Floristic diversity, regeneration status, and vegetation structure of woodlands in Metema Area, Amhara National Regional State, North-western Ethiopia

We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia Our objective was to describe plant species composition, diversity, re- generation status, and population structure by a selective approach with a systematic sampling design. A total of 74 quadrats （each for 25 m x 25 m, spaced at intervals of 150--200 m） were sampled along established tran- sect lines following the homogeneity of the vegetation. Vegetation data including cover-abundance, height, diameter at breast height （DBH）, and numbers of seedlings and saplings of woody species were analyzed using Excel spreadsheet, Shannon Weiner diversity index, and PAST version 1.62. A total of 87 vascular plant species of 74 genera and 36 families were recorded. The dominant family was Fabaceae represented by 16 （18.39 %） species of 13 genera. Shannon Weiner diversity and evenness were 3.67 and 0.82, respectively, which showed that the area was en- dowed with rich floral diversity evenly distributed. The vegetation structure, as quantified by cumulative diameter class frequency distribution, plotted as an interrupted inverted-J- shape pattern with a sharp decrease in the 2nd diameter class. This indicated poor vegetation structure. The diameter classes frequency distributions of selected species plotted in four general patterns i.e., interrupted Inverted-J-shape, J-shape, Bell-shape and Irregular-shape. In conclusion, although the area showed high floral diversity and evenness, woody species including Sterculea setigera, Boswellia papyrifera, and Pterocarpus lucens showed lowest recruitment of seedlings and saplings.

Structure formation of entanglement entropy in a system of two superconducting qubits coupled with an LC-resonator

This paper investigates theoretically the evolutions of the entanglement entropy of a system of two coupled-charge- qubits interacting with an LC-resonator. It is found that when the initial states of the two qubits are prepared in a given superposition excited state, the evolution of the von Neumann entropy of the system depends significantly on the coupling strength between the two Josephson charge qubits. With the variation of the coupling strength, the evolution of the entanglement entropy of the system forms some structures, especially the periodically bistable properties, which are the first discovered for such a system to our knowledge. It is found that the relative entropy entanglement of the system is also sensitive to the variation of the coupling strength between the two charge qubits, some novel ＇collective oscillations＇ of the relative entropy are found for the system.

Information in the Structure of Reality:the Scientific Worldview and the Fundamental Question of Philosophy

We offer a new understanding of the scientific world and the contents of the basic question of philosophy,which is based on an analysis of the phenomenon of the specific information in the various components of the structure of reality.It is shown that,in addition to material objects,processes,and events,in the real world are also intangible objects,processes and conditions that are in its information content.So the basic question of philosophy is proposed to treat the relationship as a tangible and intangible component of reality.More succinctly it can be formulated as the ratio of matter and information.This allows you to point to some new challenges studying the phenomenon of information in various components of the structure of reality.

Filtering algorithm of line structured light for long-distance obstacle detection

Since unmanned ground vehicles often encounter concave and convex obstacles in wild ground, a filtering algorithm using line structured light to detect these long distance obstacles is proposed. For the line structured light image, a ranked-order based adaptively extremum median （RAEM） filter algorithm on salt and pepper noise is presented. In the algorithm, firstly effective points and noise points in a filtering window are differentiated; then the gray values of noise points are replaced by the medium of gray values of the effective pixels, with the efficient points＇ gray values unchanged; in the end this algorithm is proved to be efficient by experiments. Experimental resuits demonstrate that the image blur, resulting into proposed algorithm can remove noise points effectively and minimize the protecting the edge information as much as possible.

Influence of environmental factors on corrosion damage of aircraft structure

Corrosion is one of the important structural integrity concerns of aging aircraft, and it is estimated that a significant portion of airframe maintenance budgets is directed towards corrosion-related problems for both military and commercial aircraft. In order to better understand how environmental factors influence the corrosion damage initiation and propagation on aircraft structure and to predict pre-corrosion test pieces of fatigue life and structural integrity of an effective approach, this paper uses the cellular automaton (CA) method to character the effect of electrolyte concentrations, dissolution probabilities, and temperature on the corrosion damage of a metal structure exposed to an aggressive environment, and the procedure for applying the local rules between the cells of the CA to simulate the corrosion damage evolution is formulated. The simulation results show that the different electrolyte concentrations, dissolution probabilities and temperature, the laws of the dissolution current with time are investigated and they obey the time power function.

