To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used ...To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used for typical museum collection replicas have been carried out.The influence of body shape and fixed measure parameters on the seismic responses of replicas and the interaction behavior between replicas and fixed measures have been explored.Based on the results,seismic effectiveness evaluation indexes of the tie up method are proposed.Reasonable suggestions for fixed strategies are given,which provide a basis for the exhibition of delicate museum collections considering the principle of minimizing seismic responses and intervention.The analysis results show that a larger ratio of height of mass center to bottom diameter led to more intense rocking responses.Increasing the initial pretension of fishing lines was conducive to reducing the seismic responses and stress variation of the lines.Through comprehensive consideration of the interaction forces and effective securement,it is recommended to apply 20%of breaking stress as the initial pretension.For specific museum collections that cannot be effectively protected by the independent tie up method,an optimized strategy of a combination of fishing lines and fasteners is recommended.展开更多
Introduction:Rotatory chair testing has been used to evaluate horizontal canal function.Frequently used tests include sinusoidal harmonic acceleration test(SHAT)and velocity step test(VST).Objectives:Assessment of age...Introduction:Rotatory chair testing has been used to evaluate horizontal canal function.Frequently used tests include sinusoidal harmonic acceleration test(SHAT)and velocity step test(VST).Objectives:Assessment of age effect on the SHAT and VST and assessment of test-retest reliability of the parameters of those two tests.Methods:A prospective study was performed on 100 subjects with no ear or vestibular complaints and normal vestibular evaluation.They were divided into two groups;Group A:below 50 years of age and Group B:50 years of age or above.SHAT was presented at frequencies 0.02,0.04,0.08,0.16,0.32,0.64 Hz with a peak velocity of 60°/s.VST was performed using a maximum velocity of 100°/s with acceleration and deceleration of 200°/s2.Thirty subjects were tested twice to assess reliability.Results:Study participants ranged in age from 20 to 67 years.Regarding group A,the mean age was30.92±7.31 and 55.36±4.61 for group B.No significant differences were found in SHAT parameters between the two groups.As well,there was no significant difference in VST per-rotatory time constant,however,post-rotatory time constant was significantly longer for Group B(P value<0.05).Intraclass correlation coefficient(ICC)values showed moderate to good reliability(ICC 0.5800.818)for SHAT parameters for the lower frequencies and indicated moderate reliability for VST time constant(ICC 0.5090.652).Conclusions:Age has no significant effect on the parameters of SHAT and VST.Test-retest reliability is generally good for both tests.展开更多
The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment po...The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.展开更多
Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged ...Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.展开更多
The matrix effects of 14 organophosphorus pesticides in 9 kinds of vegetables matrices were preliminarily studied by gas chromatography/flame photomet- ric detection(FPD) in the paper. The matrix effects of 14 organ...The matrix effects of 14 organophosphorus pesticides in 9 kinds of vegetables matrices were preliminarily studied by gas chromatography/flame photomet- ric detection(FPD) in the paper. The matrix effects of 14 organophosphoms pesticides in 9 kinds of vegetable matrices at 0.05, 0.1 and 0.2 mg/L were compared, respectively. The results showed that matrix enhancement effect and matrix attenuation effect existed in all cases, while matrix effects did not have strong correlation with concentrations of pesticides, but were related to species of vegetables and structure and polarity of pesticides.展开更多
The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided se...The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided segmented wavemakers is analyzed in this paper. The experimental investigation on the wave field distribution of short-crested waves generated by two-sided segmented wavemakers is conducted by using an array of wave gauges. Wave spectra and directional spreading function are analyzed and the results show that when the main direction is at a certain angle with the normal line of wave generators, the wave field of 3D short-crested waves generated by two-sided segmented wavemakers has good spatial uniformity within the model test area. The effective test area can provide good wave environments for seakeeping model tests of various ocean engineering structures in the deep ocean engineering basin.展开更多
