HOMOCLINIC ORBITS FOR A CLASS OF THE SECOND ORDER HAMILTONIAN SYSTEMS

The existence of homoclinic orbits is obtained by the variational approach for a class of second order Hamiltonian systems q（t） ＋ ↓△V（t, q（t）） = 0, where V（t, x） = -K（t, x） ＋ W（t, x）, K（t, x） is neither a quadratic form in x nor periodic in t and W（t, x） is superquadratic in x.

Genetic pattern of belt-wide petroliferous phenomenon in the eastern Pearl River Mouth Basin and its practical application

The Pearl River Mouth Basin （PRMB） covers an area of approximately 20× 104 km2.However,oil-gas fields detected in this area thus far are highly concentrated and controlled predominantly by second-order structural belts,the seven largest of which aggregate proved oil reserves of 7.7× 108 m3,accounting for 86％ of the total discovered reserve in the basin.These second-order structures have one common phenomenon：oil is contained in all traps present in them.In other words,they are all belt-wide petroliferous reservoirs.Research has identified eight types of second-order structural belts under two categories in the eastern PRMB.Their petroliferous properties are subject to three typical constraints：petroliferous properties of subsags hosting these structural belts,locations of these belts in the petroleum system,and availability of traps prior to the hydrocarbon expulsion and migration.The formation and distribution of oil reservoirs in these belts are characterized by subsag-belt integration and ＂three-in-one＂.The former indicates that sags and the second-order structural belts within the supply range of the sags constitute the basic units of hydrocarbon accumulations and are therefore inseparable.The latter indicates that a belt-wide petroliferous second-order structural belt always contains three important elements：hydrocarbon richness,effective pathway and pre-existing traps.

MULTIPLICITY RESULTS FOR FOURTH ORDER ELLIPTIC EQUATIONS OF KIRCHHOFF-TYPE

In this paper, we concern with the following fourth order elliptic equations of Kirchhoff type {Δ^2u-（a＋bfR^3｜↓△u｜^2dx）△u＋V（x）u=f（x,u）,x∈R^3, u∈H^2（R3）,where a, b 〉 0 are constants and the primitive of the nonlinearity f is of superlinear growth near infinity in u and is also allowed to be sign-changing. By using variational methods, we establish the existence and multiplicity of solutions. Our conditions weaken the Ambrosetti- Rabinowitz type condition.

MULTIPLICITY OF PERIODIC SOLUTIONS FOR SECOND ORDER HAMILTONIAN SYSTEMS WITH MIXED NONLINEARITIES

The multiplicity of periodic solutions for a class of second order Hamiltonian system with superquadratic plus subquadratic nonlinearity is studied in this paper.Obtained via the Symmetric Mountain Pass Lemma,two results about infinitely many periodic solutions of the systems extend some previously known results.

Existence of Ordered Solutions to Quasilinear Schrodinger Equations with General Nonlinear Term

In this paper, the existence of a pair of ordered solutions for the following class of equations in ?(1)?was studied. A bounded (PS) (Palais-Smale) sequence was constructed and the related variational principle was used to prove the existence of the positive solution. The existence of the ordered solutions is finally found.

Existence of Infinitely Many High Energy Solutions for a Fourth-Order Kirchhoff Type Elliptic Equation in R³

In this paper, we consider the following fourth-order equation of Kirchhoff type where a, b > 0 are constants, 3 < p < 5, V ∈ C (R3, R);Δ2: = Δ (Δ) is the biharmonic operator. By using Symmetric Mountain Pass Theorem and variational methods, we prove that the above equation admits infinitely many high energy solutions under some sufficient assumptions on V (x). We make some assumptions on the potential V (x) to solve the difficulty of lack of compactness of the Sobolev embedding. Our results improve some related results in the literature.

基于高光谱的山区耕地土壤有机质含量估测

以贵州省典型山区耕地土壤高光谱数据为研究对象,基于光谱变换法和机器学习原理构建贵州省山区耕地土壤有机质(SOM)含量估算模型。于2020年8月至2021年3月在贵州省13个县(区、市)采集了120个土壤样品,检测土壤可见光-近红外波段光谱信息,利用5种光谱数据变换(原始光谱、一阶微分、二阶微分、倒数对数的一阶微分、连续统去除)和4类模型(偏最小二乘回归、支持向量机、随机森林和BP神经网络)组合出不同土壤有机质含量的预测模型,按照3∶1选择训练样本和测试样本以估算山区SOM含量。结果表明,一阶微分数据变换与山区SOM含量的相关性较高,相关系数最高达到-0.635;反演模型中,基于一阶微分光谱变换构建的BP神经网络模型精度最高,训练集、测试集的决定系数(R 2)分别为0.845、0.838,测试集均方根误差(RMSE)为3.452,相对分析误差(RPD)达到2.470,其次是RF、PLSR模型的RPD较高,SVM模型的RPD最低。光谱数据变换中一阶微分法能极大程度提取出山区耕地的SOM含量信息,BP神经网络模型是估算山区SOM含量的最优模型,本研究结果可为贵州省山区耕地土壤肥力的监测以及农业生产提供理论参考。

