Intensive labor chores for broiler production could be reduced by using automated systems.However,broilers’response toward automated systems remains unclear.The experiments were conducted to determine the avoidance d...Intensive labor chores for broiler production could be reduced by using automated systems.However,broilers’response toward automated systems remains unclear.The experiments were conducted to determine the avoidance distance(AD)and the fleeing speed(FS)of 4-8 weeks old broilers toward two aerial systems,a rail with a dummy arm and a drone,operated at different speeds(0.2-1.2 m/s),and heights(0.3-1.8 m)in a commercial broiler house.The broiler AD to a human assessor was also determined for comparison.Results show that the overall mean and standard error(SE)of broiler AD were 63±3 cm for the assessor,58±1 cm for the rail,and 85±1 cm for the drone.As bird age increased from week 4 to week 8,broiler AD reduced significantly from 82 to 45 cm for the rail but showed no significant change for the drone.As the operational speed increased,broiler AD significantly increased from 54 cm(0.2 m/s)to 62 cm(0.4 m/s)for the rail,and from 81 cm(0.4 m/s)to 89 cm(1.2 m/s)for the drone.As the operational height increased,broiler AD increased from 54 cm(0.3 m)to 57 cm(1.5 m)for the rail and 81 cm(1.2 m)to 88 cm(1.8 m)for the drone.Overall mean and SE of broiler FS were 0.21±0.01 m/s for the rail and 0.65±0.01 m/s for the drone.As bird age increased from week 4 to week 8,the mean broiler FS decreased from 0.47 to 0.07 m/s for the rail and from 0.84 to 0.16 m/s for the drone.Increasing operational speed from 0.2 to 0.4 m/s for the rail and from 0.4 to 1.2 m/s for the drone significantly increased the mean FS from 0.18 to 0.24 m/s and from 0.52 to 0.78 m/s,respectively.Increasing the height of the rail from 0.3 to 1.5 m decreased the broiler FS from 0.27 to 0.16 m/s.However,increasing drone height from 1.2 to 1.8 m retained a similar FS.The outcomes of this study can help to better understand the interaction of broilers with aerial systems and provide insights into the optimization of robotic operational strategies while maintaining good broiler welfare production.展开更多
[ Objective ] The paper was to study the density restriction effects of reproductive rate of rice brown planthopper （BPH） population in super indiea and japonica hybrid rice Yongyou 6. [Method] Different amounts of ...[ Objective ] The paper was to study the density restriction effects of reproductive rate of rice brown planthopper （BPH） population in super indiea and japonica hybrid rice Yongyou 6. [Method] Different amounts of rice brown planthoppor were released to super indiea and japonica hybrid flee Yongyou 6 during fillering, booting and gain filling stage, respectively. The reproductive rate and variation dynamics of rice brown planthoppor in super rice was also investigated and analyzed. [Result] Tillering stage： the population quantity of rice brown planthoppor during booting and gain filling stage gradually increased with the increasing basal amount of its population during tillering stage; when the population density of rice brown planthopper during grain filling stage reached a certain limit （ 〉 250 head/cluster）, the population density during milking stage showed decrease trend with the increasing of such density; the development of rice brown planthoppor population in super rice Yongyou 6 showed the characteristics of fast in middle and slow in two ends. Booting stage： the development of rice brown planthopper pop- ulation from booting to gain filling stage increased with the increasing basal amount of density, and their correlation during milking stage was not significant; flee brown planthopper population still had high reproduction capacity in the middle and late stage of super rice, which had latent risk on rice yield. Gain filling stage ： when population density of rice brown planthopper 〈 70 head/cluster, the development of it population increased with the increase of basal amount of density, which had great threat to yield. [ Conclusion] The result provided theoretical basis for establishment and improvement of monitoring early warning system, cost-ef- fective control of occurrence and damage of rice brown planthopper, and improvement of the sustained control ability against rice brown planthopper.展开更多
Chitinases （EC3.2.1.14）, found in a wide range of organisms, catalyze the hydrolysis of chitin and play a major role in defense mechanisms against fungal pathogens. The alignment and typical domains were analyzed us...Chitinases （EC3.2.1.14）, found in a wide range of organisms, catalyze the hydrolysis of chitin and play a major role in defense mechanisms against fungal pathogens. The alignment and typical domains were analyzed using basic local alignment search tool （BLAST） and simple modular architecture research tool （SMART）, respectively. On the basis of the annotations of flee （Oryza sativa L.） and Arabidopsis genomic sequences and using the bio-software SignalP3.0, TMHMM2.0, TargetPl.1, and big-Pi Predictor, 25 out of 37 and 16 out of 24 open reading frames （ORFs） with chitinase activity from rice and Arabidopsis, respectively, were predicted to have signal pepfides （SPs）, which have an average of 24.8 amino acids at the N-terminal region. Some of the chitinases were secreted extracellularly, whereas some were located in the vacuole. The phylogenic relationship was analyzed with 61 ORFs and 25 known ehitinases and they were classified into 6 clusters using Clustal X and MEGA3.1. This classification is not completely consistent when compared with the traditional system that classifies the chitinases into 7 classes. The frequency of distribution of amino acid residues was distinct in different clusters. The contents of alanine, glycine, serine, and leucine were very high in each cluster, whereas the contents of methionine, histidine, tryptophan, and cysteine were lower than 20%. Each cluster had distinct amino acid characteristics. Alanine, valine, leucine, cysteine, serine, and lysine were rich in Clusters Ⅰ to Ⅵ, respectively.展开更多
