An estimate of the conversion rates of SO_2 to SO_4^(2-)- and NO_2 to HNO_(3+) NO_3^- for the evaluation air pollution in Beijing

The conversion rates of SO2 to SO42- and NO2 to HNO3+NO3- are estimated from the field-data obtained in Beijing in summer, 1988. The results show that the conversion rate of NO2 is about four times as much as that of SO2; The conversion rates have a diurnal variation in a day. On the average, the rate of SO2 is estimated to be 4.7% h-1 during the daytime and 3.4% h-1 during the nighttime. Similarly, the rate of NO2 is estimated to be 17.2% h-1 and 12% h-1 respectively.

CONVERSION RATES OF SURFACE HOX RADICALS IN BEIJING CITY

Surface OH radical concentration in Beijing City was measured by impregnated filter trapping technique-high performance liquid chromatography (IFT-HPLC). The observed concentration of OH radical showed obvious diurnal and seasonal variations, with maximum readings at noon or afternoon, similar to 80x10(6)OH/cm(3) in summer and similar to 20x10(6)-40x10(6)OH/cm(3) in fall. On the basis of measured data, the reaction rates related to the photochemical process of HO(x) (OH+HO(2)) were derived and characteristics of atmospheric chemical processes in the city were analyzed. The results showed that conversion rates of atmospheric OH and HO(2) in the summer of Beijing City were about 700x10(6) molecule/(cm(3) . s) and 600x10(6)molecule/(cm(3) . s), respectively. And the net production of OH in the air of the city mainly originated from the photolysis of the gaseous HNO(2), and the main sink of OH were the photochemical reactions with VOCs, NO(2), HCHO and CO. It was different from the clean area.

Study on the Relationships between Utilization Ratios and Conversion Rates of Nitrogen,Phosphorus and Potassium for Wheat

This paper studied the relationships between utilization ratios and conversion rates of nitrogen,phosphorus and potassium for wheat by data mining method based on data of"3414 fertilizer field trials"of wheat by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows:①the conceptual model of fertilizer utilization ratio of wheat for plot was that,Y N≈a+b×optimum nitrogen application amount+c×optimum fertilizer amount of K+d×rainfall in growth season,Y P≈a+b×optimum fertilizer amount of K+c×rainfall in growth season,Y K≈a+b×temperature in growth season+c×rainfall in growth season-d×optimum yield-e×optimum nitrogen application amount,respectively.②Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships.No significant relationships:13,of which 8 were soil nutrients,the results showed that soil nutrients had little effect on nutrient conversion rate and fertilizer utilization ratio;consistent significant relationships:4,they were all nitrogen and phosphorus,explaining the importance of nitrogen and phosphorus;contrary significant relationships:6,they were all nitrogen and phosphorus,illustrating that phosphorus and nitrogen had inhibitory effect;complementary significant relationships:31,the cause of the complementary phenomenon was that the fertilizer utilization ratio was the measuring index of fertilizer efficiency in one season,while the nutrient conversion rate was the measuring index of fertilizer efficiency in more seasons.It showed that the fertilizer utilization rate was significantly correlated,or the nutrient conversion rate was significantly correlated.

Study on the Relationship between Utilization Ratios and Conversion Rates of Nitrogen,Phosphorus and Potassium for Rice

This paper studied the relationships between utilization ratios and conversion rates of nitrogen,phosphorus and potassium for rice by data mining method based on data of"3414 fertilizer field trials"of rice by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows:①the conceptual model of fertilizer utilization ratio of rice for plot was that,Y N≈a+b×optimum yield+c×optimum fertilizer amount of K,Y P≈a+b×optimum yield,Y K≈a respectively.②Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships:①no significant relationships:25,of which 14 were soil nutrients and 9 were environmental factors,the results showed that soil nutrients and environmental factors had little effect on nutrient yield ratio and fertilizer utilization ratio;②consistent significant relationships:2,one was that yield ratio and utilization ratio of N were positively correlated with the optimum production,explaining the importance of N for production,the other was that yield ratio and utilization ratio of P had a significantly positive correlation with conversion rate and utilization ratio of N,illustrating that nitrogen and phosphorus had mutual promotion;③contrary significant relationships:5,these showed as negative correlations of fertilizer utilization ratio and positive correlation of nutrient conversion ratio;④complementary significant relationships:22,the cause of the complementary phenomenon was that the fertilizer utilization ratio was the index of fertilizer efficiency in one season,while the nutrient conversion rate was the index of fertilizer efficiency in more seasons,which showed that the fertilizer utilization rate was significantly correlated,or the nutrient conversion rate was significantly correlated.

