EFFECTS OF Mg~(2+), NaCl, CITRIC ACID, AND OTHER FACTORS ON SYNTHESIS AND ACCUMULATION OF β-CAROTENE IN DUNALIELLA SALINA

Therearemorethan4Ookindsofcarotenoids,aboutl(X)ofwhichcanbeObtainedfromoceanicmicrobesandalgae,sooceanicalgaeareconsideredthemostimPOrtanre-sourceofnaturalcarotenoids(Becker,l982).DunaliellaSalinahasdrawnnmehattentionfromanuInberofcountriesrecently,asmoreandmorestudiesshowedthatthisunicellularalgacanaccumulatelargeamountsof5-caroteneundercertainenvironmentalconditions(Li,1988).SuInInallzingthebiosyntheticmechanismof3-carotene,weknowthatacetylCoAandCO2arethehasicInaerialsfOrSYthesizing3-…     

沙地渗灌系统的自动监测与控制

通过沙地渗灌系统的应用实践以及与沟灌、漫灌进行的比较研究,着重介绍了其对水分实行自动监测与控制的功能;分析了其可向植物根群区直接供给水分和养分,减少水分蒸发,保持沙地良好水分状态的优越性。     

基于三旋转自由度激光经纬仪的结构光工程测量原理与应用

围绕具有三旋转自由度的激光经纬仪,阐述它在封闭构筑物测量中应用的优越性,提出结构光工程测量中各种扫描关系式的解算式,并用实例证明所述理论的正确性与高效率。     

基于地理信息系统的太阳直接辐射与冰川物质平衡的关系

基于冰川微地形对冰川物质平衡重要影响的认识,在考虑朝向、坡度、地形遮蔽等因素的条件下,以地理信息系统为手段,对乌鲁木齐河源１号冰川冰面太阳可能直接辐射进行了理论计算．在此基础上,建立了计算冰面任意一点物质平衡的Ｂ＝ｆ（Ｔ,Ｒ）（气温－辐射）模型．比较了该模型与Ｂ＝ｆ（Ｔ）（气温）模型、Ｂ＝ｆ（Ｐ,Ｔ）（降水－气温）模型及Ｂ＝ｆ（Ｑ）（能量平衡）模型之间的优缺点,表明该模型具有物理意义明确、计算精度较高、参数易于获得等优点,从而为计算冰川物质平衡提供了新的途径．     

FDY—9601微机测氡仪

本文介绍了由核工业北京地质研究院仪器研究中心研制的FDY－9601微机测氡仪。它是一种借助于经过加压极化处理过的聚酯薄膜片收集氡衰变产生的子体218Po（RaA）,并测量其放出的α射线强度的微机测氡仪。     

On Palaeozoic Tectonics in the Alxa Region, Inner Mongolia, China

Two ophiolitic melange belts in the Late Carboniferous formations have been discovered recently in the Alxa region. One is in the Engger Us fault and possesses properties of oceanic crust. The other is in the Badain Jaran fault and shows properties of a back-arc basin. These two faults, together with the Yagan fault, constitute the important boundaries of tectonic units in the Alax region. The four tectonic units delimited by these faults are different in rock assemblages, metamorphism and geochemistry. They reflect the nature of tectonic environments in which they are found. The tectonic units may be traced and correlated to the eastern and western neighbouring areas. The formation and evolution process of the units and their interaction in the Alxa region may be described in terms of the evolution of the Palaeo-Mongolian Ocean and its continental margins.     

Magmatic Network Structure of Volcanic Rocks in the Shengli Oilfield, Eastern China

Types of polymerized molecular network structure and degree of bond breakdown for glass phases of magmatic inclusions and glassy matrix in volcanic rocks from the Shengli oilfield have been defined by the laser Raman spectroscopic investigation. There are significant differences in types of polymerized molecular network structure and degree of bond 'breakdown of the magmatic glass phases between the non-CO2 and COa gas pools: magmatic glass phases of fluid inclusions and matrix in volcanic rocks from the CO2 gas pool contain more sheet network molecules and have a greater degree of bond beakdown than those from the non-CO2 gas pool; and when gas bubbles occur in evolving magma, magma saturated with volatile components has more sheet network molecules. The results suggest the magma-degassing mechanism of the formation of CO2 gas pools in the Shengli oilfield.     

A homogeneous model of the Deacon cell in a circumpolar ocean

Dynamics of the three-dimensional structure of the wind-driven Deacon cell in a β-plane channel are discussed in a homogeneous model in the presence of a sufficiently high ridge. The emphasis is on the water mass balance: how the northward surface Ekman drift is returned. It is demonstrated that a sufficiently high ridge can break up the geostrophic constraint and a net geostrophic volume flux across the open latitude band is allowed. It is found that: (1) the Deacon cell is a fundamentally three-dimensional structure, (2) wind forcing can drive an inter-basin water mass exchange in the Southern Ocean, and (3) zonal through-channel transport in the circumpolar ocean varies at different longitudes.     

小麦出苗至抽穗期土壤湿度预报及喷灌量计算

以黑龙江省８５０农场的资料进行分析,５至６月份小麦出苗、拔节至抽穗阶段,经常出现干旱,是需水关键期,对产量影响极大。所以利用麦田土壤湿度资料,建立经验公式,对土壤墒情进行预测预报,从而获得最佳喷灌时间及喷灌量,为节约用水、计划用水提供了可靠依据。     

甘肃中部雨养农业区土壤水分预测模式的研究

采用联合国粮农组织（ＦＡＯ）最新推荐的计算农田蒸散量的彭曼－蒙蒂斯公式（ＦＡＯ－ＰＭ）,选取甘肃中部雨养农业区定西１９８０～１９９５年的常规气象资料和１９９０～１９９５年固定地段０～１００ｃｍ的土壤湿度资料,对水平衡和Ｙ．Ｍ安格斯坦土壤水分预测模式进行对比分析,认为后者适宜于本地区的土壤水分预测,并分析了误差原因