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The Use and Exchange of Biological Control Agents for Food and Agriculture
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作者 J.C.van Lenteren M.J.W.Cock +6 位作者 J.Brodeur B.Barratt F.Bigler K.Bolckmans F.Haas P.G.Mason J.R.P.Parra 《中国生物防治学报》 CSCD 北大核心 2010年第S1期123-127,共5页
The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories o... The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be 展开更多
关键词 The Use and Exchange of Biological control agents for Food and Agriculture
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Influence of process control agents on the performance of Ni_3Al by mechanical alloying
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作者 LIAN Jiqiong MENG Jie JIA Chengchang 《Rare Metals》 SCIE EI CAS CSCD 2008年第6期648-651,共4页
The influence of process control agents (PCAs) on the mechanical properties of Ni3AI intermetallic compounds by mechanical alloying was investigated in order to develop oxide deposition reinforced intermetallics. Th... The influence of process control agents (PCAs) on the mechanical properties of Ni3AI intermetallic compounds by mechanical alloying was investigated in order to develop oxide deposition reinforced intermetallics. The PCAs in mechanical alloying were pure ligroin, 75 vol.% ligroin + 25 vol.% alcohol, 50 vol.% ligroin + 50 vol.% alcohol, 25 vol.% ligroin + 75 vol.% alcohol, and pure alcohol. The normal composition is Ni-22.9at.%Al-0.5at.%B, the ball-to-powder weight ratio is 10:1, and the milling time is 30 min. Then, the powders were sintered by spark plasma sintering under 40 MPa for 5 min at 1000℃. The results show that a higher bending strength and a higher hardness were obtained when the PCAs were 75% ligroin + 25% alcohol in mechanical alloying. The bending strength is about 2700 MPa and the hardness (HV) is more than 6 GPa. 展开更多
关键词 intermetallic compounds mechanical properties mechanical alloying process control agent spark plasma sintering
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Fire Blight Disease Caused by Erwinia amylovora on Rosaceae Plants in Kyrgyzstan and Biological Agents to Control This Disease 被引量:16
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作者 Tinatin Doolotkeldieva Saykal Bobusheva 《Advances in Microbiology》 2016年第11期831-851,共21页
Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical a... Erwinia amylovora species were isolated from the blossoms, exudates, infected fruits, leaves and bent branches of diseased apple, pear and hawthorn trees, selected in the Chy, Osh and Jalal Abad regions. Biochemical and pathogenicity tests, alongside PCR analyses, were conducted to identify the local isolates of Erwinia amylovora. The alternative antagonistic microorganisms which combat bacterium E. amylovora were tested within in vitro and in vivo conditions. The results revealed the ability of Streptomyces antagonistic bacteria to decrease fire blight severity on pear and apple trees during the first stage of the fire blight disease in leaf tissues. Streptomyces strain C1-4 suppressed E. amylovora disease symptoms in the leaf tissues and excised apple and pear shoots. The incidence of fire blight on leaves was reduced by about 70% with two applications of bacterial antagonists. Further studies at different locations in Kyrgyzstan, using large scale application, would allow for stronger recommendations to be made, including studies and recommendations on their ability to prevent disease and to use them as main components in an integrated pest management program. 展开更多
关键词 Biological control agents Fire Blight Erwinia amylovora Antagonistic Bacteria
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Rice(Oryza sativa L.)plant protection using dual biological control and plant growth-promoting agents:Current scenarios and future prospects 被引量:1
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作者 Debasis MITRA Sergio DE LOS SANTOS-VILLALOBOS +9 位作者 Fannie Isela PARRA-COTA Ana María Garcia MONTELONGO Erika Lorena BLANCO Vanessa L.LIRA Adeyemi N.OLATUNBOSUN Bahman KHOSHRU Rittick MONDAL Parameswaran CHIDAMBARANATHAN Periyasamy PANNEERSELVAM Pradeep K.DAS MOHAPATRA 《Pedosphere》 SCIE CAS CSCD 2023年第2期268-286,共19页
Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,pre... Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,predating on,or antagonizing plant pathogens and by inducing systems for plant defense.A range of methods,including plant growth-promoting microorganisms(PGPMs)as biological control agents(BCAs)(BCA-PGPMs)are used for the biological management and control of plant pathogens.Some BCAs interact with plants by inducing resistance or priming plants without direct interaction with the pathogen.Other BCAs operate via nutrient competition or other mechanisms to modulate the growth conditions for the pathogen.Generally,PGPMs can be applied alone or together with other chemicals or carriers to control various crop diseases.This review highlights the effective types of BCA-PGPMs and their applications,roles,carrier based-formulations,and responses to rice(Oryza sativa L.)pathogens.Future plant disease management prospects are promising,and growers’increasing demand for BCA-PGPM products can be exploited as an effective approach to the management of plant diseases,as well as to improve yield,environmental protection,biological resources,and agricultural system sustainability. 展开更多
