都市核心区大尺度绿色空间文化特色塑造路径--以成都市环城生态区为例

在公园城市建设的新阶段,人文关怀、绿色生态、场景营城等价值理念在城市规划建设与发展中得到审视与关注。作为兼具生态、生活、生产等复合要素的有机体,都市核心区大尺度绿色空间不仅是人们亲近自然、休闲游憩的主要场所,还是孕育文化活动、提升城市魅力的重要名片,承载着人们对美好生活的追求与向往。以成都市环城生态区为例,研究梳理都市核心区大尺度绿色空间的主要特征,从体系构建、设施布局和场景营造等维度明确绿色空间文化特色塑造的方法路径,助力环城生态区建设实现由总量控制到品质优化再到品位提升的升级,以期为类似区域的生态价值转化和文化魅力彰显提供规划思路。

Universal hierarchical symmetry for turbulence and general multi-scale fluctuation systems

Scaling is an important measure of multi-scale fluctuation systems. Turbulence as the most remarkable multi-scale system possesses scaling over a wide range of scales. She-Leveque （SL） hierarchical symmetry, since its publication in 1994, has received wide attention. A number of experimental, numerical and theoretical work have been devoted to its verification, extension, and modification. Application to the understanding of magnetohydrodynamic turbulence, motions of cosmic baryon fluids, cosmological supersonic turbulence, natural image, spiral turbulent patterns, DNA anomalous composition, human heart variability are just a few among the most successful examples. A number of modified scaling laws have been derived in the framework of the hierarchical symmetry, and the SL model parameters are found to reveal both the organizational order of the whole system and the properties of the most significant fluctuation structures. A partial set of work related to these studies are reviewed. Particular emphasis is placed on the nature of the hierarchical symmetry. It is suggested that the SL hierarchical symmetry is a new form of the self-organization principle for multi-scale fluctuation systems, and can be employed as a standard analysis tool in the general multi-scale methodology. It is further suggested that the SL hierarchical symmetry implies the existence of a turbulence ensemble. It is speculated that the search for defining the turbulence ensemble might open a new way for deriving statistical closure equations for turbulence and other multi-scale fluctuation systems.

Simulation and visualization of the displacement between CO2 and formation fluids at pore-scale levels and its application to the recovery of shale gas

This article reports recent developments and advances in the simulation of the CO2-formation fluid displacement behaviour at the pore scale of subsurface porous media. Roughly, there are three effective visualization approaches to detect and observe the CO2-formation fluid displacement mechanism at the micro-scale, namely, magnetic resonance imaging, X-ray computed tomography and fabricated micromodels, but they are not capable of investigating the dis- placement process at the nano-scale. Though a lab-on-chip approach for the direct visualization of the fluid flow behaviour in nanoscale channels has been developed using an advanced epi-fluorescence microscopy method combined with a nanofluidic chip, it is still a qualitative analysis method. The lattice Boltzmann method （LBM） can simulate the CO2 displacement processes in a two-dimensional or three-dimensional （3D） pore structure, but until now, the CO2 displace- ment mechanisms had not been thoroughly investigated and the 3D pore structure of real rock had not been directly taken into account in the simulation of the CO2 displacement process. The status of research on the applications of CO2 displacement to enhance shale gas recovery is also analyzed in this paper. The coupling of molecular dynamics and LBM in tandem is proposed to simulate the CO2-shale gas displacement process based on the 3D digital model of shale obtained from focused ion beams and scanning electron microscopy.

Decentralized Stabilization of Large-scale Uncertain Systems with State-Delays——LMIs Approach

This paper deals with the problem of decentralized robustcontrol for a class of interconnected uncertain systemswith state delays.The parameter uncertainties are un-known but norm-bounded.A new sufficient condition isobtained for each subsystem and overall system to be sta-bilizable via linear memoryless state feedback robust de-centralized controllers.The results depend on the size of the delays and are given in terms of linear matrix ine-qualities,so they are less conservative than those of delay-independent.Moreover,matching condition is not a necessary condition.Finally,an example is presented to illustrative the effectiveness of the proposed method.

Utilization Survey of Livestock Manure Resources in Large-scale Farms of Yangzhou

Based on surveying the conditions of large -scale farms and commercial manure in the each county of Yangzhou city, the situations and problems for utilization of livestock manure resources were grasped. After an analysis of the potential value of livestock manure, the suggestion and strategy for utilization of livestock manure resources were proposed based on the actual conditions in Yangzhou city.

