Constraining Anthropogenic CH_4 Emissions in Nanjing and the Yangtze River Delta,China,Using Atmospheric CO_2 and CH_4 Mixing Ratios

Methane （CH4） emissions estimated with the Intergovernmental Panel on Climate Change （IPCC） inventory method at the city and regional scale are subject to large uncertainties.In this study,we determined the CH4：CO2 emissions ratio for both Nanjing and the Yangtze River Delta （YRD）,using the atmospheric CH4 and CO2 concentrations measured at a suburban site in Nanjing in the winter.The atmospheric estimate of the CH4：CO2 emissions ratio was in reasonable agreement with that calculated using the IPCC method for the YRD （within 20％）,but was 200％ greater for the municipality of Nanjing.The most likely reason for the discrepancy is that emissions from unmanaged landfills are omitted from the official statistics on garbage production.

Measurements of NO_2 mixing ratios with topographic target light scattering-differential optical absorption spectroscopy system and comparisons to point monitoring technique

A topographic target light scattering-differential optical absorption spectroscopy （＇IbTaL-DOA~） system is de- veloped for measuring average concentrations along a known optical path and studying surface-near distributions of atmospheric trace gases. The telescope of the ToTaL-DOAS system points to targets which are located at known dis- tances from the measurement device and illuminated by sunlight. Average concentrations with high spatial resolution can be retrieved by receiving sunlight reflected from the targets, A filed measurement of NO2 concentration is performed with the ToTaL-DOAS system in Shijiazhuang in the autumn of 2011. The measurement data are compared with con- centrations measured by the point monitoring technique at the same site. The results show that the ToTaL-DOAS system is sensitive to the variation of NO2 concentrations along the optical path.

Effects of Lobe Peak-to-Trough Width Ratio on Mixing and Combustion Performance in ATR Combustors

The air-turbo-rocket(ATR)engine is a promising propulsion plant for achieving numerous surface and air launched missile missions.The application of lobed mixer in the ATR combustor can promote the mixing of the fuelrich gas and the air,thus improving the engine performance significantly.The numerical simulation method was conducted to explore the effects of lobe peak-to-trough width ratio on mixing and combustion performance in ATR combustors.Results show that:For a given peak lobe width b1,the combustion efficiency and total pressure loss decrease with the increase of trough lobe width b2;For a given b2,the combustion efficiency and total pressure loss decrease with the increase of b1;The fan-type lobed mixer with smaller b2has a better effect on promoting the combustion efficiency in the region near the ATR combustor center line than that with a pair of parallel side walls.The total pressure recovery coefficient reaches more than 0.99 at the exit of combustor in nonreactive combustion while the total pressure loss reaches more than 4%in the reacting combustion.Compared with the mixing process,more than80%of the total pressure loss is caused during combustion.

Biohydrogen Production from Synthetic Waste Co-digested with Liquid Dairy Cow Manure： Effect of Temperature and Mixing Ratio

Biohydrogen production from synthetic waste, SW （model organic fraction of municipal solid waste） co-digested with liquid dairy manure （M） was tested in batch reactions to assess the effect of temperature and mixing ratio of the substrates. A 5 × 2 factorial design experiment was conducted. Synthetic waste： manure mixtures of 1：1, 2：1, 3：1, 1：0, 0：1 （volatile solids, VS, basis） were tested at 37 （T37） and 55 ℃ （T55） using thirty 1 L laboratory scale digesters. Total VS of each mixture was 50 g/L except SW：M 0：I treatment, where total VS was 27.4 g/L. Gas samples were taken daily to determine hydrogen production, and slurry samples taken before and after experimentation, were analyzed for volatile fatty acid （VFA） concentration, volatile solid （VS） degradation, ammonium nitrogen （NH4＋-N） and pH. Hydrogen production （mL/g-VS fed） showed a significant two-factor interaction between incubation temperature and SW：M ratio （P 〈 0.001）. Maximum production of 15.8 mL/g-VS （fed） was achieved in SW：M ratio of 3：1 at 55 ℃. Generally, hydrogen productions at thermophilic temperature （T55） were significantly higher than at mesophilic （T37） temperature for all treatments （P 〈 0.001） except for SW：M 1：0 and SW：M 0：1 treatments （P 〉 0.05）. This study indicates that hydrogen production from co-digestion of synthetic waste and manure is dependent on incubation temperature and relative contribution of wastes in the mixture.