关键词 biological control agent plant disease plant growth-promoting microorganism plant health plant pathogen
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Research overview of profile control and water shut-off agents for heavy oil thermal recovery 被引量:1
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作者 ZHAO Xiu-tai FU Min-jie +2 位作者 WANG Zeng-bao DONG Lin-yan TANG Jin-yu 《特种油气藏》 CAS CSCD 北大核心 2013年第4期I0001-I0008,共8页
Heavy oil will play an important role in future resources exploitation.Factors such as reservoir heterogeneity and adverse oil/steam mobility ratio have led to severe steam channeling and fingering,thereby reduced con... Heavy oil will play an important role in future resources exploitation.Factors such as reservoir heterogeneity and adverse oil/steam mobility ratio have led to severe steam channeling and fingering,thereby reduced conformance efficiency and affected de-velopment response.Therefore,the research on profile control and water shut-off agents becomes increasingly important for thermal recovery wells.The requirements on the performances of profile control and water shut-off agents are discussed in conjunction with the physical properties of heavy oil reservoirs and the technical conditions of steam injection in China.Based on the mechanism of action,research progress and application status,5 agents are summarized including polymer gel,solid particles plugging agent,foam,water-in-oil emulsion and salt precipitation.Problems in each agent are mentioned,and optimization solutions are put for-ward.At last,the development trend of future profile control and water shut-off agents is put forward,i.e.synthesizing agents of low cost and high-temperature resistance,intensifying mechanism research,developing composite system,and researching on new technologies that are less harmful and environmental friendly. 展开更多
关键词 heavy oil thermal recovery profile control and water shut-off agents research progress development trend OVERVIEW
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Screening of Chemical Agents for Controlling Spodoptera frugiperda in Corn Fields of Panmao Township,Yunnan Province
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作者 Yongjin WANG 《Plant Diseases and Pests》 CAS 2022年第2期8-9,16,共3页
[Objectives]The paper was to effectively prevent and control the damage of Spodoptera frugiperda and to screen effective agents.[Methods]The block test of drug control was carried out,and the insect pest situation was... [Objectives]The paper was to effectively prevent and control the damage of Spodoptera frugiperda and to screen effective agents.[Methods]The block test of drug control was carried out,and the insect pest situation was investigated five times.[Results]150 mL/hm^(2) of 5%emamectin benzoate+600 mL/hm 2 of 5%lufenuron had better comprehensive control effect on S.frugiperda,and the corn yield reached 10100.55 kg/hm^(2).[Conclusions]The study provides a basis for scientific control of S.frugiperda. 展开更多
关键词 Panmao Township CORN Spodoptera frugiperda control agent SCREEN
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Evaluation of Lodging Resistance and Yield of Maize Varieties in Response to Two Ethephon Compound Agents
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作者 Yuchao LI Huiyu ZHANG +5 位作者 Changjian LI Yuling LI Guoju XU Li REN Ruiqian LU Liangfa WANG 《Asian Agricultural Research》 2025年第12期31-37,45,共8页
Using maize varieties including Zhengdan 958,Xianyu 335,Yudan 132,Xundan 20,Lianchuang 808,and Dingyou 163 as experimental materials,this study investigated the effects of two ethephon compound agents on the lodging r... Using maize varieties including Zhengdan 958,Xianyu 335,Yudan 132,Xundan 20,Lianchuang 808,and Dingyou 163 as experimental materials,this study investigated the effects of two ethephon compound agents on the lodging resistance and yield of different maize varieties across various ecological regions.The results demonstrated that the lodging resistance of maize was significantly enhanced after the application of the two chemical control agents.Specifically,the lodging rate of Xundan 20 was reduced by 6.1 percentage points following treatment with benzylaminopurine(6-BA)·ethephon(ETH),while the lodging rate of Zhengdan 958 was decreased by 6.2 percentage points after treatment with diethyl aminoethyl hexanoate(DTA-6)·ETH.In the Shangqiu area,treatment of Lianchuang 808 with DTA-6·ETH reduced its ear height coefficient by 9.8 percentage points,whereas in the Zhumadian area,treatment of Dingyou 163 with 6-BA·ETH lowered its ear height coefficient by 11.3 percentage points.Additionally,both ethephon compound agents improved the stalk puncture strength of maize.For the same maize variety,phenotypic traits such as ear length,ear diameter,and number of kernel rows showed no significant differences under different chemical control treatments.However,traits including kernel number per row,1000-kernel weight,and yield exhibited significant variations across treatments and years.Moreover,the yield performance of maize varieties after chemical control treatment varied by region.In Hebi,Zhoukou,and Zhumadian areas,the yield under the DTA-6·ETH treatment surpassed that under the 6-BA·ETH treatment,with average yield increases of 4.22%,8.41%,and 5.67%compared to the clear water control(CK),respectively.Conversely,in Shangqiu,Nanyang,and Changge areas,the 6-BA·ETH treatment outperformed DTA-6·ETH,resulting in average yield increases of 6.96%,7.54%,and 5.56%relative to CK. 展开更多
