This paper explores the correlation between the fractional variation of the ionizing continuum and CⅣbroad absorption lines(BALs)with different ionization levels.Our results reveal anti-correlations between fractiona...This paper explores the correlation between the fractional variation of the ionizing continuum and CⅣbroad absorption lines(BALs)with different ionization levels.Our results reveal anti-correlations between fractional variation of the continuum and fractional equivalency width(EW)variation of the CⅣB ALs without AlⅢB AL/mini-BALs at corresponding velocities,providing evidence for the widespread influence of the ionizing continuum variability on the variation of HiBALs.Conversely,for CⅣBALs accompanied by AlⅢBAL/mini-BALs(LoBAL groups),no significant correction is detected.The absence of such a correlation does not rule out the possibility that variations in these low-ionization lines are caused by ionizing continuum variability,but rather suggests the influence of B AL saturation to some extent.This saturation effect is reflected in the distribution of the fractional EW variation,where the CⅣBAL group accompanied by AlⅢBAL has a smaller standard deviation for the best-fitting Gaussian component than the two BAL groups without AlⅢB AL.However,the distribution of fractional variation of their continuum does not show any significant difference.Besides the saturation influence,another potential explanation for the lack of correlations in the LoBAL groups may be the effects of other variability mechanisms besides the ionization change,such as clouds transiting across the line of sight.展开更多
We have been studying the function and structure of fatty acid-containing extracellular polysaccharides (FACEPS) produced by bacteria belonging to the genus Rhodococcus. In this study, we examined the relationships be...We have been studying the function and structure of fatty acid-containing extracellular polysaccharides (FACEPS) produced by bacteria belonging to the genus Rhodococcus. In this study, we examined the relationships between the structure and emulsifying, thickening, moisture-absorption, and moisture-retention capabilities of rhodococcal FACEPS using S-2 EPS produced by R. rhodochrous strain S-2. We prepared chemically deacylated S-2 EPS (DeAcyl S-2 EPS) and palmitoylated DeAcyl S-2 EPS (ReAcyl S-2 EPS), and compared them with native S-2 EPS. All of the properties were attenuated and recovered by deacylation and reacylation of S-2 EPS, respectively. These results suggest that the fatty acid moiety of rhodococcal FACEPS is involved in such functional properties. We also showed that palmitoylation improved the emulsifying, moisture-ab-sorption, and moisture-retention abilities of other acidic polysaccharides that are commercially available. These results suggest that the acidity of the polysaccharide backbone is at least partly responsible for the observed functionality of fatty acid-containing polysaccharides. To our knowledge, this is the first report on multifunctional property of an anionic polymer incorporating low amounts of hydrophobic residues. The present findings could be useful for the creation of new multifunctional surfactants from renewable raw materials for use in various industries, e.g., in cosmetics.展开更多
In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture abso...In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.展开更多
The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer c...The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.展开更多
The key problem in physical model tests with highly reflective structures is to prevent the multiple reflections between the reflective structures and the wave maker. An active absorption wave maker system is describe...The key problem in physical model tests with highly reflective structures is to prevent the multiple reflections between the reflective structures and the wave maker. An active absorption wave maker system is described and the representative frequency method for irregular waves is proposed in this paper. Physical model tests are conducted to verify the effectiveness of the proposed method.展开更多
The reduced activation ferritic/martenstic steel CLF-1 prepared by the Southwestern Institute of Physics in China was irradiated by helium ions with an energy of 5 keV at room temperature using an electron cyclotron r...The reduced activation ferritic/martenstic steel CLF-1 prepared by the Southwestern Institute of Physics in China was irradiated by helium ions with an energy of 5 keV at room temperature using an electron cyclotron resonance (ECR) ion irradiation apparatus. After the irradiation, the helium retention and desorption were investigated using a technique of thermal desorption spectroscopy (TDS). The experiment was conducted with both the normal and welded samples. Blisters were observed after the helium ion irradiation, and the surface density of blisters in the welded samples was lower than that in the non-welded samples. Three desorption peaks were observed in both the non-welded and welded samples. These desorption peaks corresponded to those of blister ruptures and the helium release from the inner bubbles and the defects. The amount of helium retained in the welded samples was approximately the same as that in the non- welded samples, which was much less than other reduced activation materials, such as vanadium alloy and SiC/SiC composites.展开更多
