A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage cons...A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.展开更多
The desired economics of hard rock surface mining is mainly determined by the parameters of process design which minimize the overall cost per tonne of the rock mined in drilling, blasting, handling and primary crushi...The desired economics of hard rock surface mining is mainly determined by the parameters of process design which minimize the overall cost per tonne of the rock mined in drilling, blasting, handling and primary crushing in given rockmass conditions. The most effective parameters of process design could be established based on the regression models of the cumulative influence of rockmass and mine design parameters on the overall cost per tonne of the rock drilled, blasted, handled and crushed. These models could be developed from the huge data accumulated worldwide on the costs per tonne of hard rock surface mining in drilling, blasting, handling and primary crushing vs the parameters of rockmass and mine design. This paper only dwelt on the development of regression models for oversize generation, blasthole productivity and blasting cost for iron ore surface mines, whose data is available. The SPSS standard statistical correlation – regression analysis software was used in the analysis. Interpretation of the models generated shows that the individual effects of the determinant rockmass and blast design parameters on oversize generation, blasthole productivity and blasting cost are all in compliance with the findings of other researchers and the theory of explosive rock fragmentation and could be used for the estimation of oversize generation, blasthole productivity and blasting cost in rockmass and blast design conditions similar to those of the iron ore surface mines examined in this study. However, the regression models obtained here could not be used alone for the optimization of blast design because most of the determinant parameters also have conflicting effect on the other processes of drilling, handling and primary crushing the blasted rock. Also, the quality and content of the regression models could be enhanced further by increasing the content of rockmass and blast design parameters and the volume of data considered in the regression analysis.展开更多
Roundabouts in United States and other countries have been proved to be very successful, effective, and a safe traffic control treatment. Roundabouts in the context of regularly expected truck configuration have also ...Roundabouts in United States and other countries have been proved to be very successful, effective, and a safe traffic control treatment. Roundabouts in the context of regularly expected truck configuration have also been successful for effective roundabout designs;however, there are always some site specific issues for trucks accommodation at roundabouts. Therefore, there is a great need for an informational guide in the form of synthesis report for roundabout designs specific to unique trucking traffic activity. While there are not significant literatures and studies in this subject, there are few studies/reports spread out which address various issues in this subject area. This study attempts to synthesize the research and knowledge of truck accommodation at roundabouts by synthesizing various research studies, reports, and articles;various subject areas such as roundabout designs for trucking activity, roundabout designs and accommodation strategies for specialized trucking activity such as oversized trucks, truck safety at roundabouts, and motor carrier perspective of trucking at roundabouts have been analyzed and relevant knowledge has been synthesized. This synthesis can be useful o researchers, designers, planners, and decision makers to determine effective ways to address specific trucking related issues at a roundabout.展开更多
The paper describes a mathematical model of the stress-strain state of polymer composite materials in the pultrusion process of large-sized products. The influence of the pull speed on the stress-strain state of the p...The paper describes a mathematical model of the stress-strain state of polymer composite materials in the pultrusion process of large-sized products. The influence of the pull speed on the stress-strain state of the products is investigated. To determine the maximum possible pull speed series of solutions at different pull speeds are obtained. Depending on the maximum strain in the cross section of the rod determined the optimal value of pulling speed.展开更多
The exposure of both stationary and exponential pha-se cells of Saccharomyces cerevisiae diploid strainD6 to 0.15-1.5mg/ml chloroquine (ClQ) produced adose-related increase of putative monosomic,whitecycloheximide res...The exposure of both stationary and exponential pha-se cells of Saccharomyces cerevisiae diploid strainD6 to 0.15-1.5mg/ml chloroquine (ClQ) produced adose-related increase of putative monosomic,whitecycloheximide resistant colonies,and no increase ofmitotic recombinants (cross-overs).The effect obser-ved was specifically induced in strain D6.In fact,展开更多
