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
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
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
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
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
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
[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
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
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
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
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
AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from database...AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from databases.Relevant information was extracted and analyzed,using the relative risk(RR) and weighted mean deviation,as appropriate.A random or fixed effect model was used,based on the heterogeneity of the included articles,and visual inspection of funnel plots was used to evaluate publication bias.RESULTS:Nine RCTs enrolling 2620 FD cases were included;1372 cases received itopride treatment and 1248 cases received placebo or other drugs(control groups).Compared with control groups,itopride had superior RR values of 1.11 [95%CI:(1.03,1.19),P = 0.006],1.21 [95%CI:(1.03,1.44),P = 0.02],and1.24 [95%CI:(1.01,1.53),P = 0.04] for global patient assessment,postprandial fullness,and early satiety,respectively.For the Leeds Dyspepsia Questionnaire score,the weighted mean deviation was-1.38 [95%CI:(-1.75,-1.01),P < 0.01].The incidence of adverse effects was similar in the itopride and control groups.The funnel plots for all indicators showed no evidence of publication bias.CONCLUSION:Itopride has good efficacy in terms of global patients assessment,postprandial fullness,and early satiety in the treatment of patients with FD and shows a low rate of adverse reactions.Itopride can greatly improve FD syndromes-score.展开更多
[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
The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron micro...The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron microscopy respectively. After MA without PCA (dry method) for 30h, Fe0.85Ni0.15 nanocrystalline alloy powders with bcc-Fe(Ni) phase were obtained; however, powders milled with PCA (wet method) from 20 to 90 h, were unalloyed Fe-Ni mixtures with balanced morphology. It seems that dry method works efficiently in nanocrystalline alloying while wet method postpones MA but functionally fines the morphology of materials. Finally, the results were discussed considering the MA kinetics.展开更多
Objective:To evaluate 11 Cuban native Bacillus(B.)thuringiensis isolates in order to select one with the best larvicidal activity against Aedes(Ae.)aegypti and low cytotoxicity.Methods:The cry and cyt genes of the iso...Objective:To evaluate 11 Cuban native Bacillus(B.)thuringiensis isolates in order to select one with the best larvicidal activity against Aedes(Ae.)aegypti and low cytotoxicity.Methods:The cry and cyt genes of the isolates(A21,A51,L95,L910,M29,R84,R85,R87,R89,U81 and X48)were amplified by PCR.The influence of organic matter and NaCl on the larvicidal activity was tested by bioassays.Cytotoxicity was assayed on peritoneal macrophages of BALB/c mice.Results:The cyt1(Aa,Ab,Ba),cyt2,cry4aA,cry4Ba,cry11(Aa,Ba,Bb)and cry10 genes were identified in all native Cuban isolates.The larvicidal activity(LC_(90))of seven isolates was affected by the presence of organic matter in the water,while A21,A51,L910,R84,U81 and X48 had better LC_(50),LC_(90),LC_(95) than the 266/29-Ⅶ-98 control strain.The LC_(50) of two isolates was affected by the presence of NaCl and A21,A51,R85 isolate had better larvicidal activity than the 266/29-Ⅶ-98 control strain.In terms of toxicity against macrophages,the extracts of nine isolates were less cytotoxic than the control strains.Conclusions:Native isolate A21 had the main virulence factors against Ae.aegypti larvae,displayed a good larvicidal activity in presence of different factors related with Ae.aegypti breeding sites,and had low citotoxicity against macrophages.These results can contribute to the improvement of existing biological control strategies and the development of new biolarvicides.展开更多
In this paper, the numeral response and main parameters of experimental population life table were analyzed for determining the suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: ...In this paper, the numeral response and main parameters of experimental population life table were analyzed for determining the suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: (1) Under 21-31°C and 1 - 9 prey densities/leaf fragment condition, the prey consumptions of A. cucumeris increased with the temperature or prey density; (2) In 1:3 predator-prey ratio treatment, the suppression of P. citri (Ro=34.0053; T=19.4369; t=3.8204) was rather weak, it was enhanced as the ratio over 5:30, and the populations of P. citri in these treatments can be fully controlled within 4-5 days; (3) Under 25±1°C, 80-85% RH and 15L: 9D illumination conditions, the net reproductive rate, mean generation duration and the time for population double increase of P. citri (Ro=34.0053; T=19.4369; t=3.8204) were higher than those of A. cucumeris (Ro=21.8750; T=16.8943; t=3.7954). While the intrinsic rate of increase and finite rate of increase of the former (rm=0.1814; λ=1.1989) were lower than those of the latter (rm=0.1826; λ=1.2004). These results indicated that A. cucumeris is a desirable bio-control agent to suppress P. citri at lower population stage in citrus orchard.展开更多