双亲灭活的原生质体融合株啤酒酵母DR9-2的构建及其特性的研究

啤酒酵母菌株JW1-1发酵液中的双乙酰、总高级醇的含量较低,但发酵度较低,发酵液中的乙醛含量较高;啤酒酵母菌株NW7-45发酵度较高,发酵液中的乙醛含量较低,但发酵液中的双乙酰、总高级醇的含量较高。为了得到优良的菌株,以紫外线灭活的菌株JW1-1原生质体和热灭活的菌株NW7-45原生质体为亲本进行融合。经三角瓶发酵筛选,得到较优良的融合株DR9-2和DR9-24。其中融合株DR9-2以12°Bx麦芽汁为培养基,用500L的发酵罐在12℃下发酵,发酵11d发酵液的发酵度为69.5%,发酵液中的双乙酰、乙醛和总高级醇的含量分别为0.0124mg/L、7.70mg/L和61.88mg/L。从融合株DR9-2的主要发酵特性和啤酒口感品评的结果表明,该菌株在啤酒酿造工业中具有应用前景。

平动矩形贮箱刚-液耦合非线性动力学研究

首先应用H-O原理建立了矩形贮箱刚-液耦合系统平动的耦合动力学模型,在贮箱水平运动情况下,给出满足边界条件的速度势函数和液面波高的级数表达式,采用伽辽金法离散,将动力学模型转化为常微分方程组,在给定贮箱运动规律和给定外力规律两种形式下,分析了刚-液耦合系统固有频率变化规律,并应用多尺度法对系统的一阶主共振进行解析分析,研究了液体稳态解的幅频曲线,均发现跳跃及软、硬特性随液深转换的现象,在给定水平外力下,得到液体稳态解的同时还可得到刚体稳态解,两者定性性态相同。最后用数值法验证了解析解的正确性。

解析欧洲多尺度风景特质识别的5项议题

【目的】风景特质识别是进行全域风景保护、规划与管理的基础性工作之一,具有综合主观判断与客观属性的特点。系统梳理欧洲多尺度识别中定性与定量、主观与客观之间的关系,对中国全域风景特质的识别具有借鉴意义。【方法】通过文献归纳与演绎,分析风景特质定义引申出的识别主体、要素类别、感知方式、识别方法、图解形式5项议题。【结果】阐述了多尺度风景特质的层级特征,总结了宏观到微观尺度下移过程中5项议题的变化模式:识别主体由专家转向公众转变;要素类别由自然向文化转变;感知方式由间接向直接转变;识别方法由数字向人工转变;图解形式由科学性向科普性转变。归纳了多尺度识别的公式化表达。【结论】以尺度作为转变载体,解析了综合主观性和客观性的多尺度风景特质识别的基本路径,为全域风景的多样性、连续性和地域性保护、规划与管理提供帮助。

基于改进PSO-SIFT算法的油田遥感图像匹配

针对油田遥感图像在灰度有明显差异的情况下,联合位置、尺度和方向的尺度不变特征变换(PSO-SIFT)算法很难为其找到足够多的正确对应关系,且花费时间较长的问题,提出一种基于改进PSO-SIFT算法的图像匹配算法.首先采用“回”字型分块思想构建特征描述符,降低特征描述子的维度;然后使用基于全局运动建模的双边函数(BF)算法与快速样本共识(FSC)算法相结合的匹配策略,对所得的匹配对进行误匹配剔除,以增加正确匹配的数量;最后将该算法与4种同类算法及原PSO-SIFT算法进行对比.实验结果表明,该算法比同类算法精度更高,与原算法相比不仅保证了图像匹配的精度,正确匹配对数量也增加了约3倍,且匹配时间约缩短20 s.

“信噪比-两步法”的一个注记

参数设计是日本质量专家田口倡导的一种质量工程方法.从函数结构方面考察了信噪比指标下调节因子的存在性,并指出了参数设计中scale因子的重要性.

捷氏吹绵蚧生物学特征的研究

为明确捷氏吹绵蚧Icerya jacobsoni识别特征和生物学特征,研究采用室外模拟自然条件观察记录捷氏吹绵蚧不同发育阶段的生物学特征。结果显示,捷氏吹绵蚧雌雄虫具有不同的世代生活史,有典型的性二型现象,其卵呈淡黄色或乳白色,卵壳表面光滑有光泽,半透明;1龄若虫初孵化时呈卵圆形,为淡黄色,行动活泼;2龄若虫身体四周布满黄色的体缘毛,周身形成20根蜡突,末端2根常合并;3龄若虫仅存在雌虫,形似雌成虫;蛹仅存在雄虫,为离蛹;雌成虫体型椭圆形,体色橘红色,体表覆盖大量白色蜡粉,个体更大,蜡突更长;雄成虫体型小而细长,末端生有两个肉质突出物,其上各有7~10根毛。各虫态主要行为习性也不同。

