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141.
利用常规观测资料和NCEP逐6 h的1°×1°再分析资料,对2013年12月15—17日江西冬季最强连续暴雨天气过程进行诊断分析。结果表明:1)暴雨过程是由于南支槽位于大陆高压和副热带高压之间,西风气流强度弱和副热带高压的阻挡作用导致槽移动缓慢,长时间滞留导致槽前西南气流沿低层锋区爬坡而形成的。2)冬季暴雨的产生与充沛的水汽输送、较强的辐合上升运动、较长的持续时间密切相关,且与700 h Pa高度层上的水汽、动力等条件联系更紧密。3)相比一般汛期暴雨过程,冬季暴雨过程中比湿、K指数等明显偏小,大气层结比汛期暴雨要稳定得多,但该次暴雨过程在垂直速度、散度、水汽输送条件非常接近汛期暴雨相关指标。 相似文献
142.
平板冻结器超压事故的发生主要由于使用设备时操作不当和设备质量不过关而引起。对设备超压原理分析和平板冻结器在不同温度条件下的充液比例进行理论计算 ,结果表明 ,停机时 ,在室温 35℃的条件下 ,蒸发器中的充液比例达到 0 .86 0 5时 ,会引起蒸发器发生超压而爆炸。当蒸发器中充液比例在 0 .86 0 5以下时发生的超压事故 ,肯定存在设备质量不过关的因素 ;而当充液比例在 0 .86 0 5或以上时发生的超压事故 ,则是由误操作引起。。 相似文献
143.
MOLAR RATIOS OF C, N, P OF PARTICULATE MATTER AND THEIR VERTICAL FLUXES IN THE YELLOW SEA 总被引:2,自引:0,他引:2
The vertical fluxes and molar ratios of carbon, nitrogen and phosphorus of suspended particulate matter in the Yellow Sea were studied based on the analysis of suspended particulate matter,sediments and sinking particles obtained by use of moored sediment traps. The POC : PON ratios indicate that most of the particulate organic matter in the Yellow Sea water column comes from marine life rather than the continent. The vertical fluxes of SPM, POC, PON and POP in the Yellow Sea are much higher than those in other seas over the world, and present a typical pattern in shallow epicontinental seas. The estimated residence time of the bioactive elements showed that the speed of the biogeochemical process of materials in the Yellow Sea is much shorter than that in the open ocean as there was high primary productivity in this region. 相似文献
144.
1INTRODUCTIONBydefinitionurbanizationistheprocessofruralareaschangingintourbanareasinnatureforasoci-etyitisanaturallyhistoricalprocessofthetransitionfromatraditionalruraloragriculturalsocietytoamodernizedurbansocietyGAO1991.Inbriefitrepresentsa… 相似文献
145.
湛波 《广东海洋大学学报》2003,23(2):88-93
分析了技术要素按贡献参与分配的基本依据和存在问题 ,提出了技术要素按贡献参与分配的建议 :1.在企业分配领域 ,鼓励技术要素以多种形式参与收益分配 ,鼓励体制创新 ,推进技术股份化。 2 .在政府分配领域 ,政府财政科技投入比例与其科技发展对经济贡献增长率挂钩 ,科技财税政策与产业政策、税源经济吻合 ,营造科技奖励的软环境。 3.在社会分配领域 ,充分发挥技术评估部门和行业管理部门的作用 ,对进入技术市场的技术的成熟度和科技含量进行有效的测试和监管 ,保证技术商品的品质 ;技术交易当事人应具诚信态度和法制观念 ;重视中介的作用 ,把技术市场搞活。 相似文献
146.
The gastric shield and underlying stomach epithelium of Chlymas ffarreri were examined at the light and ultrastructural levels.The results showed that the gastric shield consisted of two different size lobes joined together by a narrow middle piece,the thicker lobe was shaped like a funnel,but unclosed at the lateral side;the other lobe was irregularly triangular-shaped.The transverse section of the thicker lobe was obviously laminated and gradually decreased in thickness from the peak to the margins of the shield.The underlying epithelium bore numerous about 3μm diameter spherical processes formed by the apical plasmalemma of the epithelial cells becoming blunt pseudopodia.Microvilli and some interspersed cilia were present in the areas among the spherical processes regions where only microvilli existed.Rough endoplasmic reticulum,Golgi apparatus,different-sized electron-dense secretory granules and electron-lucent vacuoles as well las abundant mitochondria were present in the underlying epithelial cells.Fused droplets of the secretion from the underlying epithelial cells formed the gastric shield. 相似文献
147.
A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these
trace metals and H2S, and other oceanographic parameters were obtained in four cruises.
Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities
of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are
shown to be Cu(S4)
2
3−
and Cu(Sn4S5)3−, Zn(HS)
2
0
and ZnHS
2
−
, Cd(HS)
2
0
and Ni(HS)
2
0
, respectively. The solid species controlling Fe2+ and Co2+ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in
the H2S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H2S−O2-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H2S−O2-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace
metals are still in the processes of reduction and precipitation.
Contribution No. 1428 from Institute of Oceanology, Academia Sinica 相似文献
148.
基于空间分析与实证的中国农业土地边际收益与全要素生产率研究(英文) 总被引:1,自引:0,他引:1
This paper attempts to explore the temporal and spatial nature of the marginal revenue of land, total factor productivity (TFP) change and its three components: technical change (TC), technical efficiency change (TEC) and scale efficiency change (SEC) as seen in Chinese agricultural production from 1995 to 1999. Based on county-level data, the study utilized both stochastic frontier and mapping analyses methods. The results show that growth in the marginal revenue of land was diverse across various regions, where most gain occurred in eastern coastal zone, while loss was in Northwest and North China. China has experienced moderate decreases in annual TFP change (-0.26%) with considerable regional variations. Specifically, the administrative intervention in grain production and the deterioration of the agricultural technology diffusion system led to a moderate drop in annual TFP change. County-level mapping analyses took into account interregional variances in TFP and its components. Regarding components of TFP, TEC differences explain the majority of regional dispersions in TFP. As developed areas in China, the Huang-Huai-Hai region and the Beijing-Tianjin-Tangshan economic zone face the challenges of land conversion and grain security amidst the process of urbanization. 相似文献
149.
150.