The online flow injection preconcentration and electrothermal atomic absorption spectrometry method were used for the determination of trace nickel in electrolytic manganese samples by sorption on a conical minicolumn...The online flow injection preconcentration and electrothermal atomic absorption spectrometry method were used for the determination of trace nickel in electrolytic manganese samples by sorption on a conical minicolumn packed with activated carbon at pH 9.0. The nickel was eluted from the minicolumn with 10%(v/v) nitric acid. An enrichment factor of 190-fold for a sample volume of 10mL was obtained. The detection limit (DL) of nickel with the use of the preconcentration method was 13ng·g -1in the original solid sample. The precision for 10 replicate determinations at 150ng·g -1 nickel concentration was 5.2% relative standard deviation (RSD). The calibration graph was linear with a correlation coefficient of r=0.9996 up to concentration of 660ng·g -1 nickel.展开更多
This experiment was conducted to determine the influences of adding organic selenium (Se) on growth properties, Se absorption and utilization, immunity and antioxidant activity in diets of Duroc weaning piglets. This ...This experiment was conducted to determine the influences of adding organic selenium (Se) on growth properties, Se absorption and utilization, immunity and antioxidant activity in diets of Duroc weaning piglets. This study was performed on 36 (average weight 7.6 kg) weaning piglets. The weaning piglets were randomly allocated to 1 of 4 homogeneous treatments (A, control treatment, no added Se;B, Sodium selenite, 0.3 mg Se/kg feed;C, yeast Se, 0.3 mg Se/kg;D, DL-methionine Se 0.3 mg Se/kg). Every treatment had 3 replicates, every replicate had 3 piglets. The experiment lasted for 35 d, with the first 7 d for adaptation. Feed intake, residual and contaminated feed were recorded every day. Every piglet weight was weighted respectively at beginning and end of experiment. Daily intake, gain weight and feed conversion rates of every replicate were calculated finally. Se concentrations of serum, blood antioxidant and immunity index were analyzed in the 36th d of experiment. The results showed average daily gain of treatment C was significant higher (P 0.05) and D had higher trend than that of treatment A and B (P = 0.06) respectively. And feed and gain ratio of C and D had trends to lower than them of A and B (P = 0.14). However, all the intake of every week and whole period had no significant differences among treatments (P > 0.05). At same time, except for the Immunoglobulin M of treatment D and C was higher than that of treatment A and B significantly (P < 0.05), all the other Se contents of serum, immunity indexes, blood cell parameters and enzymatic activities had no significant differences among treatments (P > 0.05). But they took on some obvious trends. For example, the Se contents and glutathione peroxidase activities increased successively in order of treatment A, B, C and D;the blood urea nitrogen and total bilirubin of treatment A had higher trend than that of other treatments (P = 0.06). All in all, adding to organic Se in basal diets could improve the animal’s healthy levels, growth properties and Se utilization to some extent. Relatively speaking, the DL-methionine Se had more advantages compared to yeast Se.展开更多
The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)...The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.展开更多
The sound characteristic of the piezoelectric ceramics is posed for the excellent mechanic and electric coupling performance of piezoelectric material.Two pieces of piezoelectric ceramic are used as materials of activ...The sound characteristic of the piezoelectric ceramics is posed for the excellent mechanic and electric coupling performance of piezoelectric material.Two pieces of piezoelectric ceramic are used as materials of active absorption and active isolation,two pieces of PVDF with equal distance are placed in the front of the material in order to measure the incidence plane wave and the reflected wave,the voltages are applied on the surface of the material in order to make the reflected wave and transmission wave be zero using the adaptive controlling.At last,emulation is carried out with plane wave,and good absorption and isolation effect is achieved.展开更多
Zeolite A/CS xerogel hybrid films were prepared by in-situ crystallization method with uniform structure and good strength.The hybrid films prepared from the precursor films dried at 50℃showed zeolite A was well crys...Zeolite A/CS xerogel hybrid films were prepared by in-situ crystallization method with uniform structure and good strength.The hybrid films prepared from the precursor films dried at 50℃showed zeolite A was well crystallized.The hybrid films show high water absorption,good elastic strength and Young modulus.The antimicrobial ability of the hybrid films was investigated after Ag^(+)-ion exchanged.The Ag^(+)-exchanged hybrid films with 35%(mass)content of zeolite A showed the highest antimicrobial activity,which could reduce the concentration of the microbial to zero after 7 h.展开更多
