发酵液“增浓”现象浅析

本文分析了我公司发酵液原麦汁浓度比麦汁浓度高是由巴林公式引起的；发酵条件的变化对巴林公式的计算结果有影响。

Effects of Doubled_CO_2 Concentration on Ultrastructure, Supramolecular Architecture and Spectral Characteristics of Chloroplasts from Wheat

Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.

Shear Thickening Fluids Based on Additives with Different Concentrations and Molecular Chain Lengths

Shear thickening fluids （STFs） based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol （PEG） 400, where three types of additives with different molecular chain lengths of PEG4000, PEG6000, and PEG10000 were used. For PEG10000, different concentrations, including 0, 1%, 3%, and 5%, were selected to study the influences of additive concentrations. Rheological properties of the samples were measured with a rheometer. The results show that the shear thickening effect was significantly enhanced with the increase of the concentration and the molecular chain length of additives. The mechanism of enhancement was quantitatively explained with the formation of large particles clusters.

Densification and sintering dynamics of 10NiO-NiFe_2O_4 composites doped with CaO

The effects of CaO content in the range from 0 to 4.0%, and sintering temperature on the phase composition, relative density and electrical conductivity of 10NiO-NiFe2O4 composites doped with CaO were studied. The results show that there is no change of structure for NiO or NiFe2O4; there is apparent oxygen absorbing and releasing behavior during the heating process in air for 10NiO-NiFe2O4 composites. Introduction of CaO can accelerate the densification of 10NiO-NiFe2O4 composites. The maximum value of relative density is 98.75% for composite doped with 2.0% CaO and sintered at 1 200 ℃, which is beyond about 20% for the undoped composites. The sintering activated energy of sample containing 2% CaO decreases by 15.87 kJ/mol, compared with that of the undoped sample.

Effect of CO_2 Elevation on Root Growth and Its Relationship with Indole Acetic Acid and Ethylene in Tomato Seedlings

A hydroponic experiment was carried out to study the effect of elevated carbon dioxide(CO2) on root growth of tomato seedlings.Compared with the control(350 μL L-1),CO2 enrichment(800 μL L-1) significantly increased the dry matter of both shoot and root,the ratio of root to shoot,total root length,root surface area,root diameter,root volume,and root tip numbers,which are important for forming a strong root system.The elevated CO2 treatment also significantly improved root hair development and elongation,thus enhancing nutrient uptake.Increased indole acetic acid concentration in plant tissues and ethylene release in the elevated CO2 treatment might have resulted in root growth enhancement and root hair development and elongation.

Nutrient and chlorophyll a anomaly in red-tide periods of 2003-2008 in Sishili Bay, China

Sishili Bay is the most important aquiculture and tourism area for the city of Yantai, China; however, red tides occurred frequently and have caused huge economic losses in this bay in recent years. To gain a better understanding of the local ecological environments in the bay, we conducted this research between 2003 and 2008 to analyze variations in nutrients and chlorophyll （chl-a） during high frequency red tide period （May to September）. The results show that the chl-a concentration increased from 2.70 in 2003 to 7.26 mg/m3 in 2008, while the concentration of total inorganic nitrogen （TIN） and silicate （SiO3-Si） increased lineally from 5.18 and 1.45 pmol/L in 2003 to 18.57 and 9.52 pmol/L in 2008, respectively, and the annual phosphate （PO4-P） varied between 0.15 and 0.46 μmol/L. Special attention was given to a red tide in August 2007 occurred when water temperature was high and nutrient concentrations increased sharply because of a heavy rainfall. Overall, the results show the P limitation in Sishili Bay, and reveal that red tides were caused by eutrophication from terrestrial inputs and local warm weather, particularly during rainy periods. Therefore, to control red tide, greater efforts should be made to reduce sewage discharges into Sishili Bay, particularly during rainfall seasons.

Degradation of aniline by Fe^(2+)-activated persulfate oxidation at ambient temperature

The aniline degradation by persulfate activated with ferrous ion (Fe2+ ) was investigated in batch reactor at ambient temperature. The experimental factors in aqueous solutions including persulfate concentration, Fe2+ concentration, pH and ionic strength level were discussed. It is demonstrated that, aniline degradation rate increases with increasing persulfate concentration, but much more ferrous ion inhibits the aniline degradation. When the aniline concentration is 0.10 mmol/L, the maximum aniline degradation occurs at the S2O82- to Fe2+ molar ratio of 250/5 at pH 7.0. In the pH range of 5.0-8.5, increasing pH causes higher aniline degradation. What's more, the increase of ionic strength in solution causes inhibiting in the reaction. Produced intermediates during the oxidation process were identified using gas chromatography-mass spectrometry (GC-MS) technology. And degradation pathways of aniline were also tentatively proposed.

