Application of Partial Least Squares Regression in Multimodal Integrated Forecasting of Water Vapor and Surface Air Temperature

The use of a new multi model integration method of Partial Least Squares regression (PLS) can completely eliminate the multicollinearity features to improve multi model’s integrated forecasting results of the humidity and temperature. Based on the four centers’ ensemble forecast results, namely, the European Center for Medium-Range Weather Forecasts (ECMWF), Chinese Meteorological Administration (CMA), the Japan Meteorological Agency (JMA) and the UK Met Office (UKMO), we built a 2012 multi mode (25°~60°N, 60°~150°E) 24 ~168 hours forecast time (interval 24 hours) multi model for humidity and temperature and used the four methods, like ensemble average (BREM) for eliminating the deviation, a simple set of average (EMN), Super Ensemble (SUP) and Partial Least Squares regression (PLS) for ground temperature multi model integration. We used the Root-Mean-Square Error (RMSE) and anomaly correlation coefficient (cor) to determine the effect of more modes of integration and to predict a short course of cold. The two prediction results showed that the Partial Least Squares regression (PLS) was the best multi model integrated method, more superior than the other three single modes and compared with the other three methods, it showed better prediction performance, which has certain value and application prospect.     

Assessing the influence of climate change and inter-basin water diversion on Haihe River basin,eastern China: a coupled model approach

The modeling of changes in surface water and groundwater in the areas of inter-basin water diversion projects is quite difficult because surface water and groundwater models are run separately most of the time and the lack of sufficient data limits the application of complex surface-water/groundwater coupling models based on physical laws, especially for developing countries. In this study, a distributed surface-water and groundwater coupling model, named the distributed time variant gain model–groundwater model (DTVGM-GWM), was used to assess the influence of climate change and inter-basin water diversion on a watershed hydrological cycle. The DTVGM-GWM model can reflect the interaction processes of surface water and groundwater at basin scale. The model was applied to the Haihe River Basin (HRB) in eastern China. The possible influences of climate change and the South-to-North Water Diversion Project (SNWDP) on surface water and groundwater in the HRB were analyzed under various scenarios. The results showed that the newly constructed model DTVGM-GWM can reasonably simulate the surface and river runoff, and describe the spatiotemporal distribution characteristics of groundwater level, groundwater storage and phreatic recharge. The prediction results under different scenarios showed a decline in annual groundwater exploitation and also runoff in the HRB, while an increase of groundwater storage and groundwater level after the SNWDP’s operation. Additionally, as the project also addresses future scenarios, a slight increase is predicted in the actual evapotranspiration, soil water content and phreatic recharge. This study provides valuable insights for developing sustainable groundwater management options for the HRB.     

Two‐dimensional dictionary learning for suppressing random seismic noise

Dictionary learning is a successful method for random seismic noise attenuation that has been proven by some scholars. Dictionary learning–based techniques aim to learn a set of common bases called dictionaries from given noised seismic data. Then, the denoising process will be performed by assuming a sparse representation on each small local patch of the seismic data over the learned dictionary. The local patches that are extracted from the seismic section are essentially two‐dimensional matrices. However, for the sake of simplicity, almost all of the existing dictionary learning methods just convert each two‐dimensional patch into a one‐dimensional vector. In doing this, the geometric structure information of the raw data will be revealed, leading to low capability in the reconstruction of seismic structures, such as faults and dip events. In this paper, we propose a two‐dimensional dictionary learning method for the seismic denoising problem. Unlike other dictionary learning–based methods, the proposed method represents the two‐dimensional patches directly to avoid the conversion process, and thus reserves the important structure information for a better reconstruction. Our method first learns a two‐dimensional dictionary from the noisy seismic patches. Then, we use the two‐dimensional dictionary to sparsely represent all of the noisy two‐dimensional patches to obtain clean patches. Finally, the clean patches are patched back to generate a denoised seismic section. The proposed method is compared with the other three denoising methods, including FX‐decon, curvelet and one‐dimensional learning method. The results demonstrate that our method has better denoising performance in terms of signal‐to‐noise ratio, fault and amplitude preservation.     

