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Search Results: 1 - 10 of 27861 matches for " Ma Wending "
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TESTING STUDY ON DEFORMATION FEATURES OF SURROUNDING ROCKS OF GOB-SIDE ENTRY RETAINING IN FULLY-MECHANIZED COAL FACE WITH TOP-COAL CAVING
综放沿空留巷围岩变形特征的试验研究

Zhang Dongsheng,Mao Xianbiao,Ma Wending,
张东升
,茅献彪,马文顶

岩石力学与工程学报 , 2002,
Abstract: The technique of gob-side entry retaining in fully-mechanized coal face with top-coal caving is the key measure with which the Y type ventilation manner can be used to solve the problem of face gas accumulation. According to the given conditions of Changchun Coal Mine,Luan Bureau,the equivalent material simulation testing is made,and the broken situation and shape of main roof,the influence of different support on roof activity are analysed. The study results provide scientific basis for the determination of the support of gob-side entry and the parameters of roadside filling.
A product involving the $β$-family in stable homotopy theory
Xiugui Liu,Wending Li
Mathematics , 2009,
Abstract: In the stable homotopy groups $\pi_{q(p^n+p^m+1)-3}(S)$ of the sphere spectrum $S$ localized at the prime $p$ greater than three, J. Lin constructed an essential family $\xi_{m,n}$ for $n \geq m + 2 >5$. In this paper, the authors show that the composite $\xi_{m,n}\beta_{s}\in \pi_{q(p^n+p^m+sp+s)-5}(S)$ for $2 \leq s < p$ is non-trivial, where $q=2(p-1)$ and $\beta_s \in \pi_{q(sp+s-1)-2}(S)$ is the known $\beta$-family. We show our result by explicit combinatorial analysis of the (modified) May spectral sequence.
SIMULATION EXPERIMENT STUDY ON LAW OF GOB ROOF FALL BASED ON GAS DRAINAGE
基于瓦斯抽放的顶板冒落规律模拟试验研究

HUANG Bingxiang,LIU Changyou,CHENG Qingying,LI Zenghua,MA Wending,
黄炳香
,刘长友,程庆迎,李增华,马文顶

岩石力学与工程学报 , 2006,
Abstract: 为了给采空区瓦斯抽放高位长钻孔的设计提供依据,采用相似模拟试验与关键层理论分析采空区顶板产生裂隙、断裂、冒落和离层情况及其变化规律。随工作面的推进,关键层的弯曲变形经历从缓慢-剧烈-缓慢-破断的过程:亚关键层的弯曲下沉范围明显小于主关键层。关键层破断后,其下采空区两侧垫层的弹性变形得到恢复,下沉位移出现反弹。关键层的承载作用和岩层力学特性的差异使关键层间顶板的垮落角不同。覆岩关键层的破断使工作面顶板垮落角减小、周期垮落步距和来压强度都增大。依据覆岩关键层的破断形态、顶板的垮落角和周期来压(垮落)步距可以确定瓦斯抽放钻孔的终孔位置和钻场间钻孔的压茬距离,并预测钻孔的抽放瓦斯效果。
Nonlinear optical properties and superluminal propagation in the ruby
Feng Gao,JingJun Xu,GuoQuan Zhang,WenDing Zhang
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-009-0221-4
Abstract: In this review article, we summarized the study of the weak light nonlinear properties associated with group velocity change in the ruby. The ruby could be reduced to a two-level system, in which population oscillations could lead to a subluminal result. With the modulated TEM00 beam introduced into the ruby, self-phase modulation together with Fraunhofer diffractions and nondegenerate two-wave coupling between different spatial frequency components of the beam occurs at the same time. Population oscillations, self-phase modulation together with Fraunhofer diffractions and nondegenerate two-wave coupling mechanism competes with each other, which brings a new phenomenon of self-superluminal group velocity propagation in the ruby.
Nonlinear optical properties and superluminal propagation in the ruby

Feng Gao,JingJun Xu,GuoQuan Zhang,WenDing Zhang,

科学通报(英文版) , 2010,
Abstract: In this review article,we summarized the study of the weak light nonlinear properties associated with group velocity change in the ruby.The ruby could be reduced to a two-level system,in which population oscillations could lead to a subluminal result.With the modulated TEM00 beam introduced into the ruby,self-phase modulation together with Fraunhofer diffractions and nondegenerate two-wave coupling between different spatial frequency components of the beam occurs at the same time.Population oscillations,sel...
Crystalline Velocity Equation and Kinetics Mechanism of Plagioclase Oscillatory Zoning
斜长石韵律环带的结晶速率方程及其动力学机制