It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate t...It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate testing signals.This speed measurement method is complicated,and inevitable abrasion and occasional slippage will reduce the measurement accuracy.In order to solve this problem,based on eddy current effect due to the relative movement,a speed measurement method is proposed,which is contactless and simple.In the high-speed MFL testing,eddy current induced in the specimen will cause an obvious modification to the applied field.This modified field,which is measured by Hall sensor,can be utilized to reflect the moving speed.Firstly,the measurement principle is illustrated based on Faraday’s law.Then,dynamic finite element simulations are conducted to investigate the modified magnetic field distribution.Finally,laboratory experiments are performed to validate the feasibility of the proposed method.The results show that Bmz(r1)and Bmx(r2)have a linear relation with moving speed,which could be used as an alternative measurement parameter.展开更多
In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 1...In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 10% monosultap · thiamethoxam granular formulation and 1% Bt · clothianidin granular formulation on sugarcane borders and woolly aphids were studied.The results showed that 10% monosultap·thiamethoxam GR and 1% Bt·clothianidin GR had good control effects on sugarcane borders and woolly aphids.They were ideal slow-release,long-acting,low toxic and multi-functional new pesticides used to control sugarcane borders and woolly aphids.They could be used alternately with other pesticides to delay the emergence and development of pest resistance to pesticides.The best dosage of the two pesticides in the field was 45 kg/hm^2.They could be mixed with fertilizer( 1200-1800 kg/hm^2),scattered in sugarcane ditches or at the base of sugarcane plants,and covered with soil or film from January to July.The control effect on dead heart seedlings damaged by borers could be up to above 79.2%,and the control effect on sugarcane woolly aphids could reach more than 98.8%.In comparison with the control group,the actual yield and sugar content of sugarcane increased by above 41 555 kg/hm^2 and 6.5% respectively.The application of slow-release,long-acting,strong systemic and multi-functional new agents with fertilizer around roots is convenient,precise and efficient,labor-saving,time-saving and environmentally friendly,and is worthy of being widely applied in sugarcane areas.展开更多
A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transf...A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.展开更多
Adopting the classical theory of hydrocodes,the constitutive relations of concretes are separated into an equation of state(EoS)which describes the volumetric behavior of concrete material and a strength model which d...Adopting the classical theory of hydrocodes,the constitutive relations of concretes are separated into an equation of state(EoS)which describes the volumetric behavior of concrete material and a strength model which depicts the shear properties of concrete.The experiments on the EoS of concrete is always challenging due to the technical difficulties and equipment limitations,especially for the specimen size effect on the EoS.Although some researchers investigate the shock properties of concretes by fly-plate impact tests,the specimens used in their tests are usually in one size.In this paper,the fly-plate impact tests on concrete specimens with different sizes are performed to investigate the size effect on the shock properties of concrete materials.The mechanical background of the size effect on the shock properties are revealed,which is related to the lateral rarefaction effect and the deviatoric stress produced in the specimen.According to the tests results,the modified EoS considering the size effect on the shock properties of concrete are proposed,which the bulk modulus of concrete is unpredicted by up to 20% if size effects are not accounted for.展开更多
The main objective of this study is to develop a new protocol for bench-scale dispersant effectiveness testing adapted for subsea dispersants injection (SSDI). The new approach includes turbulence conditions, dispersa...The main objective of this study is to develop a new protocol for bench-scale dispersant effectiveness testing adapted for subsea dispersants injection (SSDI). The new approach includes turbulence conditions, dispersant injection techniques and quantification of effectiveness, more representative for a SSDI operation. Results from the new system are compared to dispersant effectiveness measured with established laboratory methods, used for screening dispersants for surface application. The most significant result is that the dispersant ranking obtained with the new test relevant for subsea releases was very different compared to the ranking obtained by screening methods used for surface application of dispersants. This strongly indicates that existing standard methods for dispersant effectiveness testing designed for simulating conditions relevant for surface application of dispersants, are less relevant for SSDI effectiveness testing and justify the need for a more relevant method. Such a Dispersant Injection Effectiveness Test (DIET) is suggested and documented in this study.展开更多
[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal do...[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal dose(LD_(50))was determined by acute toxicity test with the toxic reaction and mortality of mice as indexes.Sixty Kunming mice were randomly divided into 6 groups:normal control group,model group(ConA-induced liver injury model),Jinchuan formula plum wine high,medium and low dose groups(1.0,0.5,0.25 g/kg)and silybin group(0.1 g/kg).The levels of ALT,AST,LDH in serum and TG,VLDL in liver were measured.After HE staining,the pathological changes of liver tissue in mice were observed,and the liver protective effect of Jinchuan formula plum wine extract was analyzed and evaluated.[Results]LD_(50)was 11.18 g/kg,and the 95%confidence limit of LD_(50)was 10.31-12.05 g/kg.The high-dose group of Jinchuan formula plum wine extract could significantly reduce the serum ALT and AST activities of ConA-induced liver injury mice(P<0.05).[Conclusions]Jinchuan formula plum wine extract is relatively safe,and also has a protective effect on liver injury.展开更多