Influence of earth gravity on reaction engineering of tubular reactor for high concentration tungsten ion-exchange

The influence of gravity on the reaction engineering of tubular reactor is studied by analyzing the residence time distribution curves.The results show that upflow-feeding mode is more beneficial compared with downflow-feeding mode,since the flow pattern of the fluid in the reactor is closer to plug flow.The result of dynamic experiment conducted in ion-exchange of tungsten metallurgy is as good as that in reaction engineering of ion-exchange column.Whether downflow-feeding or upflow-feeding mode is adopted,breakthrough time decreases when solution concentration increases.Upflow-feeding mode has longer breakthrough time and greater improvement in adsorption capacity especially with high WO3 concentration in ion-exchange.

Method of oxygen-enriched two-stage underground coal gasification

Two-stage underground coal gasification was studied to improve the caloric value of the syngas and to extend gas production times.A model test using the oxygen-enriched two-stage coal gasification method was carried out.The composition of the gas produced,the time ratio of the two stages,and the role of the temperature field were analysed.The results show that oxygen-enriched two-stage gasification shortens the time of the first stage and prolongs the time of the second stage.Feed oxygen concentrations of 30%, 35%,40%,45%.60%,or 80%gave time ratios（first stage to second stage） of 1：0.12,1：0.21.1：0.51,1：0.64, 1：0.90.and 1：4.0 respectively.Cooling rates of the temperature field after steam injection decreased with time from about 19.1-27.4℃/min to 2.3-6.8℃/min.But this rate increased with increasing oxygen concentrations in the first stage.The caloric value of the syngas improves with increased oxygen concentration in the first stage.Injection of 80%oxygen-enriched air gave gas with the highest caloric value and also gave the longest production time.The caloric value of the gas obtained from the oxygenenriched two-stage gasification method lies in the range from 5.31 MJ/Nm^3 to 10.54 MJ/Nm^3.

Extraction of Cadmium from Sewage Sludge Using Polyepoxysuccinic Acid

Polyepoxysuccinic acid （PESA）, as an environmental benign biodegradable chelant, was used to remove heavy metals from the sewage sludge of Shanghai Taopu Wastewater Treatment Plant. The extraction of cadmium （Cd） from sewage sludge using aqueous solution of PESA was studied. It was found that PESA was capable of extracting Cd from the sludge, and the extraction efficiency was dependent on both pH and the concentration of the chelating reagent. The extraction efficiency decreased gradually with increasing of pH, whereas the dependency on pH decreased as the concentration of PESA increased. In the case of the high PESA to total metal ratio, e.g., 10：1, the extraction efficiency reached above 70% within the pH range from 1 to 7. The highest extraction efficiency obtained in tbe experiment was 78%. By comparing the contents of the heavy metals in sewage sludge before and after the extraction, it was found that the extracted Cd came mainly from the four fractions： acid-soluble, reducible, oxidizable, and water-soluble fractions.

Rheological and drag reduction properties of hydroxypropyl xanthan gum solutions

Hydroxypropyl xanthan gum(HXG) was prepared from xanthan gum(XG) and propylene oxide under alkaline condition. Rheological and drag reduction properties of different concentrations of aqueous HXG and XG solution were studied. The micro-structure network of HXG and XG solutions was investigated by Cryo-FESEM. The results showed that HXG and XG solutions could exhibit shear thinning property. The apparent viscosity of6 g·L-1HXG solution was 1.25 times more than that of 6 g·L-1XG solution. The storage modulus G′ and the loss modulus G″ of HXG solutions were greater than those of XG solutions, and thixotropic and viscoelastic properties were more significant in HXG solutions. The HXG and XG solutions reduced the pressure drop of straight pipe, and the maximum drag reduction of 1 g·L-1HXG and XG in smooth tube reached 72.8% and 68.1%, respectively. Drag reduction rate was increased as the concentration increased. The HXG solution may become a new polymeric drag reducer.