Study on the Relationships between Utilization Ratios and Conversion Rates of Nitrogen,Phosphorus and Potassium for Maize

This paper studied the relationships between utilization ratios and conversion rates of nitrogen,phosphorus and potassium for maize by data mining method based on data of"3414 fertilizer field trials"of maize by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows:①the conceptual model of fertilizer utilization ratio of maize for plot was that,Y N≈a+b×optimum yield,Y P≈a+b×optimum yield-c×optimum nitrogen application amount-d×optimum potassium application amount,Y K≈a-b×optimum nitrogen application amount-c×temperature in growth season-d×rainfall in growth season,respectively.②Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships.No significant relationships:22,of which 16 were soil nutrients and 5 were environmental factors,the results showed that soil nutrients and environmental factors had little effect on nutrient conversion rate and fertilizer utilization ratio;consistent significant relationships:14,illustrating that conversion rate and utilization ratio of maize were consistent in most cases,and it was because that maize was planted for a long term,and its fertilizer absorption law was basically stable;contrary significant relationships:0,illustrating that there was no reverse relationship between conversion rate and utilization ratio of maize;complementary significant relationships:18,the cause of the complementary phenomenon was that the fertilizer utilization ratio was the measuring index of fertilizer efficiency in one season,while the nutrient conversion rate was the measuring index of fertilizer efficiency in more seasons.It showed that the fertilizer utilization ratio was significantly correlated,or the nutrient conversion rate was significantly correlated.

Improving the Conversion Success Rate of Hepatocellular Carcinoma: Focus on the Use of Combination Therapy with a High Objective Response Rate

The high mortality rate in hepatocellular carcinoma(HCC)is partially due to the fact that a significant number of patients are diagnosed at an intermediate or advanced stage,with surgical treatment options unavailable.Conversion therapy,which involves both locoregional and systemic treatments,has the potential to downstage tumors in selected patients with initially unresectable HCC,thereby making surgical treatment a possibility and potentially increasing long-term survival.To optimize the conversion rate,it is necessary to maximize successful conversions and clearly define the target population for conversion treatment through a collaborative effort.In this review article,we summarize the clinical experience and evidence for conversion therapy in patients with‘potentially resectable’HCC from four perspectives:1)defining the target population for conversion therapy,2)selecting the appropriate conversion strategy,placing emphasis on the utilization of combination therapy that exhibits a significant objective response rate,3)determining the timing and urgency of surgical resection,4)promoting the adoption of a multidisciplinary team model.The authors are optimistic that with the continuous progress in treatment and a deeper understanding of HCC,the success rate of HCC conversion therapy will increase,and the overall survival of HCC patients will be prolonged.

Conversion regular patterns of acetic acid,propionic acid and butyric acid in UASB reactor

On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used,the conversion regulations would have changed accordingly. Relationships of different substrates vary according to their locations. In the whole reactor, propionate's conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate's conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates' conversion. The ethanol type fermentation of the acidogenic phase is the optimal acid type fermentation for the two phase anaerobic process.

Interannual variations in energy conversion and interaction between the mesoscale eddy field and mean flow in the Kuroshio south of Japan

