When China launched the first com-munication satellite for Algeria on December 11,it marked a milestone in joint aerospace cooperation be-tween the two countries.Fired from the Xichang Satellite Launch Center in south...When China launched the first com-munication satellite for Algeria on December 11,it marked a milestone in joint aerospace cooperation be-tween the two countries.Fired from the Xichang Satellite Launch Center in southwest China’s Sichuan Province,the sate-llite will be used for a variety of purposes,inclu-ding television broadcast,e-governance,and broadband access.It’s a demonstration of how far展开更多
Tunnel-type anchorages(TTAs)installed in human gathering areas are characterized by a shallow burial depth,and in many instances,they utilize soft rock as the bearing stratum.However,the stability control measures and...Tunnel-type anchorages(TTAs)installed in human gathering areas are characterized by a shallow burial depth,and in many instances,they utilize soft rock as the bearing stratum.However,the stability control measures and the principle of shallow TTAs in soft rock have not been fully studied.Hence,a structure suitable for improving the stability of shallow TTAs in soft rock strata,named the anti-pull tie(APT),was added to the floor of the back face.Physical tests and numerical models were established to study the influence of the APT on the load transfer of TTAs,the mechanical response of the surrounding rock,the stress distribution of the interface,and the failure model.The mechanical characteristics of APTs were also studied.The results show that the ultimate bearing capacity of TTAs with an APT is increased by approximately 11.8%,as compared to the TTAs without an APT.Also,the bearing capacity of TTAs increases approximately linearly with increasing height,width,length,and quantity of APTs,and decreases approximately linearly with increasing distance from the back face and slope angle of the tie slope.The normal squeezing between the tie slope and the surrounding rock increases the shear resistance of the interface and expands the range of the surrounding rock participating in bearing sharing.Both tension and compression zones exist in the APT during loading.The tension zone extends from the tie toe to the tie bottom along the tie slope.The range of the tie body tension zone constantly expands to the deep part of the APT with an increasing load.The peak tensile stress value is located at the tie toe.The distribution of compressive stress in the tie body is the largest at the tie top,followed by the tie slope,and then the tie bottom.展开更多
“The Jakarta-Bandung High-Speed Railway(HSR)is a crucial achievement in practical cooperation between China and Indonesia,”said Paulus Rudolf Yuniarto,a researcher at the Indonesia National Research and Innovation A...“The Jakarta-Bandung High-Speed Railway(HSR)is a crucial achievement in practical cooperation between China and Indonesia,”said Paulus Rudolf Yuniarto,a researcher at the Indonesia National Research and Innovation Agency.展开更多
Green mining is concerned with mining in a sustainable manner, such that the needs of the present are met without compromising future generations. The achievement of this objective depends on balancing social, environ...Green mining is concerned with mining in a sustainable manner, such that the needs of the present are met without compromising future generations. The achievement of this objective depends on balancing social, environmental and economic objectives and has to have regard to both active mining operations and legacy issues associated with mine closure. Ground engineering has a critical role in achieving green mining objectives but its contribution is characterised by pervasive uncertainty. Uncertainty equates to risk. This means that ground engineering should be practiced within a risk management framework that aims to both prevent unwanted outcomes and to mitigate their consequences to an acceptable level. This keynote address presents the fundamentals of risk management and demonstrates its effectiveness by reference to improvements in the safety performance of the NSW coal sector over the past three decades.Nevertheless, ground control remains a mix of art and science, relying heavily on judgements which should be premised on knowledge, skill and experience(that is, competence). Risk management has now been enshrined in mining legislation and operating practice in Australia for over two decades.Notwithstanding this, near-hit and accident and incident investigations, commissions of inquiry and legal proceedings almost invariably identify deficiencies and opportunities for improvements necessary to achieve the objectives of sustainable mining. Three of the more important opportunities which have global application in relation to ground engineering are discussed. These relate to the vexing issue of defining competency in ground engineering; the criteria for undertaking rigorous risk assessment; and the need for ground engineers to become involved in mine rehabilitation and closure planning over the full life cycle of a mine, commencing at the prefeasibility stage.展开更多
Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is described.The instrument made continuous recordings(up to ten per second)of the three-dim...Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is described.The instrument made continuous recordings(up to ten per second)of the three-dimensional positions of a reflector situated at 1/2 or 1/4 of the length of the tie during vertical oscillation induced by an impulsive load.The recording slips,vibration amplitudes(and their accuracy),hourly diagram and experimental spectra of vibrations,and the corresponding frequencies were calculated.The results were verified by comparing them with the vibration frequencies and indirectly the tension and fixed support constraint calculated from accelerometric measurements.The study provides interesting information on the accuracies of the reflector′s three-dimensional coordinates,but highlighted certain limits in the application of robotized total stations for measuring vibration frequencies of ties in masonry arches.展开更多
Like a big rock thrown into the pond of current international power configuration, the event of September 11 revealed the turbulent undercurrents beneath its seemingly tranquil surface. The splashdown effect has sprea...Like a big rock thrown into the pond of current international power configuration, the event of September 11 revealed the turbulent undercurrents beneath its seemingly tranquil surface. The splashdown effect has spread beyond the United States to reach every corner of our planet. It has triggered realignment in big power relations and will have its far-展开更多
Chinese President Xi Jinping and Portuguese President Marcelo Rebelo de Sousa on February 8 exchanged congratulations on the 40th anniversary of the establishment of China-Portugal diplomatic relations.
The sign rank test is taught in virtually all introductory Statistics classes. When teaching the sign rank test the students are told to ignore the ties. Ignoring ties that support the null hypothesis is not logical. ...The sign rank test is taught in virtually all introductory Statistics classes. When teaching the sign rank test the students are told to ignore the ties. Ignoring ties that support the null hypothesis is not logical. Why should valid data that support the null hypothesis be ignored? The approach taken here demonstrates a method for testing with ties included. A typical problem presentation in a text book would indicate that if you had ten ties in a sample of size fifty the tie scores would be excluded. However, the ten tie scores are a very valuable piece of statistical information which should not be ignored. The method demonstrated here shows that a different conclusion is reached in some cases when the ties are not excluded. Further many sign tests often will have ties because in some cases the data are not a cardinal number, but an ordinal number chosen from a set often results in ties. The alternative approach uses a one-tailed distribution and considers both +’s and -'s separated. A two-tailed test for equal variances is done with a one-tail of an F distribution. This alternate approach to the sign test allows the use of important statistical information which has been ignored with the traditional sign rank test.展开更多
Some changes have indeed taken place in international situation from September 11 to Iraq war. Changes in big power relations in particular have given food for thought. Today Ⅰ would like to focus on the changes in t...Some changes have indeed taken place in international situation from September 11 to Iraq war. Changes in big power relations in particular have given food for thought. Today Ⅰ would like to focus on the changes in the relations among China, Russia and the United States as well as my consideration of China’s diplomacy.展开更多
Chinese President Xi Jinping, French President Emmanuel Macron, German Chancellor Angela Merkel and European Commission President Jean- Claude Juncker met in Paris on March 26 and agreed to strengthen China-European U...Chinese President Xi Jinping, French President Emmanuel Macron, German Chancellor Angela Merkel and European Commission President Jean- Claude Juncker met in Paris on March 26 and agreed to strengthen China-European Union (EU) relations and global governance cooperation.展开更多
As the Trump administration promotes its Indo-Pacific strategy in a very high-profile manner, the position of South Asia in the US foreign strategy has been growing in importance, which has led to an elevation of rela...As the Trump administration promotes its Indo-Pacific strategy in a very high-profile manner, the position of South Asia in the US foreign strategy has been growing in importance, which has led to an elevation of relations between the US and many countries in the region. In particular, the development of US-Sri Lanka relationship is worth reviewing, not only because it sets an example of growing relations between the US and small "Indo-Pacific" countries, but also because it will bring new variables to the security situation in the Bay of Bengal and the Indian Ocean.展开更多
