摘要:
Pretreatment by a white-rot fungus Coriolus versicolor B1 under different conditions and saccharification of bamboo were investigated. The saccharification rate was significantly enhanced and a maximum saccharification rate of 37.0% was achieved after pretreatment. Reducing sugars yield was 223.2 mg/g of bamboo residues, which was 2.34 times that of the raw material. It was feasible to treat bamboo residues with B1 for the saccharification of bamboo.
关键词:
RNase A;Sodium dodecyl sulphate;Structure and activity
摘要:
The structure and activity of RNase A in sodium dodecyl sulphate solutions were investigated at 25.0 ±0.1 and pH 7.00. The results show that with increasing sodium dodecyl sulphate concentration, the structure of RNase A is collapsed gradually, however, the activity of RNase A is first increased and then decreased. This is mainly due to the different effect of SDS at different SDS concentration.
摘要:
A procedure for direct determination of trace elements in muscle tissue of hairtail was developed using inductively coupled plasma-atomic emission spectrometry and electrothermal vaporization with slurry sampling. Due to use of polytetrafluoroethylene as the chemical modifier, the vaporization behaviors of analytes from the slurry and the aqueous standard solutions were very similar. In this case, the aqueous standards could be used for the calibration of slurry samples. The main factors influencing this method were studied systematically. The detection limits for Cr, Ni, Zn, Cd, and Pb were 3.1, 10.5, 176, 6.9, and 83 ng/mL, respectively, and the relative standard deviations were less than 10%. The proposed method was applied to the determination of trace Cr, Ni, Zn, Cd, and Pb in hairtail samples with satisfactory accuracy and precision. A certified reference material of mussel (GBW 08571) was analyzed, and good agreement was obtained between the results from the proposed method and certificate values.
关键词:
chemiluminescence;flow injection analysis;ultrafiltration;oxytetracycline;human serum albumin
摘要:
Binding properties of oxytetracycline (OTC) and human serum albumin (HSA) have been studied in details. This investigation was based on flow injection chemiluminescence (FI-CL) analysis and ultrafiltration (UF) sampling technique. Chemiluminescence (CL) emission was observed during oxidation or OTC with KMnO4 in acidic medium in the presence of formaldehyde as a sensitizer. Coupled with flow injection technique, OTC can be determined in the range of 8.0 x 10(-7)-1.2 x 10(-4) mol L-1. Oxytetracycline and HSA were mixed in different molar ratios and incubated at 37+/-0.5 degrees C. An ultrafiltration probe was introduced to the sample containing unbound drug and the concentration of this free drug was determined by the CL method. The obtained data were analysed applying the Scatchard plot. The binding constant (K) and the number of binding sites (n) were 3.19 x 10(4) (mol L-1) and 1.10, respectively.
摘要:
Established in 1978, Acta Physiologiae Plantarum is an international journal publishing peer-reviewed articles on all facets of plant physiology at various levels of biological organization, ranging from relevant aspects in molecular and cell biology to biochemistry.
摘要:
The effects of fumed silica on the rheology of a blended silicate solution were studied by both recording curves of the shear storage and loss moduli (G' and G") over angular frequency and temperature, and measuring the relative apparent viscosity with variety of the fumed silica concentration at various steady angular velocity and temperature. Results show that the fumed silica has obvious effects on the blended silicate solution, especially in the regimes of high angular frequency. A shear thickening phenomenon for the blended silicate solution and a shear thinning phenomenon for the solution filled with fumed silica were observed by dynamic shear measurements. The steady measurement also indicates that the more fumed silica concentration, the higher relative apparent viscosity.
摘要:
This experiment was conducted to compare the effects of feeding DL-2-hydroxy-4-(methylthio)butanoic acid (HMTBA) and DL-methionine (DLM) supplemented corn-soybean-cottonseed meal diets on growth performance, carcass composition, and muscle color of broilers. The trial was designed as a 2x3x2 factorial experiment, including two methionine (Met) sources (HMTBA and DLM), three equimolar graded levels of Met supplementation (i.e., 0.08, 0.16, and 0.24% in the starter diet and 0.07, 0.14, and 0.21% in the grower and finisher diets, respectively), and two sexes (male and female). Additionally, one basal diet for each sex was formulated to be limiting in Met to test the dosage response of increasing supplemental Met levels. Four hundred and twenty 10-d-old broilers were randomly allotted to 14 treatments (seven each for males and females), with five replicate pens per treatment and six chicks per pen. There was no difference (p>0.05) between the two Met sources in growth performance and muscle deposition of broilers throughout the whole experimental period (d 10 to 49). With the increasing Met supplementation levels, average daily gain was increased (quadratic; p<0.01) during the starter, grower, and overall phases, average daily feed intake was increased (quadratic; p<0.01) during the starter phase, and feed:gain ratio was decreased (quadratic; p<0.05) during the grower and overall phases. At the end of finisher phase, Met supplementation increased breast muscle content (quadratic; p<0.01) and thigh muscle content (linear; p<0.05), and decreased abdominal fat content (quadratic; p<0.02). Compared to the broiler fed DLM, broilers fed HMTBA had superior breast and thigh muscle coloration (p<0.01). Male broilers had higher weight gain and feed intake and better feed conversion than female broilers (p<0.01). The fat content of thigh muscle in female broilers was higher than that of male broilers (p<0.03). The best fit comparison of HMTBA vs. DLM was determined by Schwarz Bayesian Criteria index, which indicated that the average relative bioefficacy of HMTBA vs. DLM was 120% with 95% confidence limit 67 to 172%. These results indicated that Met supplementation improved growth performance and carcass quality of broilers fed corn-soybean-cottonseed meal diets irrespective of Met sources. Compared to DLM, HMTBA has the same molar bioefficacy on improving the growth performance and carcass quality of broilers; however, HMTBA fed birds had superior meat color to DLM fed birds.