The Havriliak-Negami model for dynamic viscoelastic material behavior and Biot＇s theory of poroelasticity are employed to develop an exact solution for three-dimensional scattering effect of harmonic plane P-SV waves...The Havriliak-Negami model for dynamic viscoelastic material behavior and Biot＇s theory of poroelasticity are employed to develop an exact solution for three-dimensional scattering effect of harmonic plane P-SV waves from a circular cavity lined with a multilayered fluid-filled shell of infinite length containing viscoelastic damping materials and embedded within a fluid-saturated permeable surrounding soil medium. The analytical results are illustrated with numerical examples where the effects of liner/coating structural arrangement, viscoelastic material properties, liner-soil interface bonding condition, seismic excitation frequency, and angle of incidence on the induced dynamic stress concentrations are evaluated and discussed to obtain representative values of the parameters that characterize the system. It is demonstrated that incorporating viscoelastic damping materials with a low shear modulus in the constrained layer configuration is an efficient means of enhancing the overall seismic isolation performance, especially for near-normally incident seismic shear waves where the amplitudes of induced dynamic stresses may be reduced by up to one-third of those without isolation in a relatively wide frequency range. Some additional cases are considered and good agreements with solutions available in the literature are obtained.展开更多
[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice v...[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice varieties were compared and analyzed with two methods. Method 1 ： the compound was extracted by the mixture of anhydrous ethanol and methylene chloride （ WV = 1：1 ） at 60 ℃ for 3 h in water bath; the extract was isolated and detected by gas chromatography-mass spectrometry using HP-5 capillary column with scan monitoring mode. Method 2： the main metabolites in aromatic rice seeds were detected using headspaee solid phase micro-extraction and gas chromatography mass spectrometry （GC-MS）. [ Result ] Fifteen types of common metabolites were found in 9 different aromatic rice varieties. Method 1 was more effective than method 2 in detecting the main metabolites in aromatic rice seeds. [ Conclusion] This study provides an important reference for clarifying the metabolic pathway of main metabolites in aromatic rice and lays the foundation for further rice breeding.展开更多
The surface properties of superfine alumina trihydrate （ATH） after surface modification were studied by measuring the contact angle, active ratio, oil adsorption, total organic carbon, adsorption ratio, and Fourier ...The surface properties of superfine alumina trihydrate （ATH） after surface modification were studied by measuring the contact angle, active ratio, oil adsorption, total organic carbon, adsorption ratio, and Fourier transform infrared （FTIR） spectrum. The contact angle increased initially and then slowly decreased with an increase of the amount of stearic acid. However, the surface flee energy decreased ini- tially and then increased. Surface modification with stearic acid or sodium stearate can benefit from elevating temperature. The base surface tension component and the free energy of Lewis acid-base both declined sharply following the surface modification. Excess stearic acid was physically adsorbed in the form of multilayer adsorption, and an interaction between oxygen on the ATH surface and hydroxyl in stearic acid was subsequently determined. Our results further indicated that the contact angle and adsorption ratio can be used as control indicators for surface modification compared with active ratio, oil adsorption and total organic carbon.展开更多
A novel method for the prediction of RNA secondary structure was proposed based on the particle swarm optimization（PSO）. PSO is known to be effective in solving many different types of optimization problems and know...A novel method for the prediction of RNA secondary structure was proposed based on the particle swarm optimization（PSO）. PSO is known to be effective in solving many different types of optimization problems and known for being able to approximate the global optimal results in the solution space. We designed an efficient objective function according to the minimum free energy, the number of selected stems and the average length of selected stems. We calculated how many legal stems there were in the sequence, and selected some of them to obtain an optimal result using PSO in the right of the objective function. A method based on the improved particle swarm optimization（IPSO） was proposed to predict RNA secondary structure, which consisted of three stages. The first stage was applied to encoding the source sequences, and to exploring all the legal stems. Then, a set of encoded stems were created in order to prepare input data for the second stage. In the second stage, IPSO was responsible for structure selection. At last, the optimal result was obtained from the secondary structures selected via IPSO. Nine sequences from the comparative RNA website were selected for the evaluation of the proposed method. Compared with other six methods, the proposed method decreased the complexity and enhanced the sensitivity and specificity on the basis of the experiment results.展开更多