基于图像特征的汉字字形相似度计算

汉字作为一种数量众多,结构复杂的象形文字,其字形的相似度计算对汉语的错别字识别和纠正具有重要意义。将汉字视为图形,通过尺度不变特征变换算法提取汉字的特征点,并利用汉字间特征点的对应关系,提出了一种基于特征点的相似度计算方法。对《通用规范汉字表》的8105个汉字进行了相似度分析,结果表明,该方法和人的认知结果比较一致。

On the horizontal distribution of algal-bloom in Chaohu Lake and its formation process

Based on the remote sensing images of algae, the present work analyzes the horizontal distribution characteristics of algal blooms in Chaohu Lake, China, which also reveals the frequency of algal blooms under different wind directions. Further, an unstructured-grid, three-dimensional finite-volume coastal ocean model （FVCOM） is applied to investigate the wind-induced currents and the transport pro- cess to explain the reason why algal blooms occur at the detected places. We first deduce the primary distribution of biomass from overlaid satellite images, and explain the formation mechanism by analyzing the pollution sources, and simulating the flow field and transportation process under prevailing wind over Chaohu Lake. And then, we consider the adjustment action of the wind on the corresponding day and develop a two-time scale approach to describe the whole formation process of algae horizontal distribution in Chaohu Lake. That is, on the longer time scale, i.e., during bloom season, prevailing wind determines the primary distribution of biomass by inducing the characteristic flow field; on the shorter time scale, i.e., on the day when bloom occurs, the wind force adjusts the primary distribution of biomass to form the final distribution of algal bloom.

Nonlinear study of the dynamic behavior of a string-beam coupled system under combined excitations

In this paper,the nonlinear dynamic behavior of a string-beam coupled system subjected to external,parametric and tuned excitations is presented.The governing equations of motion are obtained for the nonlinear transverse vibrations of the string-beam coupled system which are described by a set of ordinary differential equations with two degrees of freedom.The case of 1：1 internal resonance between the modes of the beam and string,and the primary and combined resonance for the beam is considered.The method of multiple scales is utilized to analyze the nonlinear responses of the string-beam coupled system and obtain approximate solutions up to and including the second-order approximations.All resonance cases are extracted and investigated.Stability of the system is studied using frequency response equations and the phase-plane method.Numerical solutions are carried out and the results are presented graphically and discussed.The effects of the different parameters on both response and stability of the system are investigated.The reported results are compared to the available published work.

基于Mask-RCNN的纸质医药包装钢印字符识别

为实现纸质医药包装钢印字符的实时检测,设计一种基于图像处理和深度学习的钢印字符识别系统。系统首先采用多种图像处理的方法对原始打光下的图像进行预处理,从而自动提取图片中的感兴趣区域,并将其输入训练好的Mask-RCNN网络进行实例分割,得到每张图片中的不同字符的像素位置与其字符数值。实验结果表明,对比传统的字符识别方法,该方法可以很好地解决纸质医药包装钢印字符图片中灰度跳变不明显的问题,准确分割出纸质包装盒图片中的钢印字符并进行标记,其字符的识别准确率达到99%,为生产线上钢印字符的识别和记录提供了新的解决思路,具有较高的实用价值。

Laboratory investigation of a new scale inhibitor for preventing calcium carbonate precipitation in oil reservoirs and production equipment

The formation of mineral scale is a complex problem during the oilfield operations. Scale inhibitors are widely used to prevent salt precipitation within reservoirs, in downhole equipment, and in production facilities. The scale inhibitors not only must have high effectiveness to prevent scale formation, but also have good adsorption- desorption characteristics, which determine the operation duration of the scale inhibitors. This work is focused on the development of a new scale inhibitor for preventing cal- cium carbonate formation in three different synthetic for- mation waters. Scale inhibition efficiency, optical density of the solution, induction time of calcium carbonate for- mation, corrosion activity, and adsorption-desorption ability were investigated for the developed scale inhibitor. The optimum concentration of hydrochloric acid in the inhibitor was determined by surface tension measurement on the boundary layer between oil and the aqueous scale inhibitor solution. The results show that the optimum mass percentage of 5 % hydrochloric acid solution in the inhi- bitor was in the range of 8 % to 10 %. The new scale inhibitor had high efficiency at a concentration of 30 mg/L. The results indicate that the induction period for calcium carbonate nucleation in the presence of the new inhibitor was about 3.5 times longer than the value in the absence of the inhibitors. During the desorption process at reservoir conditions, the number of pore volumes injected into the carbonate core for the developed inhibitor was significantly greater than the volume of a tested industrial inhibitor, showing better adsorption/desorption capacity.

