Animal husbandry is an essential pillar sector in China.However,the wastewater including a mixture of feces,urine,and flushing water from livestock and poultry farming poses serious environmental risks if not properly...Animal husbandry is an essential pillar sector in China.However,the wastewater including a mixture of feces,urine,and flushing water from livestock and poultry farming poses serious environmental risks if not properly managed or over-applied.This paper analyzes the existing challenges in the utilization of livestock manure,focusing on source control,process management,and end-use treatment.To address these issues,it proposes establishing a sustainable long-term mechanism.Key recommendations include enhancing source control,strengthening policy support to alleviate the financial burden on enterprises,aligning with market demands,intensifying the promotion of technologies and equipment development,and improving manure quality.In addition,advocating for grain-efficient animal husbandry and promoting diversified utilization through bio-chain approaches are essential.展开更多
Maca is an important health-care product. Recently, maca industry devel- ops fast in Yunnan Province, but still falls behind of foreign industries, due to dis- advantages of being late starter and poor economy. In the...Maca is an important health-care product. Recently, maca industry devel- ops fast in Yunnan Province, but still falls behind of foreign industries, due to dis- advantages of being late starter and poor economy. In the research, maca industry development was analyzed in terms of production bases, processing enterprises, dis- tribution in dominant areas, planting and processing technology system, and eco- nomic benefits, and the restriction factors were explored. Finally, some measures were proposed, including reinforcement of organization and leading roles in a macroscopic way, giving supports to financial investment, broadening financing chan- nels, speeding up construction of raw material production bases, improving modern science and technology development, establishing technology support system, culti- vating leading enterprises, building marketing system, and supervision on product eualitv.展开更多
Although there are appropriate stipulations for the chattel guarantees in the law of China, this guarantee system could not adapt to the request of economy's development because of the following reasons: the scope...Although there are appropriate stipulations for the chattel guarantees in the law of China, this guarantee system could not adapt to the request of economy's development because of the following reasons: the scope of chattel guarantees is narrow according to relevant stipulations; the transaction cost of the chattel is high; mortgage registration of chattel is in a mess; lack of efficiently executive guarantee system, etc. To counter the problems existing in the present Chinese chattel guarantee system, in this article, the author proposed some corresponding suggestions and countermeasures, hoping to perfect the chattel guarantee system in China.展开更多
This paper introduces the development and present situation of meat industry in Henan Province so as to get comprehensive understanding of this industry,including the advantages and insufficiencies of this industry,an...This paper introduces the development and present situation of meat industry in Henan Province so as to get comprehensive understanding of this industry,including the advantages and insufficiencies of this industry,and then puts forward some countermeasures for the future development of the meat products of Henan Province,to realize the rapid,healthy and sustainable development of meat industry in Henan and create huge economic and social benefits in Henan.展开更多
Needs analysis is an essential step in planning an oral presentation course in an ESP context.This paper illustrates two important areas in the relevant needs analysis: target situation analysis and present situation ...Needs analysis is an essential step in planning an oral presentation course in an ESP context.This paper illustrates two important areas in the relevant needs analysis: target situation analysis and present situation analysis.展开更多
Currently,sustainable agricultural development in China is facing some big challenges of how to promote the present developing pattern,to lengthen material transformation chain,to increase the utilization rate of mate...Currently,sustainable agricultural development in China is facing some big challenges of how to promote the present developing pattern,to lengthen material transformation chain,to increase the utilization rate of material and energy in agricultural system and to form a healthy agricultural ecological circulation system.China is a major country producing crops and straws.Both high-efficient utilizing pattern of straw and technological system are needed urgently.According to the field survey,we point out the status of straw utilization and the main recycling pattern in typical farming areas in Sichuan,China through the literature review and data collection.Based on the statistical analysis,the economic,environmental and social benefits of each utilization way are analyzed,and the methods and measures are proposed in order to promote recycling utilization of the straw in Sichuan farming area,and to offer theoretical guidance for energy saving,food safety,and pollution control.展开更多
The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Caraj...The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces（belts）, such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type（BIF）, magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type（BIF） as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.展开更多
The present situation of welding machinery industry in China is presented in detail.On the basis of the analysis, the future development and practicable way are proposed.