Comparison of nominal and standardized catch per unit effort data in quantifying habitat suitability of skipjack tuna in the equatorial Pacific Ocean

In the western and central Pacific Ocean, upper strata waters exhibit highly dynamic oceanographic features under ENSO variability. This has been proved to be responsible for the dynamic change of both abundance and zonal distribution of skipjack tuna(Katsuwonus pelamis). Although causality has been suggested by researchers using physical–biological interaction models, cumulative evidence needs to be obtained and the tenability of assertion needs to be tested from an ecological habitat perspecti...     

Geochronology and geochemistry of the Early Cretaceous Jigongshan and Qijianfeng batholiths in the Tongbai orogen, central China: implications for lower crustal delamination

The Jigongshan and Qijianfeng batholiths in the Tongbai orogen consist mainly of porphyritic hornblende-biotite monzogranite, biotite monzogranite, and biotite syenogranite, which are variably intruded by lamprophyre, diorite, and syenogranite dykes. Mafic microgranular enclaves commonly occur in the hornblende-biotite monzogranite, whereas surmicaceous enclaves are found in the biotite monzogranite. Both batholiths have zircon U–Pb ages ranging from ca. 139 to 120 Ma, indicating their emplacement in the Early Cretaceous. The hornblende-biotite monzogranite has an adakitic affinity marked by relatively high Sr/Y and (La/Yb) _N ratios, lack of Eu anomalies, low MgO and Ni contents, and Na₂O > K₂O. Its chemical compositions, combined with enriched Sr–Nd isotopic signatures, suggest formation by dehydration melting of mafic rocks in a thickened lower crust. This thickened crust resulted from the Permo-Triassic subduction-collision between the North China and South China blocks and persisted until the Early Cretaceous. The biotite monzogranite and biotite syenogranite have low Al₂O₃, CaO, and Sr contents, low Rb/Sr, FeOt/MgO, and (Na₂O + K₂O)/CaO ratios, and flat HREE patterns with moderate to weak Eu anomalies. They were produced by partial melting of crustal materials under relatively low pressure. Partial melting at different crustal levels could have significantly contributed to mechanical weakening of the crust. The diorite and lamprophyre dykes show linear trends between SiO₂ and major or trace elements on Harker diagrams, with two lamprophyre samples containing normative nepheline and olivine. These rocks have high La/Yb and Dy/Yb ratios, both displaying co-variation with contents of Yb. They were originated from relatively deep lithospheric mantle followed by fractionation of olivine + clinopyroxene + apatite + Fe–Ti oxides. Extensive partial melting in the lithospheric mantle indicates relatively high temperatures at this level. We suggest that the presence of adakitic magmas, thickened but weakened crust and high temperatures in the lithosphere mantle point to lower crustal delamination in the Early Cretaceous in the Tongbai orogen.     

The existence of transversal homoclinic orbits in a planar circular restricted four-body problem

In this paper, we study the existence of transversal homoclinic orbits in a planar circular restricted four-body problem, based on the perturbation theory of integrable Hamiltonian systems. We start from a planar circular restricted four-body model and regard it as a perturbation of the two-body model. Then, in order to conveniently study unbounded orbits, we transform the infinite points to finite points by a non-canonical transformation, arriving at a non-Hamiltonian system with degenerate fixed points. According to the extended Melnikov method, we finally prove that there exist transversal homoclinic orbits in this four-body model.     

