西平线越永寿梁线路方案研究

新建铁路西安至平凉线线路穿越永寿梁,通过对越永寿梁线路方案分析与比较,总结越岭选线的几点基本原则。

西平线路基病害分析及整治方案

西平线自2013年12月开通运行以来,经历了6年的风风雨雨,期间还经受住了60年一遇的大雨侵袭的考验。为全面掌握西平线路基状态,我段积极与地方国土资源局联系,借阅地质灾害相关资料,准确掌握铁路沿线地质灾害分布情况;结合现场病害实际情况,有针对性的采取相应措施,切实提升全线设备质量。

西平线引入平凉铁路地区方案比选

通过分析平凉地区研究年度的客货车流，对西平线的引入平凉铁路地区，进行了方案比选，并从工程投资和客货列车走行距离及效果两方面，提出了西平线引入平凉铁路地区的推荐方案．

Micromorphological Features of Diagnostic Horizons in Several soils in Southwest China: Implication for Soil Taxonomic Classification

The comparative studies on micromorphological features in diagnostic horizons of Stagnic Anthrosols, Ustic Ferrosols and Ustic Vertosols in southwestern China were conducted to underpin the rationale for Chinese Soil Taxonomy. The following findings were explored: (1) Stagnic Anthrosols had the specific micromorphological features, e.g., the humic formation in anthrostagnic epipedon, the platy structures in plow subhorizon, the secondary formation of ferromanganese and the weakly optical-orientation clay domains in hydragric horizon, etc.: (2) The groundmasses of ferric horizon in Ustic Ferrosols appeared in hue of 2.5YR or redder, and had pellicular grain structure; (3) Ustic Vertosols had a crust horizon (Acr), and crack structure dominated in Acr and angular blocky structure in disturbed horizon; (4) Because of the distinct differences in micromorphological features among these three soils, the specific micromorphological features might be employed as diagnostic horizons to differentiate soils while the quantifiable micromorphological features might potentially be selected as diagnostic indices for Chinese soil taxonomic classification.

Global Well-posedness of the Generalized Long-short Wave Equations

In the present paper, we investigate the well-posedness of the global solutionfor the Cauchy problem of generalized long-short wave equations. Applying Kato＇s methodfor abstract quasi-linear evolution equations and a priori estimates of solution,we get theexistence of globally smooth solution.

Geostrophic meridional transport in tropical Northwest Pacific based on Argo profiles

Absolute geostrophic currents in the North Pacific Ocean were calculated using P-vector method from newly gridded Argo profiling float data collected during 2004-2009. The meridional volume transport of geostrophic currents differed significantly from the classical Sverdrup balance, with differences of 10×106 -20×106 m3 /s in the interior tropical Northwest Pacific Ocean. Analyses showed that errors of wind stress estimation could not explain all of the differences. The largest differences were found in the areas immediately north and south of the bifurcation latitude of the North Equatorial Current west of the dateline, and in the recirculation area of the Kuroshio and its extension, where nonlinear eddy activities were robust. Comparison of the geostrophic meridional transport and the wind-driven Sverdrup meridional transport in a high-resolution OFES simulation showed that nonlinear effects of the ocean circulation were the most likely reason for the differences. It is therefore suggested that the linear, steady wind-driven dynamics of the Sverdrup theory cannot completely explain the meridional transport of the interior circulation of the tropical Northwest Pacific Ocean.

Optimal heat source for the interannual variability of the western North Pacific summer monsoon

Using 132-member experiments based on a linear baroclinic atmospheric model(LBM), this study investigates the optimal heat source forcing the interannual variability of the western North Pacific summer monsoon(WNPSM). The 132 members are forced by localized atmospheric heat sources distributed homogeneously over regions from 55°S to 55°N, each 10° latitude × 30° longitude in size. The atmospheric responses to all the heating constitute an ensemble to examine the relative contribution of each local heat source to the strength of the WNPSM. The result indicates that the combination of an atmospheric heating(cooling) source over the subtropical Northwest Pacific and a cooling(heating) source over the tropical Indian Ocean and the midlatitudes from China to the southern part of Japan is the pattern most effective at enhancing(weakening) the WNPSM.Besides, the optimal heat source pattern identified by the LBM simulations is similar to the observed atmospheric heating anomalies associated with WNPSM interannual variability. The results suggest that any external forcing that leads to a similar heating structure as the optimal thermal forcing pattern could lead to an anomalous WNPSM.