关键词 MAIZE Chemical control agent Lodging traits YIELD
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Preliminary Study on Control Effects of Five Kinds of Fungicides against Wheat Scab 被引量:1
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作者 Chen Wujian Ye Xiufen +4 位作者 Zhang Changjie Hu Yufeng Wu Jianguo Chai Rongyao Zhang Zhen 《Plant Diseases and Pests》 CAS 2013年第3期9-11,共3页
[Objective] This paper was to improve the current status that the fungicide carbendazim as the single agent was largely applied in the control against wheat scab. [ Method] Five kinds of fungicides on sales and new ag... [Objective] This paper was to improve the current status that the fungicide carbendazim as the single agent was largely applied in the control against wheat scab. [ Method] Five kinds of fungicides on sales and new agents against wheat scab were selected for field trials. [ Result] 25% JS399 - 19 SC, 30% te- buconazoh · thiram WP, 75% trifloxystrobin · tebuconasole WDG and 10% ZJ0712 JG could effectively control wheat scab, and the control effects of one time or two times application were better than control agent carbendasim; the control efficacy of two times application was improved in different degrees against one time ap- vlication. [ Conclusion] The naner vrevided basis for the control atminst wheat scab. 展开更多
关键词 Wheat scab control agents Conta'ol effects
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Microwave absorption performance of FeCoNiAlCr_(0.9)alloy powders by adjusting the amount of process control agent 被引量:6
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作者 Yuping Duan Huifang Pang +2 位作者 Xin Wen Xuefeng Zhang Tongmin Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第18期209-216,共8页
Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA play... Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA plays an active role in the crystallinity of powders,and regulate the thickness and size distribution of flake particles.As the volume of PCA increases,the real and imaginary parts(ε′andε″)of complex permittivity get increased by the enhancement of the interface polarization and surface polarization,while the increase in the real and imaginary parts(μ′andμ″)of complex permeability arises from the increased anisotropic energy.The addition of PCA not only promotes the reflection loss but also extends the effective bandwidth(up to 4.28 GHz).Here,the performance adjustment of HEA electromagnetic absorber is realized by forthrightly changing the process parameters of ball milling. 展开更多
关键词 FeCoNiAlCr_(0.9) Ball milling Electromagnetic performance Process control agent
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Application of foam technology for dust control in underground coal mine 被引量:15
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作者 Ren Wanxing Wang Deming +1 位作者 Guo Qing Zuo Bingzhao 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期13-16,共4页
In order to effectively control the dust in the underground coal mine,this study proposes and develops a new technology for dust control by foam,and briefly demonstrates the advantage of the foam technology for dust c... In order to effectively control the dust in the underground coal mine,this study proposes and develops a new technology for dust control by foam,and briefly demonstrates the advantage of the foam technology for dust control,such as the good isolation performance,large contact area,high wetting ability,strong adhesion and so on.Besides,the details of the technology are introduced,including the foam agent,foam generator,and foam production process.Then the paper studies the relationship between the foaming agent concentration and liquid surface tension,and explains the principle of the foam generator.The technology is applied in heading face.The application results show that the foam has a remarkable effect on dust control in underground coal mines. 展开更多
关键词 Coal dust Dust control Foaming agent Foam generator
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Effects of 4 Types of Remediation Agents on Reducing Cd Contents in Soil and Rice on Cd-contaminated Farmland 被引量:2
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作者 HU Qing-yun TANG You-gen +4 位作者 ZHANG Zhi-qiang LUO Ying ZHANG Xiao-yi XIAO Huan AO He-jun 《Agricultural Science & Technology》 CAS 2021年第3期7-12,共6页