Crystal Structure and Electronic Structure of a Luminescent Compound 2-(2-Pyridyl) Benzimidazole

The crystal structure of 2-(2-pyridyl) benzimidazole was determined by single- crystal X-ray diffraction at 193(2) K. It crystallizes in orthorhombic system, space group Pbca with unit cell constants a = 10.6204(7), b = 10.1407(4), c = 18.6327(8) , Z = 8, V = 2006.7(2) 3, Dc = 1.292 g/cm3, F(000) = 816 and m(MoK) = 0.081 mm-1. The structure was refined to R = 0.0317 and wR = 0.0454 for 795 observed reflections with I > 2s(I). In the solid state, it has an emission maximum at 369 nm, while in solution (DMSO), the maximum excitation is at 372 nm. Quantum chemistry calculation was performed by the method of density functional theory. Theoretical results show that atom N is the reactive site when coordinating with a metal, and the electronic structure of the title compound presents excellent carrier transport properties.

基于论元结构和论元角色的英语-(a)tion型后缀动词名物词具体义研究

英语双音节和多音节及物动词大多可以通过添加-(a)tion或同类后缀的形式构成相应的动词名物词。宏观上讲,这类词有具体和抽象两种意义,抽象义往往和原动词的意义十分接近,表示动作或行为本身,而具体义则可从相应动词的论元结构和论元角色来找到语义依据。具体来说,具体义往往可以通过原动词论元结构中的某一论元或其上位词来表达。英语这类名物词的具体义与相应动词论元的这种内在关系的形成,与动词词义本身以及人类的认知规律均有重要联系。

基于计算流体力学的抛物面壁旋流器数值仿真研究

为了进一步提高小型水力旋流器分离细微颗粒的能力,提出一种新型抛物面壁水力旋流器。应用计算流体力学软件Fluent分析比较了抛物面壁和圆锥面壁在不同条件下的分离特性、内部流场及颗粒物轨迹规律。在综合考虑分离效率以及体积大小的基础上,对抛物面壁进行选型优化。结果表明,抛物面壁旋流器各项分离性能的指标均更佳,压力梯度与速度梯度优势更明显,整体分离效率更高。得到最佳结构参数为,底流口直径8 mm、锥体高度175.54 mm,抛物线方程为y=-0.39164x^(2)+19.7166x-318.14。

Regeneration dynamics of dominant tree species along an altitudinal gradient in moist temperate valley slopes of the Garhwal Himalaya

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to understand the regeneration dynamics of the dominant tree species along an altitudinal gradient in naturally regen- erating, restricted access forest. The overall regeneration status was fairly high in the study area. Most of the native canopy and undercanopy domi- nants had frequent reproduction and expanding populations, which sug- gests the stability of forest structure/composition and further expansion of dominant species. The overall regeneration of trees in the forest had a greater contribution of middle and understurey species. Because of infre- quent rep＇roduction and declining populations of some of the dominant native species viz., Abies pindrow, Alnus nepalensis and Betula alnoides, structural/compositional changes in the future are expected in respective forests dominated by them..4bies pindrow and Taxus baccata need im- mediate attention by forest managers for their survival in the area. Seed- lings were found to be more prone to competition from herb and shrubs than saplings.

A Novel Verification Approach of Workflow Schema

A workflow schema is an abstract description of the business processed by workflow model, and plays a critical role in analyzing, executing and reorganizing business processes. The verification issue on the correctness of complicated workflow schemas is difficult in the field of workflow. We make an intensive study of it in this paper. We present here local errors and schema logic errors （global errors） in workflow schemas in detail, and offer some constraint rules trying to avoid schema errors during modeling. In addition, we propose a verification approach based on graph reduction and graph spread, and give the algorithm. The algorithm is implemented in a workflow prototype system e-ScopeWork.