In this paper, the effects of zinc （Zn） and magnesium （Mg） addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, ...In this paper, the effects of zinc （Zn） and magnesium （Mg） addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, protection efficiency, and polarized potential were the parameters used. The percentages of Zn and Mg in the anodes were varied from 2% to 8% Zn and 1% to 4% Mg. The alloys produced were tested as sacrificial anodes for the protection of mild steel in seawater at room temperature. Current efficiency as high as 88.36% was obtained in alloys containing 6% Zn and 1% Mg. The polarization potentials obtained for the coupled （steel/Al-based alloys） are as given in the Pourbaix diagrams, with steel lying within the immunity region/cathodic region and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week was measured and protection efficiency values as high as 99.66% and 99.47% were achieved for the A1-6%Zn-l%Mg cast anode. The microstructures of the cast anodes comprise of intermetallic structures of hexagonal Mg3Zn2 and body-centered cubic A12Mg3Zn3. These are probably responsible for the breakdown of the passive alumina film, thus enhancing the anode efficiency.展开更多
[ Objective ] The study aimed to screen rational seedling raising date and seedling raising mode for plateau japonica rice, in order to reduce the effect of low temperature on seedlings. [ Method ] The seedlings of co...[ Objective ] The study aimed to screen rational seedling raising date and seedling raising mode for plateau japonica rice, in order to reduce the effect of low temperature on seedlings. [ Method ] The seedlings of conventional japonica rice Hexi 22-2 and giant embryo No. 1 japonica rice were treated at day tempera- ture 12℃/night temperature 8℃ and day temperature 14 ℃/night temperature 10 ℃, and the indicators including chlorophyll content, soluble sugar content, sol- uble protein content, survival rate, plant height, number of ≥ 1 cm roots, leaf wilting degree and aboveground dry matter weight were determined after treated for 0, 3 and 6 d, respectively. [ Result] Chlorophyll content of seedlings decreased when treated by low temperature for a certain period; with the prolongation of treat- ment time, contents of soluble sugar and soluble protein in some low temperature treatments increased, while plant height, number of ≥ 1 cm roots and aboveground dry matter weight increased slowly, but the growth rate was significantly lower than that at room temperature; with the decrease of temperature and the prolongation of treatment time, leaf wilting degree increased. The comprehensive experimental results showed that with the increasing duration of low temperature, when two japonica rice varieties grew under the same low temperature, seedlings grew more and more slowly, probably because the lower the treatment temperature, the greater the damage on plants. Giant Embryo No. 1 had weaker cold tolerance than Hexi 22-2. [ Conclusion] The study provides a theoretical basis for formula- tion of seedling raising technique of plateau japonica rice.展开更多
When an immobile prey has detected an immobile predator nearby, predation risk is greater when the predator is closer. Consequently, prey flee with shorter latency as standing distance （predator-prey distance when bo...When an immobile prey has detected an immobile predator nearby, predation risk is greater when the predator is closer. Consequently, prey flee with shorter latency as standing distance （predator-prey distance when both are still） decreases. Since it was first reported in 2009, this relationship has been confirmed in the few species studied. However, little is known about the functional relationship between standing distance and latency to flee （LF）. We hypothesized that LF increases as standing distance increases at short distances, but reaches a plateau at longer distances where prey can escape reliably if attacked. We simulated immobile predators by moving slowly into positions near striped plateau lizards Sceloporus virgatus, stopping and then remaining immobile, and recording LF from the stopping time. LF increased from shorter to longer standing distances in a decelerating manner. The relationship was concave downward, and LF was indistinguishable among the longer standing distance groups. Latency to flee appears to reach a plateau or approach an asymptotic value as stand- ing distance increases. The effect size of standing distance was large, indicating that S. virgatus sensi- tively adjusts LF to the level of risk associated with standing distance. Relationships between risk assessment and theoretical zones associated with risk, its assessment by prey, and escape decisions are discussed. Effect sizes of standing distance were substantial to large in all studies to date, indicating that standing distance is an important predation risk factor when both predator and prey are immobile.展开更多