The theory of active absorption of the perforated plate is proposed in this paper.The perforated plate is used as the material of active absorption and the depth of the cavity behind the perforated plate is changed ac...The theory of active absorption of the perforated plate is proposed in this paper.The perforated plate is used as the material of active absorption and the depth of the cavity behind the perforated plate is changed according to the resonant frequency of the perforated plate.The rigid wall is moved to produce resonance so that the absorption coefficient can reach the maximal level.It is shown from the numerical calculation that when the perforated plate resonates,the moving distance is large at low frequencies,and the absorption coefficient is low under certain conditions.Perforated plate resonance is effective for single frequency of incident sound wave,which is difficult for the wide frequency,so active absorption based on airflow is posed,and the numerical calculation and experiment are carried out.The results denote that this method of active absorption is practical.展开更多
While we process observational data of the Flares 22, two rare phenomena of microwave ultra fast absorption (MUFA) are found for the first time. They occurred at 3 67 GHz and 4 00 GHz in the atmospheric layers above b...While we process observational data of the Flares 22, two rare phenomena of microwave ultra fast absorption (MUFA) are found for the first time. They occurred at 3 67 GHz and 4 00 GHz in the atmospheric layers above both active regions of NOAA/USAF 4808 and 5060 in the interval 05 h50 m17 s~05 h50 m25 s UT on May 19, 1987 and 07 h38 m50 s~07 h38 m58 s UT on June 29, 1988, respectively. These absorption phenomena were observed with Phoenix Ⅱ Micowave Spectrometer at three frequencies (1 42, 2 84 and 3 67 GHz) and (1 42, 2 84 and 4 00 GHz) at Yunnan observatory. Spike emissions appeared at both 2 84 GHz and 1 42 GHz. The notable observational characteristics of both absorption phenomena are given. A possible absorption mechanism of MUFA is discussed.展开更多
In order to meet the requirements of the marine environment for microwave absorption(MA)materials,we put forward the strategy of constructing multi-functional composite materials,which integrate microwave absorption,a...In order to meet the requirements of the marine environment for microwave absorption(MA)materials,we put forward the strategy of constructing multi-functional composite materials,which integrate microwave absorption,anti-corrosion,and antibacterial properties.Herein,graphene oxide(GO)was used as a template to induce the growth of zeolitic imidazolate framework-8(ZIF-8),simultaneously as a two-dimensional(2D)nanocontainers to load corrosion inhibitors to achieve pH-responsive and self-healing properties.Finally,quaternary ammonium salt(dimethyl octadecyl(3-trimethoxylsilyl propyl)ammonium chloride(DMAOP))and sodium ascorbate(VCNa)were introduced to achieve synergistic antibacterial activity and the reduction of GO.The 2D strip-like structure of ZIF-8 was due to the confined growth induced by the electrostatic attraction between ZIF-8 and GO sheets.The as-obtained reduced GO(RGO)/ZIF-8/DMAOP5 exhibited excellent microwave absorption(MA)properties,with a minimum reflection loss(RL)value of-47.08 dB at 12.73 GHz when the thickness was 2.8 mm.Moreover,the effective absorption bandwidth reached 6.84 GHz.After soaking in 3.5%NaCl solution for 35 days,the RGO/ZIF-8/DMAOP5-0.7%coating still achieved an impedance value of 4.585×107Ω·cm^(2) and a protective efficiency of 99.994%,providing superior anti-corrosion properties.In addition,fantastic antibacterial activity was obtained,with the antibacterial rates of RGO/ZIF-8/DMAOP_(10) reaching 99.39%and 100%against Escherichia coli and Staphylococcus aureus.This work could open new avenues towards the development of a new generation of multifunctional MA materials.展开更多
In this study,the influence of hydraulic retention time on feasibility,efficiency and membrane foul- ing of slightly polluted surface water treatment by a high concentration PAC-MF bioreactor were investigated. During...In this study,the influence of hydraulic retention time on feasibility,efficiency and membrane foul- ing of slightly polluted surface water treatment by a high concentration PAC-MF bioreactor were investigated. During three months operation,TOC,NH4 + -N,nitrobenzene,and TMP were measured to evaluate the MBR performance. The results show that,when HRT reduces from 3 h to 1 h,removal efficiency of TOC and ammonia-nitrite decrease a little. However,there is little effect of HRT on nitrobenzene. And the optimal hydraulic retention time is 1 h.展开更多
We report the discovery of a broad absorption line (BAL) of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of...We report the discovery of a broad absorption line (BAL) of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of a BAL, which is sometimes seen in powerful quasars with high accretion rates, in a BL Lac object. The BAL was clearly detected in its spectra spanning two epochs at a high luminosity state taken in the Sloan Digital Sky Survey (SDSS), while it disappeared in three SDSS spectra taken at a low luminosity state. The BAL and its variability pattern were also found in its historical multi-epoch spectra in the literature, but have been overlooked previously. In its high resolution radio maps, PKS 0138-097 shows a core plus a one- sided parsec-scale jet. The BAL variability can be interpreted as follows: The optical emission is dominated by the core in a high state and by the jet in a low state and the BAL material is located between the core and jet so that the BAL appears only when the core is shining. Our discovery suggests that outflows may also be produced in active galactic nuclei at a low accreting state.展开更多