A field experiment was carried out in Cd-contaminated rice fields in a county of Hengyang to explore the effects of different types of remediation agents on the contents of soil available Cd and rice Cd,and rice yield... A field experiment was carried out in Cd-contaminated rice fields in a county of Hengyang to explore the effects of different types of remediation agents on the contents of soil available Cd and rice Cd,and rice yield by using one rice variety Longliangyouhuazhan,and 4 kinds of remediation agents:DG foliar control agent,SMA microbial inoculant,XFJ organic fertilizer and LXM calcium-and silicon-based passivator as test materials.The results showed that compared with CK,after applying DG foliar control agent,soil available Cd content increased rather than decreased,whereas rice Cd content decreased,not reaching a significant level.When applied with SMA microbial inoculant,soil pH value,soil available Cd and rice Cd contents showed a downward then upward trend with the increase of its application rates.Between 3 levels of SMA treatments,the content of soil available Cd in SMA2 was the lowest,decreased by 8.59%in comparison with CK,contrarily,two other SMA treatments were increasing instead of decreasing in the content of soil available Cd.The application of XFJ organic fertilizer and LXM calcium-and silicon-based passivator increased soil pH value,and reduced soil available Cd and rice Cd contents;the contents of soil available Cd and rice Cd decreased with their application rates increasing.Compared with CK,XFJ3 reduced soil available Cd content by 9.40%,and significantly reduced rice Cd content by 57.28%.In LXM3 treatment,soil available Cd content reduced by 14.57%,rice Cd content was 71.57%lower than CK,reaching the lowest level.In general,LXM calcium-and silicon-based passivator had the best Cd reduction effect,with the optimal application amount of 6000 kg/hm^(2). 展开更多
关键词 RICE Remediation of Cd-contaminated farmland Foliar control agent Organic fertilizer Microbial inoculant Calcium-and silicon-based passivator Cd reduction effect
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Evaluation of ceramsite loss control agent in acid fracturing of naturally fractured carbonate reservoir 被引量:1
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作者 Zhang Lufeng Mou Jianye +1 位作者 Cheng Xiangzheng Zhang Shicheng 《Natural Gas Industry B》 2021年第3期302-308,共7页
In the acid fracturing of naturally fractured carbonate reservoirs,excessive acid leak off is the main factor limiting fracture propagation and live acid penetration distance.To reduce acid leakage and enhance the sti... In the acid fracturing of naturally fractured carbonate reservoirs,excessive acid leak off is the main factor limiting fracture propagation and live acid penetration distance.To reduce acid leakage and enhance the stimulation effect,ceramsite loss control agents have been widely applied in acid fracturing.However,the leak off reduction behavior of ceramsite has not yet been systematically investigated.Therefore,a conventional core-flooding acidizing system with a hollowed-out Hastelloy cylinder was used to perform a series of acid leak off experiments.Experimental results show that 1.the smaller the size of the ceramsite,the better thefiltration reduction effect;2.the higher the injection rate,the greater the acid carrying capacity,which is conducive to the loss of the control agent entering the fracture and acid-etched grooves;and 3.under laboratory conditions,the optimal ceramsite dosage is 4 g.This study deepens the understanding of acid leak off in carbonate reservoirs and provides fundamental information forfield acid fracturing design. 展开更多
关键词 Acid leak off Loss control agent CERAMSITE Core-flooding
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Study of Water Treatment Residue Used as a Profile Control Agent
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作者 Hou Tianjiang Zhao Huating +2 位作者 Li Zongtian Zhao Puchun Xiao Liping 《Petroleum Science》 SCIE CAS CSCD 2005年第4期50-55,共6页
A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a de... A large amount of residue from the water treatment process has gradually accumulated and thus caused serious environmental pollution in waterflood oilfields. The water treatment residue is a grey suspension, with a density of 1.08 g/cm^3, and mainly contains over 65% of light CaCO3, MgCO3, CaSO4, Fe2S3 and Ca(OH)2. This paper ascertains the effect of water treatment residue on core permeability and its application in oilfields. Coreflooding tests in laboratory were conducted in two artificial cores and one natural core. Core changes were evaluated by cast model image analysis, mercury injection method and scanning electron microscopy (SEM). Fresh water was injected into another natural core, which was plugged with water treatment residue, to determine the effective life. The results indicate that the water treatment residue has a strongly plugging capability, a resistance to erosion and a long effective life, and thus it can be used as a cheap raw material for profile control. In the past 8 years, a total of 60,164 m^3 of water treatment residue has been used for profile control of 151 well treatments, with a success ratio of 98% and an effective ratio of 83.2%. In the field tests, the profile control agent increased both starting pressure and injection pressure of injectors, and decreased the apparent water injectivity coefficient, significantly improving intake profiles and lengthening average service life of injectors. 28,381 tons of additional oil were recovered from these corresponding oil wells, with economic benefits of ¥3,069.55×10^4 (RMB) and a remarkable input-output ratio of 8.6:1. 展开更多