In order to establish the system of high frequency plant regeneration for japonica rice mature embryos, the effects of different concentrations of CuSO4 and uniconazole on in vitro culture of mature embryos were studi...In order to establish the system of high frequency plant regeneration for japonica rice mature embryos, the effects of different concentrations of CuSO4 and uniconazole on in vitro culture of mature embryos were studied using three rice cultivars of Kongyu 131, Longjing 24, and Dongnong 425 as test materials. The results showed that callus induction and differentiation of japonica rice mature embryos were apparently improved on the medium with 10-15 μmol·L-1 CuSO4 and 0.50-1.00 mg·L-1 uniconazole. Induction and differentiation rates of different genotype rice mature embryos displayed different sensitivities to CuSO4 and uniconazole. For the callus induction frequency of three varieties, the optimal concentration of CuSO4 was 15.0 mol·L-1. When the concentration of CuSO4 was 15 μmol·L-1, the plantlet differentiation rates of Kongyu 131 and Dongnong 425 got to the highest, while the concentration of CuSO4 was 10 μmol·L-1 for Longjing 24. For the callus induction and plantlet differentiation rates of Kongyu 131 and Dongnong 425, the ideal concentration of uniconazole was 0.50 mg·L-1 and for Longjing 24 was 1.00 mg·L-1.展开更多
The ionization process of B2＋ by H＋ impact is studied using the continuum-distorted-wave eikonal-initial-state （CDW-EIS） method and the modified free electron peak approximation （M-FEPA）, respectively. Total, si...The ionization process of B2＋ by H＋ impact is studied using the continuum-distorted-wave eikonal-initial-state （CDW-EIS） method and the modified free electron peak approximation （M-FEPA）, respectively. Total, single-, and double- differential cross sections from ls and 2s orbitals are presented for the energy range from 10 keV/u to 10 MeV/u. Com- parison between the results from the two methods demonstrates that the total and single-differential cross sections for the high-energy incident projectile case can be well evaluated using the simple M-FEPA model. Moreover, the M-FEPA model reproduces the essential features of the binary-encounter （BE） bump in the double-differential cross sections. Thus, the BE ionization mechanism is discussed in detail by adopting the M-FEPA model. In particular, the double- and single- differential cross sections from the 2s orbital show a high-energy hip, which is different from those from the ls orbital. Based on Ref. [1], the Compton profiles of B2＋ for ls and 2s orbitals are given, and the hips in DDCS and SDCS from the 2s orbital are explained.展开更多
By coupling the standard and the conservative level set methods, an improved conservative level set method is proposed to capture the free surface smoothly with excellent mass conservation properties. The improvement ...By coupling the standard and the conservative level set methods, an improved conservative level set method is proposed to capture the free surface smoothly with excellent mass conservation properties. The improvement lies in the fact that the surface normal is computed from a signed distance function instead of the Heaviside function. Comparing with the conservative level set method, the inevitable numerical discretization errors to point the surface normal in arbitrary directions could be eliminated, and the instability of the numerical solution could be improved efficiently. The advantage is clear in the straightforward combination of the standard level set and the conservative level set and a little effort is taken in coding compared with other coupled methods. The present method is validated with several well-known benchmark problems, including the 2-D Zalesak＇s disk rotating, the 3-D sphere stretching in deformation vortex and the dam break flow simulation. The results are shown to be in good agreement with the published experimental data and numerical results.展开更多
I Introduction The abnormal photoreaction property of o-nitrobenzaldehyde, which is one of the standard scintillators and the reference material in quantum etficient measurement of photochernistry, has been paid much ...I Introduction The abnormal photoreaction property of o-nitrobenzaldehyde, which is one of the standard scintillators and the reference material in quantum etficient measurement of photochernistry, has been paid much attention to. Up to now, however, its photoreaction mechanism has not been cleared yet. Tech et al observed the ESR spectrum produced in the photochemical reaction of alcohol solution of o-nitrobenzaldehyde, but they did not展开更多
Novel reverse-conducting IGBT （RC-IGBT） with anti-parallel MOS controlled thyristor （MCT） is proposed. Its major feature is the introduction of an automatically controlled MCT at the anode, by which the anodeshort...Novel reverse-conducting IGBT （RC-IGBT） with anti-parallel MOS controlled thyristor （MCT） is proposed. Its major feature is the introduction of an automatically controlled MCT at the anode, by which the anodeshort effect is eliminated and the voltage snapback problem is solved. Furthermore, the snapback-free characteristics can be realized in novel RC-IGBT by a single cell with a width of 10 μm with more uniform current distribution. As numerical simulations show, compared with the conventional RC-IGBT, the forward conduction voltage is reduced by 35% while the reverse conduction voltage is reduced by 50% at J = 150 A/cm2.展开更多