Agricultural contamination with pesticides is a challenging problem for both human and bee health. Consequently, a number of laboratories performing pesticides residues analyse in honey and honey products has graduall...Agricultural contamination with pesticides is a challenging problem for both human and bee health. Consequently, a number of laboratories performing pesticides residues analyse in honey and honey products has gradually increased in recent years. In the framework of their accreditations according to ISO 17025 standard, these laboratories must control their performances through interlaboratory comparison. Interprofessional Bureau of Analytical Studies (BIPEA) organizes regular proficiency testing schemes (PTS) in many analytical domains, including the analysis of pesticides in honey, to compare the performances of the laboratories. As an example, one test was conducted in October 2015 using an organic honey spiked with 21 pesticides, at levels between 15 ^g/kg and 200 ^g/kg, with 27 participating laboratories. This test was intended for the identification and quantification of 21 molecules of pesticides residues. The techniques used by the laboratories were GC-MS-MS, LC-MS-MS, GC-MS and GC-ECD, according to the molecules. Participating laboratories were required to return their results on a dedicated website after a period of one month, and a statistical treatment of the data was performed according to ISO 13528 standard. Assigned (consensus) values were calculated from the participants’ results and the performances of the laboratories could then be evaluated individually and collectively according to ISO 17043 standard. The results of this test were satisfactory for detection and quantification, whatever the analytical technique. The molecules were correctly identified by the laboratories and the recovery rates ranged from 56% up to 88%. The dispersions of the results, studied through the coefficients of variation, were also satisfactory ranging from 7% to 30%. This test showed that the laboratories participating routinely in this kind of tests are very competent in the analysis of pesticides residues in honey. It also allowed the participating laboratories to draw up a general inventory of their analytical skills, and it was a very useful tool to detect bias or non-compliant results. It acted as a warning signal for the implementation of corrective and/or curative actions in the laboratories.展开更多
AIM:To compare the costs and effectiveness of no screening and no eradication therapy, the population- based Helicobacter pylori (H pylori) serology screening with eradication therapy and 13C-Urea breath test (UBT) wi...AIM:To compare the costs and effectiveness of no screening and no eradication therapy, the population- based Helicobacter pylori (H pylori) serology screening with eradication therapy and 13C-Urea breath test (UBT) with eradication therapy. METHODS:A Markov model simulation was carried out in all 237 900 Chinese males with age between 35 and 44 from the perspective of the public healthcare provider in Singapore. The main outcome measures were the costs, number of gastric cancer cases prevented, life years saved, and quality-adjusted life years (QALYs) gained from screening age to death. The uncertainty surrounding the cost-effectiveness ratio was addressed by one-way sensitivity analyses. RESULTS:Compared to no screening, the incremental cost-effectiveness ratio (ICER) was $16 166 per life year saved or $13 571 per QALY gained for the serology screening, and $38 792 per life year saved and $32 525 per QALY gained for the UBT. The ICER was $477 079 per life year saved or $390 337 per QALY gained for the UBT compared to the serology screening. The cost- effectiveness of serology screening over the UBT was robust to most parameters in the model. CONCLUSION:The population-based serologyscreening for H pylori was more cost-effective than the UBT in prevention of gastric cancer in Singapore Chinese males.展开更多
Effect of various pesticides (insecticides, fungicides and herbicides) has been studied on growth and efficiency of symbiotic properties of 3 fast growing Rhizobium sp. under green house conditions. The results reveal...Effect of various pesticides (insecticides, fungicides and herbicides) has been studied on growth and efficiency of symbiotic properties of 3 fast growing Rhizobium sp. under green house conditions. The results revealed adverse effects on plant growth and nitrogen fixing capacity as measured by dry weight and total nitrogen content of plants infected with pesticide treated Rhizobium. Of the pesticides tested, herbicides were found to be more effective on the above parameters than the insecticides and fungicides.展开更多
