霾等大气环境遥感监测,水华、水质参数、水表温度、热污染、核电厂温排水等水环境遥感监测,以及土壤含水量、地表温度、干旱、城市热岛效应等生态环境遥感监测的应用。同时,指出目前国产卫星红外载荷业务化应用程度不高、辐射定标能力不足、应用反演算法原创性不强、地面观测和试验验证能力不足等问题;并提出需大力发展国产红外传感器、提高辐射定标能力、发展国内原创监测算法、建设大型环保应用综合试验场等建议,以促进红外遥感技术在环境保护领域的应用和发展。     

通用劈窗算法的NOAA-18(N)AVHRR/3数据地表温度遥感反演与验证

本文以NOAA-18(N)AVHRR/3数据,运用通用劈窗技术获得地表温度。首先,利用MODTRAN 4模拟不同地表和大气状况下热红外通道(Ch4,10.3~11.3μm和Ch5,11.5~12.5μm)的星上亮温,并建立模拟数据库。其次,按照地表温度、大气可降水汽含量、地表比辐射率和观测天顶角,对模拟数据库分组,确定出各分组的通用劈窗算法系数。然后,将构建的地表温度反演模型应用到NOAA-18(N)AVHRR/3数据,模型所需的地表比辐射率由NDVI阈值法确定,大气可降水汽含量是利用Li等(2003)提出的一种劈窗的协方差与方差比的方法来估算。反演结果表明:在观测天顶角小于30°或者大气可降水汽含量小于3.5 g/cm2时,地表温度反演的均方根误差小于1.0K;在观测天顶角小于45°并且大气可降水汽含量小于5.5g/cm2情况下,均方根误差小于1.5K。最后,利用美国通量站的实测数据对地表温度反演结果进行了验证,结果表明均方根误差小于1.8K。     

Sea surface temperature and salinity reconstruction based on stable isotopes and Mg/Ca of planktonic foraminifera in the western Pacific Warm Pool during the last 155 ka

Changes in sea surface temperature(SST), seawater oxygen isotope(δ 18 O sw), and local salinity proxy(δ 18 O sw-ss) in the past 155 ka were studied using a sediment core(MD06-3052) from the northern edge of the western Pacifi c Warm Pool(WPWP), within the fl ow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ 18 O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO 2 profi le showed a close connection between the WPWP and the Antarctic. Values of δ 18 O sw exhibited very similar variations to those of mean ocean δ 18 O sw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ 18 O sw-ss refl ect a more saline condition during high local summer insolation(SI) periods. Such correspondence between δ 18 O sw-ss and local SI in the WPWP may refl ect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their infl uence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP.     

Characteristics and formation causes of Qingdao Cold Water Mass

In this work,the main characteristics of the Qingdao Cold Water Mass were studied by using“the comparison analysis method”based on 1980 temperature,salinity and dissolved oxygen data on the western South Yellow Sea.The formation cause of the water mass was analyzed based on February of 1959 temperature and salinity data for this area and on some other authors’studies.The results showed that the Qingdao Cold Water Mass has growing and vanishing processes：appears in the last ten days of March;has stable pattern in April;is biggest in its area in May;becomes small in its area in June;vanishes in July.It comes from the northem Shandong Coastal Water and is characterized by low temperature and salinity and high disolved oxygen.The mass is formed under the joint effects of anticyclonic circulation and solar radiation.     

Early development of Chondrus ocellatus Holm （Gigartinaceae, Rhodophyta）

1 INTRODUCTION Red algae C. ocellatus lives in temperate zone of coastal area, and inhabits at substrates from high tide to low tide regions. Its life history is composed of three phases: tetrasporophyte, gametophyte and carposporophyte. Chondrus is one o…