The study is focused on the phenomenon of diffusion of water through the shells of two coconut species (coconut nucifera) of Cameroun. The kinetics absorption of water was studied experimentally by the gravimetric met...The study is focused on the phenomenon of diffusion of water through the shells of two coconut species (coconut nucifera) of Cameroun. The kinetics absorption of water was studied experimentally by the gravimetric method with discontinuous control of the mass of the samples at the temperature of 23℃. The mature coconut shells were cleaned mechanically, cut in a spherical shape and placed in a drying oven with 105℃ for 4 hours before being plunged in distilled water at 23℃. This study made it possible not only to determine the rate of water absorbed, but also to model the water kinetic absorption of the shells. Of the two models tested (Peleg and Page), the Page model predicted very well the experimental data. The Fick law made it possible to evaluate the effective diffusivity coefficients at the initial and final phases of absorption. The effective diffusivity coefficient was given from the Arrhenius equation.展开更多
We report the discovery of Balmer broad absorption lines (BALs) in the quasar LBQS 1206+1052 and present a detailed analysis of the peculiar absorption line spectrum. Besides the Mg II λλ2796, 2803 doublet, BALs ...We report the discovery of Balmer broad absorption lines (BALs) in the quasar LBQS 1206+1052 and present a detailed analysis of the peculiar absorption line spectrum. Besides the Mg II λλ2796, 2803 doublet, BALs are also detected in the He I* multiplet at λλ2946, 3189, 3889 A arising from the metastable helium 2 3 S level, and in Hα and Hβ from the excited hydrogen H I* n = 2 level, which are rarely seen in quasar spectra. We identify two components in the BAL troughs of v ~ 2000 km s 1 width: One component shows an identical profile in H I*, He I* and Mg II with its centroid blueshifted by v c ≈ 726 km s-1 . The other component is detected in He I* and Mg II with v c ≈ 1412 km s-1 . We estimate the column densities of H I*, He I*, and Mg II, and compare them with possible level population mechanisms. Our results favor the scenario that the Balmer BALs originate in a partially ionized region with a column density of N H ~ 10 21 10 22 cm-2 for an electron density of n e ~ 10 6 10 8 cm-3 via Lyα resonant scattering pumping. The harsh conditions needed may help to explain the rarity of Balmer absorption line systems in quasar spectra. With an i-band PSF magnitude of 16.50, LBQS 1206+1052 is the brightest Balmer-BAL quasar ever reported. Its high brightness and unique spectral properties make LBQS 1206+1052 a promising candidate for followup high-resolution spectroscopy, multi-band observations, and long-term monitoring.展开更多
Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alk...Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alkyl(1-phenylsulfonyl) cycloalkane carboxylate com- pounds to their chromatographic retention (capacity factor lgKW) and the toxicity for photo- bacterium phosphoreum (–lgEC50) were developed by using the molecular structural parameters as theoretical descriptors (r2 = 0.9501, 0.9488). The two quantitative correlation equations were consequently cross validated by leave-one-out (LOO) validation method with q2 of 0.9113 and 0.9281, respectively. The result showed that the two equations achieved in this work by B3LYP/6-31G* are both more advantageous than those from AM1, and can be used to predict the lgKW and –lgEC50 of congeneric organics.展开更多
基金supported by the Guangxi Natural Science Foundation(No.2021GXNSFBA220044)the National Natural Science Foundation of China(No.11903002)the Research Project of Baise University(No.2019KN04)。
文摘This paper explores the correlation between the fractional variation of the ionizing continuum and CⅣbroad absorption lines(BALs)with different ionization levels.Our results reveal anti-correlations between fractional variation of the continuum and fractional equivalency width(EW)variation of the CⅣB ALs without AlⅢB AL/mini-BALs at corresponding velocities,providing evidence for the widespread influence of the ionizing continuum variability on the variation of HiBALs.Conversely,for CⅣBALs accompanied by AlⅢBAL/mini-BALs(LoBAL groups),no significant correction is detected.The absence of such a correlation does not rule out the possibility that variations in these low-ionization lines are caused by ionizing continuum variability,but rather suggests the influence of B AL saturation to some extent.This saturation effect is reflected in the distribution of the fractional EW variation,where the CⅣBAL group accompanied by AlⅢBAL has a smaller standard deviation for the best-fitting Gaussian component than the two BAL groups without AlⅢB AL.However,the distribution of fractional variation of their continuum does not show any significant difference.Besides the saturation influence,another potential explanation for the lack of correlations in the LoBAL groups may be the effects of other variability mechanisms besides the ionization change,such as clouds transiting across the line of sight.