Using 19-year satellite altimetric data, variations in the eddy kinetic energy, energy exchanges and interaction between the eddy fi eld and mean fl ow are discussed for the Kuroshio south of Japan. In the seasonal cycle, the eddy kinetic energy level is a minimum in December/January and a maximum in April/May. In addition to seasonal variations, the eddy kinetic energy undergoes interannual changes. The energy transfers mainly from the mean fl ow to the eddy fi eld in the Kuroshio south of Japan, and dominant energy exchanges mainly occur along the Kuroshio path south of Japan in each year from 1993 to 2011. In addition, there is often barotropic instability south of Honshu. Regarding interactions between the eddy fi eld and mean fl ow, cyclonic and anticyclonic accelerations are also found along the Kuroshio path and they fl ank each other. There is cyclonic acceleration always imposed on southeast of Kyushu, and anticyclonic acceleration dominates south of Honshu from 2001 to mid-2005. Reynolds stress is used to explain the dynamic process of energy exchange. Furthermore, lag-correlation and linear regression analysis show that variability of the energy conversion rate and Reynolds stress involve responses to eddy acceleration at two time scales. The enhanced eddy acceleration induces large Reynolds stress, and enhanced Reynolds stress or barotropic instability further enforces energy transfer from the mean fl ow to the eddy fi eld.

Phase conversion and removal of impurities during oxygen-rich alkali conversion of high titanium slag

In order to achieve high-efficiency alkali conversion and impurity removal of high titanium slag under the condition of low alkali concentration,a new way of oxygen-rich alkali conversion in KOH solution was proposed.The conversion law of element occurrence state and the influence of the conversion conditions on the titanium conversion rate and removal rate of silicon and aluminum were studied.The results showed that the KOH solution converted the titanium oxide in high titanium slag into whisker-like potassium titanate.Silicon and aluminum elements were dissolved into the solution.Under the following conditions,KOH concentration of 6 mol/L,conversion temperature of 260℃,initial oxygen partial pressure of 2 MPa,liquid−solid ratio of 35 mL/g,conversion time of 4 h,and high titanium slag particle size of 48−74μm,the conversion rate of titanium was 97.0%,and the removal rates of silicon and aluminum were 90.2%and 76.2%,respectively.Oxygen-rich alkali conversion product was converted to rutile with a TiO_(2) grade of 99.1%by acid hydrolysis conversion.

Modeling the kinetics of methane conversion in steam reforming process of coke-oven gas based on experimental data

Steam-reforming is an effective approach for upgrading methane and hydrocarbon of coke-oven gas into CO and HE, but the kinetic behavior needs more study. We investigated the conversion of methane in coke-oven gas by steam reforming process in an electric tubular flow at 14 kPa with temperature varying from .500 ℃ to 9.50 ℃, and developed a kenetic model for, ignoring the effects of adsorption and diffusion. The optimal dynamic conditions for methane conversion 14 kPa are as follows： the ratio of the amount of water to the amount of methane is from 1.1 to 1.3; the reaction temperature is from 1 223 K to 1 273 K. The methane conversion rate is larger than 95% when the ratio of the amount of water to the amount of methane is 1.2 at a temperature above 1 223 K with the residence time up to 0.75 s.

High concentration xylene decomposition and diagnostic analysis by non-thermal plasma in a DBD reactor

Dielectric barrier discharge（DBD） is utilized to decompose xylene vapor in mobile gas under normal atmospheric pressure.The plasma is generated by an AC power source with a frequency of 6 kHz.In the experiment,the discharge power on the DBD reactor was calculated by a Lissajous figure,and the specific input energy（SIE） of different discharge voltage or residence time was obtained.The concentrations of xylene,carbon monoxide and carbon dioxide in the gas were analyzed by gas chromatography.The spectra of DBD were diagnosed using a spectrometer.We calculated the conversion rate（CR）,mineralization rate（MR） and carbon dioxide selectivity.The relationship between these quantities and the SIE was analyzed.The experimental results show that high concentration xylene can be decomposed mostly by DBD plasma.The CR can reach as high as 90%with the main product of carbon dioxide.

Stand structure, phenology and litterfall dynamics of a subtropical mangrove Bruguiera gymnorrhiza