A Risk Comparison between Lifestyle,Socioeconomic Status,and Radiation:A Cohort Study of Cancer Mortality among Japanese Nuclear Workers (J-EPISODE)Shin’ichi Kudo1,Akemi Nishide1,2,Hiroshige Furuta1,Noboru Ishizawa1,...A Risk Comparison between Lifestyle,Socioeconomic Status,and Radiation:A Cohort Study of Cancer Mortality among Japanese Nuclear Workers (J-EPISODE)Shin’ichi Kudo1,Akemi Nishide1,2,Hiroshige Furuta1,Noboru Ishizawa1,Shin Saigusa1(1.Institute of Radiation Epidemiology,Radiation Effects Association;2.College of Life Sciences,Ibaraki Christian University,Ibaraki,Japan)Abstract:The health effects of low-dose radiation exposure have been a source of controversy.One possible reason is that epidemiological studies that compare radiation risk with other factors,such as lifestyle or socioeconomic status,have been limited.The aim of this study is to conduct a comparison of the cancer risk of mortality between radiation,lifestyle habits (such as smoking),and socioeconomic status (such as years of education) among Japanese nuclear workers.We assembled a cohort of41,742 male nuclear workers in Japan who answered a lifestyle questionnaire survey conducted during 2003-2004.展开更多
It is an honor to be the guest editor of this special issue on Current Consensus and Controversy on Male Lower Urinary Tract Symptoms(LUTS)/Benign Prostatic Hyperplasia(BPH).As the title implies,one can write on a wid...It is an honor to be the guest editor of this special issue on Current Consensus and Controversy on Male Lower Urinary Tract Symptoms(LUTS)/Benign Prostatic Hyperplasia(BPH).As the title implies,one can write on a wide range of topics related to this urological problem that is common worldwide.展开更多
As an active player in the global capital market,Chinese ompanies are making changes n the world farming market.The website of the Voice of Russia reported that the Chinese companies are busy in the world farm product...As an active player in the global capital market,Chinese ompanies are making changes n the world farming market.The website of the Voice of Russia reported that the Chinese companies are busy in the world farm product market with acquisition of farm product,food and beverage companies,for which over USD12 billion was spent last year.展开更多
According to the weather men last winter was one of theworst in living memory.We live in the depths of the country,and my whole family a-gree that it was certainly a winter we shall never forget.Snow be-gan to fall at...According to the weather men last winter was one of theworst in living memory.We live in the depths of the country,and my whole family a-gree that it was certainly a winter we shall never forget.Snow be-gan to fall at round about the beginning of the New Year and con-tinued on and off for approximately ten days.At first we were all thrilleds to see it.It fell silently and relent-展开更多
During two years odd period from Dec.1987 to Feb.1990,there had been repeatedly pollution-flashoverfailures on our 500 kV transmission lines,resulting in a wide scopeblackout.There were eleven 500 kV lines altogether ...During two years odd period from Dec.1987 to Feb.1990,there had been repeatedly pollution-flashoverfailures on our 500 kV transmission lines,resulting in a wide scopeblackout.There were eleven 500 kV lines altogether in North-east,East and North China power grids,where pollution-flashover failureshappened one after another on 36 transmission line towers (poles).Since 500 kV transmission lines are the main trunks of high展开更多
猝死综合征（Sudden Death Svndrome,SDS）又称急性死亡综合征（ADS）、翻跳病（Fhp-overs Disease）等,是现代家禽养殖业中颇令人头疼的顽症之一。它不但可发生在肉仔鸡上,在火鸡、蛋鸡及肉种鸡上也均有发生。肉仔鸡3-35日龄多发;蛋鸡...猝死综合征（Sudden Death Svndrome,SDS）又称急性死亡综合征（ADS）、翻跳病（Fhp-overs Disease）等,是现代家禽养殖业中颇令人头疼的顽症之一。它不但可发生在肉仔鸡上,在火鸡、蛋鸡及肉种鸡上也均有发生。肉仔鸡3-35日龄多发;蛋鸡初产多发;肉种鸡20-28周龄（初产）时多发。展开更多
920647 Comparative effects of commonvasodilators on experimental cardiac fai-lure. LI Zhijian (李志坚), et al. Dept Cardiol,2nd Hosp, Tianjin Med Coll. Tianjin Med J1992; 20(8): 456-458. A 9×9 latin square design...920647 Comparative effects of commonvasodilators on experimental cardiac fai-lure. LI Zhijian (李志坚), et al. Dept Cardiol,2nd Hosp, Tianjin Med Coll. Tianjin Med J1992; 20(8): 456-458. A 9×9 latin square design was employed forcomparing the effects of (1) placebo, (2) nitr-oprusside, (3) phentolamine, (4) isosorbide dini-trate. (5) captopril, (6)展开更多
Thanks to TikTok,a 2021 case study about a man who went into organ failure and needed amputations(截肢)after eating leftovers went viral online,bringing up questions about how to avoid the same outcome.