文摘Intensive labor chores for broiler production could be reduced by using automated systems.However,broilers’response toward automated systems remains unclear.The experiments were conducted to determine the avoidance distance(AD)and the fleeing speed(FS)of 4-8 weeks old broilers toward two aerial systems,a rail with a dummy arm and a drone,operated at different speeds(0.2-1.2 m/s),and heights(0.3-1.8 m)in a commercial broiler house.The broiler AD to a human assessor was also determined for comparison.Results show that the overall mean and standard error(SE)of broiler AD were 63±3 cm for the assessor,58±1 cm for the rail,and 85±1 cm for the drone.As bird age increased from week 4 to week 8,broiler AD reduced significantly from 82 to 45 cm for the rail but showed no significant change for the drone.As the operational speed increased,broiler AD significantly increased from 54 cm(0.2 m/s)to 62 cm(0.4 m/s)for the rail,and from 81 cm(0.4 m/s)to 89 cm(1.2 m/s)for the drone.As the operational height increased,broiler AD increased from 54 cm(0.3 m)to 57 cm(1.5 m)for the rail and 81 cm(1.2 m)to 88 cm(1.8 m)for the drone.Overall mean and SE of broiler FS were 0.21±0.01 m/s for the rail and 0.65±0.01 m/s for the drone.As bird age increased from week 4 to week 8,the mean broiler FS decreased from 0.47 to 0.07 m/s for the rail and from 0.84 to 0.16 m/s for the drone.Increasing operational speed from 0.2 to 0.4 m/s for the rail and from 0.4 to 1.2 m/s for the drone significantly increased the mean FS from 0.18 to 0.24 m/s and from 0.52 to 0.78 m/s,respectively.Increasing the height of the rail from 0.3 to 1.5 m decreased the broiler FS from 0.27 to 0.16 m/s.However,increasing drone height from 1.2 to 1.8 m retained a similar FS.The outcomes of this study can help to better understand the interaction of broilers with aerial systems and provide insights into the optimization of robotic operational strategies while maintaining good broiler welfare production.
文摘[ Objective ] The paper was to study the density restriction effects of reproductive rate of rice brown planthopper （BPH） population in super indiea and japonica hybrid rice Yongyou 6. [Method] Different amounts of rice brown planthoppor were released to super indiea and japonica hybrid flee Yongyou 6 during fillering, booting and gain filling stage, respectively. The reproductive rate and variation dynamics of rice brown planthoppor in super rice was also investigated and analyzed. [Result] Tillering stage： the population quantity of rice brown planthoppor during booting and gain filling stage gradually increased with the increasing basal amount of its population during tillering stage; when the population density of rice brown planthopper during grain filling stage reached a certain limit （ 〉 250 head/cluster）, the population density during milking stage showed decrease trend with the increasing of such density; the development of rice brown planthoppor population in super rice Yongyou 6 showed the characteristics of fast in middle and slow in two ends. Booting stage： the development of rice brown planthopper pop- ulation from booting to gain filling stage increased with the increasing basal amount of density, and their correlation during milking stage was not significant; flee brown planthopper population still had high reproduction capacity in the middle and late stage of super rice, which had latent risk on rice yield. Gain filling stage ： when population density of rice brown planthopper 〈 70 head/cluster, the development of it population increased with the increase of basal amount of density, which had great threat to yield. [ Conclusion] The result provided theoretical basis for establishment and improvement of monitoring early warning system, cost-ef- fective control of occurrence and damage of rice brown planthopper, and improvement of the sustained control ability against rice brown planthopper.
基金This work was supported by the 863 Program (No. 2002AA245041), the National Natural Science Foundation of China (No. 30260006), and the R&D Foundation of Yunnan Province (No. 2003GP06).
文摘Chitinases （EC3.2.1.14）, found in a wide range of organisms, catalyze the hydrolysis of chitin and play a major role in defense mechanisms against fungal pathogens. The alignment and typical domains were analyzed using basic local alignment search tool （BLAST） and simple modular architecture research tool （SMART）, respectively. On the basis of the annotations of flee （Oryza sativa L.） and Arabidopsis genomic sequences and using the bio-software SignalP3.0, TMHMM2.0, TargetPl.1, and big-Pi Predictor, 25 out of 37 and 16 out of 24 open reading frames （ORFs） with chitinase activity from rice and Arabidopsis, respectively, were predicted to have signal pepfides （SPs）, which have an average of 24.8 amino acids at the N-terminal region. Some of the chitinases were secreted extracellularly, whereas some were located in the vacuole. The phylogenic relationship was analyzed with 61 ORFs and 25 known ehitinases and they were classified into 6 clusters using Clustal X and MEGA3.1. This classification is not completely consistent when compared with the traditional system that classifies the chitinases into 7 classes. The frequency of distribution of amino acid residues was distinct in different clusters. The contents of alanine, glycine, serine, and leucine were very high in each cluster, whereas the contents of methionine, histidine, tryptophan, and cysteine were lower than 20%. Each cluster had distinct amino acid characteristics. Alanine, valine, leucine, cysteine, serine, and lysine were rich in Clusters Ⅰ to Ⅵ, respectively.