Analyzed of the present situation of Chinese coal mines safety in production and the reasons for coal mining accident,and realized the coal mines safety in production, which should increase the legal safeguards of coa...Analyzed of the present situation of Chinese coal mines safety in production and the reasons for coal mining accident,and realized the coal mines safety in production, which should increase the legal safeguards of coal mine safety in production,and safety input,established the comprehensive coal mine safety evaluation system,comprehen- sively enhance quality of coal mine workers,established and improved early warning me- chanism of safety production of coal mine.展开更多
In this paper,based on the study of Chenopodium quinoa Willd.planting,it is concluded that the current situations of large-scale development of C.quinoa Willd.include the following four aspects:first,the research on C...In this paper,based on the study of Chenopodium quinoa Willd.planting,it is concluded that the current situations of large-scale development of C.quinoa Willd.include the following four aspects:first,the research on C.quinoa Willd.varieties needs to be strengthened;second,it is insufficient to master the training environment and cultivation techniques;third,the large-scale planting of C.quinoa Willd.is not enough;fourth,the degree of mechanization of C.quinoa Willd.planting is not enough.In view of the above situation,this paper puts forward the following effective suggestions to strengthen the large-scale development of C.quinoa Willd.:the first is to increase the investment in C.quinoa Willd.variety research;the second is to strengthen the analysis of introduction and screening of C.quinoa Willd.varieties;the third is to study the best planting environment and cultivation techniques of C.quinoa Willd.;the fourth is to increase the scale of mechanized production of C.quinoa Willd.;the fifth is to increase the research and development of C.quinoa Willd.related products and their deep processing technology.展开更多
After several rounds of phased ups and downs of development,rural animal husbandry finally presents a shrinking and depressed development situation under the comprehensive action of the failure of transformation and u...After several rounds of phased ups and downs of development,rural animal husbandry finally presents a shrinking and depressed development situation under the comprehensive action of the failure of transformation and upgrading and the increasing production costs and breeding risks.Actively exploring and guiding the healthy and sound development of rural animal husbandry is not only an important measure to promote the construction of ecological agriculture,but also the main starting point to realize the revitalization of rural industry.This paper analyzes the present situation of the development of rural animal husbandry in recent years,the influence of animal husbandry on the construction of ecological agriculture and the revitalization of rural industry,and puts forward the corresponding measures,in order to promote the steady and efficient development of animal husbandry in the grand strategy of revitalizing rural industry.展开更多
Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. T...Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. The results show that p H,DO,CODMn,petroleum,and heavy metals( Cu,Pb,Zn,Cd,Hg,As and Cr) in the sea area near the Aojiang estuary did not exceed the second-class standard of Seawater Quality Standard( GB 3097-1997),but both inorganic nitrogen and reactive phosphate in the sea area exceeded the second-class standard seriously,and the water quality of the sea area was in an eutrophic state; domestic sewage and fertilizer loss were the main sources of nitrogen and phosphorus. The standard index of most evaluation factors of sediment quality except for Zn was smaller than 1,meeting the demands of sediment quality for environmental protection.展开更多
In recent years,with China＇s continuous investment in shale gas exploration and the continuous efforts of scientific workers,China’s shale gas exploration and development has achieved leap-forward development.In2011...In recent years,with China＇s continuous investment in shale gas exploration and the continuous efforts of scientific workers,China’s shale gas exploration and development has achieved leap-forward development.In2011,China＇s State Council approved shale gas as a new mineral resource.In 2014,shale gas was first proved at geological reserves of 106.8 billion m^3.展开更多
Rice production, hybrid rice development, breeding, production of hybrid seeds, and popularization condition were introduced in this study. The chief obstacles preventing hybrid rice from growing have been found and t...Rice production, hybrid rice development, breeding, production of hybrid seeds, and popularization condition were introduced in this study. The chief obstacles preventing hybrid rice from growing have been found and the concerned countermeasures were put forward.展开更多
