脊波导激励腔的实验研究

在理论和实验的基础上 ,对近截止脊波导微波谐振腔进行了分析和设计 ,通过合理选择脊波导的截面尺寸和腔端结构 ,可以实现场的单模传输和场沿纵向的均匀分布 ,并在不同的工作气体气压下 ,给出了放电实验结果     

EFFECT OF ANTHROPOGENIC CO_2 ON THE pH AND THE SATURATION STATES OF CALCITE AND ARAGONITE OF SEAWATER

unODUcrIONIntereStinthecarboncycehasinamsedbouseoftheobservedincreaseinatmosphericCO,leveIsduetothebumingoffossilfuelandthedearingofforestsre-sultinginlargedhaticandbiogeochdrica1consequenas(ChenandDrake,l986).Experi-mentalstudisofp1antShaveshownresponsesoftypically2O%-4O%highergroWthunderdoubledCo,conditions.Ontheotherhand,theeffedofelevatalCO=conditionsinincreasinggroWth,knownastheCO,fertilimtioneffed,isnotbe1ievedtobetwortantintheoasns(Schimeletal.,1995).Althoughithasbeensuggestedt…     

FLUXES OF SEAWATER AND SOME DISSOLVED CHEMICALS IN THE BASHI STRAIT

An Acoustic Doppler Current Profiler (ADCP) was used in Nov. 1990 measure the seawaterfluxes in a southeast-northwest cross-section in the Bashi Strait to a depth of 400 m. Measuredconcentrations of dissolved oxygen (DO), phosphate (PO_4), nitrate (NO_3), silicate (SiO_2), total alkalinity(TA) and calculated total CO_2, (TCO_2) and the current speed were used to estimate the flux densities(concentration times current speed) of seawater and chemicals.The fluxes of nutrients were near zero near surface and increased with depth. For oxygen andcarbonates, the distributions of flux had structures similar to that of the curmt speed field.     

孢粉浓度统计法在西北土类堆积物的应用

本文以宁夏水洞沟全新统剖面为例,运用孢粉浓度统计法对我国西北地区土类堆积物进行了初步研究,并与传统的孢粉百分比统计法所得结果进行了对比。文中,运用电子计算机进行了孢粉资料整理,划分出了七个孢粉组合带,基本上符合我国北方全新世气候变化的一般规律。结果表明,两种方法所反映的古植被、古气候变化趋势基本一致。在孢粉数量丰富的情况下,孢粉浓度统计在图式上表现得更突出和明显;在孢粉数量较少时,用百分比统计法更便于说明问题。     

广西龙胜地区上元古界浅变质岩元素地球化学

元素地球化学研究表明：广西龙胜地区上元古界浅变质含砾砂岩、细砂岩、粉砂岩及大理岩的成矿元素丰度普遍较高，具有显著浓集和后期叠加作用；含砾板岩、板岩、千枚岩及硅质岩的元素丰度较低，没有明显的浓集和后期叠加作用     

长沙市SO_2浓度分布的数值模拟

本文用数值解扩散方程的方法模拟了长沙市SO_2的浓度分布,并比较了两种扩散系数模型的模拟结果,认为作者曾经给出的扩散系数较取扩散系数为粘性系数时为好。最后提出了一种评价、比较模式的方法     

FEEDING OF ACANTHOCYLOPS ROBUSTUS ON ZOOPLANKTON

Feeding of freshwater cyclopoid copepod Acanthocyclops robustus on zooplankton was examined by aseries of feeding experiments during August-September of 1993. Study results showed A. robustus can cap-ture and eat all type items provided from the Staly Haklovsky fishpond, a shallow eutrophic water bodynear Budejovice City, Czech Republic. Selation by the predator was determined largely by prey body-sizeand density, but was also affected by prey types. Variable but significant changes in feeding rates werefound in various size distribution and concentration of prey types. Percentages of small (80-235μm)andlarge (445-6l0μm) prey consumed were 42.47 and 3.85%, respectively.Starvation did not cause statisticallysignificant difference. The feeding on Ceriodaphnia quadrangula showed significant difference between largeand small prey.Feeding rate increased with increasing prey concentration.     

STRATEGY OF MAIZE'S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE

Jilin Province is one of the main grain-producing provinces of China, which has dominant position in maize production, by the view of its advantages in policy, location, breed and market. And after entering WTO,some measures have been taken to enhance maize competitive ability. But there are some difficulties in concentrating production to maize advantaged areas. This paper expounds the basis that Jilin Province becomes the advantage area of maize, analyzes the problems and puts forward the supporting policy. Some strategic measures are proposed,as developing comparable advantages, carrying out the strategy of un-equilibrium development and cultivating advantaged product areas of maize to rapidly improve the international competitive ability and productivity of maize in Jilin Province, cast the agricultural predicament off and promote the agricultural development into a new stage.     