We evaluated the phenology and litterfall dynamics of the mangrove Bruguiera gymnorrhiza（L.）Lamk along the Okukubi River, Okinawa Island, Japan.Over 3 years, this species showed the highest litterfall of leaves and stipules in summer and the lowest litterfall in winter. From Kendall＇s coefficient of concordance, the monthly changes in leaf, stipule, and branch were strongly and significantly concordant among years. Leaf and stipule litterfall could be governed by monthly maximum wind speed, monthly day length, and monthly mean air temperature. Branch litterfall depended on monthly maximum wind speed and monthly rainfall, and increased exponentially with increasing monthly maximum wind speed. Mean total litterfall was 11.8 Mg ha^（-1）yr^（-1）, with the largest component being leaf litterfall（65.8 %）. Annual leaf litterfall per plot was almost constant regardless of the tree density of the plot. Mean leaf longevity was 18 months.Flower and mature propagule litterfall might be influenced by monthly mean air temperature, monthly day length and monthly mean air temperature. The average development periods from flower buds to flowers and flower buds to mature propagules were 1 and 8 months, respectively.Except for leaf and branch, all vegetative and reproductive organ litterfall had clear annual cycles. B. gymnorrhiza showed a positive correlation between leaf production and reproductive organ production.

Research on Plasma Chemistry Reactions in C_3H_6/NO/O_2/N_2 Mixture Gases

A DBD-type （dielectric barrier discharge） NTP （non-thermal plasma） reactor was designed and an experimental system was established, in order to study the mechanism of plasma chemistry reactions in a gas mixture of C3H6/NO/O2/N2. This paper is focused on a. the effects of the initial concentrations of both NO and 02 upon NO conversion rate and the variations of NOx and 03 concentrations versus SED （specific energy density） when mixed gases of NO/O2/N2 passed the NTP reactor; b. the effects of the initial concentration of C3H6 upon NO oxidation and reduction reactions in mixed gases of NO/N2/CaH6 and NO/N2/O2/C3H6. The conclusions drawn are as follows, a. When the mixed gases of NO/O2/N2 passed the NTP reactor, NO was simultaneously involved in oxidation and reduction reactions with the former dominant and NO2 concentration increased at the NTP reactor outlet. The NO conversion rate decreased with the increase of the initial concentration of NO and 02, the O3 concentration firstly increased and then decreased with the increase in SED value, b. NO reduction reaction was very weak and energy consumption was very high in a mixed gases of NO/N2. However, when C3H6 was added, the NO conversion rate was significantly increased. When 63H6 was added to the mixed gases of NO/O2/N2, the NO conversion rate was significantly increased and the energy consumption was considerably reduced.

非线性等转化率法研究聚苯乙烯热解反应活化能与转化率的关系

首次采用非线性等转化率法研究了聚苯乙烯在氮气中不同升温速率下的非等温热重曲线,通过程序拟合得到了热解过程中活化能Eα与转化率α的关系。实验结果显示,在氮气中聚苯乙烯存在一个失重阶段,起始热解温度随升温速率的增大而升高。动力学拟合结果显示,热解初始阶段的活化能值较低,约为80 kJ/mol,主要对应于聚合物链中弱键的任意断裂反应,其反应速度很快;随着反应的进行,活化能Eα逐渐增大,当α>0.3后趋于平缓,此阶段Eα的平均值约为145 kJ/mol,反应主要为聚合物链本身的断裂、解聚;当α>0.9时,Eα值迅速减小,反应以链终止反应为主。

Reaction Process of Heavy Hydrocarbons Hydrogenation in Ebullated Bed

The properties and structural changes of unconverted oil(UCO)obtained from ebullated bed hydrogenation at different residue conversion rates were analyzed to clarify the reaction process of heavy components.Meanwhile,the processing routes of UCO,delayed coking,and solvent deasphalting,were investigated.The results showed that with the increase of conversion,the impurity removal rate increased;meanwhile the contents of sulfur and metal in UCO decreased,while the contents of nitrogen and residual carbon increased,and the colloidal stability of UCO became worse.The structural parameters of UCO indicated that the change in molecular structure of heavy oil mainly covered the opening of cycloalkanes ring,hydrogenation saturation of aromatic rings and dealkylation reaction during hydrogenation in the ebullated bed;the aromatic structure was basically unchanged at high conversion,and was mainly due to the ring opening of cycloalkanes and the fracture reaction of alkyl side chains.The coking route of UCO showed that low sulfur petroleum coke with different grades could be prepared by adjusting the conversion in ebullated bed to produce UCOs with different properties.The coke generating coefficient and sulfur transfer coefficient in UCO coking process were higher than those in residue coking.The properties of deasphalted oil(DAO)of UCO were significantly improved and could be used as FCC or hydrocracking feedstock.The DAO yield of UCO feedstock at high conversion was higher,and its sulfur content was lower and CCR value was higher.