Dalbergia odorifera is particularly scarce,and the D. odorifera furniture and commercial raw materials on the market are mainly old furniture and agricultural tools,as well as commercially collected D. odorifera logs....Dalbergia odorifera is particularly scarce,and the D. odorifera furniture and commercial raw materials on the market are mainly old furniture and agricultural tools,as well as commercially collected D. odorifera logs. The logs and high-grade furniture made from D. odorifera are extremely expensive. It takes several decades for D. odorifera to grow into wood. At present,there is only a small area of newly planted and regenerated forest,and the planting area of D. odorifera is about 15 000 ha in Hainan Island,distributed in the low altitude area of Hainan Island. It is suggested that Hainan D. odorifera island should be built through the transformation of low-yielding forest land,the use of wasteland and marginal cultivated land,land around houses,green belt and roadside land for the cultivation of D. odorifera,and the development area can be up to 100 000-150 000 ha. It is necessary to mobilize farmers to revitalize the rural green economy,plant D. odorifera,beautify the environment,and increase the economic resources of rural trees; actively publicize the legal nature and obligation of D. odorifera protection,and create a strong atmosphere for each family to plant and protect D. odorifera.展开更多
1.IntroductionHigh-purity elements are the basic materials in electronics,communication,aerospace,atomicenergy and semiconductor material industries.Its development is a decisive factor for high-tech in-dustries.The h...1.IntroductionHigh-purity elements are the basic materials in electronics,communication,aerospace,atomicenergy and semiconductor material industries.Its development is a decisive factor for high-tech in-dustries.The high-purification of non-ferrous metals is of great significance.It conduces to determining展开更多
Grub is one of the major pests affecting yield and quality of sweet potato. Although traditional chemical pesticides have quick effect, the disadvantages of high toxicity, strong pest resistance, and heavy pollution h...Grub is one of the major pests affecting yield and quality of sweet potato. Although traditional chemical pesticides have quick effect, the disadvantages of high toxicity, strong pest resistance, and heavy pollution hinder the development of modern ecological agriculture, while physical means such as light trapping, sex pheromone method and biological control methods are more safe and lasting compared with chemical means. To provide reference and guidance for grub control and sweet potato production, the control methods against sweet potato grubs are comprehensively explored, and strategy and prospects of using biological technology to control pests are analyzed.展开更多
Rock drillability reflects the drill bit fragments rock hardly or easily. At present, rock drillability classification indexes have rock single axle compressive strength, point load intensity, fracture stress during c...Rock drillability reflects the drill bit fragments rock hardly or easily. At present, rock drillability classification indexes have rock single axle compressive strength, point load intensity, fracture stress during chiseling, drill speed, chiseling specific work, acoustic parameter, cutting magnitude and so on. Every index reflects rock drillability but isnt overall. It is feasible that using many indexes of fuzzy mathematics method etc. to evaluate rock drillability.展开更多
The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety,product quality leve...The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety,product quality level and its actual application situation on automobile supplied by present industrially developed country metallurgy enterprises,it is pointed that the variety of low-alloy spring steel wire rod for domestic automobile can't satisfy the requirements of automobile industry development,compare with overseas advanced technology,product quality has the following gaps:the first is that steel purity is low,the control level of non-metallic inclusions is not steady,there is often large grain difficult deforming non-deformation inclusions existing,the control level of steel purity has big difference,the level of large steel factory is high,but its steady has a large gap compare with foreign advanced level,not to mention small steel factory which research and development powder is low.The second is surface complete decarburization can't be avoided completely.The third is that surface defects are more.The fourth is that composition segregation and structure segregation are not steady,steel wire can't be drawn normally when the segregation is serious.In all,the segregation of 55SiCrA is superior to 60Si2MnA obviously.The industrialization of domestic high level low-alloy spring steel wire rod can't seek quick success and instant benefits,independent innovation perseveringly must be adopted,the success may be reached after master core technologies and adopt the science way of step by step.展开更多
文摘Animal husbandry is an essential pillar sector in China.However,the wastewater including a mixture of feces,urine,and flushing water from livestock and poultry farming poses serious environmental risks if not properly managed or over-applied.This paper analyzes the existing challenges in the utilization of livestock manure,focusing on source control,process management,and end-use treatment.To address these issues,it proposes establishing a sustainable long-term mechanism.Key recommendations include enhancing source control,strengthening policy support to alleviate the financial burden on enterprises,aligning with market demands,intensifying the promotion of technologies and equipment development,and improving manure quality.In addition,advocating for grain-efficient animal husbandry and promoting diversified utilization through bio-chain approaches are essential.
