“地方”理论视角下的网络游记研究——以北京三里屯游记分析为例

近年来针对网络游记的研究逐渐增加,网络游记已经成为地方感量表以外,另一个研究旅游地地方意象和游客旅游体验的重要手段。大多数网络游记研究采用了内容分析法,通过对关键词的抓取形成定量数据,以此判断旅游地在游客中形成的地方意象,为旅游地规划提供了重要的依据。这类研究以人文主义地理学的"地方"概念为依据,利用对旅游者的主观地方感受和个体地方认知来勾勒旅游地的地方性,然而又并非对人文主义研究方法的全面应用。文章重新梳理了人文主义、社会建构学派和结构化理论3种不同研究视角下的"地方"概念,并尝试以不同的"地方"理论视角对蚂蜂窝网站上关于北京三里屯的游记进行分析,探讨了网络游记研究的多种可能性。除了体现个人地方经验以外,对网络游记的分析同样可以深入到社会结构对个人地方感受的影响,以及撰写和传播网络游记这一实践行为本身是如何将个人地方经验转化为社会建构的地方性。

论劳伦斯·布依尔“地方”理论之嬗变

通过对生态学者劳伦斯·布依尔的"地方"理论进行探讨,发现他在生态批评三部曲中先后提出了"自然地方"、"文化地方"和"世界地方"的概念。其"地方"理论发展脉络与生态批评研究以自然为导向的"第一次浪潮",以文化为导向的"第二次浪潮",和以全球化为导向的"第三次浪潮"的发展节奏不谋而合,是对生态批评理论的丰富和深化。

基于“地方蜂鸣—区域管道”理论的城市网络外部性研究框架构建

近年来,随着城市间各类流要素联系的增强,城市网络外部性对城市发展的作用愈发明显,但当前的研究主要集中在集聚外部性层面,对于城市网络外部性的探讨仍显不足。在综述城市网络外部性研究进展的基础上,提出“地方蜂鸣—区域管道”理论并基于此构建城市网络外部性与城市高质量发展联系的研究框架:一方面构建城市网络外部性对城市高质量发展作用的“过程—机理—效应”理论与内容框架;另一方面从结构网络视角构建包含尺度嵌套、强度、均衡度等多维度的城市网络外部性评价指标体系,以对城市网络外部性的直接作用与空间溢出效应进行探讨。

Natural environment suitability for human settlements in China based on GIS

With the degeneration of environment and acceleration of urbanization,human environment has attracted great attention worldwide.This paper sets up the Human Settlements Environment Index(HEI) model and evaluates the natural environment suitability for Human Settlements in China based on GIS technology.The results show that the HEI of China decreases from southeast to northwest in general,HEI is significantly correlated with population density at grid size and the correlation coefficient(r) between them reaches 0.93,which indicates that natural environment suitability for Human Settlements has a significant influence on population distribution.Most people in China mainly concentrate in areas with high natural environment suitability.The total suitable area is 430.47×104 km2,which accounts for nearly 45% of the total land area in China,while the proportion of people living in the area reaches 96.56%.With a population density of 18 people per square kilometer,the critical area is the transitional region for people to live in China.The critical area covers 225.11×104 km2 with a population of 41.12 million.The non-suitable area covers 304.42×104 km2 with a population of only 2.49 million.

Influence of climate and tectonic movements on granite landforms in China

Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of Iongtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300-400 m, 2000 m and 3600 m above the sea level respectively.

Types and spatial combinations of Danxia landform of Fangyan in Zhejiang Province

The prominent types of Danxia landform in Fangyan include enclosed valleys, mesas, peaks, stone columns and grooves etc. Their spatial combinations have regular configurations along the northwest–southeast direction: typical grooves and caves are located in the northwestern Wufengshuyuan mainly; abundant fresh collapsed stones may be observed in central Jimingfeng and Taohuafeng; stone drums and stone columns are in the southeastern Shiguliao particularly; enclosed valleys are encircling joints of peaks and plains from three directions east, west, and south. Their spatial combinations reflect that the developments of Danxia landform have undergone stages of geomorphic cyclical erosion in the form of weathering, collapse, transportation, sedimentation and other processes, together with the "sculpture" of external forces mainly as tectonic uplift. The picturesque Danxia landform began its formation at that point. Danxia landform developed mainly in the strata of Fangyan Formation (K1f) caused by the alluvial fan-braided river phase of anterior fan in the late period of the Early Cretaceous. Regular patterns of weathering of stones and features of braided alluvial phase sediments may be verified by the analysis of three groups of experimental data. Danxia landform of Fangyan is a unique representative of the "adolescent" development type in the application of the World Natural Heritages status in China, by virtue of its outstanding universal aesthetic and scientific value.