文摘The Havriliak-Negami model for dynamic viscoelastic material behavior and Biot＇s theory of poroelasticity are employed to develop an exact solution for three-dimensional scattering effect of harmonic plane P-SV waves from a circular cavity lined with a multilayered fluid-filled shell of infinite length containing viscoelastic damping materials and embedded within a fluid-saturated permeable surrounding soil medium. The analytical results are illustrated with numerical examples where the effects of liner/coating structural arrangement, viscoelastic material properties, liner-soil interface bonding condition, seismic excitation frequency, and angle of incidence on the induced dynamic stress concentrations are evaluated and discussed to obtain representative values of the parameters that characterize the system. It is demonstrated that incorporating viscoelastic damping materials with a low shear modulus in the constrained layer configuration is an efficient means of enhancing the overall seismic isolation performance, especially for near-normally incident seismic shear waves where the amplitudes of induced dynamic stresses may be reduced by up to one-third of those without isolation in a relatively wide frequency range. Some additional cases are considered and good agreements with solutions available in the literature are obtained.
基金Supported by National Natural Science Foundation of China(U1604110,31600992,U1404319,31270727)Key Science and Technology Program of Henan Province(152102110100,152102110036)+6 种基金Major Project of Science and Technology of Henan Province(121100110200)Project of Scientific and Technological Innovation Team for Colleges and Universities in Henan Province(14IRTSTHN012)Students Innovation and Training Program of Institution of Higher Learning in Henan Province(201710477018Y)Key Research Projects of Henan Higher Education Institutions(15A180059,16B180006)Students Innovation and Training Program of XYNU(201710477032)Nanhu Scholars Program for Young Scholars of XYNY(2016054)Open Project of the Institute for Conservation and Utilization of Agro-bioresources in Dabie Mountains
文摘[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry （GC-MS）. [ Method] The main metabolites in seeds of 9 different aromatic rice varieties were compared and analyzed with two methods. Method 1 ： the compound was extracted by the mixture of anhydrous ethanol and methylene chloride （ WV = 1：1 ） at 60 ℃ for 3 h in water bath; the extract was isolated and detected by gas chromatography-mass spectrometry using HP-5 capillary column with scan monitoring mode. Method 2： the main metabolites in aromatic rice seeds were detected using headspaee solid phase micro-extraction and gas chromatography mass spectrometry （GC-MS）. [ Result ] Fifteen types of common metabolites were found in 9 different aromatic rice varieties. Method 1 was more effective than method 2 in detecting the main metabolites in aromatic rice seeds. [ Conclusion] This study provides an important reference for clarifying the metabolic pathway of main metabolites in aromatic rice and lays the foundation for further rice breeding.
基金financially supported by the National Natural Science Foundation of China (No. 51274242)
文摘The surface properties of superfine alumina trihydrate （ATH） after surface modification were studied by measuring the contact angle, active ratio, oil adsorption, total organic carbon, adsorption ratio, and Fourier transform infrared （FTIR） spectrum. The contact angle increased initially and then slowly decreased with an increase of the amount of stearic acid. However, the surface flee energy decreased ini- tially and then increased. Surface modification with stearic acid or sodium stearate can benefit from elevating temperature. The base surface tension component and the free energy of Lewis acid-base both declined sharply following the surface modification. Excess stearic acid was physically adsorbed in the form of multilayer adsorption, and an interaction between oxygen on the ATH surface and hydroxyl in stearic acid was subsequently determined. Our results further indicated that the contact angle and adsorption ratio can be used as control indicators for surface modification compared with active ratio, oil adsorption and total organic carbon.