Determination of physical properties for the mixtures of [BMIM]Cl with different organic solvents

Physical properties including refractive index, density, viscosity and conductivity for binary mixtures of l-butyl- 3-methyl imidazolium chloride （[BMIM]CI） and different organic solvents at 298.15 K have been investigated. Ex- cess molar volumes have been calculated and obtained data has been fitted by the Redlich-Kister equation. The density and refractive index were found to increase with increasing concentration of [BMIM]CI, however, excep- tions do exist as in the case of dimethyl sulfoxide （DMSO）/[BMIM]CI. For DMSO/[BMIM]CI, the density decreases with increasing concentration. The addition of different organic solvents was able to disrupt the interactions within mixtures, leading to free mobility of ions. The free mobility of ions has been found to enhance conductivity and decrease viscosity to varying extents in all mixtures studied. It has been observed that solubility parameters, dielectric constants and composition of the solvents used play a vital role in determining the resultant properties. The data obtained will play an important role in understanding the effect of the addition of organic solvents in ILs to enhance their applicability.

Effect of CO_2 enrichment on competition between Skeletonema costatum and Heterosigma akashiwo

We investigated the effect of CO2 enrichment and initial inoculum density on competition between Skeletonema costatum and Heterosigma akashiwo,two common algae seen in algal blooms.The initial inoculum density(0.2×104,0.4×104,0.8×104 cells/ml) had a significant effect on population growth and competition between H.akashiwo and S.costatum.The time required for population growth to reach the exponential growth phase and stationary phase decreased significantly as the initial density increased.When the two species were cultured together,S.costatum tended to outcompete H.akashiwo,especially when present at higher initial ratios.CO_2 enrichment(5 000μl/L CO_2) increased the maximum population density and carrying capacity of H.akashiwo but decreased these measures for S.costatum.Thus,CO_2 enrichment favored the growth of H.akashiwo over S.costatum.

Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamys farreri

Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment.

Introduction of CMIP5 Experiments Carried out with the Climate System Models of Beijing Climate Center

The climate system models from Beijing Climate Center, BCC_CSM1.1 and BCC_CSM1.1-M, are used to carry out most of the CMIP5 experiments. This study gives a general introduction of these two models, and provides main information on the experiments including the experiment purpose, design, and the external forcings. The transient climate responses to the CO2 concentration increase at 1% per year are presented in the simulation of the two models. The BCC_CSM1.1-M result is closer to the CMIP5 multiple models ensemble. The two models perform well in simulating the historical evolution of the surface air temperature, globally and averaged for China. Both models overestimate the global warming and underestimate the warming over China in the 20th century. With higher horizontal resolution, the BCC_CSM1.1-M has a better capability in reproducing the annual evolution of surface air temperature over China.

Decomposition and Products of Wheat and Rice Straw from a FACE Experiment Under Flooded Conditions

Winter wheat and rice straw produced under ambient and elevated CO2 in a China rice-wheat rotation free-air CO2 enrichment （FACE） experiment was mixed with a paddy soil at a rate of 10 g kg^-1 （air-dried）, and the mixture was incubated under flooded conditions at 25℃ to examine the differences in decomposition as well as the products of crop residues produced under elevated CO2. Results showed that the C/N ratio and the amount of soluble fraction in the amended rice straw grown under elevated CO2 （FR） were 9.8% and 73.1% greater, and the cellulose and lignin were 16.0% and 9.9% lesser than those of the amended rice straw grown under ambient CO2 （AR）, respectively. Compared with those of the AR treatment, the CO2-C and CH4-C emissions in the FR treatment for 25 d were increased by 7.9% and 25.0%, respectively; a higher ratio of CH4 to CO2 emissions induced by straw in the FR treatment was also observed. In contrast, in the treatments with winter wheat straw, the CO2-C and CH4-C emissions, the ratio of straw-induced CH4 to CO2 emissions, and the straw composition were not significantly affected by elevated CO2, except for an 8.0% decrease in total N and a 9.7% increase in C/N ratio in the wheat straw grown under elevated CO2. Correlation analysis showed that the net CO2-C and CH4-C emission from straw and the ratio of straw-induced CH4 to CO2 emissions were all exponentially related to the amount of soluble fraction in the amended straw （P 〈0.05）. These indicated that under flooded conditions, the turnover and CH4 emission from crop straw incorporated into soil were dependent on the effect of elevated CO2 on straw composition, and varied with crop species. Incorporation of rice straw grown under elevated CO2 would stimulate CH4 emission from flooded rice fields, whereas winter wheat straw grown under elevated CO2 had no effect on CH4 emission.