Correlated Features of Horizontal Movement-Deformation on the North and East Margins of the Qinghai-Xizang Block before the Kunlun Earthquake with M_S=8.1

The high-precision GPS data observed from the northeast margin of the Qinghai-Xizang （Tibet） block and the Sichuan-Yunnan GPS monitoring areas in 1991 （1993）, 1999 and 2001 revealed that： before the Kunlun earthquake with Ms =8.1 on November 14, 2001, the dynamic variation features of horizontal movement-deformation field in the north and east marginal tectonic areas of the Qinghai-Xizang （Tibet） block had some correlated features. That is to say, under the general background of inherited movement, the movement intensifies in the two areas weakened synchronously and the state of deformation changed when the great earthquake was impending. Analysis and study in connection with geological structures showed that before the Kunlun Ms8.1 earthquake, the correlated variations of movement-deformation on the boundaries of Qinghai-Xizang （Tibet） block were related to the disturbing stress field caused by the extensive and rapid stress-strain accumulation in the late stage of large earthquake preparation. Owing to the occurrence of large earthquake inside the block, the release of large amount of strain energy, and the adjustment of tectonic stress field, in relevant structural positions （especially zones not penetrated by historical strong earthquake ruptures） in boundary zones where larger amount of strain energy was accumulated, stress-strain may be further accumulated or else released through rupture.

Evaluation of the systematic set-up errors using electronic portal image device in the radiotherapy procedures

Objective： The aim of this work was to quantify the extent of set-up errors to conduct a quality assurance （QA） aspect of treatment delivery, verification of the treatment field＇s position on different days using electronic portal. Methods： This study was carried out on 12 patients, treated for pelvis tumor; and total of 240 images obtained by electronic portal image device （EPID） were analyzed. The EPIs acquire using EPID attached to the Siemens linear accelerator. The anatomy match- ing software （Theraview） was used and displacement in two dimensions were noted for each treatment field to study patient setup errors. Results： The percentages of mean deviations less than 5 mm in X direction were 65% ＆ 92%, from 5-10 mm were 31% ＆ 19% and more than 10 mm were 11% ＆ 9% forNP and lateral direction respectively. The percentages of mean deviations less than 5 mm in Y direction were 65% ＆ 63%, from 5-10 mm were 33% ＆ 28% and more than 10 mm were 22% ＆ 29%. The mean deviations in 2D-vector errors were 〈 5 mm in 47% and 46%, 5-10 mm in 36% and 37% and 〉 10 mm in 37% and 37% of images in the NP and lateral direction respectively. Conclusion： The results revealed that the ranges of set up errors are immobilization method to improve reproducibility. The observed variations were not within the limits..

A Major Landslide Involving an Inverted Paleochannel in Sierra County, New Mexico

A landslide that probably dates to the end of the Pleistocene has been found in Sierra County. The feature consists of three sub-parallel segments, covering an area about 8 km wide and 10 km long. The head of the slide deposits consists of a northeast-trending paleochannel forming an inverted topography. The paleochannel deposits contain many boulders with sizes up to 1.5 meter diameter, indicating flow rate as high as 100 m3/s. The paleochannel ridge is mostly underlain by the hidden lateral contact of the Cretaceous Crevasse Canyon Formation and by the Tertiary Love Ranch and is sharply defined by Yoast Draw valley that cuts a water gap through the 25 m high inverted ridge. The landslide body consists of Love Ranch Formation overlain by a substantial cover of Quaternary fanglomerate. A series of northwest-trending faults have influenced the landslide. The broad western upslope segment of the slide has been washed away, leaving only trace evidence of a landslide. A low slide plane angle of less than 1% slope suggests a seismic trigger.

