By using 126 earthquake focal mechanism solutions (M S≥4.7) during the period of 1963～1998, modern tectonic stress field in North China is inverted by means of the step by step convergence. The inversion results ind...By using 126 earthquake focal mechanism solutions (M S≥4.7) during the period of 1963～1998, modern tectonic stress field in North China is inverted by means of the step by step convergence. The inversion results indicate that the tectonic stress field in the research region is clearly variational in space and time: (1) The middling principal stress axis σ 2 is basically vertical. The maximum and minimum principal stress axes σ 1 and σ 2 are nearly horizontal, but the azimuths of σ 1 and σ 3 are inconsistent in different districts and periods. (2) Before the Tangshan earthquake in 1976, the three principal stress axes are uniform. The azimuth of maximum principal stress axis σ 1 is 68° (striking in a NEE-SWW direction). (3) After the Tangshan earthquake, the maximum principal stress axis σ 1 and minimum principal stress axis σ 3 have variations in different districts. In the northern area of North China and on the eastern side of the Tancheng-Lujiang fault zone, the maximum principal stress axis σ 1 is also striking in a NEE-SWW direction. Its azimuth is 68°. It is the same as that before the Tangshan earthquake. In the southern area of North China, the maximum principal stress axis σ 1 is striking in a E-W direction and its azimuth is 87°.展开更多
This paper studies the thermal performance of outdoor residential spaces in the old part—historical part—of Sana’a city in the winter period and its impact on the residents’ satisfaction who occupied the buildings...This paper studies the thermal performance of outdoor residential spaces in the old part—historical part—of Sana’a city in the winter period and its impact on the residents’ satisfaction who occupied the buildings which overlook these spaces and use them on a pedestrian comfort basis. The analysis was carried out through the results of field measurements which study the temperature, relative humidity, and the air movement inside the selected outdoor spaces in the period of winter (2 months) data recorded through the devices used and compared with those obtained from the General Authority of Meteorology and Aviation—Meteorology Sector. Despite the passage of years, the author remained occupied with the opinion of the people whose homes overlook those outdoors spaces and what is their opinion of their performance. Therefore, an assessment was conducted in November 2020 to know the opinion of the people about the performance of these outdoor spaces and to compare the results of the field measurements with the results of the assessment. The measurements were conducted by using data-loggers that spread in some outdoor spaces in 7 spaces in old city of Sana’a and in its modern extension during the winter period which is the time of concern of this work. The measurements showed that the outdoor residential spaces in the old city of Sana’a are represented an advantage for winter climate over that of the modern city, so the focus in this paper was on that outdoors with the question of the users of the outdoor spaces in the old city only to clarify their satisfaction with it and whether it has succeeded as well from their point of view. Results presented in this paper are important to consider the relationship between the climatical performance of outdoor spaces and the comfort of the residents in the urban environment and give implications for urban planners and architects to improve the climate-based design methodology towards sustainable developments.展开更多
文摘By using 126 earthquake focal mechanism solutions (M S≥4.7) during the period of 1963～1998, modern tectonic stress field in North China is inverted by means of the step by step convergence. The inversion results indicate that the tectonic stress field in the research region is clearly variational in space and time: (1) The middling principal stress axis σ 2 is basically vertical. The maximum and minimum principal stress axes σ 1 and σ 2 are nearly horizontal, but the azimuths of σ 1 and σ 3 are inconsistent in different districts and periods. (2) Before the Tangshan earthquake in 1976, the three principal stress axes are uniform. The azimuth of maximum principal stress axis σ 1 is 68° (striking in a NEE-SWW direction). (3) After the Tangshan earthquake, the maximum principal stress axis σ 1 and minimum principal stress axis σ 3 have variations in different districts. In the northern area of North China and on the eastern side of the Tancheng-Lujiang fault zone, the maximum principal stress axis σ 1 is also striking in a NEE-SWW direction. Its azimuth is 68°. It is the same as that before the Tangshan earthquake. In the southern area of North China, the maximum principal stress axis σ 1 is striking in a E-W direction and its azimuth is 87°.
文摘This paper studies the thermal performance of outdoor residential spaces in the old part—historical part—of Sana’a city in the winter period and its impact on the residents’ satisfaction who occupied the buildings which overlook these spaces and use them on a pedestrian comfort basis. The analysis was carried out through the results of field measurements which study the temperature, relative humidity, and the air movement inside the selected outdoor spaces in the period of winter (2 months) data recorded through the devices used and compared with those obtained from the General Authority of Meteorology and Aviation—Meteorology Sector. Despite the passage of years, the author remained occupied with the opinion of the people whose homes overlook those outdoors spaces and what is their opinion of their performance. Therefore, an assessment was conducted in November 2020 to know the opinion of the people about the performance of these outdoor spaces and to compare the results of the field measurements with the results of the assessment. The measurements were conducted by using data-loggers that spread in some outdoor spaces in 7 spaces in old city of Sana’a and in its modern extension during the winter period which is the time of concern of this work. The measurements showed that the outdoor residential spaces in the old city of Sana’a are represented an advantage for winter climate over that of the modern city, so the focus in this paper was on that outdoors with the question of the users of the outdoor spaces in the old city only to clarify their satisfaction with it and whether it has succeeded as well from their point of view. Results presented in this paper are important to consider the relationship between the climatical performance of outdoor spaces and the comfort of the residents in the urban environment and give implications for urban planners and architects to improve the climate-based design methodology towards sustainable developments.