In this study, extractability of 13 organochlorine pesticides aged in six different soil types, was investigated. Acceptable recoveries were achieved for most of the analytes spiked into five of the soil types. No app...In this study, extractability of 13 organochlorine pesticides aged in six different soil types, was investigated. Acceptable recoveries were achieved for most of the analytes spiked into five of the soil types. No apparent correlation was perceptible between the soil characteristics and extractability of the aged analytes, signifying exhaustiveness of the extraction. However, recovery was considerably minimized (<75%) in the clay ensuring the hypothesis of study stating “extraction efficiency might be matrix dependent”. Therefore, the study demonstrates importance of optimizing extraction conditions even for those believed to be less prone to matrix effect, due to distinct properties of analyte-matrix interactions.展开更多
CET-6 is a nationwide and standardized test to evaluate college students' English levels. Now more than 10 million college students take part in the exam every year. On August 14, 2013, the CET-4 and CET-6 examina...CET-6 is a nationwide and standardized test to evaluate college students' English levels. Now more than 10 million college students take part in the exam every year. On August 14, 2013, the CET-4 and CET-6 examination committee reformed the structure of the CET-6 papers. After that the sentence translation was changed into paragraph translation,the scores of translation section also increased to 15 points which is more difficult and more important than before. There is no doubt that CET-6will exert a great impact on the teaching and learning of College English in China. This thesis focuses on the washback effect of CET-6 translation test towards college English teaching and learning.First of all, this paper introduces the CET-6 translation test requirements, and the score requirements of translation part. The author also illustrates some significant language testing research of both domestic and foreign scholars, and explains the concept of reliability and validity. Secondly, through the survey method of interviews and questionnaire the author study the characteristics of teaching in college classroom, the effect of translation teaching, and how do students to study translation. The author makes a further research on the interaction between the translation test and the teaching and learning based on the relevant theories. At last, the author finds that the negative washback effect of the CET-6 translation test is greater than the positive one. The author reflects on the current translation teaching and learning in China, and hopes to minimize the negative effects of CET-6 translation test.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
基金Beijing Nova Program under Grant No.2022036National Key Research and Development Program under Grant No.2019YFC1521000。
文摘To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used for typical museum collection replicas have been carried out.The influence of body shape and fixed measure parameters on the seismic responses of replicas and the interaction behavior between replicas and fixed measures have been explored.Based on the results,seismic effectiveness evaluation indexes of the tie up method are proposed.Reasonable suggestions for fixed strategies are given,which provide a basis for the exhibition of delicate museum collections considering the principle of minimizing seismic responses and intervention.The analysis results show that a larger ratio of height of mass center to bottom diameter led to more intense rocking responses.Increasing the initial pretension of fishing lines was conducive to reducing the seismic responses and stress variation of the lines.Through comprehensive consideration of the interaction forces and effective securement,it is recommended to apply 20%of breaking stress as the initial pretension.For specific museum collections that cannot be effectively protected by the independent tie up method,an optimized strategy of a combination of fishing lines and fasteners is recommended.
文摘Introduction:Rotatory chair testing has been used to evaluate horizontal canal function.Frequently used tests include sinusoidal harmonic acceleration test(SHAT)and velocity step test(VST).Objectives:Assessment of age effect on the SHAT and VST and assessment of test-retest reliability of the parameters of those two tests.Methods:A prospective study was performed on 100 subjects with no ear or vestibular complaints and normal vestibular evaluation.They were divided into two groups;Group A:below 50 years of age and Group B:50 years of age or above.SHAT was presented at frequencies 0.02,0.04,0.08,0.16,0.32,0.64 Hz with a peak velocity of 60°/s.VST was performed using a maximum velocity of 100°/s with acceleration and deceleration of 200°/s2.Thirty subjects were tested twice to assess reliability.Results:Study participants ranged in age from 20 to 67 years.Regarding group A,the mean age was30.92±7.31 and 55.36±4.61 for group B.No significant differences were found in SHAT parameters between the two groups.As well,there was no significant difference in VST per-rotatory time constant,however,post-rotatory time constant was significantly longer for Group B(P value<0.05).Intraclass correlation coefficient(ICC)values showed moderate to good reliability(ICC 0.5800.818)for SHAT parameters for the lower frequencies and indicated moderate reliability for VST time constant(ICC 0.5090.652).Conclusions:Age has no significant effect on the parameters of SHAT and VST.Test-retest reliability is generally good for both tests.