China applied for restoration of its status as the GATT founding member in1986. The country has made great endeavor in reducing customs duties, removing non-tariff barriers, enhancing protection of intellectual proper...China applied for restoration of its status as the GATT founding member in1986. The country has made great endeavor in reducing customs duties, removing non-tariff barriers, enhancing protection of intellectual property rights andservice trades, launching reform of the foreign trade regime, eliminating trade bar-riers and improving environment for foreign investment. Over the past 14 years,China has taken part in 26 relevant multilateral meetings and hundreds of bilateralnegotiations.展开更多
文摘When China launched the first com-munication satellite for Algeria on December 11,it marked a milestone in joint aerospace cooperation be-tween the two countries.Fired from the Xichang Satellite Launch Center in southwest China’s Sichuan Province,the sate-llite will be used for a variety of purposes,inclu-ding television broadcast,e-governance,and broadband access.It’s a demonstration of how far
基金the financial support provided by the National Natural Science Foundation of China(Grant No.42302332)the Special Funding of Chongqing Postdoctoral Research Project(Grant No.2022CQBSHTB2061,2022CQBSHTB1010)+3 种基金the Chongqing Postdoctoral Science Foundation(Grant No.CSTB2022NSCQ-BHX0738,CSTB2023NSCQBHX0223)the China Postdoctoral Science Foundation(Grant No.2023M730432)the Natural Science Foundation of Chongqing(Grant No.CSTB2023NSCQMSX0913,cstc2021jcyj-msxm X0869)the Postdoctoral Science Foundation of Chongqing Jiaotong University(Grant No.F1220105,22JDKJC-A008)。
文摘Tunnel-type anchorages(TTAs)installed in human gathering areas are characterized by a shallow burial depth,and in many instances,they utilize soft rock as the bearing stratum.However,the stability control measures and the principle of shallow TTAs in soft rock have not been fully studied.Hence,a structure suitable for improving the stability of shallow TTAs in soft rock strata,named the anti-pull tie(APT),was added to the floor of the back face.Physical tests and numerical models were established to study the influence of the APT on the load transfer of TTAs,the mechanical response of the surrounding rock,the stress distribution of the interface,and the failure model.The mechanical characteristics of APTs were also studied.The results show that the ultimate bearing capacity of TTAs with an APT is increased by approximately 11.8%,as compared to the TTAs without an APT.Also,the bearing capacity of TTAs increases approximately linearly with increasing height,width,length,and quantity of APTs,and decreases approximately linearly with increasing distance from the back face and slope angle of the tie slope.The normal squeezing between the tie slope and the surrounding rock increases the shear resistance of the interface and expands the range of the surrounding rock participating in bearing sharing.Both tension and compression zones exist in the APT during loading.The tension zone extends from the tie toe to the tie bottom along the tie slope.The range of the tie body tension zone constantly expands to the deep part of the APT with an increasing load.The peak tensile stress value is located at the tie toe.The distribution of compressive stress in the tie body is the largest at the tie top,followed by the tie slope,and then the tie bottom.
文摘“The Jakarta-Bandung High-Speed Railway(HSR)is a crucial achievement in practical cooperation between China and Indonesia,”said Paulus Rudolf Yuniarto,a researcher at the Indonesia National Research and Innovation Agency.
文摘Green mining is concerned with mining in a sustainable manner, such that the needs of the present are met without compromising future generations. The achievement of this objective depends on balancing social, environmental and economic objectives and has to have regard to both active mining operations and legacy issues associated with mine closure. Ground engineering has a critical role in achieving green mining objectives but its contribution is characterised by pervasive uncertainty. Uncertainty equates to risk. This means that ground engineering should be practiced within a risk management framework that aims to both prevent unwanted outcomes and to mitigate their consequences to an acceptable level. This keynote address presents the fundamentals of risk management and demonstrates its effectiveness by reference to improvements in the safety performance of the NSW coal sector over the past three decades.Nevertheless, ground control remains a mix of art and science, relying heavily on judgements which should be premised on knowledge, skill and experience(that is, competence). Risk management has now been enshrined in mining legislation and operating practice in Australia for over two decades.Notwithstanding this, near-hit and accident and incident investigations, commissions of inquiry and legal proceedings almost invariably identify deficiencies and opportunities for improvements necessary to achieve the objectives of sustainable mining. Three of the more important opportunities which have global application in relation to ground engineering are discussed. These relate to the vexing issue of defining competency in ground engineering; the criteria for undertaking rigorous risk assessment; and the need for ground engineers to become involved in mine rehabilitation and closure planning over the full life cycle of a mine, commencing at the prefeasibility stage.