文摘We have been studying the function and structure of fatty acid-containing extracellular polysaccharides (FACEPS) produced by bacteria belonging to the genus Rhodococcus. In this study, we examined the relationships between the structure and emulsifying, thickening, moisture-absorption, and moisture-retention capabilities of rhodococcal FACEPS using S-2 EPS produced by R. rhodochrous strain S-2. We prepared chemically deacylated S-2 EPS (DeAcyl S-2 EPS) and palmitoylated DeAcyl S-2 EPS (ReAcyl S-2 EPS), and compared them with native S-2 EPS. All of the properties were attenuated and recovered by deacylation and reacylation of S-2 EPS, respectively. These results suggest that the fatty acid moiety of rhodococcal FACEPS is involved in such functional properties. We also showed that palmitoylation improved the emulsifying, moisture-ab-sorption, and moisture-retention abilities of other acidic polysaccharides that are commercially available. These results suggest that the acidity of the polysaccharide backbone is at least partly responsible for the observed functionality of fatty acid-containing polysaccharides. To our knowledge, this is the first report on multifunctional property of an anionic polymer incorporating low amounts of hydrophobic residues. The present findings could be useful for the creation of new multifunctional surfactants from renewable raw materials for use in various industries, e.g., in cosmetics.
文摘In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.
文摘The effects of polyaspartate protease fertilizer enhancer, made from oyster shell proteins, on the absorption of soil nutrition and the enzymatic activities of crops were studied. It has been found that the enhancer contributes 30%, 50% and 50% augmentation of nitrogen (N), phosphate (P) and potassium (K) absorption respectively and about 20% of nitrate reductase and peroxide enzyme activities of crops. These results show that polyaspartate protease fertilizer enhancer could improve significantly the absorption and utilization efficiencies of soil nutrition and the activities of nitrate reductase and peroxide enzyme of crops, thus elevating the utilization rates of chemical fertilizers to a certain extent.
基金TheworkwasfinanciallysupportedbytheNationalNaturalScienceFoundationofChina(GrantNo .5 990 90 0 1)andFokYingTungEducationFoundation (No .810 68)
文摘The key problem in physical model tests with highly reflective structures is to prevent the multiple reflections between the reflective structures and the wave maker. An active absorption wave maker system is described and the representative frequency method for irregular waves is proposed in this paper. Physical model tests are conducted to verify the effectiveness of the proposed method.
基金supported by National Natural Science Foundation of China (50701017)Japan-China Core University Program on Plasma and Nuclear Fusion
文摘The reduced activation ferritic/martenstic steel CLF-1 prepared by the Southwestern Institute of Physics in China was irradiated by helium ions with an energy of 5 keV at room temperature using an electron cyclotron resonance (ECR) ion irradiation apparatus. After the irradiation, the helium retention and desorption were investigated using a technique of thermal desorption spectroscopy (TDS). The experiment was conducted with both the normal and welded samples. Blisters were observed after the helium ion irradiation, and the surface density of blisters in the welded samples was lower than that in the non-welded samples. Three desorption peaks were observed in both the non-welded and welded samples. These desorption peaks corresponded to those of blister ruptures and the helium release from the inner bubbles and the defects. The amount of helium retained in the welded samples was approximately the same as that in the non- welded samples, which was much less than other reduced activation materials, such as vanadium alloy and SiC/SiC composites.