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
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
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
The present study concerns understanding the effect of process parameters on the characteristics and flowability of nanocrystalline CoNiCrAlY powder synthesized by mechanical milling.Mechanical milling has been conduc...The present study concerns understanding the effect of process parameters on the characteristics and flowability of nanocrystalline CoNiCrAlY powder synthesized by mechanical milling.Mechanical milling has been conducted in a planetary ball mill with tungsten carbide(WC)ball,with ball to powder ratio of 10:1 at 300 rpm speed,using 1%stearic acid and toluene as process control agent(PCA)with time varying from 10 h to 36 h.The synthesized nanocrystalline powder were characterized by Scanning Electron Microscopy,X-ray Diffraction technique,X-ray Photoelectron Spectroscopy,and Differential Scanning Calorimetry.Subsequently,flowability in terms of Hausner ratio was assessed by Tap Density Tester.Average particle size of the powder was found to decrease from 33μm to 22μm after 10 h of milling and further increases to 43μm and 38μm after 25 and 36 h of milling,respectively,in stearic acid medium.However,in toluene medium particle size continuously decreases from 33μm to 9.7μm with increasing milling time.The particle morphology changes from spherical to platelet shape at low milling hours in both of the media.After 25 h of milling,the shape of the particles is nearly spherical for stearic acid and irregular for toluene used as a PCA.Crystallize size was found to decrease with increasing milling time from 147 nm to 7.7 nm and to 6.4 nm in stearic acid and toluene media,respectively.There was presence ofγ,γʹ,β,hcp-Co,Al_(2)O_(3)and AlOOH phases on the powder particles milled in both the medium.The measured Hausner ratio of the powders was found to vary from 1.18 to 1.32 in stearic acid medium,and was found to increase with increasing milling time.On the other hand,in toluene media flowability decreases(Hausner ratio increases from 1.33 to 1.44)with increasing milling time.展开更多
文摘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.
文摘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.
文摘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.
文摘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).
文摘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.
文摘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.
文摘[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.
文摘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
文摘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
基金financial support from the National Natural Science Foundation of China (71173014 and 71210004)the China Scholarship Council (201306030053)
文摘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.
基金The financial support by the National Natural Science Foundation of China (No.51104153)the Fundamental Research Fundsfor the Central Universities (No.2011QNB11)
文摘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.
基金Supported by The Natural Science Foundation of Zhejiang Province of China,No. LY12H29002Traditional Chinese Medicine Science Foundation of Zhejiang Province of China,No. 2011ZB032
文摘AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from databases.Relevant information was extracted and analyzed,using the relative risk(RR) and weighted mean deviation,as appropriate.A random or fixed effect model was used,based on the heterogeneity of the included articles,and visual inspection of funnel plots was used to evaluate publication bias.RESULTS:Nine RCTs enrolling 2620 FD cases were included;1372 cases received itopride treatment and 1248 cases received placebo or other drugs(control groups).Compared with control groups,itopride had superior RR values of 1.11 [95%CI:(1.03,1.19),P = 0.006],1.21 [95%CI:(1.03,1.44),P = 0.02],and1.24 [95%CI:(1.01,1.53),P = 0.04] for global patient assessment,postprandial fullness,and early satiety,respectively.For the Leeds Dyspepsia Questionnaire score,the weighted mean deviation was-1.38 [95%CI:(-1.75,-1.01),P < 0.01].The incidence of adverse effects was similar in the itopride and control groups.The funnel plots for all indicators showed no evidence of publication bias.CONCLUSION:Itopride has good efficacy in terms of global patients assessment,postprandial fullness,and early satiety in the treatment of patients with FD and shows a low rate of adverse reactions.Itopride can greatly improve FD syndromes-score.
基金Supported by Science and Technology Support Project for Functional Areas of Food Production in Ningbo City (200903C1011009)
文摘[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.
文摘The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron microscopy respectively. After MA without PCA (dry method) for 30h, Fe0.85Ni0.15 nanocrystalline alloy powders with bcc-Fe(Ni) phase were obtained; however, powders milled with PCA (wet method) from 20 to 90 h, were unalloyed Fe-Ni mixtures with balanced morphology. It seems that dry method works efficiently in nanocrystalline alloying while wet method postpones MA but functionally fines the morphology of materials. Finally, the results were discussed considering the MA kinetics.