Research on the Dynamic Change of Regional Stress Fields before the M_S8.0 Wenchuan Earthquake

Using the digital telemetric seismic waveform data of Chengdu and Kunming, this article studies the focal mechanism solutions and the apparent stress values of a large number of small earthquakes, and then analyzes the dynamic variation of regional stress fields and the spatio- temporal distribution of apparent stress values. The annual variation values of the azimuth of average principal stress field before the May 12, 2008 Ms8.0 Wenchuan earthquake in the Sichuan-Yunnan region were 58° from 2003 to 2004, 85° from 2003 to 2005,61° from 2006 to 2007 and 90° from 2006 to April 2008 respectively. In recent years, deflection or disturbances occurred in the azimuth of the average principal stress field in the Sichuan-Yunnan region. Analysis shows that this may be related to the change of stress field states of crustal blocks before and after the December 26, 2004 Ms9.0 Sumatra earthquake and the 2008 Ms8.0 Wenchuan earthquake. The ratio of thrust-type earthquakes in the Sichnan-Qinghai block was on the higher side in the period from 2006 to 2007, and the source faulting type of the regional moderate and small earthquakes had changed before the Ms8.0 Wenchnan earthquake. The change of state of the stress field is consistent with the changes in block displacement fields revealed by GPS data and the crustal shortening velocity vertical to the Longmenshan fault zone. Based on the radiation energy calculated from all bands of the seismic waveform, the value of apparent stress σapp is obtained. The fluctuation shape of the fitting trend of the apparent stress is related to the intensity of regional seismicity. It reveals that the micro- dynamic fluctuation process of the regional stress value is similar to the azimuth transition of the regional principal compressive stress field, which can be used to probe for pregnant physical processes. Areas with a higher value of apparent stress σapp are possible areas of potential seismic risk. It can be seen from the spatial distribution of the medium and shortterm apparent stress σapp before the Ms8.0 Wenchuan earthquake, the Longmenshan fault zone is in a low stress distribution area, and the relatively high apparent stress is in the peripheral area. These images may show medium and short-term locking phenomena near the seismogenic tectonics of the Ms8.0 Wenchuan earthquake. For example, changes with time of the focal parameter consistency of the sub-blocks in Sichuan and Yunnan Provinces, continual increase of thrust-type earthquakes in the Sichuan-Qinghai block and the appearance of spatial distribution areas of high apparent σapp stress. The work on this aspect was continued after the Ms8.0 Wenchuan earthquake, and the results seem to be shown a clearer relationship between these phenomena and future great earthquakes.

Digital regionalization of geomorphology in Xinjiang

This paper presents a method of geomorphologic regionalization for Xinjiang, with the use of Srtm-DEM (resolution 90 m) and TM images for 1990 (resolution 30 m). After interpretation and classification of geomorphologic types, the present research focuses on the qualitative and quantitative distribution of different geomorphologic types based on geographical grid analysis. Then, by using system clustering analysis method, geomorphologic types are grouped into divisions. The resulting geomorphologic regionalization hierarchy of Xinjiang includes three levels, i.e., macro-landform divisions, medium-landform divisions, and micro-landform divisions, containing 6, 23 and 200 types, respectively. This method makes it possible to digitally delimit geomorphologic regions. Comparison and verification show that the spatial precision of the boundaries of geomorphologic subareas in Xinjiang is very high.

Research of the Activity of Earthquakes Induced by Water Injection of Salt Mining in Changning County,Sichuan Province

According to information from on-the-spot investigations, the tectonics of salt mining areas and digital seismic records, we studied the activity of earthquakes induced by water pumping in and out of the salt mines in Shuanghe town, Changning county, Sichuan Province. The study found that the rates of water injection and extraction in the Shuanghe salt mining region were evenly matched before April 2006 and earthquake activity was stable. On the other hand, shallow small and moderate earthquake numbers increased sharply after the water injection rate became much larger than the water extraction rate. Large injection over a long time may causes the permeation of water through pre-existing small fractures and micro-cracks in the Changning anticlinal and accelerate the rupture of micro tectonic formations in nearby regions, inducing small earthquake swarm activity. The Q value calculated by using digital earthquake records indicates a relatively inhomogeneous medium in this area. The results of the accurate location of small earthquakes show that sources are relatively shallow and are concentrated at a depth of 2km to 3km. Focal mechanism solutions reveal a normal dip-slip character of shallow earthquakes. All of these show certain characteristics of earthquake activity induced by water injection.