文摘The online flow injection preconcentration and electrothermal atomic absorption spectrometry method were used for the determination of trace nickel in electrolytic manganese samples by sorption on a conical minicolumn packed with activated carbon at pH 9.0. The nickel was eluted from the minicolumn with 10%(v/v) nitric acid. An enrichment factor of 190-fold for a sample volume of 10mL was obtained. The detection limit (DL) of nickel with the use of the preconcentration method was 13ng·g -1in the original solid sample. The precision for 10 replicate determinations at 150ng·g -1 nickel concentration was 5.2% relative standard deviation (RSD). The calibration graph was linear with a correlation coefficient of r=0.9996 up to concentration of 660ng·g -1 nickel.
文摘This experiment was conducted to determine the influences of adding organic selenium (Se) on growth properties, Se absorption and utilization, immunity and antioxidant activity in diets of Duroc weaning piglets. This study was performed on 36 (average weight 7.6 kg) weaning piglets. The weaning piglets were randomly allocated to 1 of 4 homogeneous treatments (A, control treatment, no added Se;B, Sodium selenite, 0.3 mg Se/kg feed;C, yeast Se, 0.3 mg Se/kg;D, DL-methionine Se 0.3 mg Se/kg). Every treatment had 3 replicates, every replicate had 3 piglets. The experiment lasted for 35 d, with the first 7 d for adaptation. Feed intake, residual and contaminated feed were recorded every day. Every piglet weight was weighted respectively at beginning and end of experiment. Daily intake, gain weight and feed conversion rates of every replicate were calculated finally. Se concentrations of serum, blood antioxidant and immunity index were analyzed in the 36th d of experiment. The results showed average daily gain of treatment C was significant higher (P 0.05) and D had higher trend than that of treatment A and B (P = 0.06) respectively. And feed and gain ratio of C and D had trends to lower than them of A and B (P = 0.14). However, all the intake of every week and whole period had no significant differences among treatments (P > 0.05). At same time, except for the Immunoglobulin M of treatment D and C was higher than that of treatment A and B significantly (P < 0.05), all the other Se contents of serum, immunity indexes, blood cell parameters and enzymatic activities had no significant differences among treatments (P > 0.05). But they took on some obvious trends. For example, the Se contents and glutathione peroxidase activities increased successively in order of treatment A, B, C and D;the blood urea nitrogen and total bilirubin of treatment A had higher trend than that of other treatments (P = 0.06). All in all, adding to organic Se in basal diets could improve the animal’s healthy levels, growth properties and Se utilization to some extent. Relatively speaking, the DL-methionine Se had more advantages compared to yeast Se.
基金supported by the National Natural Science Foundation of China(22221005 and 22008033).
文摘The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51175195,15A460041)
文摘The sound characteristic of the piezoelectric ceramics is posed for the excellent mechanic and electric coupling performance of piezoelectric material.Two pieces of piezoelectric ceramic are used as materials of active absorption and active isolation,two pieces of PVDF with equal distance are placed in the front of the material in order to measure the incidence plane wave and the reflected wave,the voltages are applied on the surface of the material in order to make the reflected wave and transmission wave be zero using the adaptive controlling.At last,emulation is carried out with plane wave,and good absorption and isolation effect is achieved.
基金We are grateful for financial support from the National&Local Joint Engineering Research Center for Deep Utilization Technology of Rock-salt Resource(SF201804)Opening Topic of Key Laboratory of Attapulgite Resources Utilization in Jiangsu Province(HPK201804)Jiangsu Province Industry University Research Project(BY2019133).
文摘Zeolite A/CS xerogel hybrid films were prepared by in-situ crystallization method with uniform structure and good strength.The hybrid films prepared from the precursor films dried at 50℃showed zeolite A was well crystallized.The hybrid films show high water absorption,good elastic strength and Young modulus.The antimicrobial ability of the hybrid films was investigated after Ag^(+)-ion exchanged.The Ag^(+)-exchanged hybrid films with 35%(mass)content of zeolite A showed the highest antimicrobial activity,which could reduce the concentration of the microbial to zero after 7 h.
