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旧砂的冷却和均匀化有利减少铸件废品
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作者 洪海燕 《铁道机车车辆工人》 1996年第11期26-28,共3页
1 存在问题 图1所示的构造形式常常会产生作业问题。这些问题主要涉及造型中的废品(起模过程中铸型的部分粘模)和铸件废品。这两种废品可追溯到型砂的质量。 出现这种情况的主要原因是输送到混砂机里的旧砂的性能不稳定。生产计划包含... 1 存在问题 图1所示的构造形式常常会产生作业问题。这些问题主要涉及造型中的废品(起模过程中铸型的部分粘模)和铸件废品。这两种废品可追溯到型砂的质量。 出现这种情况的主要原因是输送到混砂机里的旧砂的性能不稳定。生产计划包含了差别很大的铸件重量,因而砂的热负荷也有很大差异,从而导致型砂温度以及膨润土和碳载体损失差异很大这一常见的后果。 展开更多
关键词 铸造 型涛 旧砂 冷却 均匀化 铸件废品
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Representation of the Arctic Oscillation in the CMIP5 Models 被引量:4
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作者 ZUO Jin-Qing LI Wei-Jing REN Hong-Li 《Advances in Climate Change Research》 SCIE 2013年第4期242-249,共8页
The temporal variability and spatial pattern of the Arctic Oscillation(AO)simulated in the historical experiment of26 coupled climate models participating in the Coupled Model Intercomparison Project Phase 5(CMIP5)are... The temporal variability and spatial pattern of the Arctic Oscillation(AO)simulated in the historical experiment of26 coupled climate models participating in the Coupled Model Intercomparison Project Phase 5(CMIP5)are evaluated.Spectral analysis of the monthly AO index indicates that 23 out of the 26 CMIP5 models exhibit no statistically significant spectral peak in the historical experiment,as seen in the observations.These models are able to reproduce the AO pattern in the sea level pressure anomaly field during boreal winter,but the intensity of the AO pattern tends to be overestimated in all the models.The zonal-mean zonal wind anomalies associated with the AO is dominated by a meridional dipole in the mid-high latitudes of the Northern Hemisphere during boreal winter,which is well reproduced by only a few models.Most models show significant biases in both strength and location of the dipole compared to the observation.In considering the temporal variability as well as spatial structures in both horizontal and vertical directions,the MPI-ESM-P model reproduces an AO pattern that resembles the observation the best. 展开更多
关键词 Arctic Oscillation model evaluation coupled climate model CMIP5
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Impacts of Climatic Change on River Runoff in Northern Xinjiang of China over Last Fifty Years 被引量:6
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作者 YANG Yuhui CHEN Yaning +2 位作者 LI Weihong WANG Minzhong SUN Guili 《Chinese Geographical Science》 SCIE CSCD 2010年第3期193-201,共9页
The characteristics of climatic change and fiver runoff, as well as the response of fiver runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over t... The characteristics of climatic change and fiver runoff, as well as the response of fiver runoff to climatic change in the northern Xinjiang are analyzed on the basis of the hydrological and meteorological data over the last 50 years by the methods of Mann-Kendall nonparametric test and the nonlinear regression model. The results show that: 1) The temperature and the precipitation increased significantly in the whole northern Xinjiang, but the precipitation displayed no obvious change, or even a decreasing trend in the northern mountainous area of the northern Xinjiang. 2) River runoff varied in different regions in the northern Xinjiang. It significantly increased in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang (p = 0.05), while slightly ificreased in the west of the northern Xinjiang. 3) North Atlantic Oscillation (NAO) affects fiver runoff by influencing temperature and precipitation. The NAO and precipitation had apparent significant correlations with the fiver runoff, but the temperature did not in the northern Xinjiang. Since the mid-1990s fiver runoff increase was mainly caused by the increasing temperature in the northern slope of the Tianshan Mountains and the north of the northern Xinjiang. Increased precipitation resulted in increased fiver runoff in the west of the northern Xinjiang. 展开更多
关键词 climatic change river runoff Mann-Kendall test nonlinear regression model NAO northern Xinjiang
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Two Types of Arctic Oscillation and Their Associated Dynamic Features 被引量:1
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作者 SHI Ning BUEH Cholaw 《Atmospheric and Oceanic Science Letters》 2011年第5期287-292,共6页