Formation conditions and exploration direction of large natural gas reservoirs in the oil-prone Bohai Bay Basin, East China

The Bohai Bay Basin is a typical oil-prone basin, in which natural gas geological reserves have a small proportion. In this basin, the gas source rock is largely medium-deep lake mudstone with oil-prone type Ⅱ2-Ⅱ1 kerogens, and natural gas preservation conditions are poor due to active late tectonic movements. The formation conditions of large natural gas fields in the Bohai Bay Basin have been elusive. Based on the exploration results of Bohai Bay Basin and comparison with large gas fields in China and abroad, the formation conditions of conventional large-scale natural gas reservoirs in the Bohai Bay Basin were examined from accumulation dynamics, structure and sedimentation. The results show that the formation conditions of conventional large natural gas reservoirs in Bohai Bay Basin mainly include one core element and two key elements. The core factor is the strong sealing of Paleogene "quilt-like" overpressure mudstone. The two key factors include the rapid maturation and high-intensity gas generation of source rock in the late stage and large scale reservoir. On this basis, large-scale nature gas accumulation models in the Bohai Bay Basin have been worked out, including regional overpressure mudstone enriching model, local overpressure mudstone depleting model, sand-rich sedimentary subsag depleting model and late strongly-developed fault depleting model. It is found that Bozhong sag, northern Liaozhong sag and Banqiao sag have favorable conditions for the formation of large-scale natural gas reservoirs, and are worth exploring. The study results have important guidance for exploration of large scale natural gas reservoirs in the Bohai Bay Basin.

Multi-fractal Behaviors of Relative Humidity over China

The multi-fractal ity over China are studied behaviors of relative humid using the multi-fractal de trended fluctuation analysis （DFA） method. Three multi fractal parameters （the spectrum width Aa, the asymmetry Aaas, and the long-range correlation exponent a0） of the singularity spectrum are introduced to quantify the multi-fractal behaviors. The results show that multi-frac tality exists in daily humidity records over most stations in China and is mainly due to the broad distribution of the probability density of the sequence values. Strong multi fractal behaviors over some stations in the Yunnan, Guangdong, and Inner Mongolia provinces are obvious. These behaviors are mainly caused by different long range correlations between large and small fluctuations. The asymmetry of the singularity of relative humidity records is weak, except for a small number of stations in the far east and west of China, where the singularity spec trum is left-skewed. Finally, the long-range correlations in North China are stronger than those in South China, which indicates better predictability in North China. By studying the parameters of the multi-fractal spectrum, various data of long-range power law correlations of the relative humidity records are obtained, which may pro vide theoretical support for climate prediction.

Scale-Invariance Exists in the Series of Character Intervals in the Four Great Chinese Novels

The scale-invariance behavior has been widely observed in English or other phonetic language texts. In the present study, we examine whether the semantic language, Chinese can also show this behavior. Typically, the scale-invariance behavior is examined in the series of character intervals for the four great Chinese novels by a method of detrended fluctuation analysis. We observe that the scale-invariance behavior characterized by a scaling exponent around 0.60 exists in each novel. Moreover, we divide each novel into three parts with equal number of chapters, and we also observe the existence of scale-invariance in the interval series for each part. Interestingly, we find that there is evident difference in the scaling exponents between the first(or second) part and the third part in the novel of A dream of red mansions, and the difference between parts is not evident for the other three novels. Our observation suggests that there are two writing styles in A dream of red mansions, which are consistent with current prevailing view that the first 80 chapters and the last 40 chapters were accomplished by Xueqin Cao and E Gao, respectively. Our method may shed light on the identification of writing styles in written texts.

影响跨境电商从业人员跨文化能力的个人因素分析

基于文化间性视角的跨文化能力模型,以跨境电商企业从业人员为受试对象,构建跨境电商从业人员跨文化能力自评量表,采用混合研究方法,从情感、认知、行为和道德四个维度探究跨境电商从业人员的跨文化能力表现。结果表明,跨境电商从业人员的跨文化能力总体水平较高,但从业人员的个人习得特质对其跨文化能力的特定维度有不同影响。研究建议,应深入探究跨境电商从业人员跨文化能力的内涵及影响各维度表现的因素,有针对性地开展跨文化能力培训,并完善考评、保障和激励机制,通过从业者跨文化能力的整体提升,来优化跨境电商企业的持续竞争力,促进跨境电商产业的良性发展。