基金Supported by the National Natural Science Foundation of China(No60971089)
文摘A novel method for the prediction of RNA secondary structure was proposed based on the particle swarm optimization（PSO）. PSO is known to be effective in solving many different types of optimization problems and known for being able to approximate the global optimal results in the solution space. We designed an efficient objective function according to the minimum free energy, the number of selected stems and the average length of selected stems. We calculated how many legal stems there were in the sequence, and selected some of them to obtain an optimal result using PSO in the right of the objective function. A method based on the improved particle swarm optimization（IPSO） was proposed to predict RNA secondary structure, which consisted of three stages. The first stage was applied to encoding the source sequences, and to exploring all the legal stems. Then, a set of encoded stems were created in order to prepare input data for the second stage. In the second stage, IPSO was responsible for structure selection. At last, the optimal result was obtained from the secondary structures selected via IPSO. Nine sequences from the comparative RNA website were selected for the evaluation of the proposed method. Compared with other six methods, the proposed method decreased the complexity and enhanced the sensitivity and specificity on the basis of the experiment results.
文摘In this paper, the effects of zinc （Zn） and magnesium （Mg） addition on the performance of an aluminum-based sacrificial anode in seawater were investigated using a potential measurement method. Anodic efficiency, protection efficiency, and polarized potential were the parameters used. The percentages of Zn and Mg in the anodes were varied from 2% to 8% Zn and 1% to 4% Mg. The alloys produced were tested as sacrificial anodes for the protection of mild steel in seawater at room temperature. Current efficiency as high as 88.36% was obtained in alloys containing 6% Zn and 1% Mg. The polarization potentials obtained for the coupled （steel/Al-based alloys） are as given in the Pourbaix diagrams, with steel lying within the immunity region/cathodic region and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week was measured and protection efficiency values as high as 99.66% and 99.47% were achieved for the A1-6%Zn-l%Mg cast anode. The microstructures of the cast anodes comprise of intermetallic structures of hexagonal Mg3Zn2 and body-centered cubic A12Mg3Zn3. These are probably responsible for the breakdown of the passive alumina film, thus enhancing the anode efficiency.
基金Supported by Key Scientific Research Project of Sichuan Provincial Department of Education "Cultivation Physiology and Technique of Plateau Japonica Rice"(10ZA067)
文摘[ Objective ] The study aimed to screen rational seedling raising date and seedling raising mode for plateau japonica rice, in order to reduce the effect of low temperature on seedlings. [ Method ] The seedlings of conventional japonica rice Hexi 22-2 and giant embryo No. 1 japonica rice were treated at day tempera- ture 12℃/night temperature 8℃ and day temperature 14 ℃/night temperature 10 ℃, and the indicators including chlorophyll content, soluble sugar content, sol- uble protein content, survival rate, plant height, number of ≥ 1 cm roots, leaf wilting degree and aboveground dry matter weight were determined after treated for 0, 3 and 6 d, respectively. [ Result] Chlorophyll content of seedlings decreased when treated by low temperature for a certain period; with the prolongation of treat- ment time, contents of soluble sugar and soluble protein in some low temperature treatments increased, while plant height, number of ≥ 1 cm roots and aboveground dry matter weight increased slowly, but the growth rate was significantly lower than that at room temperature; with the decrease of temperature and the prolongation of treatment time, leaf wilting degree increased. The comprehensive experimental results showed that with the increasing duration of low temperature, when two japonica rice varieties grew under the same low temperature, seedlings grew more and more slowly, probably because the lower the treatment temperature, the greater the damage on plants. Giant Embryo No. 1 had weaker cold tolerance than Hexi 22-2. [ Conclusion] The study provides a theoretical basis for formula- tion of seedling raising technique of plateau japonica rice.
文摘When an immobile prey has detected an immobile predator nearby, predation risk is greater when the predator is closer. Consequently, prey flee with shorter latency as standing distance （predator-prey distance when both are still） decreases. Since it was first reported in 2009, this relationship has been confirmed in the few species studied. However, little is known about the functional relationship between standing distance and latency to flee （LF）. We hypothesized that LF increases as standing distance increases at short distances, but reaches a plateau at longer distances where prey can escape reliably if attacked. We simulated immobile predators by moving slowly into positions near striped plateau lizards Sceloporus virgatus, stopping and then remaining immobile, and recording LF from the stopping time. LF increased from shorter to longer standing distances in a decelerating manner. The relationship was concave downward, and LF was indistinguishable among the longer standing distance groups. Latency to flee appears to reach a plateau or approach an asymptotic value as stand- ing distance increases. The effect size of standing distance was large, indicating that S. virgatus sensi- tively adjusts LF to the level of risk associated with standing distance. Relationships between risk assessment and theoretical zones associated with risk, its assessment by prey, and escape decisions are discussed. Effect sizes of standing distance were substantial to large in all studies to date, indicating that standing distance is an important predation risk factor when both predator and prey are immobile.