基金Supported by Special Foundation of National Science and Technology Infrastructure Program(2006FY110700)Yunnan Science and Technology Innovation and Strengthening Planning(2007C0219Z)Special Foundation for Yunan Province Bioindustry([2011]274)~~
文摘Maca is an important health-care product. Recently, maca industry devel- ops fast in Yunnan Province, but still falls behind of foreign industries, due to dis- advantages of being late starter and poor economy. In the research, maca industry development was analyzed in terms of production bases, processing enterprises, dis- tribution in dominant areas, planting and processing technology system, and eco- nomic benefits, and the restriction factors were explored. Finally, some measures were proposed, including reinforcement of organization and leading roles in a macroscopic way, giving supports to financial investment, broadening financing chan- nels, speeding up construction of raw material production bases, improving modern science and technology development, establishing technology support system, culti- vating leading enterprises, building marketing system, and supervision on product eualitv.
文摘Although there are appropriate stipulations for the chattel guarantees in the law of China, this guarantee system could not adapt to the request of economy's development because of the following reasons: the scope of chattel guarantees is narrow according to relevant stipulations; the transaction cost of the chattel is high; mortgage registration of chattel is in a mess; lack of efficiently executive guarantee system, etc. To counter the problems existing in the present Chinese chattel guarantee system, in this article, the author proposed some corresponding suggestions and countermeasures, hoping to perfect the chattel guarantee system in China.
文摘This paper introduces the development and present situation of meat industry in Henan Province so as to get comprehensive understanding of this industry,including the advantages and insufficiencies of this industry,and then puts forward some countermeasures for the future development of the meat products of Henan Province,to realize the rapid,healthy and sustainable development of meat industry in Henan and create huge economic and social benefits in Henan.
文摘Needs analysis is an essential step in planning an oral presentation course in an ESP context.This paper illustrates two important areas in the relevant needs analysis: target situation analysis and present situation analysis.
基金Supported by the National Key Technology R & D Program(2007B-AD89B15)
文摘Currently,sustainable agricultural development in China is facing some big challenges of how to promote the present developing pattern,to lengthen material transformation chain,to increase the utilization rate of material and energy in agricultural system and to form a healthy agricultural ecological circulation system.China is a major country producing crops and straws.Both high-efficient utilizing pattern of straw and technological system are needed urgently.According to the field survey,we point out the status of straw utilization and the main recycling pattern in typical farming areas in Sichuan,China through the literature review and data collection.Based on the statistical analysis,the economic,environmental and social benefits of each utilization way are analyzed,and the methods and measures are proposed in order to promote recycling utilization of the straw in Sichuan farming area,and to offer theoretical guidance for energy saving,food safety,and pollution control.