文摘The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.
基金supported by the National Natural Science Foundation of China(30070122).
文摘Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.
文摘The matrix effects of 14 organophosphorus pesticides in 9 kinds of vegetables matrices were preliminarily studied by gas chromatography/flame photomet- ric detection(FPD) in the paper. The matrix effects of 14 organophosphoms pesticides in 9 kinds of vegetable matrices at 0.05, 0.1 and 0.2 mg/L were compared, respectively. The results showed that matrix enhancement effect and matrix attenuation effect existed in all cases, while matrix effects did not have strong correlation with concentrations of pesticides, but were related to species of vegetables and structure and polarity of pesticides.
基金financially supported by the National Natural Science Foundation of China(Grant No.51239007)
文摘The size and shape of the effective test area are crucial to consider when short-crested waves are created by segmented wavemakers. The range of the effective test area of short-crested waves simulated by two-sided segmented wavemakers is analyzed in this paper. The experimental investigation on the wave field distribution of short-crested waves generated by two-sided segmented wavemakers is conducted by using an array of wave gauges. Wave spectra and directional spreading function are analyzed and the results show that when the main direction is at a certain angle with the normal line of wave generators, the wave field of 3D short-crested waves generated by two-sided segmented wavemakers has good spatial uniformity within the model test area. The effective test area can provide good wave environments for seakeeping model tests of various ocean engineering structures in the deep ocean engineering basin.
基金supported in part by the National Natural Science Foundation of China(Grant No.92060114)in part by the Sichuan Science and Technology Program(Nos.2022YFS0524 and 2022YFG0044).
文摘It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate testing signals.This speed measurement method is complicated,and inevitable abrasion and occasional slippage will reduce the measurement accuracy.In order to solve this problem,based on eddy current effect due to the relative movement,a speed measurement method is proposed,which is contactless and simple.In the high-speed MFL testing,eddy current induced in the specimen will cause an obvious modification to the applied field.This modified field,which is measured by Hall sensor,can be utilized to reflect the moving speed.Firstly,the measurement principle is illustrated based on Faraday’s law.Then,dynamic finite element simulations are conducted to investigate the modified magnetic field distribution.Finally,laboratory experiments are performed to validate the feasibility of the proposed method.The results show that Bmz(r1)and Bmx(r2)have a linear relation with moving speed,which could be used as an alternative measurement parameter.
基金Supported by Sugar Crop Research System(CARS-170303)Training Project of"Yunling Industry Technology Leading Talent"(2018LJRC56)Special Funds for Construction of Modern Agricultural Industrial Technology System of Yunnan Province(YNGZTX-4-92)
文摘In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 10% monosultap · thiamethoxam granular formulation and 1% Bt · clothianidin granular formulation on sugarcane borders and woolly aphids were studied.The results showed that 10% monosultap·thiamethoxam GR and 1% Bt·clothianidin GR had good control effects on sugarcane borders and woolly aphids.They were ideal slow-release,long-acting,low toxic and multi-functional new pesticides used to control sugarcane borders and woolly aphids.They could be used alternately with other pesticides to delay the emergence and development of pest resistance to pesticides.The best dosage of the two pesticides in the field was 45 kg/hm^2.They could be mixed with fertilizer( 1200-1800 kg/hm^2),scattered in sugarcane ditches or at the base of sugarcane plants,and covered with soil or film from January to July.The control effect on dead heart seedlings damaged by borers could be up to above 79.2%,and the control effect on sugarcane woolly aphids could reach more than 98.8%.In comparison with the control group,the actual yield and sugar content of sugarcane increased by above 41 555 kg/hm^2 and 6.5% respectively.The application of slow-release,long-acting,strong systemic and multi-functional new agents with fertilizer around roots is convenient,precise and efficient,labor-saving,time-saving and environmentally friendly,and is worthy of being widely applied in sugarcane areas.