基金Supported by Program in 12th Five-year Plan Rural Areas National Science and Technology Plan(2013BAD20B04)Tackle Key in Science and Technology of Chinese Science and Technology Ministry(2011BAD35B02-01)Program in Sience and Technology of Chinese Science and Technology Ministry(2011BAD16B11)
文摘In order to establish the system of high frequency plant regeneration for japonica rice mature embryos, the effects of different concentrations of CuSO4 and uniconazole on in vitro culture of mature embryos were studied using three rice cultivars of Kongyu 131, Longjing 24, and Dongnong 425 as test materials. The results showed that callus induction and differentiation of japonica rice mature embryos were apparently improved on the medium with 10-15 μmol·L-1 CuSO4 and 0.50-1.00 mg·L-1 uniconazole. Induction and differentiation rates of different genotype rice mature embryos displayed different sensitivities to CuSO4 and uniconazole. For the callus induction frequency of three varieties, the optimal concentration of CuSO4 was 15.0 mol·L-1. When the concentration of CuSO4 was 15 μmol·L-1, the plantlet differentiation rates of Kongyu 131 and Dongnong 425 got to the highest, while the concentration of CuSO4 was 10 μmol·L-1 for Longjing 24. For the callus induction and plantlet differentiation rates of Kongyu 131 and Dongnong 425, the ideal concentration of uniconazole was 0.50 mg·L-1 and for Longjing 24 was 1.00 mg·L-1.
基金Project supported by the National Basic Research Program of China (Grant No. 2013CB922200)the National Natural Science Foundation of China (Grant Nos. 11005049, 11025417, 10979007, and 10974021)
文摘The ionization process of B2＋ by H＋ impact is studied using the continuum-distorted-wave eikonal-initial-state （CDW-EIS） method and the modified free electron peak approximation （M-FEPA）, respectively. Total, single-, and double- differential cross sections from ls and 2s orbitals are presented for the energy range from 10 keV/u to 10 MeV/u. Com- parison between the results from the two methods demonstrates that the total and single-differential cross sections for the high-energy incident projectile case can be well evaluated using the simple M-FEPA model. Moreover, the M-FEPA model reproduces the essential features of the binary-encounter （BE） bump in the double-differential cross sections. Thus, the BE ionization mechanism is discussed in detail by adopting the M-FEPA model. In particular, the double- and single- differential cross sections from the 2s orbital show a high-energy hip, which is different from those from the ls orbital. Based on Ref. [1], the Compton profiles of B2＋ for ls and 2s orbitals are given, and the hips in DDCS and SDCS from the 2s orbital are explained.
基金supported by the National Natural Science Foundation of China(Grant No.51279050)the National High Technology Research and Development Program of China(863 Program,Grant No.2012BAK10B04)the Non-profit Industry Financial Program of Ministry of Water Resources of China(Grant No.201301058)
文摘By coupling the standard and the conservative level set methods, an improved conservative level set method is proposed to capture the free surface smoothly with excellent mass conservation properties. The improvement lies in the fact that the surface normal is computed from a signed distance function instead of the Heaviside function. Comparing with the conservative level set method, the inevitable numerical discretization errors to point the surface normal in arbitrary directions could be eliminated, and the instability of the numerical solution could be improved efficiently. The advantage is clear in the straightforward combination of the standard level set and the conservative level set and a little effort is taken in coding compared with other coupled methods. The present method is validated with several well-known benchmark problems, including the 2-D Zalesak＇s disk rotating, the 3-D sphere stretching in deformation vortex and the dam break flow simulation. The results are shown to be in good agreement with the published experimental data and numerical results.
基金Project supported by the National Natural Science Foundation of China.
文摘I Introduction The abnormal photoreaction property of o-nitrobenzaldehyde, which is one of the standard scintillators and the reference material in quantum etficient measurement of photochernistry, has been paid much attention to. Up to now, however, its photoreaction mechanism has not been cleared yet. Tech et al observed the ESR spectrum produced in the photochemical reaction of alcohol solution of o-nitrobenzaldehyde, but they did not
基金supported by the National Natural Science Foundation of China(No.51237001)the Fundamental Research Funds for the Central Universities of China(No.E022050205)
文摘Novel reverse-conducting IGBT （RC-IGBT） with anti-parallel MOS controlled thyristor （MCT） is proposed. Its major feature is the introduction of an automatically controlled MCT at the anode, by which the anodeshort effect is eliminated and the voltage snapback problem is solved. Furthermore, the snapback-free characteristics can be realized in novel RC-IGBT by a single cell with a width of 10 μm with more uniform current distribution. As numerical simulations show, compared with the conventional RC-IGBT, the forward conduction voltage is reduced by 35% while the reverse conduction voltage is reduced by 50% at J = 150 A/cm2.