关键词 Water treatment residue coreflooding test profile control agent permeability modification field application
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Performance Analysis of a Profile Control Agent for Waste Drilling Fluid Treatment
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作者 Xueyu Zhao 《Fluid Dynamics & Materials Processing》 EI 2023年第7期1897-1905,共9页
A method for the treatment of hazardous waste drilling fluids,potentially leading to environmental pollution,is considered.The waste drilling fluid is treated with an inorganic flocculant,an organic flocculant,and a p... A method for the treatment of hazardous waste drilling fluids,potentially leading to environmental pollution,is considered.The waste drilling fluid is treated with an inorganic flocculant,an organic flocculant,and a pH regulator.The profile control agent consists of partially hydrolyzed polyacrylamide,formaldehyde,hexamethylenetetramine,resorcinol,phenol,and the treated waste drilling fluid itself.For a waste drilling fluid concentration of 2500 mg/L,the gelling time of the profile control agent is 25 h,and the gelling strength is 32,000 mPa.s.Compared with the profile control agent prepared by recirculated water under the same conditions,the present profile control agent displays better stability,salt-resistance,and performance. 展开更多
关键词 Waste drilling fluid profile control agent cross-linking system GEL environmental protection
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Hierarchical robot control structure and Newton's divided difference approach to robot path planning
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作者 Chan Kit Wai, Prahlad Vadakkepat, Xiao Peng (Dept. of Electrical and Computer Engineering, National University of Singapore, Singapore 119260) 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2001年第3期303-308,共6页
A hierarchical robot control is proposed for robot soccer system. The Newton’s divided difference is utilized in robot path planning. This paper describes the problems encoutered, software design considerations, visi... A hierarchical robot control is proposed for robot soccer system. The Newton’s divided difference is utilized in robot path planning. This paper describes the problems encoutered, software design considerations, vision algorithm and controls of individual robots. The solutions to the problems implemented are simple and direct. It is observed that many of the ideas and solutions can be evolved based on simple theories and concepts. This paper focuses on software structure of multi agent controls, vision algorithm and simple path planning method. 展开更多
关键词 path plannin Newton’s divided difference multi agent controls
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Secondary Metabolites of Entomopathogenic Fungi, Biological Alternative for the Control of Agricultural Pests and Disease: Present and Perspectives
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作者 Nallely San Juan-Maldonado Silvia Rodríguez-Navarro +2 位作者 Alejandro Angel-Cuapio José Norberto Vásquez Bonilla Juan Esteban Barranco-Florido 《Advances in Enzyme Research》 CAS 2024年第1期1-15,共15页
The use of entomopathogenic fungi (EF) in recent years has been highly effective against the different orders of insects considered pests of agricultural importance and their conidia have been commonly applied, but it... The use of entomopathogenic fungi (EF) in recent years has been highly effective against the different orders of insects considered pests of agricultural importance and their conidia have been commonly applied, but it has been reported that these are sensitive to the environmental conditions. For this reason, biopesticides products have been formulated based on secondary metabolites, recently. These biomolecules participate as biological control agent, such as: cyclic depsipeptides, amino acids, polyketides, polyphenols and terpenoids, affecting their morphology, life cycle and insect behavior. The use of secondary metabolites of entomopathogenic fungi opens the possibility of application in a more efficient way for the control of agricultural pests in a compatible with the environment and human health;therefore, it is important to know, analyzing the type of molecules, their effects, and their different methods of application. 展开更多
关键词 Secondary Metabolites Entomopathogenic Fungi Biological control Agent
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Research and Application of Multi-medium Profile Control and Oil Displacement Technology in Steam Flooding Wells
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作者 LISuqin 《外文科技期刊数据库(文摘版)工程技术》 2022年第1期203-207,共5页