Characteristics of the Zhengzhou Laoyachen Fault Revealed by Seismic Exploration Data

Exploration and research of fault activities are the fundamentals of earthquake prediction and prevention and disaster reduction. In order to determine the location, characteristics and activities of the Zhengzhon-Laoyachen fault, shallow seismic prospecting with different exploration depth across the Laoyachen fault was carried out in the northern suburbs of Zhengzhou city in 2006. The images of the subterranean structure and tectonics at depths of 30m- 6000m have been available by applying the combined methods of explosive seismic sources and vibrator seismic sources, as well as the combination of diverse observation systems with different parameters. The outcome indicates that the Laoyachen fault is a normal fault running NW and dipping NE, which offsets stratums ahead of Neogene （N）. However, no fault displacements are found in the interior stratums of Q ＋ N.

An Overview of the Study on Stress Magnitude

Crustal stress field holds an important position in geodynamics research, such as in plate motion simulations, uplift of the Qinghai-Xizang (Tibet) Plateau and earthquake preparation and occurrence. However, most of the crustal stress studies emphasize particularly on the determination of stress direction, with little study being done on stress magnitude at present. After reviewing ideas on a stress magnitude study from geological, geophysical and various other aspects, a method to estimate the stress magnitude in the source region according to the deflection of stress direction before and after large earthquakes and the stress drop tensor of earthquake rupture has been developed. The proposed method can also be supplemented by the average apparent stress before and after large earthquakes. The stress direction deflection before and after large earthquakes can be inverted by massive focal mechanisms of foreshocks and aftershocks and the stress drop field generated by the seismic source can be calculated by the detailed distribution of the earthquakes rupture. The mathematical relationship can then be constructed between the stress drop field, where its magnitude and direction are known and the stress tensor before and after large earthquakes, where its direction is known but magnitude is unknown, thereby obtaining the stress magnitude. The average apparent stress before and after large earthquakes can be obtained by using the catalog of broadband radiated energy and seismic moment tensor of foreshocks and aftershocks and the different responses to stress drops. This relationship leads to another estimation of stress magnitude before a large earthquake. The stress magnitude and its error are constrained by combining the two methods, which provide new constraints for the geodynamics study.

THE PROBLEM OF LARGE DEFORMATION IN SOFTROCK ENGINEERING AND PRACTICAL ANALYSIS OF FLOOR-HEAVING

At present, the mechanics theories studying softrock engineering generally depend onlinear small-deformation hypothesis of chosital mechanics. Although these theorics can be considered with the physical non-linear features of softrock, it is still an approximate theory of geometricsmall-deformation. Because of the specific characteristics of medium environment, the problem ofsoftrock engineering should be thought as large deformation. This article wili prove the advantagesof large deformation theory in solving softrock problem with an example of the No. 2 pit of NalongCoal Mine. This will provide a beneficai method for the studying of large deformation mechanics ofsoftrock engineering.

First-Principles Study on Native Defect Complexes in InN

We present first-principles calculations of the formation energy of different native defects and their complexes in wurtzite InN using density-functional theory and the pseudopotential plane-wave method. Our calculations are aimed in the three cases： N/In = 1, N/In 〉 1 （N-rich）, and N/In 〈 1 （In-rich）. Our results indicate that the antisite defect has the lowest formation energy under N/In = 1. The formation energy of nitrogen interstitial （nitrogen vacancy） defect is significantly low under the N-rich （In-rich） condition. Thus the antisite defect is an important defect if N/In = 1, and the nitrogen interstitial （nitrogen vacancy） defect is a vital defect under the N-rich （In-rich） condition. The atomic site relaxation around the nitrogen interstitial and vacancy is investigated. Our calculations show that the nitrogen vacancy cannot be observed although it is one of the most important defects in InN. Our results are confirmed by experiments.

Nonlinear morphological characteristics of debris flow in Dongcheng area of Helong,Jilin

Helong City is located in the northeastern Changbai Mountain with a poor geological environment,there often occur debris flows,collapses and landslides;especially debris flows restrict the local economic development. Based on fractal theory and the surveying data of 34 debris flows,the authors studied fractal feature of debris flow gully and its various situations of fractal dimensions in different observation scales. The nonlinear relation reveals the development of non-uniformity and self similarity of debris flow gully.

Analysis of the Adjacent Terrain Effect on the Properties of Ground Motion

The explicit finite element analysis method combined with the artificial transmitting boundary theory is performed to evaluate the adjacent terrain effects on ground motion,and the influence of the distance between adjacent terrains on the topographical amplification effects on ground motion is studied. The results show that:( 1) Compared to the case of a single hill,the presence of adjacent hills has little effect on the shape of the spectral ratio curve,but has a significant effect on the value of spectral ratio,which is dependent on the locations of observation points.( 2) The presence of adjacent hills has a greater effect on high-frequency ground motion,and with the increase of the distance between adjacent hills,such an effect weakens gradually,and the effect of the composite topography combined with multiple hills on ground motion gradually approaches that of a single hill.