基金Supported by the Key Laboratory of Microsatellites,Chinese Academy of Sciences
文摘A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained.
基金supported by the National Natural Science Foundation of China[Grant Nos.51938011 and 51908405]Australian Research Council。
文摘Adopting the classical theory of hydrocodes,the constitutive relations of concretes are separated into an equation of state(EoS)which describes the volumetric behavior of concrete material and a strength model which depicts the shear properties of concrete.The experiments on the EoS of concrete is always challenging due to the technical difficulties and equipment limitations,especially for the specimen size effect on the EoS.Although some researchers investigate the shock properties of concretes by fly-plate impact tests,the specimens used in their tests are usually in one size.In this paper,the fly-plate impact tests on concrete specimens with different sizes are performed to investigate the size effect on the shock properties of concrete materials.The mechanical background of the size effect on the shock properties are revealed,which is related to the lateral rarefaction effect and the deviatoric stress produced in the specimen.According to the tests results,the modified EoS considering the size effect on the shock properties of concrete are proposed,which the bulk modulus of concrete is unpredicted by up to 20% if size effects are not accounted for.
文摘The main objective of this study is to develop a new protocol for bench-scale dispersant effectiveness testing adapted for subsea dispersants injection (SSDI). The new approach includes turbulence conditions, dispersant injection techniques and quantification of effectiveness, more representative for a SSDI operation. Results from the new system are compared to dispersant effectiveness measured with established laboratory methods, used for screening dispersants for surface application. The most significant result is that the dispersant ranking obtained with the new test relevant for subsea releases was very different compared to the ranking obtained by screening methods used for surface application of dispersants. This strongly indicates that existing standard methods for dispersant effectiveness testing designed for simulating conditions relevant for surface application of dispersants, are less relevant for SSDI effectiveness testing and justify the need for a more relevant method. Such a Dispersant Injection Effectiveness Test (DIET) is suggested and documented in this study.
文摘[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal dose(LD_(50))was determined by acute toxicity test with the toxic reaction and mortality of mice as indexes.Sixty Kunming mice were randomly divided into 6 groups:normal control group,model group(ConA-induced liver injury model),Jinchuan formula plum wine high,medium and low dose groups(1.0,0.5,0.25 g/kg)and silybin group(0.1 g/kg).The levels of ALT,AST,LDH in serum and TG,VLDL in liver were measured.After HE staining,the pathological changes of liver tissue in mice were observed,and the liver protective effect of Jinchuan formula plum wine extract was analyzed and evaluated.[Results]LD_(50)was 11.18 g/kg,and the 95%confidence limit of LD_(50)was 10.31-12.05 g/kg.The high-dose group of Jinchuan formula plum wine extract could significantly reduce the serum ALT and AST activities of ConA-induced liver injury mice(P<0.05).[Conclusions]Jinchuan formula plum wine extract is relatively safe,and also has a protective effect on liver injury.
文摘Agricultural contamination with pesticides is a challenging problem for both human and bee health. Consequently, a number of laboratories performing pesticides residues analyse in honey and honey products has gradually increased in recent years. In the framework of their accreditations according to ISO 17025 standard, these laboratories must control their performances through interlaboratory comparison. Interprofessional Bureau of Analytical Studies (BIPEA) organizes regular proficiency testing schemes (PTS) in many analytical domains, including the analysis of pesticides in honey, to compare the performances of the laboratories. As an example, one test was conducted in October 2015 using an organic honey spiked with 21 pesticides, at levels between 15 ^g/kg and 200 ^g/kg, with 27 participating laboratories. This test was intended for the identification and quantification of 21 molecules of pesticides residues. The techniques used by the laboratories were GC-MS-MS, LC-MS-MS, GC-MS and GC-ECD, according to the molecules. Participating laboratories were required to return their results on a dedicated website after a period of one month, and a statistical treatment of the data was performed according to ISO 13528 standard. Assigned (consensus) values were calculated from the participants’ results and the performances of the laboratories could then be evaluated individually and collectively according to ISO 17043 standard. The results of this test were satisfactory for detection and quantification, whatever the analytical technique. The molecules were correctly identified by the laboratories and the recovery rates ranged from 56% up to 88%. The dispersions of the results, studied through the coefficients of variation, were also satisfactory ranging from 7% to 30%. This test showed that the laboratories participating routinely in this kind of tests are very competent in the analysis of pesticides residues in honey. It also allowed the participating laboratories to draw up a general inventory of their analytical skills, and it was a very useful tool to detect bias or non-compliant results. It acted as a warning signal for the implementation of corrective and/or curative actions in the laboratories.