基金supported by the National Natural Science Foundation of China (grant No. 40773038the Program of High-level Geological Talents (201309)Youth Geological Talents (201112) of the China Geological Survey
文摘The metamorphosed sedimentary type of iron deposits（BIF） is the most important type of iron deposits in the world, and super-large iron ore clusters of this type include the Quadrilatero Ferrifero district and Carajas in Brazil, Hamersley in Australia, Kursk in Russia, Central Province of India and Anshan-Benxi in China. Subordinated types of iron deposits are magmatic, volcanic-hosted and sedimentary ones. This paper briefly introduces the geological characteristics of major super-large iron ore clusters in the world. The proven reserves of iron ores in China are relatively abundant, but they are mainly low-grade ores. Moreover, a considerate part of iron ores are difficult to utilize for their difficult ore dressing, deep burial or other reasons. Iron ore deposits are relatively concentrated in 11 metallogenic provinces（belts）, such as the Anshan-Benxi, eastern Hebei, Xichang-Central Yunnan Province and middle-lower reaches of Yangtze River. The main minerogenetic epoches vary widely from the Archean to Quaternary, and are mainly the Late Archean to Middle Proterozoic, Variscan, and Yanshanian periods. The main 7 genetic types of iron deposits in China are metamorphosed sedimentary type（BIF）, magmatic type, volcanic-hosted type, skarn type, hydrothermal type, sedimentary type and weathered leaching type. The iron-rich ores occur predominantly in the skarn and marine volcanic-hosted iron deposits, locally in the metamorphosed sedimentary type（BIF） as hydrothermal reformation products. The theory of minerogenetic series of mineral deposits and minerogenic models has applied in investigation and prospecting of iron ore deposits. A combination of deep analyses of aeromagnetic anomalies and geomagnetic anomalies, with gravity anomalies are an effective method to seeking large and deep-buried iron deposits. China has a relatively great oresearching potential of iron ores, especially for metamorphosed sedimentary, skarn, and marine volcanic-hosted iron deposits. For the lower guarantee degree of iron and steel industry, China should give a trading and open the foreign mining markets.
文摘The present situation of welding machinery industry in China is presented in detail.On the basis of the analysis, the future development and practicable way are proposed.
基金the Educational Department Project of Liaoning Province(No.20060382)
文摘Analyzed of the present situation of Chinese coal mines safety in production and the reasons for coal mining accident,and realized the coal mines safety in production, which should increase the legal safeguards of coal mine safety in production,and safety input,established the comprehensive coal mine safety evaluation system,comprehen- sively enhance quality of coal mine workers,established and improved early warning me- chanism of safety production of coal mine.
文摘In this paper,based on the study of Chenopodium quinoa Willd.planting,it is concluded that the current situations of large-scale development of C.quinoa Willd.include the following four aspects:first,the research on C.quinoa Willd.varieties needs to be strengthened;second,it is insufficient to master the training environment and cultivation techniques;third,the large-scale planting of C.quinoa Willd.is not enough;fourth,the degree of mechanization of C.quinoa Willd.planting is not enough.In view of the above situation,this paper puts forward the following effective suggestions to strengthen the large-scale development of C.quinoa Willd.:the first is to increase the investment in C.quinoa Willd.variety research;the second is to strengthen the analysis of introduction and screening of C.quinoa Willd.varieties;the third is to study the best planting environment and cultivation techniques of C.quinoa Willd.;the fourth is to increase the scale of mechanized production of C.quinoa Willd.;the fifth is to increase the research and development of C.quinoa Willd.related products and their deep processing technology.
文摘After several rounds of phased ups and downs of development,rural animal husbandry finally presents a shrinking and depressed development situation under the comprehensive action of the failure of transformation and upgrading and the increasing production costs and breeding risks.Actively exploring and guiding the healthy and sound development of rural animal husbandry is not only an important measure to promote the construction of ecological agriculture,but also the main starting point to realize the revitalization of rural industry.This paper analyzes the present situation of the development of rural animal husbandry in recent years,the influence of animal husbandry on the construction of ecological agriculture and the revitalization of rural industry,and puts forward the corresponding measures,in order to promote the steady and efficient development of animal husbandry in the grand strategy of revitalizing rural industry.
文摘Based on the monitoring results of environmental quality in the sea area near the Aojiang estuary in Wenzou during 2010-2012,the present situation of environmental quality in the sea area was analyzed and evaluated. The results show that p H,DO,CODMn,petroleum,and heavy metals( Cu,Pb,Zn,Cd,Hg,As and Cr) in the sea area near the Aojiang estuary did not exceed the second-class standard of Seawater Quality Standard( GB 3097-1997),but both inorganic nitrogen and reactive phosphate in the sea area exceeded the second-class standard seriously,and the water quality of the sea area was in an eutrophic state; domestic sewage and fertilizer loss were the main sources of nitrogen and phosphorus. The standard index of most evaluation factors of sediment quality except for Zn was smaller than 1,meeting the demands of sediment quality for environmental protection.