In this paper,the dynamical evolutions of two types of Arctic Oscillation (AO),the stratospheric (S) and tropospheric (T) types,have been investigated on an intermediate time scale in terms of transient eddy feedback ... In this paper,the dynamical evolutions of two types of Arctic Oscillation (AO),the stratospheric (S) and tropospheric (T) types,have been investigated on an intermediate time scale in terms of transient eddy feedback forcing and three-dimensional Rossby wave propagation.S-Type (T-type) events are characterized by an anomalous stratospheric polar vortex that is in phase (out of phase) with its tropospheric counterpart.Approximately onethird of AO events,both positive and negative,are T-type events.For the positive phase of a T-type event,the formation and maintenance of stratospheric positive anomalies over the polar cap are associated with an upward propagation of Rossby wave packets originating from the near-tropopause altitude over northeastern Asia.However,such upward propagating features are not found for S-type events.In the troposphere,transient eddy feedback forcing is primarily responsible for the meridional seesaw structure of both the S-and T-type events,with an additional contribution from Rossby wave propagation. 展开更多
关键词 Arctic Oscillation stratospheric polar vortex Rossby wave transient eddy feedback forcing
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Interdecadal and Interannnual Variabilities of the Antarctic Oscillation Simulated by CAM3 被引量:1
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作者 XUE Feng SUN Dan ZHOU Tian-Jun 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第6期515-520,共6页
Based on four sets of numerical simulations prescribed with atmospheric radiative forcing and sea surface temperature(SST) forcing in the Community Atmospheric Model version 3(CAM3), the interannual and interdecadal v... Based on four sets of numerical simulations prescribed with atmospheric radiative forcing and sea surface temperature(SST) forcing in the Community Atmospheric Model version 3(CAM3), the interannual and interdecadal variabilities of the Antarctic oscillation(AAO) during austral summer were studied. It was found that the interannual variability is mainly driven by SST forcing. On the other hand, atmospheric radiative forcing plays a major role in the interdecadal variability. A cooling trend was found in the high latitudes of the Southern Hemisphere(SH) when atmospheric radiative forcing was specified in the model. This cooling trend tended to enhance the temperature gradient between the mid and high latitudes in the SH, inducing a transition of the AAO from a negative to a positive phase on the interdecadal timescale. The cooling trend was also partly weakened by the SST forcing, leading to a better simulation compared with the purely atmospheric radiative forcing run. Therefore, SST forcing cannot be ignored, although it is not as important as atmospheric radiative forcing. 展开更多
关键词 Antarctic oscillation interannual variability interdecadal variability
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A possible bias of simulating the post-2000 changing ENSO 被引量:1
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作者 Fei Zheng Wen Zhang +1 位作者 Jinyi Yu Quanliang Chen 《Science Bulletin》 SCIE EI CAS CSCD 2015年第21期1850-1857,共8页
Since the late 1990s, a climate shift has occurred over the tropical Pacific that is characterized with a La Nifia-like mean state. Coincident with this climate shift, climate models' skills in predicting the El Nifi... Since the late 1990s, a climate shift has occurred over the tropical Pacific that is characterized with a La Nifia-like mean state. Coincident with this climate shift, climate models' skills in predicting the El Nifio Southern Oscillation (ENSO) events in the 2000s are sig- nificantly lower than in the 1980s-1990s, A common bias is likely to exist in contemporary ENSO models that got amplified after the climate shift. In this study, we identify this model bias to be the wind-sea surface temperature coupling processes over the tropical Pacific. Evidence is presented to show that this coupling process experienced an obvious shift around year 2000 in its coupling strength and coupling center. A simple ENSO coupled model is used to demonstrate that the changing properties of the post-2000 ENSO events can be more realistically simulated if this model bias is alleviated. 展开更多
关键词 ENSO Wind-SST coupling - Biascorrection Climate shift
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