文摘AIM:To compare the costs and effectiveness of no screening and no eradication therapy, the population- based Helicobacter pylori (H pylori) serology screening with eradication therapy and 13C-Urea breath test (UBT) with eradication therapy. METHODS:A Markov model simulation was carried out in all 237 900 Chinese males with age between 35 and 44 from the perspective of the public healthcare provider in Singapore. The main outcome measures were the costs, number of gastric cancer cases prevented, life years saved, and quality-adjusted life years (QALYs) gained from screening age to death. The uncertainty surrounding the cost-effectiveness ratio was addressed by one-way sensitivity analyses. RESULTS:Compared to no screening, the incremental cost-effectiveness ratio (ICER) was $16 166 per life year saved or $13 571 per QALY gained for the serology screening, and $38 792 per life year saved and $32 525 per QALY gained for the UBT. The ICER was $477 079 per life year saved or $390 337 per QALY gained for the UBT compared to the serology screening. The cost- effectiveness of serology screening over the UBT was robust to most parameters in the model. CONCLUSION:The population-based serologyscreening for H pylori was more cost-effective than the UBT in prevention of gastric cancer in Singapore Chinese males.
文摘Effect of various pesticides (insecticides, fungicides and herbicides) has been studied on growth and efficiency of symbiotic properties of 3 fast growing Rhizobium sp. under green house conditions. The results revealed adverse effects on plant growth and nitrogen fixing capacity as measured by dry weight and total nitrogen content of plants infected with pesticide treated Rhizobium. Of the pesticides tested, herbicides were found to be more effective on the above parameters than the insecticides and fungicides.
基金financial support provided by the Swedish International Development Agencythe Department for Research Co-operation(SIDA/SAREC)and the International Science Program(ISP).
文摘In this study, extractability of 13 organochlorine pesticides aged in six different soil types, was investigated. Acceptable recoveries were achieved for most of the analytes spiked into five of the soil types. No apparent correlation was perceptible between the soil characteristics and extractability of the aged analytes, signifying exhaustiveness of the extraction. However, recovery was considerably minimized (<75%) in the clay ensuring the hypothesis of study stating “extraction efficiency might be matrix dependent”. Therefore, the study demonstrates importance of optimizing extraction conditions even for those believed to be less prone to matrix effect, due to distinct properties of analyte-matrix interactions.
文摘CET-6 is a nationwide and standardized test to evaluate college students' English levels. Now more than 10 million college students take part in the exam every year. On August 14, 2013, the CET-4 and CET-6 examination committee reformed the structure of the CET-6 papers. After that the sentence translation was changed into paragraph translation,the scores of translation section also increased to 15 points which is more difficult and more important than before. There is no doubt that CET-6will exert a great impact on the teaching and learning of College English in China. This thesis focuses on the washback effect of CET-6 translation test towards college English teaching and learning.First of all, this paper introduces the CET-6 translation test requirements, and the score requirements of translation part. The author also illustrates some significant language testing research of both domestic and foreign scholars, and explains the concept of reliability and validity. Secondly, through the survey method of interviews and questionnaire the author study the characteristics of teaching in college classroom, the effect of translation teaching, and how do students to study translation. The author makes a further research on the interaction between the translation test and the teaching and learning based on the relevant theories. At last, the author finds that the negative washback effect of the CET-6 translation test is greater than the positive one. The author reflects on the current translation teaching and learning in China, and hopes to minimize the negative effects of CET-6 translation test.
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.