川东北下三叠统飞仙关组鲕粒白云岩孔喉的空间展布与刻画

孔喉特征是储集层研究的核心,厘清储集层孔喉在三维空间中的展布对油气勘探与开发意义重大。文中借助微纳米CT立体成像技术和数字岩心技术对川东北飞仙关组残余鲕粒白云岩的孔喉特征进行刻画与描述,建立了微纳米级的孔喉三维空间展布模型,并计算了孔喉半径、形状因子、空间连通性等表征参数。此外,结合扫描电镜、压汞曲线等传统方法,对所建立的模型进行了有益的探讨和补充。结果表明,川东北地区残余鲕粒白云岩孔隙类型主要有粒间孔、粒间溶孔（铸模孔）、晶间（溶）孔、晶间缝和微裂隙等。其中,晶间孔和微裂隙为连通的喉道,其最小值可达20～30 nm。样品重结晶强烈,受重结晶晶体的生长及后期压实等改造作用的影响,喉道堵塞,储集层渗透性差。     

云南省临沧市勐托新近系褐煤的微量元素地球化学特征

为研究云南临沧勐托新近系褐煤的微量元素地球化学特征,共采集了11个褐煤样品,采用ICP MS和ICP CCT MS(As和Se)对煤中微量元素进行了测试。结果表明：与中国煤相比,勐托褐煤中Rb(96.1 mg/kg)、Sb(15.3 mg/kg)和Cs(25.9 mg/kg)显著富集,W(10.6 mg/kg)和U(20.2 mg/kg)富集,Be(7.84 mg/kg)、Ga(16.1 mg/kg)、As(11.6 mg/kg)、Cd(0.67 mg/kg)、Sn(6.66 mg/kg)、Pb(34.6 mg/kg)、Bi(3.86 mg/kg)和Th(28.2 mg/kg)稍富集,微量元素组成与大寨富锗煤不同,与酸性花岗岩物源供应有关。勐托褐煤中REY含量范围为121~420 mg/kg,平均251 mg/kg,均较大寨富锗褐煤高,且以Ce显著正异常和Eu显著负异常为特征,明显区别于大寨褐煤,Eu负异常和上陆壳标准化的REY分配模式均表明勐托褐煤中稀土元素受盆地周边花岗岩风化陆源碎屑供应影响。     

重庆龙潭组煤中稀土元素地球化学及地质成因分析

运用电感耦合等离子体质谱(ICP MS)、X射线荧光光谱(XRF)、X射线衍射(XRD)等方法对重庆龙潭组煤中稀土元素的地球化学特征进行研究。结果表明,各煤样稀土元素分布模式相似,总体呈左高右低的宽缓的“V”型曲线,轻稀土曲线段“右倾”,重稀土曲线段较为“平坦”,成煤沼泽受陆源碎屑影响较大。南桐5#煤稀土元素含量高,接近全国平均值的2倍,受汉南古陆、大巴山古陆和龙门山岛屿控制,少量陆源碎屑物来自康滇古陆。东林6#煤中的稀土元素含量低于全国平均值水平,海水作用明显,煤样中稀土元素含量未受碱性火山灰的影响,但其底板受碱性火山灰影响强烈。根据煤层稀土元素含量及其比值分析,研究区龙潭组为海湾/潟湖潮坪及浅海碳酸盐沉积的沉积环境。     

华北克拉通北缘赤峰地区显生宙麻粒岩的发现及其意义

华北克拉通构造体制从稳定向活动的转折是值得关注的问题。文中结合华北克拉通北缘赤峰和宁城晚古生代和早中生代两期麻粒岩捕虏体及其寄主闪长岩的研究,讨论其形成的不同构造背景,从而探讨体制转折的起始时期。赤峰柴胡栏子二叠纪镁铁质麻粒岩及其寄主闪长岩的锆石SHRIMP U-Pb年龄分别为（262.3±3.1） Ma和（256.6±6.5） Ma,宁城河南营子三叠纪镁铁质麻粒岩及其寄主闪长岩的锆石SHRIMP U-Pb年龄分别为（229.7±2.6） Ma和（221±3） Ma。在上述两个地区还发现晚古生代二叠纪的闪长岩脉等。通过对比研究认为：二叠纪岩浆活动具有大陆裂谷初始阶段的特点,高场强元素含量比较低;而三叠纪高场强元素的增高显示地幔部分熔融程度的提高。二叠纪岩浆活动与此时全球构造演化及邻兴蒙造山带出现的双峰式火山活动密切相关。而晚三叠世岩浆活动则与底侵背景下陆内伸展作用有关,是构造体制转折的标志。