基金National Natural Science Foundation of China(No.51705545)。
文摘The theory of active absorption of the perforated plate is proposed in this paper.The perforated plate is used as the material of active absorption and the depth of the cavity behind the perforated plate is changed according to the resonant frequency of the perforated plate.The rigid wall is moved to produce resonance so that the absorption coefficient can reach the maximal level.It is shown from the numerical calculation that when the perforated plate resonates,the moving distance is large at low frequencies,and the absorption coefficient is low under certain conditions.Perforated plate resonance is effective for single frequency of incident sound wave,which is difficult for the wide frequency,so active absorption based on airflow is posed,and the numerical calculation and experiment are carried out.The results denote that this method of active absorption is practical.
文摘While we process observational data of the Flares 22, two rare phenomena of microwave ultra fast absorption (MUFA) are found for the first time. They occurred at 3 67 GHz and 4 00 GHz in the atmospheric layers above both active regions of NOAA/USAF 4808 and 5060 in the interval 05 h50 m17 s~05 h50 m25 s UT on May 19, 1987 and 07 h38 m50 s~07 h38 m58 s UT on June 29, 1988, respectively. These absorption phenomena were observed with Phoenix Ⅱ Micowave Spectrometer at three frequencies (1 42, 2 84 and 3 67 GHz) and (1 42, 2 84 and 4 00 GHz) at Yunnan observatory. Spike emissions appeared at both 2 84 GHz and 1 42 GHz. The notable observational characteristics of both absorption phenomena are given. A possible absorption mechanism of MUFA is discussed.
基金supported by the National Natural Science Foundation of China(Nos.51903213 and 5217130190)the Science and Technology Planning Project of Sichuan Province(Nos.2023NSFSC1952 and 2022ZYD0028)+1 种基金the Central Government Guides Local Science and Technology Development Special Funds to freely explore basic research projects(No.2021Szvup124)the Fundamental Research Funds for the Central Universities(No.2682021GF004).
文摘In order to meet the requirements of the marine environment for microwave absorption(MA)materials,we put forward the strategy of constructing multi-functional composite materials,which integrate microwave absorption,anti-corrosion,and antibacterial properties.Herein,graphene oxide(GO)was used as a template to induce the growth of zeolitic imidazolate framework-8(ZIF-8),simultaneously as a two-dimensional(2D)nanocontainers to load corrosion inhibitors to achieve pH-responsive and self-healing properties.Finally,quaternary ammonium salt(dimethyl octadecyl(3-trimethoxylsilyl propyl)ammonium chloride(DMAOP))and sodium ascorbate(VCNa)were introduced to achieve synergistic antibacterial activity and the reduction of GO.The 2D strip-like structure of ZIF-8 was due to the confined growth induced by the electrostatic attraction between ZIF-8 and GO sheets.The as-obtained reduced GO(RGO)/ZIF-8/DMAOP5 exhibited excellent microwave absorption(MA)properties,with a minimum reflection loss(RL)value of-47.08 dB at 12.73 GHz when the thickness was 2.8 mm.Moreover,the effective absorption bandwidth reached 6.84 GHz.After soaking in 3.5%NaCl solution for 35 days,the RGO/ZIF-8/DMAOP5-0.7%coating still achieved an impedance value of 4.585×107Ω·cm^(2) and a protective efficiency of 99.994%,providing superior anti-corrosion properties.In addition,fantastic antibacterial activity was obtained,with the antibacterial rates of RGO/ZIF-8/DMAOP_(10) reaching 99.39%and 100%against Escherichia coli and Staphylococcus aureus.This work could open new avenues towards the development of a new generation of multifunctional MA materials.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50978068)International Science and Technology Cooperation Project (China,Japan and Korea) (Grant No.2010DFA92460)China National Water Pollution Control and Management Technology of Major Project (Grant No.2009ZX07424-005)
文摘In this study,the influence of hydraulic retention time on feasibility,efficiency and membrane foul- ing of slightly polluted surface water treatment by a high concentration PAC-MF bioreactor were investigated. During three months operation,TOC,NH4 + -N,nitrobenzene,and TMP were measured to evaluate the MBR performance. The results show that,when HRT reduces from 3 h to 1 h,removal efficiency of TOC and ammonia-nitrite decrease a little. However,there is little effect of HRT on nitrobenzene. And the optimal hydraulic retention time is 1 h.