Wrinkle-crease interaction behavior simulation of a rectangular membrane under shearing

Wrinkling analysis of a rectangular membrane with a single crease under shearing is performed to understand the wrinkle-crease interaction behaviors. The crease is considered by introducing the residual stresses from creasing and the effective modulus into the baseline configuration with assumed circular cross-sectional crease geometry. The wrinkling analysis of the creased membrane is then performed by using the direct perturb-force （DP） simulation technique which is based on our modified displacement components （MDC） method. Results reveal that the crease may influence the stress transfer path in the membrane and further change the wrinkling direction. The crease appears to improve the bending stiffness of the membrane which has an effective resistance on the wrinkling evolution. The effects of the crease orientation on wrinkle-crease interaction are studied toward the end of this paper. The results show that the wrinkling amplitude, wavelength, and direction increase as the crease orientation increases, and the wrinkling number decreases with the increasing crease orientation. These results will be of great benefit to the analysis and the control of the wrinkles in the membrane structures.

DEEP-UV CONFOCAL FLUORESCENCE IMAGING AND SUPER-RESOLUTION OPTICAL MICROSCOPY OF BIOLOGICAL SAMPLES

A wide range of techniques has been developed to image biological samples at high spatial and temporal resolution.In this paper,we report recent results from deep-UV confocal fAuorescence microscopy to image inherent emission from fuorophores such as tryptophan,and structured ilumination microscopy(SIM)of biological materials.One motivation for developing deep-UV fhuorescence imaging and SIM is to provide methods to complement our measurements in the emerging field of X-ray coherent diffractive imaging.

GEOTECTONIC BACKGROUND OF PYROPHYLLITE MINERALIZATION AND ORE-BEARING VOLCANIC FORMATION IN SOUTHEASTERN COASTAL AREAS,CHINA

The volcanic gas-liguid type of pyrophyllite deposits in the SoutheasternCoastal areas, China are the product of tectono-magama-volcanism in Diwa regions. The pyro-phyllite ore-bearing volcanic formation were formed in the maximum-mobility period of Diwa, which are mainly the Late Jurassic strata and are secondly the Early Cretaceous volcanic-sedi-mentary rock series strata. The lithology of the host rock is mainly rhyolitic crystal-vitric tuff, and the chemical composition is characterized by high silicon rich alumium and low iron, be-longing to the acid-intermediate-acid rock and the kalicalc-calc-alkalic series and the rhyo-lite-rhyodacite assemblage. They play an important role in the pyrophyllite mineralization.

政策视角下我国档案利用服务中部门合作结构与演进

厘清档案利用服务中的部门合作结构与演进特征,有助于促进部门协同机制建设,并提升档案利用服务水平。本文以中央层级档案利用服务相关政策为研究对象,将我国档案利用服务政策演进分为政策初创阶段、政策深化阶段、政策体系化阶段与政策转型阶段,这四个阶段呈现参与政策制定的部门逐渐增多,“高位推动”转向国务院部委为主的变化。运用关联网络分析方法探讨档案利用服务中部门合作结构及其演进特征,分析发现:部门合作不断扩大及趋于集中,并形成了多元化的共同体;部门合作整体构型由“松散型”转向“中心边缘型”;部门合作局部构型则由“二元组”演变为“三元交互”。为促进跨部门政策协同,针对当前档案利用服务中部门合作规模较小、稳定性较弱,且整体连通性不强的特点,提出应充分利用全国档案查询利用服务平台,并建立档案利用服务联席会议制度的建议。

汽车空调涡旋压缩机排气孔优化研究

针对汽车空调涡旋压缩机排气孔处气体流动变化产生的流动损失问题,对排气孔结构进行优化,以期降低流动损失并提高排气压力。通过三维动网格模型对不同排气孔结构的涡旋压缩机排气过程进行瞬态仿真,发现腰果形排气孔更大的截面积使其拥有更好的开启特性,可有效降低排气损失,提高排气稳定性。在对腰果形排气孔采取进一步扩压式优化后,发现其可以更加有效地降低排气速度并提高排气压力。

结构性资产负债表衰退及其宏观经济效应与政策协整

疫后恢复政策组合拳,有力承托了中国宏观经济运行的积极因素,但当前经济下行压力依然突出,部分领域发展呈现明显波动,亟须有能够“对症下药”的理论解释和宏观政策应对。构建NK-DSGE模型,探讨结构性资产负债表衰退的宏观经济效应以及相应政策协整问题。研究结果展示,典型事实蕴含中国不存在总体资产负债表衰退,但存在结构性资产负债表衰退的证据。在宏观层面,结构性资产负债表衰退冲击会导致宏观经济较长时期下滑,乃至引发债务-通缩风险,而在微观层面,减轻资产负债表衰退企业的债务厌恶和改善正常经营企业的融资约束有助于减弱上述影响。调节效应分析表明,结构性资产负债表衰退会抑制技术进步与需求扩张对产出的促进作用,但在技术进步情形下,上述抑制作用有限。为减小福利损失,财政政策应盯住衰退类企业债务,货币政策应锚定高融资约束企业债务,并提高政策反应力度,宏观审慎政策应提高对资产价格的敏感度。上述结论为理解微观层面债务厌恶所产生的宏观合力以及设计实施相应政策搭配提供参考。