黔东南民族文化生态保护区非物质文化遗产的生态响应和环境秩序

以黔东南民族文化生态保护区为例,运用地理学相关空间分析方法以及线性扩散接连分析法,对非物质文化遗产(非遗)生态要素进行分析。主要结论有:①黔东南非遗分布具亲山性、亲水性特点,3个区域的文化-生态要素各有不同;②非遗的环境依赖程度因文化类型不同而存在差异,其中制作、营造、医药、生产以及饮食酿制类非遗的生态依赖最明显;③非遗具有一定的生态脆弱性,生物多样性减少、土壤侵蚀、水质污染、气候变化等问题会影响到文化保护与传承;④非遗一方面依赖生态,一方面也因生态作用而扮演了建构、维系地方环境秩序的角色,直接表现为非遗推动跨县、跨海拔、跨地形地貌的生产分工与合作,在促进民族交流中具有积极作用。

秦岭北麓西安段峪口村落洪涝适应性营建智慧研究

秦岭北麓西安段为洪涝灾害多发区域.在长期同雨洪博弈共生的过程中,当地传统村落形成了以低技术、低成本、低维护为特征的洪涝适应性智慧.在洪涝风险日益增多的当下,这些传统实践智慧对促进区域人水和谐、洪涝韧性和可持续发展具有重要借鉴意义.以秦岭北麓典型区域内峪口传统村落为例,基于田野调查、多源数据比对互证法和图解分析法,本文旨在阐明洪涝适应与村落营建关系的基础上,在选址、街巷布局及洪涝管控设施系统等三个方面,系统研究其洪涝适应性营建智慧,以期在新时期为城乡洪涝韧性人居环境规划营建,提供理论和经验借鉴.

Residents'Satisfaction with Public Services in Mountainous Areas:An Empirical Study of Southwestern Sichuan Province,China

Abstract： Enhancing the efficiency of public services is essential to residents in mountainous areas. It is also important to promote sus- tainable development of these regions. Analysing residents＇ satisfaction with public services in mountainous areas can help in evaluating outcomes of fiscal investment and identifying potential coping approaches for improving public service efficiencies. The residents＇ satisfaction with public services and the factors that influence such satisfaction were examined in this study. A study of 12 towns located in the southwestern Sichuan Province was performed using an entropy-weighted analytic hierarchy process （EWAHP）, the technique for order preference by similarity to ideal solution （TOPSIS） and Tobit regression methods. The results indicate that： 1） the spatial distribu- tion of satisfaction with public services is non-uniform, and the spatial distribution structure varies for different types of public services. 2） Residents＇ satisfaction with public services is influenced by both objective and subjective factors. Population density, economic dis- tance, social and cultural divisions and elevation are the major objective factors, whereas bounded rationality, the hierarchy of needs and service expectations are the main subjective factors. The most effective strategies for enhancing residents＇ satisfaction with public ser- vices are likely to be clustering the population, choosing supply centres with different public services, regulating the cultural division in ethnic minority towns, selecting supply priorities in accordance with residents＇ needs, implementing targeted intervention policies and establishing ＇bottom-up＇ and ＇top-down＇ integrated decision-making mechanisms. Keywords： mountainous areas; public services; residents＇ satisfaction; entropy-weighted analytic hierarchy process （EWAHP）; technique for order preference by similarity to ideal solution （TOPSIS）; Tobit regression; southwestern Sichuan Province

Superlinear Fourth-order Elliptic Problem without Ambrosetti and Rabinowitz Growth Condition

This paper deals with superlinear fourth-order elliptic problem under Navier boundary condition. By using the mountain pass theorem and suitable truncation, a multiplicity result is established for all λ〉 0 and some previous result is extended.

Multiplicity of Homoclinic Solutions for Second Order Hamiltonian Systems with Local Conditions at the Origin

In this paper,the multiplicity of homoclinic solutions for second order non-autonomous Hamiltonian systemsü(t)-L(t)u(t)+▽uW(t,u(t))=0 is obtained via a new Symmetric Mountain Pass Lemma established by Kajikiya,where L∈C(R,RN×N)is symmetric but non-periodic,W∈C1(R×RN,R)is locally even in u and only satisfies some growth conditions near u=0,which improves some previous results.