文摘In recent years,with China＇s continuous investment in shale gas exploration and the continuous efforts of scientific workers,China’s shale gas exploration and development has achieved leap-forward development.In2011,China＇s State Council approved shale gas as a new mineral resource.In 2014,shale gas was first proved at geological reserves of 106.8 billion m^3.
基金Supported by Cooperation Project of Science and Technology Innovation Ministry of Malaysia.(07-04-01PB015)~~
文摘Rice production, hybrid rice development, breeding, production of hybrid seeds, and popularization condition were introduced in this study. The chief obstacles preventing hybrid rice from growing have been found and the concerned countermeasures were put forward.
基金Supported by the Applied Technology Research and Development Demonstration and Extension Project in Hainan Province(ZDXM2014101)
文摘Dalbergia odorifera is particularly scarce,and the D. odorifera furniture and commercial raw materials on the market are mainly old furniture and agricultural tools,as well as commercially collected D. odorifera logs. The logs and high-grade furniture made from D. odorifera are extremely expensive. It takes several decades for D. odorifera to grow into wood. At present,there is only a small area of newly planted and regenerated forest,and the planting area of D. odorifera is about 15 000 ha in Hainan Island,distributed in the low altitude area of Hainan Island. It is suggested that Hainan D. odorifera island should be built through the transformation of low-yielding forest land,the use of wasteland and marginal cultivated land,land around houses,green belt and roadside land for the cultivation of D. odorifera,and the development area can be up to 100 000-150 000 ha. It is necessary to mobilize farmers to revitalize the rural green economy,plant D. odorifera,beautify the environment,and increase the economic resources of rural trees; actively publicize the legal nature and obligation of D. odorifera protection,and create a strong atmosphere for each family to plant and protect D. odorifera.
文摘1.IntroductionHigh-purity elements are the basic materials in electronics,communication,aerospace,atomicenergy and semiconductor material industries.Its development is a decisive factor for high-tech in-dustries.The high-purification of non-ferrous metals is of great significance.It conduces to determining
基金Supported by National High-tech Research and Development Program(863Project)(2012AA101204)Science and Technology Support Program of Jiangsu Province(BE2012336)Cooperation Project of Chinese Academy of Agricultural Sciences and Beijing Daxing District
文摘Grub is one of the major pests affecting yield and quality of sweet potato. Although traditional chemical pesticides have quick effect, the disadvantages of high toxicity, strong pest resistance, and heavy pollution hinder the development of modern ecological agriculture, while physical means such as light trapping, sex pheromone method and biological control methods are more safe and lasting compared with chemical means. To provide reference and guidance for grub control and sweet potato production, the control methods against sweet potato grubs are comprehensively explored, and strategy and prospects of using biological technology to control pests are analyzed.
文摘Rock drillability reflects the drill bit fragments rock hardly or easily. At present, rock drillability classification indexes have rock single axle compressive strength, point load intensity, fracture stress during chiseling, drill speed, chiseling specific work, acoustic parameter, cutting magnitude and so on. Every index reflects rock drillability but isnt overall. It is feasible that using many indexes of fuzzy mathematics method etc. to evaluate rock drillability.
文摘The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety,product quality level and its actual application situation on automobile supplied by present industrially developed country metallurgy enterprises,it is pointed that the variety of low-alloy spring steel wire rod for domestic automobile can't satisfy the requirements of automobile industry development,compare with overseas advanced technology,product quality has the following gaps:the first is that steel purity is low,the control level of non-metallic inclusions is not steady,there is often large grain difficult deforming non-deformation inclusions existing,the control level of steel purity has big difference,the level of large steel factory is high,but its steady has a large gap compare with foreign advanced level,not to mention small steel factory which research and development powder is low.The second is surface complete decarburization can't be avoided completely.The third is that surface defects are more.The fourth is that composition segregation and structure segregation are not steady,steel wire can't be drawn normally when the segregation is serious.In all,the segregation of 55SiCrA is superior to 60Si2MnA obviously.The industrialization of domestic high level low-alloy spring steel wire rod can't seek quick success and instant benefits,independent innovation perseveringly must be adopted,the success may be reached after master core technologies and adopt the science way of step by step.