An Evaluation of Nearshore Sediment Data after the Deepwater Horizon Blowout

The deepwater horizon blowout led to the release of 4.9 million barrels of crude oil into the Gulf of Mexico （GOM）. Here the paper analyzes available sediment datasets to determine whether changes in petrogenic contaminants are evident in GOM sediment following the blowout. Locations sampled by EPA （Environmental Protection Agency）, British Petroleum （BP） and NOAA （National Oceanic and Atmospheric Administration） were reduced and grouped into 46 similar locations and analyzed. Eleven groups suggested an increase in PAIl （polycyclic aromatic hydrocarbon） and nickel, one group showed a statistically significant increase in Phenanthrene. Four locations were analyzed for time trends and differences between initial and peak concentrations of oil range organics （ORO）, diesel range organics （DRO）, vanadium and nickel. One location had significant increases in ORO, DRO and vanadium and a suggestive increase in nickel. Correlations between ORO/DRO, ORO/V, ORO/Ni, V/Ni were computed （RE= 0.85, 0.67, 0.64, 0.92, respectively）. Overall, the analyses suggest that future monitoring should employ a sampling strategy that coordinates response sampling to previously sampled locations, such that baseline datasets can be used in detection of event associated contamination.

Stability and a fast calculation method of travel speed of pulse peak in convergence zone

A long-range sound propagation experiment was conducted in the West Pacific Ocean in summer 2013.The signals received by a towed array indicate that the travel speed of pulse peak(TSPP)in the convergence zones is stable.Therefore,an equivalent sound speed can be used at all ranges in the convergence zones.A fast calculation method based on the beam-displace-ment ray-mode(BDRM)theory and convergence zone theory is proposed to calculate this equivalent sound speed.The computation speed of this proposed method is over 1000 times faster than that of the conventional calculation method based on the normal mode theory,with the computation error less than 0.4%compared with the experimental result.Also,the effect of frequency and sound speed profile on the TSPP is studied with the conventional and fast calculation methods,showing that the TSPP is almost independent of the frequency and sound speed profile in the ocean surface layer.

SOURCE－TYPE SOLUTIONS OF A QUASILINEAR DEGENERATE PARABOLIC EQUATION WITH ABSORPTION

The existence and nonexistence of non-trivial solutions for the Cauchy problem of the formare studied.

An Insight into Machine Learning Algorithms to Map the Occurrence of the Soil Mattic Horizon in the Northeastern Qinghai-Tibetan Plateau

Soil diagnostic horizons, which each have a set of quantified properties, play a key role in soil classification. However, they are difficult to predict, and few attempts have been made to map their spatial occurrence. We evaluated and compared four machine learning algorithms, namely, the classification and regression tree(CART), random forest(RF), boosted regression trees(BRT), and support vector machine(SVM), to map the occurrence of the soil mattic horizon in the northeastern Qinghai-Tibetan Plateau using readily available ancillary data. The mechanisms of resampling and ensemble techniques significantly improved prediction accuracies(measured based on area under the receiver operator characteristic curve score(AUC)) and produced more stable results for the BRT(AUC of 0.921 ± 0.012, mean ± standard deviation) and RF(0.908 ± 0.013) algorithms compared to the CART algorithm(0.784 ± 0.012), which is the most commonly used machine learning method. Although the SVM algorithm yielded a comparable AUC value(0.906 ± 0.006) to the RF and BRT algorithms, it is sensitive to parameter settings, which are extremely time-consuming.Therefore, we consider it inadequate for occurrence-distribution modeling. Considering the obvious advantages of high prediction accuracy, robustness to parameter settings, the ability to estimate uncertainty in prediction, and easy interpretation of predictor variables, BRT seems to be the most desirable method. These results provide an insight into the use of machine learning algorithms to map the mattic horizon and potentially other soil diagnostic horizons.