秩序与规范:媒介视域下祁连山地区口传文学研究

充满自然气息和生命特征的口传文学是祁连山地区“文化走廊”的有机组成部分,生活在该区域的族群在处理与自然、社会、自我的关系时形成了一系列融合历史、风俗、秩序与规范的口传文学。丰富的口传文学在历史传承中濡化为族群成员共享的社会经验,遵守的秩序与规范。文章通过对祁连山地区典型性口传文学的描述,试图了解伴随互联网媒介技术的迅速传播,传统口传文学传播空间、传播路径和传播关系发生改变,继而对传统口传文学时代搭建的社会结构、社会秩序、社会规范产生一定影响。

山居笔记:从六盘山到宝塔山

本文以长征之路最后三个节点的建筑创作为例,探索西部山地建筑创作的一般原则,寻找建筑与周边环境的风水关系和建筑内在的逻辑秩序,试图达到散文创作中形散而神不散的创作高度。

中天山北坡冬季降雪变化及其影响因子分析

利用中天山北坡17个国家级气象站1978—2020年冬季逐日降水、气温要素等观测资料,采用多种统计方法,分析冬季降雪时空变化特征及其与气象因子的关系,结果表明:降雪日数和降雪量区域分布相似,均呈“城区多,山区少”分布特征;小雪日减少是导致总雪日减小的直接原因,中雪和暴雪显著增多是造成总降雪量增多的主要原因;持续1 d降水过程是冬季主要降雪过程,随着持续时间的增长,降水过程显著减少,≥5 d降水过程仅占2.8%;近43 a中天山北坡气候呈现较明显的暖湿化趋势,1987年、1994年分别发生降雪量由少变多和平均气温由低变高的突变;降雪量与年降水量、冬季平均最低气温、降雪日数呈显著正相关,年降水量越大、冬季最低气温越低、出现降雪日数越多,冬季降雪量就越大,反之越小。

基于博弈组合赋权-TOPSIS法的富水软岩山岭隧道塌方风险评价

为提高富水软岩山岭隧道塌方风险评价等级的精确性,提出了一种基于博弈组合赋权-逼近理想解排序(technique for order preference by similarity to an ideal solution,TOPSIS)法的隧道塌方风险评价模型。首先,在查阅相关文献并结合工程实际情况的基础上,构建了包括工程地质、勘查设计、组织管理和环境气候4个一级指标、16个二级指标在内的富水软岩山岭隧道塌方风险评估指标体系;其次,针对传统层次分析法在分析处理不确定性信息能力较弱的情况下,通过引入D数理论对其进行改进从而确定主观权重,提高了在确定权重值过程中专家对指标的偏好性,充分利用了专家的经验,为充分考虑所选评价指标间存在的相关性和冲突性,更加合理确定权重系数,优选CRITIC法确定客观权重,通过采用博弈论将主、客权重值进行组合优化,得出最优综合解经加权规范化后基于TOPSIS法进行风险等级判定;最后,运用该评价模型对黄砂隧道中的5个样本隧道区段进行了实例分析。结果表明:进出口样本隧道段风险等级均为3级,而其他隧道洞身段风险等级均为2级,经勘查了解到隧道进出口区段相较于隧道洞身本身存在偏压、涌水等不利因素,因此评估结果与实际情况相吻合,验证了所提模型具有一定的适用性。

含临界指标的周期渐近的分数阶Schr dinger-Poisson系统正解的存在性

主要考察含临界非局部项的周期渐近的分数阶Schr dinger-Poisson系统解的存在性,通过运用山路定理和集中紧性原理,最终得到了正解的存在性.

Existence Result for Discrete Problems with Dependence on the First Order Difference

In this paper, we prove the existence of a positive solution and a negative solution for a class of second order difference equations with dependence on the first order difference. Our proofs are based on the Mountain Pass Lemma and iterative methods.

基于随机参数有序Logit的山区高速公路追尾事故严重程度分析

【目的】基于2012年到2017年汉宁高速河池至棋盘关段的1039条追尾事故数据,对山区高速公路追尾事故的主要影响因素进行分析。【方法】根据事故发生的时间,按白天和夜晚对数据进行分类,分别建立随机参数Logit模型。通过计算各显著变量的边际效用值,来定量分析各影响因素对追尾事故的影响程度。【结果】试验结果表明:白天和夜晚的事故严重程度、影响因素及影响程度均存在明显差异。【结论】性别、道路纵坡因素仅在夜晚模型中显著,节假日因素仅在白天模型中显著。部分变量虽在夜晚和白天模型中都显著,但边际效应却明显不同。

大岗山毛竹林中主要树种生态位及DCA排序分析

为探讨竹林中毛竹(Phyllostachys edulis)与木本植物间的生态位关系,主要采用Levins、MacArthur-Levins和Pearson等指数,对江西大岗山天然毛竹林中20个主要树种的生态位宽度、生态位重叠及种间相关性等生态特征进行了分析和DCA排序研究。结果表明:毛竹是竹林中最强的优势种,其生态位最宽(BA=0.711),且对其他树种生态位重叠度较大(Oij>0.30),而其他多数树种对毛竹生态位重叠度则较小(Oji<0.25),说明它对其他树种具有较明显竞争优势。同时,竹林内种间负关联种对数占67.89%,大多树种间存在较大的生态异质性与资源利用差异性,它们可长期共存,形成较为稳定的竹木混交林,尤其是毛竹与丝栗栲、山乌桕、杉木等树种更易形成竹阔(杉)混交林。