基金Supported by the National Natural Science Foundation of China(Grant Nos. 10973012 and 11033007)the National Basic Research Program of China (973 program Grant Nos.2007CB815405 and 2009CB824800)
文摘We report the discovery of a broad absorption line (BAL) of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of a BAL, which is sometimes seen in powerful quasars with high accretion rates, in a BL Lac object. The BAL was clearly detected in its spectra spanning two epochs at a high luminosity state taken in the Sloan Digital Sky Survey (SDSS), while it disappeared in three SDSS spectra taken at a low luminosity state. The BAL and its variability pattern were also found in its historical multi-epoch spectra in the literature, but have been overlooked previously. In its high resolution radio maps, PKS 0138-097 shows a core plus a one- sided parsec-scale jet. The BAL variability can be interpreted as follows: The optical emission is dominated by the core in a high state and by the jet in a low state and the BAL material is located between the core and jet so that the BAL appears only when the core is shining. Our discovery suggests that outflows may also be produced in active galactic nuclei at a low accreting state.
文摘The study is focused on the phenomenon of diffusion of water through the shells of two coconut species (coconut nucifera) of Cameroun. The kinetics absorption of water was studied experimentally by the gravimetric method with discontinuous control of the mass of the samples at the temperature of 23℃. The mature coconut shells were cleaned mechanically, cut in a spherical shape and placed in a drying oven with 105℃ for 4 hours before being plunged in distilled water at 23℃. This study made it possible not only to determine the rate of water absorbed, but also to model the water kinetic absorption of the shells. Of the two models tested (Peleg and Page), the Page model predicted very well the experimental data. The Fick law made it possible to evaluate the effective diffusivity coefficients at the initial and final phases of absorption. The effective diffusivity coefficient was given from the Arrhenius equation.
基金supported by the National Natural Science Foundation of China(Grants Nos.10973013 and 11033007)the Fundamental Research Funds for the Central Universities through grant WK 2030220006+8 种基金the SOA project CHINARE2012-02-03Funding for the SDSS and SDSS-Ⅱ has been provided by the Alfred P.Sloan Foundationthe Participating Institutionsthe National Science Foundationthe U.S. Department of Energythe National Aeronautics and Space Administrationthe Japanese Monbukagakushothe Max Planck Societythe Higher Education Funding Council for England
文摘We report the discovery of Balmer broad absorption lines (BALs) in the quasar LBQS 1206+1052 and present a detailed analysis of the peculiar absorption line spectrum. Besides the Mg II λλ2796, 2803 doublet, BALs are also detected in the He I* multiplet at λλ2946, 3189, 3889 A arising from the metastable helium 2 3 S level, and in Hα and Hβ from the excited hydrogen H I* n = 2 level, which are rarely seen in quasar spectra. We identify two components in the BAL troughs of v ~ 2000 km s 1 width: One component shows an identical profile in H I*, He I* and Mg II with its centroid blueshifted by v c ≈ 726 km s-1 . The other component is detected in He I* and Mg II with v c ≈ 1412 km s-1 . We estimate the column densities of H I*, He I*, and Mg II, and compare them with possible level population mechanisms. Our results favor the scenario that the Balmer BALs originate in a partially ionized region with a column density of N H ~ 10 21 10 22 cm-2 for an electron density of n e ~ 10 6 10 8 cm-3 via Lyα resonant scattering pumping. The harsh conditions needed may help to explain the rarity of Balmer absorption line systems in quasar spectra. With an i-band PSF magnitude of 16.50, LBQS 1206+1052 is the brightest Balmer-BAL quasar ever reported. Its high brightness and unique spectral properties make LBQS 1206+1052 a promising candidate for followup high-resolution spectroscopy, multi-band observations, and long-term monitoring.
基金This work was financially supported by the National Basic Research Program of China (2003CB415002), the China Postdoctoral Science Foundation (No. 2003033486) and the Natural Science Research Fund of University in Jiangsu (04KJB150149)
文摘Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alkyl(1-phenylsulfonyl) cycloalkane carboxylate com- pounds to their chromatographic retention (capacity factor lgKW) and the toxicity for photo- bacterium phosphoreum (–lgEC50) were developed by using the molecular structural parameters as theoretical descriptors (r2 = 0.9501, 0.9488). The two quantitative correlation equations were consequently cross validated by leave-one-out (LOO) validation method with q2 of 0.9113 and 0.9281, respectively. The result showed that the two equations achieved in this work by B3LYP/6-31G* are both more advantageous than those from AM1, and can be used to predict the lgKW and –lgEC50 of congeneric organics.