U.S.Secretary of Commerce Gina Raimondo made a high-profile trip to China last August.There,she talked up the“enormous"Chinese market and the incredible“appetite among U.S.businesses to continue to do business&...U.S.Secretary of Commerce Gina Raimondo made a high-profile trip to China last August.There,she talked up the“enormous"Chinese market and the incredible“appetite among U.S.businesses to continue to do business"there.While no significant deals were unveiled during her visit,it did leave the impression that the White House intended to continue open dialogue and continue doing business with China.展开更多
基金supported by Chinese National Natural Science Foundation (No. 51809016 and No. 51979152)Chongqing Municipal Natural Science Foundation (No. cstc2019jcyjmsxmX0645)
文摘A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of rock blasting fragmentation is simulated, and the scheme is further optimized. Numerical analysis results showed that pocket charges and satellite blastholes can only improve bench top fragmentation, but they cannot reduce the oversize in the middle and bottom of bench as well as the toe problem. The new blasting approach of combined blastholes with different diameters can effectively reduce the oversize boulders and toes as well as the production costs.
文摘The desired economics of hard rock surface mining is mainly determined by the parameters of process design which minimize the overall cost per tonne of the rock mined in drilling, blasting, handling and primary crushing in given rockmass conditions. The most effective parameters of process design could be established based on the regression models of the cumulative influence of rockmass and mine design parameters on the overall cost per tonne of the rock drilled, blasted, handled and crushed. These models could be developed from the huge data accumulated worldwide on the costs per tonne of hard rock surface mining in drilling, blasting, handling and primary crushing vs the parameters of rockmass and mine design. This paper only dwelt on the development of regression models for oversize generation, blasthole productivity and blasting cost for iron ore surface mines, whose data is available. The SPSS standard statistical correlation – regression analysis software was used in the analysis. Interpretation of the models generated shows that the individual effects of the determinant rockmass and blast design parameters on oversize generation, blasthole productivity and blasting cost are all in compliance with the findings of other researchers and the theory of explosive rock fragmentation and could be used for the estimation of oversize generation, blasthole productivity and blasting cost in rockmass and blast design conditions similar to those of the iron ore surface mines examined in this study. However, the regression models obtained here could not be used alone for the optimization of blast design because most of the determinant parameters also have conflicting effect on the other processes of drilling, handling and primary crushing the blasted rock. Also, the quality and content of the regression models could be enhanced further by increasing the content of rockmass and blast design parameters and the volume of data considered in the regression analysis.
文摘Roundabouts in United States and other countries have been proved to be very successful, effective, and a safe traffic control treatment. Roundabouts in the context of regularly expected truck configuration have also been successful for effective roundabout designs;however, there are always some site specific issues for trucks accommodation at roundabouts. Therefore, there is a great need for an informational guide in the form of synthesis report for roundabout designs specific to unique trucking traffic activity. While there are not significant literatures and studies in this subject, there are few studies/reports spread out which address various issues in this subject area. This study attempts to synthesize the research and knowledge of truck accommodation at roundabouts by synthesizing various research studies, reports, and articles;various subject areas such as roundabout designs for trucking activity, roundabout designs and accommodation strategies for specialized trucking activity such as oversized trucks, truck safety at roundabouts, and motor carrier perspective of trucking at roundabouts have been analyzed and relevant knowledge has been synthesized. This synthesis can be useful o researchers, designers, planners, and decision makers to determine effective ways to address specific trucking related issues at a roundabout.