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桐柏县固庙—新集1：20万金银异常评价方法及效果

随着河南区域化探扫面工作的结束，异常评价是摆在我们面前的当务之急。近年来，随着地质工作的不断深入，我们在异常评价程序及方法上作了一些探索，下面以桐柏县固庙—新集１：２０万金银异常评价方法及效果为例，重点加以讨论。     

延边地区火山岩型金矿地球化学及成矿作用研究

延边地区北部大面积出露中生界（Ｊ３）火山岩系，为正常的钙碱性系列，由玄武岩－安山岩－石英安山岩组成，以富含ＡＳ、Ａｇ、Ｓｂ、ＡＳ、Ｂｉ为特征。其中的金矿床可分为两类即蚀变岩型高温热液矿床和浅成中低温热液矿床。同位素资料表明，其成矿热液主要来自火山岩浆。     

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地震前后垂直形变场动态演化的量化指标

提出一种表达垂直形变场动态演化过程的量化指标——区域应变率、应变集中度。在此基础上，对南北地震带各水准监测区近30年的垂直形变资料进行了实际计算．并结合具体震例进行了对比研究。结果表明：量化指标在一定程度上能够反映地震前后形变场的动态演化过程和地壳运动状态，对地震的中长期预报有一定的积极意义。     

成都市冬季重污染日气象条件成因分析及预报

本文通过对成都10个重污染日进行天气学分析,将污染浓度与气象要素进行聚类、研究了重污染日形成原因及污染浓度与气象要素的关系。在此基础上,建立了SO_2、TSP日平均浓度分级预报方程。     

辽宁省主要金矿化集中区特征及今后找矿工作建议

辽宁省位于华北地台北缘，其地质构造演化主要经历了地台基底形成（Ａｒ－Ｐｔ１）、盖层沉积（Ｐｔ２－Ｔ２）、地台活化（Ｔ３以后）三个阶段。按成矿物质来源、成矿环境、成矿作用、矿点矿化点空间分布规律及物化探异常特征，辽宁省可划分出朝阳县小塔子—北票迷力营子、义县红石砬子—刘龙台、葫芦岛市水泉、建昌县温杖子、凌源市柏杖子、阜新县地宫—建设、浑南、浑北、盖县猫岭、辽阳田家围子—凤城弟兄山及丹东市沿江等１２个金的主要矿化集中区。辽宁省今后的地质勘查工作应注意以下几点：（１）要更新找矿观念，注意寻找新类型和大型超大型矿床；（２）按区域成矿条件，选好找矿重点突破区；（３）精确地认识和了解已知矿床，坚持就矿找矿；（４）坚持“五统一”的部署原则，利用地质、地球物理及地球化学方法进行综合找矿。     

Latitudinal distribution of CO2 and CH4 on the route of the Chinese Arctic Research Expedition 2003

1 Introduction From July 10th to September 26, 2003,“Xuelong”scientific expedition icebreaker executed the 2nd Chinese Arctic Research Expedition (CHINARE2003). The voyage star- ted from Shanghai to Dalian via Yellow Sea and Bo Hai and the cruising rout…     

锤击桩基动测的导纳谱研究

本文从集中参数模型入手，讨论了单自由度和多自由度振动系统的导纳谱形式与特征，给出了完整桩与各种缺损桩的导纳振幅谱判断依据及计算处理方法，为导纳谱法在实际中的更好应用提供了理论说明。     

某地区泥盆系铀矿床特征及其成矿规律

文章应用地洼成矿理论和构造地球化学方法，研究了某地区Ｆ１等成矿断裂带的构造地球化学特点和元素的变化规律以及铀不断累增富集成矿的作用过程。在形成泥盆系富铀地层的基础上，经历了后期构造—岩浆活化作用的改造，形成预富矿化场—动力改造热液成矿，形成构造热液型铀矿化—表生淋积，形成叠生富矿段，使之发展成为具有层控、岩控、构控和时控等特点的多因复成型铀矿床，从而为本区进一步找矿指明了方向。     

CO2 concentration and flux near ground in marsh of the Sanjiang plain of Northeast China

There is limited information available on CO₂ concentration and flux over marsh. The objective of this work was to characterize CO₂ concentration and flux within and above marsh plant (Carex lasiocarpa Ehrh. and C. pseudocuraica F. Schm) canopy at heights 0.5, 1.0 and 1.5 m. CO₂ concentration was measured sequentially every 3 hours by using an infrared gas analyzer. Soil and air temperature, wind speed, net radiation and soil heat flux were also measured simultaneously. Extremely daily minimum and maximum CO₂ concentration ranged from 250 to 754 μmd/mol for the 4-year work. The typical minimum and maximum values ranged from 314 to 464 μmol/mol at the height of marsh plant (about 0.5 m) during the fruiting period and mature date. The seasonal changes in CO₂ concentration show that the minimum CO₂ concentration occurred in the fruiting period and mature date, and both of their minimum values were 314 μmol/mol. This illustrates that CO₂ consumed by photosynthesis was stable during the period. The flux of CO₂ can be thought as a turbulent diffusion phenomenon. By micrometeorological methods, the diurnal CO₂ fluxes were measured in the flowering period, fruiting period, early mature date, late mature date and yellow-ripe stage. Their values were −0.18, 38.15,24.13,10.9 and 4.91 μmol/mol respectively.     

水中硫酸盐测定方法研究

对EDTA容量法测定水中硫酸根时，对加入沉淀剂后样品静置时间对测定结果的影响进行了研究。结果表明，在本法规定的浓度范围内，样品静置时间对测定结果无影响。