平台经济赋能实体经济发展研究——来自中国省级面板数据的证据

随着数字经济快速发展,平台经济逐渐成长为具有重要影响力的经济模式,其特性为实体经济的增长赋予了新的动能。本文采用2012~2022年间中国省级面板数据,研究平台经济是否能够促进实体经济发展。实证结果表明,平台经济能够显著地对实体经济发展产生正向影响。进一步的研究发现,产业结构、数字普惠金融和财政分权度均能强化平台经济对实体经济发展的正向影响,上述因素在推动平台经济与实体经济融合发展中发挥重要作用。本文的研究为理解当前我国平台经济与实体经济之间的关系提供了经验证据。

基于计算机视觉和视频插帧的结构振动测试与模态识别

结构振动测试和模态参数识别是基于结构动态特性进行结构健康监测(SHM)的基本方法。为克服传统接触式测试的不便,引入了非接触式计算机视觉方法,其中以智能手机为数据采集装置的方法受到越来越多的关注。然而智能手机相机往往因为性能受限无法满足需求,从而导致测量结果精度下降。为此,提出一种改进的视频插帧算法EQVI-T与改进的边缘检测算法,通过提高原始视频的帧率和提出的特征点追踪方法共同提升计算精度。为验证这一方法的有效性,将其应用于试验室模型的位移响应监测和模态参数识别,并进行了定量和定性评估。结果表明,所提方法在提高测量精度和准确性方面具有显著优势,展示了其在结构振动测试中的潜在应用价值。

结构参数对CO_(2)离心压缩机的性能影响分析

为研究各关键结构参数对CO_(2)离心压缩机性能的影响,针对某MW级压缩CO_(2)储能系统低压段中的一级进行了一维设计和三维数值模拟。基于该模型研究了叶片数、叶顶间隙、叶片出口安装角和叶轮出口相对宽度4种关键结构参数对压缩机性能的影响。研究结果表明:叶片出口安装角和叶顶间隙对离心压缩机性能的影响最大,其次是叶片数和叶轮出口相对宽度;增加叶片出口安装角度可显著提高压缩机的做功量及压比,但过大角度会使得流动损失增大而造成效率的降低;随着叶顶间隙的增大,泄漏流动会更加严重,从而影响压缩机的性能;减少叶片数量会减小叶片对流体的约束,更易产生流动分离;叶轮出口相对宽度与压缩机设计流量相关,过小的相对宽度会增大摩擦、泄漏等损失,进而影响压缩机性能及运行工况范围。

库车坳陷阿瓦特地区巴西改组构造变形与油气成藏特征

库车坳陷前陆冲断带构造变形主要发生在喜马拉雅运动中—晚期,前人确定了盐上浅层褶皱构造变形的启动时间,但对盐下冲断构造变形与油气成藏时间的研究缺少绝对定年的约束。以库车坳陷阿瓦特地区为例,利用岩相学观察、方解石U-Pb定年、流体包裹体分析等资料,分析阿瓦特地区下白垩统巴西改组储集层成岩作用、方解石脉体形成时间及油气成藏过程,确定了阿瓦特地区巴西改组构造变形和油气成藏时间。结果表明:阿瓦特地区巴西改组储集层发育2期方解石,早期方解石胶结物形成年龄为(98.0±14.0)Ma,晚期方解石脉体形成年龄为(3.7±1.0)Ma,代表了盐下冲断构造变形时间;方解石脉体中发育1期油包裹体和1期气包裹体,通过流体包裹体均一温度、埋藏史和热史,推断油充注时间为4.0—3.0 Ma,天然气充注时间为3.0—1.0 Ma,早期油藏经历了上新世晚期气洗改造,形成现今的凝析气藏。