Block A was fully transferred in December 2011, and has experienced thermal connection, displacement and steam breakthrough. It is currently in the stage of "erosion adjustment". Affected by factors such as ... Block A was fully transferred in December 2011, and has experienced thermal connection, displacement and steam breakthrough. It is currently in the stage of "erosion adjustment". Affected by factors such as reservoir heterogeneity and long development time of steam flooding, the high permeability layer in the block has a single-layer breakthrough in the longitudinal direction and a one-way breakthrough of steam in the transverse direction, resulting in uneven reservoir utilization. In order to further expand the swept volume of steam and improve the efficiency of steam flooding, the multi-medium profile control and oil displacement technology research has been carried out, the formulation of high-temperature profile control agent and foaming agent has been optimized, and a reasonable injection method has been designed. The field implementation of 8 well groups has achieved remarkable oil increase effect, and this technology has broad application prospects. 展开更多
关键词 steam flooding MULTI-MEDIA high temperature profile control agent vesicant
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Barnyardgrass control with agent of actinomycetes
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作者 YU Liuqing Wu Linfu CNRRI,Hangzhou 310006,China ZHU Biying Second Inst of Oceanography,SOA,Hangzhou 310012,China 《Chinese Rice Research Newsletter》 1997年第1期6-7,共2页
Species of actinomycetes were collected andisolated from soil samples which were pickedfrom vegetable field,park land,and forest inHangzhou,Zhejiang Province.They were in-oculated in 250 ml flasks each containing 50 m... Species of actinomycetes were collected andisolated from soil samples which were pickedfrom vegetable field,park land,and forest inHangzhou,Zhejiang Province.They were in-oculated in 250 ml flasks each containing 50 mlliquid medium and fermented on a rotary shak-er at 28℃.The agents for actinomycetes wereobtained seven days later.Four species of acti-nomycetes were selected through biological as-say.Experiments were conducted in the 展开更多
关键词 Barnyardgrass control with agent of actinomycetes
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The Preparation of Ultra-fine Calcium Carbonate and Its properties Study
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作者 Peilin WANG Shenhai WANG 《International Journal of Technology Management》 2015年第3期100-103,共4页
This article adopts the double decomposition method, select the appropriate experimental conditions and operation process, respectively add appropriate amount of sodium carboxymethyl cellulose (CMC) as crystal contr... This article adopts the double decomposition method, select the appropriate experimental conditions and operation process, respectively add appropriate amount of sodium carboxymethyl cellulose (CMC) as crystal control agent to study the influence of crystalline of ultrafine calcium carbonate. The experimental results show that the different concentrations of CMC as crystal control agent on the morphology and crystal structure of calcium carbonate have obvious effect, which emerge morphology change from square to spherical, crystalline transition from calcite to aragonite. Thus, the results provide experimental data and theoretical basis for the use of different additives, and provide experimental basis and feasible solution for this kind of reaction. 展开更多
关键词 Superfine calcium carbonate Crystal control agents Morphology and size control Action mechanism
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Productivity effect and overuse of pesticide in crop production in China 被引量:24
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作者 ZHANG Chao Guanming Shi +1 位作者 SHEN Jian HU Rui-fa 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第9期1903-1910,共8页
Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental e... Chinese farmers are often accused of overusing pesticides that play a crucial role in enhancing crop yield by reducing losses to crop pests. Pesticide overuse has caused a series of negative health and environmental externalities. This paper quantiifes the productivity effect and the optimal amount of pesticides in rice, cotton and maize production in China from the economic perspective. Using survey data col ected in 2012 and 2013, both Cobb-Douglas and Weibul damage control speciifcations are used to estimate the production function. Results show that pesticides have statistical y signiifcant pro-ductivity effect on crop yield. On the condition of Weibul damage control speciifcations, the marginal products of 1 kg of the active ingredients of pesticides for rice, cotton and maize are 71.06, 22.73 and 98.45 kg, respectively. However, 57, 64 and 17%of the actual amount of pesticides are overused for rice, cotton and maize, respectively. Moreover, the productivity effect of pesticides would be overestimated using Cobb-Douglas speciifcation without incorporating a damage control agent. 展开更多
关键词 productivity effect damage control agent pesticide overuse marginal product
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