摘要:
Although the spatial genetic differentiation that occurs in animal populations has been extensively studied, information on temporal variations in genetic structure and diversity is still lacking, especially for animals with oscillating populations. In the present study, we used the mtDNA D-loop sequence to assess the temporal genetic variation in samples from six successive years for the greater long-tailed hamster, Tscherskia triton. Sampling was carried out between 1998 and 2003 in cropland on the North China Plain, China. A total of 108 individuals were analyzed. The temporal samples showed a high level of genetic diversity. Substantial genetic changes in haplotype frequencies over time were detected for the hamster population. Random genetic drift and migration are likely to be the major factors responsible for the observed temporal pattern. The genetic diversity of the hamster population was higher in years with higher population density, and lower in years with lower population density. The result supports our hypothesis that genetic diversity decreases when population density declines in animals whose population oscillates greatly between years. The combined effects of inbreeding and genetic drift caused by reproduction, dispersal and population size might play important roles in the observed changes in genetic structure and diversity between years.
作者机构:
[Yi Lin] Huazhong Univ Sci & Technol, Dept Control Sci & Engn, Wuhan 430074, Peoples R China.;Wuhan Polytech Univ, Dept Math & Phys, Wuhan, Peoples R China.;Slippery Rock Univ, Dept Math, Slippery Rock, PA 16057 USA.
通讯机构:
[Yi Lin] H;Huazhong Univ Sci & Technol, Dept Control Sci & Engn, Wuhan 430074, Peoples R China.
摘要:
An understanding of the dynamic behavior of trace elements leaching from coal mine spoil is important in predicting the groundwater quality. The relationship between trace element concentrations and leaching times, pH values of the media is studied. Column leaching tests conducted in the laboratory showed that there was a close correlation between pH value and trace element concentrations. The longer the leaching time, the higher the trace element concentrations. Different trace elements are differently affected by pH values of leaching media. A numerical model for water flow and trace element transport has been developed based on analyzing the characteristics of migration and transformation of trace elements leached from coal mine spoil. Solutions to the coupled model are accomplished by Eulerian-Lagrangian localized adjoint method. Numerical simulation shows that rainfall intensity determined maximum leaching depth. As rainfall intensity is 3.6ml/s, the outflow concentrations indicate a breakthrough of trace elements beyond the column base, with peak concentration at 90cm depth. And the subsurface pollution range has a trend of increase with time. The model simulations are compared to experimental results of trace element concentrations, with reasonable agreement between them. The analysis and modeling of trace elements suggested that the infiltration of rainwater through the mine spoil might lead to potential groundwater pollution. It provides theoretical evidence for quantitative assessment soil-water quality of trace element transport on environment pollution.
摘要:
The method of reconstructing NURBS surface -with features is proposed in this paper. Features including boundary curves and feature points are recognized from the scanned data. An initial surface is constructed with boundary curves. The desired NURBS is determined by modifying the initial surface to pass through feature points. Lagrange multiplier is used to find the solution. The error analysis is then done. Examples are given to verify the algorithm at last. The method can keep some features fixed and be widely used in CAD modeling.
会议论文集名称:
Lecture Notes in Control and Information Sciences
摘要:
The ability to detect a new fault class can be a useful feature for an intelligent fault classification and diagnosis system. In this paper, we adopt two novelty detection methods, the support vector data description (SVDD) and the Parzen density estimation, to represent known fault class samples, and to detect new fault class samples. The experiments on real multi-class bearing fault data show that the SVDD can give both high identification rates for the prescribed ‘unknown’ fault samples and the known fault samples, which shows an advantage over the Parzen density estimation method in our experiments, via choosing the appropriate SVDD algorithm parameters.