文摘Measurement of the vibration frequencies of eight ties set in masonry arches of a church by means of a robotic total station is described.The instrument made continuous recordings(up to ten per second)of the three-dimensional positions of a reflector situated at 1/2 or 1/4 of the length of the tie during vertical oscillation induced by an impulsive load.The recording slips,vibration amplitudes(and their accuracy),hourly diagram and experimental spectra of vibrations,and the corresponding frequencies were calculated.The results were verified by comparing them with the vibration frequencies and indirectly the tension and fixed support constraint calculated from accelerometric measurements.The study provides interesting information on the accuracies of the reflector′s three-dimensional coordinates,but highlighted certain limits in the application of robotized total stations for measuring vibration frequencies of ties in masonry arches.
文摘Like a big rock thrown into the pond of current international power configuration, the event of September 11 revealed the turbulent undercurrents beneath its seemingly tranquil surface. The splashdown effect has spread beyond the United States to reach every corner of our planet. It has triggered realignment in big power relations and will have its far-
文摘Chinese President Xi Jinping and Portuguese President Marcelo Rebelo de Sousa on February 8 exchanged congratulations on the 40th anniversary of the establishment of China-Portugal diplomatic relations.
文摘The sign rank test is taught in virtually all introductory Statistics classes. When teaching the sign rank test the students are told to ignore the ties. Ignoring ties that support the null hypothesis is not logical. Why should valid data that support the null hypothesis be ignored? The approach taken here demonstrates a method for testing with ties included. A typical problem presentation in a text book would indicate that if you had ten ties in a sample of size fifty the tie scores would be excluded. However, the ten tie scores are a very valuable piece of statistical information which should not be ignored. The method demonstrated here shows that a different conclusion is reached in some cases when the ties are not excluded. Further many sign tests often will have ties because in some cases the data are not a cardinal number, but an ordinal number chosen from a set often results in ties. The alternative approach uses a one-tailed distribution and considers both +’s and -'s separated. A two-tailed test for equal variances is done with a one-tail of an F distribution. This alternate approach to the sign test allows the use of important statistical information which has been ignored with the traditional sign rank test.
文摘Some changes have indeed taken place in international situation from September 11 to Iraq war. Changes in big power relations in particular have given food for thought. Today Ⅰ would like to focus on the changes in the relations among China, Russia and the United States as well as my consideration of China’s diplomacy.
文摘Chinese President Xi Jinping, French President Emmanuel Macron, German Chancellor Angela Merkel and European Commission President Jean- Claude Juncker met in Paris on March 26 and agreed to strengthen China-European Union (EU) relations and global governance cooperation.
文摘As the Trump administration promotes its Indo-Pacific strategy in a very high-profile manner, the position of South Asia in the US foreign strategy has been growing in importance, which has led to an elevation of relations between the US and many countries in the region. In particular, the development of US-Sri Lanka relationship is worth reviewing, not only because it sets an example of growing relations between the US and small "Indo-Pacific" countries, but also because it will bring new variables to the security situation in the Bay of Bengal and the Indian Ocean.
文摘China applied for restoration of its status as the GATT founding member in1986. The country has made great endeavor in reducing customs duties, removing non-tariff barriers, enhancing protection of intellectual property rights andservice trades, launching reform of the foreign trade regime, eliminating trade bar-riers and improving environment for foreign investment. Over the past 14 years,China has taken part in 26 relevant multilateral meetings and hundreds of bilateralnegotiations.