Study on Free Amino Acid and Short Peptide Fertilizer Production by Solid State Fermented Castor Bean Meal

Using microbial fermentation to increase the content of free amino acids and short peptides in the organic fertilizer for castor bean meal can effectively promote plant growth and improve fruit quality.Using free amino acid and short peptide content as an indicator,through single factor and response surface optimization experiments,the process parameters(moisture content,fermentation time and inoculum quantity)of castor meal solid-state fermentation were optimized.The best process parameters for the solid-state fermentation were:the moisture content 62%,the fermentation time 20 d,and the inoculum quantity 0.23%.The moisture content had the greatest impact on the conversion rate of free amino acids and short peptides,and the protein conversion rate reached 65.6%.The scale-up experiment under the optimal conditions showed that the solid-state fermentation using the inoculum had a significant beneficial effect compared with other fermentation methods.The fermentation of castor cake fertilizer provides a theoretical and practical basis for production feasibility,and has important guiding significance for the effective utilization of castor bean meal.

Kinetic model on coke oven gas with steam reforming

The effects of factors such as the molar ratio of H2O to CH4 (n(H2O)/n(CH4)), methane conversion temperature and time on methane conversion rate were investigated to build kinetic model for reforming of coke-oven gas with steam. The results of experiments show that the optimal conditions for methane conversion are that the molar ratio of H2O to CH4 varies from 1.1 to 1.3 and the conversion temperature varies from 1 223 to 1 273 K. The methane conversion rate is more than 95% when the molar ratio of H2O to CH4 is 1.2, the conversion temperature is above 1 223 K and the conversion time is longer than 0.75 s. Kinetic model of methane conversion was proposed. All results demonstrate that the calculated values by the kinetic model accord with the experimental data well, and the error is less than 1.5%.

The decadally modulating eddy field in the upstream Kuroshio Extension and its related mechanisms

Both the level of the high-frequency eddy kinetic energy（HF-EKE） and the energy-containing scale in the upstream Kuroshio Extension（KE） undergo a well-defined decadal modulation, which correlates well with the decadal KE path variability. The HF-EKE level and the energy-containing scales will increase with unstable KE path and decrease with stable KE path. Also the mesoscale eddies are a little meridionally elongated in the stable state, while they are much zonally elongated in the unstable state. The local baroclinic instability and the barotropic instability associated with the decadal modulation of HF-EKE have been investigated. The results show that the baroclinic instability is stronger in the stable state than that in the unstable state, with a shorter characteristic temporal scale and a larger characteristic spatial scale. Meanwhile, the regional-averaged barotropic conversion rate is larger in the unstable state than that in the stable state. The results also demonstrate that the baroclinic instability is not the dominant mechanism influencing the decadal modulation of the mesoscale eddy field, while the barotropic instability makes a positive contribution to the decadal modulation.

Analysis of Influencing Factors in Production of Selenium-enriched Eggs

Selenium is an essential trace element for human health.Eating selenium-enriched eggs is conducive to easily and effectively solving the problem of selenium deficiency.In the production process of selenium-enriched eggs,different selenium sources,additive doses,feeding time,and the addition of other vitamins,trace elements,and methionine in the diet will influence the deposition of selenium in eggs.Through this review,it is intended to provide a reference for the practical,safe and economical production of selenium-enriched eggs.

A Condensed Gas-Phase Chemical Model and Its Application

Using the 'lumped mechanism' and 'counting species' methods, we developed a condensed gas-phase chemical model based on a simplified one. The modified quasi-steady-state approximation (QSSA) scheme and the error redistribution mass conservation technique are adopted to solve the atmospheric chemistry kinetic equations. Results show that the condensed model can well simulate concentration variations of gas species such as SO2, NOX, O-3, H2O2 and conversion rates of SO2 and NOX transformation to H2SO4 and HNO3. These results are in good agreement with those from the simplified model. The conversion rates of SO2 and NOX under different initial concentrations and meteorological conditions are computed, and the results can be directly applied to regional acid deposition model.