Wu Pingxiao,Wu Jingping,Li Caiwei,Xiao Wending,
吴平霄
,吴金平

岩石学报 , 1998,
Abstract: 根据物理化学基本原理,建立了斜长石韵律环带形成的数学模型。从晶体生长的基本原理出发,提出了按非连续机制生长的斜长石晶体结晶速率表达式。该速率表达式具有过饱和→成核→耗尽循环的反馈特征。斜长石中小尺度韵律环带起因于自组织过程,而与环境因素无关。其成因对应着相对静态的环境。
Uptake and Distribution of Cd in Sweet Maize Grown on Contaminated Soils: A Field-Scale Study
Wending Xu,Guining Lu,Zhi Dang,Changjun Liao,Qiangpei Chen,Xiaoyun Yi
Bioinorganic Chemistry and Applications , 2013, DOI: 10.1155/2013/959764
Abstract: Maize is an economic crop that is also a candidate for use in phytoremediation in low-to-moderately Cd-contaminated soils, because the plant can accumulate high concentration of Cd in parts that are nonedible to humans while accumulating only a low concentration of Cd in the fruit. Maize cultivars CT38 and HZ were planted in field soils contaminated with Cd and nitrilotriacetic acid (NTA) was used to enhance the phytoextractive effect of the maize. Different organs of the plant were analyzed to identify the Cd sinks in the maize. A distinction was made between leaf sheath tissue and leaf lamina tissue. Cd concentrations decreased in the tissues in the following order: sheath > root > lamina > stem > fruit. The addition of NTA increased the amount of Cd absorbed but left the relative distribution of the metal among the plant organs essentially unchanged. The Cd in the fruit of maize was below the Chinese government’s permitted concentration in coarse cereals. Therefore, this study shows that it is possible to conduct maize phytoremediation of Cd-contaminated soil while, at the same time, harvesting a crop, for subsequent consumption. 1. Introduction Heavy metal contamination of agricultural soils is a worldwide problem [1], and in China the problem is especially serious. If all of the low- or moderately-contaminated croplands were removed from agriculture production, then it would be impossible to meet the Chinese people’s food needs. Cadmium (Cd) is one of the most mobile and bioavailable heavy metals in soil and can have eco-toxicological impacts on many organisms, including humans, plants, and animals, even at low concentrations [2, 3]. Maize is a familiar agricultural crop that is widely adapted to regions of China and can be cultivated easily. It has greater dry-mass than many heavy metal hyperaccumulative plants, such as Thlaspi caerulescens and Arabidopsis halleri. The roots and straws of maize can accumulate many kinds of heavy metals, including Cd, from contaminated soil. Fortunately, the seeds and fruits from maize generally accumulate metals at lower concentrations than leaves or roots [1]. After harvesting seeds and/or fruits from the plants, the straw, and roots, with their load of toxic metals, can be removed from the contaminated soil. With each successive growth cycle, the contaminated soil becomes cleaner than before. One of the species used in the present study was sweet maize CT38, which was screened from many maize cultivars as an optimal cultivar for heavy metal by pot test [4]. The other cultivar was sweet maize HZ, which was the
脊柱骨巨细胞瘤的诊断与治疗进展
Diagnosis and management of giant cell tumor of bone in the spine: a brief review

黄稳定,蔡维泺,李俊宽,
HUANG Wending
, CAI Weiluo, LI Junkuan, et al

- , 2018, DOI: 10.19401/j.cnki.1007-3639.2018.08.009
Abstract: 脊柱骨巨细胞瘤(giant cell tumor of bone,GCTB)较为少见,诊断依靠临床、影像和病理三结合原则。脊柱GCTB的治疗难度较大,目前还没有基于循证医学的治疗流程和共识,因而具有很强的挑战性。手术仍然是脊柱GCTB治疗的首选方法,术前选择性动脉栓塞、完整切除肿瘤及术后辅助使用地诺单抗(denosumab)是目前推荐的综合治疗方法。整块切除是脊柱GCTB的理想治疗方式,但手术方法的选择需要遵循个体化原则,根据不同的部位制定不同的手术方案。地诺赛麦对于手术无法完全切除、复发及转移性GCTB的治疗具有一定的优势,术前使用能够有效降低GCTB外科分期,并为整块切除手术创造条件,具有广泛的应用前景。
The Equitable Total Chromatic Number of Some Join graphs  [PDF]
Gang MA, Ming MA
Open Journal of Applied Sciences (OJAppS) , 2012, DOI: 10.4236/ojapps.2012.24B023
Abstract: A proper total-coloring of graph G is said to be?equitable if the number of elements (vertices and edges) in any?two color classes differ by at most one, which the required?minimum number of colors is called the equitable total chromatic?number. In this paper, we prove some theorems on equitable?total coloring and derive the equitable total chromatic numbers?of Pm V?Sn, Pm V?Fn and Pm V Wn.
Improvements and Generalizations of Stochastic Knapsack and Multi-Armed Bandit Approximation Algorithms: Full Version
Will Ma
Computer Science , 2013,
Abstract: The multi-armed bandit (MAB) problem features the classical tradeoff between exploration and exploitation. The input specifies several stochastic arms which evolve with each pull, and the goal is to maximize the expected reward after a fixed budget of pulls. The celebrated work of Gittins et al. [GGW89] presumes a condition on the arms called the martingale assumption. Recently, A. Gupta et al. obtained an LP-based 1/48-approximation for the problem with the martingale assumption removed [GKMR11]. We improve the algorithm to a 4/27-approximation, with simpler analysis. Our algorithm also generalizes to the case of MAB superprocesses with (stochastic) multi-period actions. This generalization captures the framework introduced by Guha and Munagala in [GM07a, GM07b], and yields new results for their budgeted learning problems. Also, we obtain a (1/2-eps)-approximation for the variant of MAB where preemption (playing an arm, switching to another arm, then coming back to the first arm) is not allowed. This contains the stochastic knapsack problem of Dean, Goemans, and Vondrak [DGV08] with correlated rewards, where we are given a knapsack of fixed size, a set of jobs each with a joint distribution for its size and reward, and the objective is to maximize expected reward before the knapsack size is exhausted. Our (1/2-eps)-approximation improves the 1/16 and 1/8 approximations of [GKMR11] for correlated stochastic knapsack with cancellation and no cancellation, respectively, providing the first tight algorithm for these problems that matches the integrality gap of 2. We sample probabilities from an exponential-sized dynamic programming solution, whose existence is guaranteed by an LP projection argument. We hope this technique can also be applied to other dynamic programming problems which can be projected down onto a small LP.
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