As a well-known city of oil in China, Daqing City is unique in natural conditions with variety of soils. Among them, a large part belongs to the saline—alkaline land, which reduces the ability of filed sound as well as causes diversity of eco-environment issues. In this paper, the existing technologies to reclaim the saline-alkaline land are summarized to analyze its application context. Finally combining with the nature research and natural status of saline-alkaline components in Daqing, the integrated various ways to improve the cultivated land are put forward.
Abstract:The purpose of this study is to spatiotemporally explore the characteristics of urban temperatures based on multi-temporal satellite data and historical in situ measurements. As one of the most rapidly urbanized cities in Canada, Saskatoon (SK) was selected as our study area. Surface brightness retrieving, Pearson correlation, linear regression modeling, and buffer analysis were applied to different satellite datasets. The results indicate that both Landsat and MODIS data can yield pronounced estimations of daily air temperature with a significantly adjusted R 2 of 0.803 and 0.518 at the spatial scales of 120 m and 1000 m, respectively. MODIS monthly LST data is highly suitable for monitoring the trend of monthly urban air temperature throughout summer (June, July, and August) due to a high average R 2 of 0.8 (P<0.05), especially for the warmest month (July). Our findings also reveal that both the Saskatchewan River and urban green spaces have statistically significant cooling effects on the surrounding urban surface temperatures within 500 m and 200 m, respectively. In addition, a multiple linear regression model with four influential factors as independent variables can be developed to estimate urban surface temperatures with a highest adjusted R 2 of 0.649 and a lowest standard error of 0.076.
Abstract-In order to study the impact that land reclamation had on coastline of Fujian Province, three phases of Landsat TM/ETM+ image, spanning 15 years, were used to monitor the coastline change. The entire coastline was extracted from preprocessed Landsat TM/ETM+ images based on edge detection operator-Canny. We also improved the computational efficiency of image analysis by developing an image blocking algorithm with the IDL embedded in ENVI software. The length of the coastline for each imagewas calculated through the spatial calculation function of GIS platform, which shows that the length of Fujian coastline ranges from 3167.4km to 3218.2km, and to 3304.7km. Our results also indicate that the land reclamation in Fujian Province has caused the coastal lineto become shorter year by year.
Along with the increasing development of Chinese urbanization, there have been a lot of cities facing the problem of old city renewal. However, during the process of re-plan and reconstruction of the old city, there is a series of changing that refers to the changing of land-use function, adjustment of land layout and the improvement of development intensity, which would change the load and setting of the urban infrastructures. Therefore, how to renew the municipal facilities safely and effectively to guarantee the routine life of people has become a crucial problem in the old city renewal. This paper takes the case study of Hengdaohezi town emphasizing the discussion on re-planning the municipal facilities in the process of old city renewal. Here, the author suggested that municipal facility planning should be carried out under the premise of safety and reliability. In the process of analysis, it should give consideration on the change of urban function and character as well, in order to make the municipal facility planning more scientific and reasonable providing support for the old city renewal from the perspective of municipal engineering.
The disposable mechanism is a kind of extraordinary mechanism widely applied in plenty of fields such as aerospace and military industries. Different from the conventional mechanism, it is known for its short work time. Thus, the conception of designing such mechanism is based on static strength check, neglecting other factors including fatigue and abrasions which gradually lead to invalidity. This paper mainly discusses the feasibility of neglecting fatigue in disposable mechanical design and lays the foundation of the principles in such design theoretically.
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