Effects of Alginate Gel on Rheological Properties of Hair-tail (Trichiurus lepturus) Surimi

Effects of alginate gel at different concentrations on rheological properties of hair-tail (Trichiurus lepturus) surimi were investigated. Alginate gel (1% - 3%) exhibited enhanced effects, especially when alginate gel concentration increased. The rheological properties of mixture samples were studied by the time sweep, frequency sweep and temperature sweep. The critical strain values of the mixture samples for the onset of non-linear viscoelasticity were about 5%. The storage modulus G' of the mixture samples increased with time for 4 h. The frequency sweep showed that G' was greater than G" for all the mixture gels with different alginate gel concentrations, and values of both n' and n" for all samples were low (<0.2), these constants corresponding to G' and G", and indicating the elasticity of mixture gels. The values of storage modulus G' decreased during heating process and increased with decreasing temperature.

Effect of coal slurry on the corrosion of coal-mine equipment

The corrosion of coal mine equipment immersed in coal slurry is addressed. The corrosion of low carbon steel samples immersed in coal slurries of different concentrations （80, 130, and 180g/L） prepared from coals of different rank （long-flame coal, meager lean coal, and anthracite） and different granularity （0.25-0.5 ram, 0.074-0.25 mm, and less than 0.074 mm particle size） was studied by the electrochemical method of polarization curve measurement, controlled potential sweeping, and continuous scanning. The results show that the corrosion rate in an anthracite slurry, where the coal has high coalification, is far greater than corrosion in a long-flame or a meager lean coal slurry. Furthermore the corrosion current, polarization current, and corrosion rate of low carbon steel become larger, and the polarizability becomes smaller, as the coal particle size decreases. The same trend is seen as the concentration of the coal slurry increases.

A simple method for purification of genomic DNA from whole blood using Fe_3O_4/Au composite particles as a carrier

Objective： To establish a method of genomic DNA extraction from whole blood using Fe3O4/Au composite particles as a carrier. Methods： Two crucial conditions （sodium chloride concentration and amount of the magnetic particles） were optimized and 8 different human whole blood samples were used to purify genomic DNA under the optimal condition. Then agarose gel electrophoresis and polymerase cbain reaction （PCR） were performed. Results： The optimal binding condition was 1.5 mol/L NaC1/10% PEG, and the optimal amount of Fe3O4/Au composite particles was 600μg. The yields of the genomic DNA from 100μl of different whole blood samples were 2-5 μg, and the ratio of A260/A280 was in the range of 1.70-1.90. The size of genomic DNA was about 23 kb and the PCR was valid. Conclusion： The purification system using Fe3O4/Au composite microparticles has advantages in high yield, high purity, ease of operating, time saving and avoiding centrifugation. The purified sample was found to function satisfactorily in PCR amplification.

Effect of Transport Time and Handling on Physiological Responses of Cattle

The objective of this work was to determine the effect of transport time （up to 11 hours） on animal welfare. 540 animals （cows, bulls and calves）, three transport times of 2, 4 to 6, and 10 to 11 hours, and two space allowances （2 m2 and 1.5 m2 per animal for cows and bulls; and 1.2 m2 and 0.8 m2 per animal for calves） were used for the experiment during transport from farms to the abattoir in Uppsala, Sweden. Measurements were made on five animals on each trip. Stress response parameters considered were cortisol, glucose, lactate, creatine kinase and heart rate. Blood samples were taken before and after transport. Heart rate sensors were mounted on the animals at least 30 minutes before loading and measurements were made continuously from farms to the abattoirs until stunning. The results of heart rate measurement indicated that loading, un-loading and forced movement in the stunning box were the most stressful events. However, the results of statistical analysis confirmed that transport time doesn＇t have significant effect （P 〈 0.05） on heart rate. Concentration level of cortisol increased by 10 folds during short transport. However, cortisol concentration decreased with an increase of transport times （P 〈 0.01）. Glucose concentrations increased with transport time in all animal categories （P ≤ 0.01）. Transport time has significant effect on concentration levels of glucose （P ≤ 0.01）, creatine kinase （P 〈 0.001） and lactate （P 〈 0.01） particularly after 6 hours journey time.