文摘Objective:To evaluate 11 Cuban native Bacillus(B.)thuringiensis isolates in order to select one with the best larvicidal activity against Aedes(Ae.)aegypti and low cytotoxicity.Methods:The cry and cyt genes of the isolates(A21,A51,L95,L910,M29,R84,R85,R87,R89,U81 and X48)were amplified by PCR.The influence of organic matter and NaCl on the larvicidal activity was tested by bioassays.Cytotoxicity was assayed on peritoneal macrophages of BALB/c mice.Results:The cyt1(Aa,Ab,Ba),cyt2,cry4aA,cry4Ba,cry11(Aa,Ba,Bb)and cry10 genes were identified in all native Cuban isolates.The larvicidal activity(LC_(90))of seven isolates was affected by the presence of organic matter in the water,while A21,A51,L910,R84,U81 and X48 had better LC_(50),LC_(90),LC_(95) than the 266/29-Ⅶ-98 control strain.The LC_(50) of two isolates was affected by the presence of NaCl and A21,A51,R85 isolate had better larvicidal activity than the 266/29-Ⅶ-98 control strain.In terms of toxicity against macrophages,the extracts of nine isolates were less cytotoxic than the control strains.Conclusions:Native isolate A21 had the main virulence factors against Ae.aegypti larvae,displayed a good larvicidal activity in presence of different factors related with Ae.aegypti breeding sites,and had low citotoxicity against macrophages.These results can contribute to the improvement of existing biological control strategies and the development of new biolarvicides.
文摘In this paper, the numeral response and main parameters of experimental population life table were analyzed for determining the suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: (1) Under 21-31°C and 1 - 9 prey densities/leaf fragment condition, the prey consumptions of A. cucumeris increased with the temperature or prey density; (2) In 1:3 predator-prey ratio treatment, the suppression of P. citri (Ro=34.0053; T=19.4369; t=3.8204) was rather weak, it was enhanced as the ratio over 5:30, and the populations of P. citri in these treatments can be fully controlled within 4-5 days; (3) Under 25±1°C, 80-85% RH and 15L: 9D illumination conditions, the net reproductive rate, mean generation duration and the time for population double increase of P. citri (Ro=34.0053; T=19.4369; t=3.8204) were higher than those of A. cucumeris (Ro=21.8750; T=16.8943; t=3.7954). While the intrinsic rate of increase and finite rate of increase of the former (rm=0.1814; λ=1.1989) were lower than those of the latter (rm=0.1826; λ=1.2004). These results indicated that A. cucumeris is a desirable bio-control agent to suppress P. citri at lower population stage in citrus orchard.
文摘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.
文摘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.
基金Raiganj University,IndiaInstituto Tecnológico de Sonora,México+7 种基金Campo Experimental Norman E.Borlaug-Instituto Nacional de Investigaciones Forestales,Agrícolas y Pecuarias(INIFAP),MéxicoUniversidad Nacional Experimental del Táchira,VenezuelaFederal University of Pernambuco,BrazilFederal University of Agriculture,NigeriaUniversity of Tabriz,IranIndian Council of Agricultural Research(ICAR)-National Rice Research Institute for supportthe Government of West Bengal,India for the Swami Vivekananda Merit Cum Means Ph.D.Scholarship(No.WBP191584588825)the Department of Science and Technology(DST),India for Inspire Fellowship(No.IF190457)。
文摘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.
基金the Indian Space Research Organization(ISRO),India,Science and Engineering Research Board,N.Delhi(POWER Fellowship,SPF/2021/000073,Dt.11-03-2021),Ministry of Human Resource Development(MHRD)Government of India(under IMPRINT-2,sanction letter IMP/2018/001162,Dt.02-01-2019)+1 种基金Department of Science and Technology(DST),N.Delhi(DST/TSG/AMT/2015/636/G,Dt.18-06-2018,DST/TDT/AMT/2017/074(G),Dt.12-09-2018)Alexander von Humboldt Foundation。
文摘The present study concerns understanding the effect of process parameters on the characteristics and flowability of nanocrystalline CoNiCrAlY powder synthesized by mechanical milling.Mechanical milling has been conducted in a planetary ball mill with tungsten carbide(WC)ball,with ball to powder ratio of 10:1 at 300 rpm speed,using 1%stearic acid and toluene as process control agent(PCA)with time varying from 10 h to 36 h.The synthesized nanocrystalline powder were characterized by Scanning Electron Microscopy,X-ray Diffraction technique,X-ray Photoelectron Spectroscopy,and Differential Scanning Calorimetry.Subsequently,flowability in terms of Hausner ratio was assessed by Tap Density Tester.Average particle size of the powder was found to decrease from 33μm to 22μm after 10 h of milling and further increases to 43μm and 38μm after 25 and 36 h of milling,respectively,in stearic acid medium.However,in toluene medium particle size continuously decreases from 33μm to 9.7μm with increasing milling time.The particle morphology changes from spherical to platelet shape at low milling hours in both of the media.After 25 h of milling,the shape of the particles is nearly spherical for stearic acid and irregular for toluene used as a PCA.Crystallize size was found to decrease with increasing milling time from 147 nm to 7.7 nm and to 6.4 nm in stearic acid and toluene media,respectively.There was presence ofγ,γʹ,β,hcp-Co,Al_(2)O_(3)and AlOOH phases on the powder particles milled in both the medium.The measured Hausner ratio of the powders was found to vary from 1.18 to 1.32 in stearic acid medium,and was found to increase with increasing milling time.On the other hand,in toluene media flowability decreases(Hausner ratio increases from 1.33 to 1.44)with increasing milling time.