文摘The paper describes a mathematical model of the stress-strain state of polymer composite materials in the pultrusion process of large-sized products. The influence of the pull speed on the stress-strain state of the products is investigated. To determine the maximum possible pull speed series of solutions at different pull speeds are obtained. Depending on the maximum strain in the cross section of the rod determined the optimal value of pulling speed.
文摘The exposure of both stationary and exponential pha-se cells of Saccharomyces cerevisiae diploid strainD6 to 0.15-1.5mg/ml chloroquine (ClQ) produced adose-related increase of putative monosomic,whitecycloheximide resistant colonies,and no increase ofmitotic recombinants (cross-overs).The effect obser-ved was specifically induced in strain D6.In fact,
文摘A Risk Comparison between Lifestyle,Socioeconomic Status,and Radiation:A Cohort Study of Cancer Mortality among Japanese Nuclear Workers (J-EPISODE)Shin’ichi Kudo1,Akemi Nishide1,2,Hiroshige Furuta1,Noboru Ishizawa1,Shin Saigusa1(1.Institute of Radiation Epidemiology,Radiation Effects Association;2.College of Life Sciences,Ibaraki Christian University,Ibaraki,Japan)Abstract:The health effects of low-dose radiation exposure have been a source of controversy.One possible reason is that epidemiological studies that compare radiation risk with other factors,such as lifestyle or socioeconomic status,have been limited.The aim of this study is to conduct a comparison of the cancer risk of mortality between radiation,lifestyle habits (such as smoking),and socioeconomic status (such as years of education) among Japanese nuclear workers.We assembled a cohort of41,742 male nuclear workers in Japan who answered a lifestyle questionnaire survey conducted during 2003-2004.
文摘It is an honor to be the guest editor of this special issue on Current Consensus and Controversy on Male Lower Urinary Tract Symptoms(LUTS)/Benign Prostatic Hyperplasia(BPH).As the title implies,one can write on a wide range of topics related to this urological problem that is common worldwide.
文摘As an active player in the global capital market,Chinese ompanies are making changes n the world farming market.The website of the Voice of Russia reported that the Chinese companies are busy in the world farm product market with acquisition of farm product,food and beverage companies,for which over USD12 billion was spent last year.
文摘According to the weather men last winter was one of theworst in living memory.We live in the depths of the country,and my whole family a-gree that it was certainly a winter we shall never forget.Snow be-gan to fall at round about the beginning of the New Year and con-tinued on and off for approximately ten days.At first we were all thrilleds to see it.It fell silently and relent-
文摘During two years odd period from Dec.1987 to Feb.1990,there had been repeatedly pollution-flashoverfailures on our 500 kV transmission lines,resulting in a wide scopeblackout.There were eleven 500 kV lines altogether in North-east,East and North China power grids,where pollution-flashover failureshappened one after another on 36 transmission line towers (poles).Since 500 kV transmission lines are the main trunks of high
文摘猝死综合征（Sudden Death Svndrome,SDS）又称急性死亡综合征（ADS）、翻跳病（Fhp-overs Disease）等,是现代家禽养殖业中颇令人头疼的顽症之一。它不但可发生在肉仔鸡上,在火鸡、蛋鸡及肉种鸡上也均有发生。肉仔鸡3-35日龄多发;蛋鸡初产多发;肉种鸡20-28周龄（初产）时多发。
文摘920647 Comparative effects of commonvasodilators on experimental cardiac fai-lure. LI Zhijian (李志坚), et al. Dept Cardiol,2nd Hosp, Tianjin Med Coll. Tianjin Med J1992; 20(8): 456-458. A 9×9 latin square design was employed forcomparing the effects of (1) placebo, (2) nitr-oprusside, (3) phentolamine, (4) isosorbide dini-trate. (5) captopril, (6)
文摘Thanks to TikTok,a 2021 case study about a man who went into organ failure and needed amputations(截肢)after eating leftovers went viral online,bringing up questions about how to avoid the same outcome.
文摘U.S.Secretary of Commerce Gina Raimondo made a high-profile trip to China last August.There,she talked up the“enormous"Chinese market and the incredible“appetite among U.S.businesses to continue to do business"there.While no significant deals were unveiled during her visit,it did leave the impression that the White House intended to continue open dialogue and continue doing business with China.