Variations of CO2 Mixing Ratios in the Air near the Ground in the European Territory of Russia

The instrumentation, method and measurement results used for measurements of CO2 concentrations in surface air of Obninsk （55.1° N, 36.9° E, 183 m above the sea level） located at a distance of 105 km to the south-west of Moscow are presented. Proposed is a method of experimental data filtering allowing one to separate natural and anthropogenic variations of CO2 concentrations. It is shown that minimal concentrations of CO2 registered in Obninsk and at the continental stations of GAW WMO characterize not only the ＂regional background＂ but also coincide with the data from GAW WMO background stations located in the oceanic regions. In this connection, one can assume that the excess in measured CO2 concentration over its minimal values, making about 5-6 ppm, is connected with an anthropogenic emission, and the continent should be considered as an anthropogenic source of C02.

Determination Multipole Mixing Ratios and Transition Strengths of Gamma Rays from Level Studies of 93Mo （p, nγ） Reaction

The multipole mixing ratios have been calculated by a2-ratio method, from levels of 93Mo（p, nγ） reaction. The branching ratios of such γ-transitions are used to calculate the total gamma widths. Besides, the transition strengths and probabilities have been calculated for γ-transitions from excited states whose life times have been reported previously. The results are found to be in general in good agreement with the previous results populated from the previous work.

O,H,and Sr isotope evidence for origin and mixing processes of the Gudui geothermal system,Himalayas,China

Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in China's Mainland.Located about 150 km southeast of Lhasa City,the capital of Tibet,the Gudui geothermal field belongs to the Sangri-Cuona rift belt,also known as the Sangri-Cuona geothermal belt,and is representative of the non-volcanic geothermal systems in the Himalayas.In this study,oxygen-18 and deuterium isotope compositions as well as 87Sr/86Sr ratios of water samples collected from the Gudui geothermal field were characterized to understand the origin and mixing processes of the geothermal fluids at Gudui.Hydrogen and oxygen isotope plots show both,deep and shallow reservoirs in the Gudui geothermal field.Deep geothermal fluids are the mixing product of magmatic and infiltrating snow-melt water.Calculations show that the magma fluid component of the deep geothermal fluids account for about 21.10%-24.04%;magma fluids lay also be a contributing source of lithium.The linear relationship of the 87Sr/86Sr isotopic ratio versus the 1/Sr plot indicates that shallow geothermal fluids form from the mixing of deep geothermal fluids with cold groundwater.Using a binary mixing model with deep geothermal fluid and cold groundwater as two end-members,the nixing ratios of the latter in most surface hot springs samples were calculated to be between 5% and 10%.Combined with basic geological characteristics,hydrogen and oxygen isotope characteristics,strontium concentration,87Sr/(86)Sr ratios,and the binary mixing model,we infer the 6 th-Class Reservoirs Evolution Conceptual Model(6-CRECM) for the Gudui geothermal system.This model represents an idealized summary of the characteristics of the Gudui geothermal field based on our comprehensive understanding of the origin and mixing processes of the geothermal fluid in Gudui.This study may aid in identifying the geothermal and geochemical origin of the Gudui high-temperature hydrothermal systems in remote Tibet of China,whose potential for geothermal development and utilization is enormous and untapped.

Estimating the shareholder's terminal payoff based on insurer's solvency ratio in mixed fractional Brownian market

This paper studies the insurer’s solvency ratio model in a class of mixed fractional Brownian motion(MFBM) market, where the prices of assets follow a Wick-It? stochastic differential equation driven by the MFBM, by the method of the stochastic calculus of the MFBM and the pricing formula of European call option for the MFBM, the explicit formula for the expected present value of shareholders’ terminal payoff is given. The model extends the existing results.

Effect of Pelleted Total Mixed Ration with Different Concentrate-roughage Ratios on Production Performance and Serum Biochemical Parameters of Fattening Hainan Black Goats

[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic background and similar initial weight of(14.08±0.13) kg were randomly assigned into three treatments. Goats were fed with Juncao + concentrate(control group), pelleted total mixed ration I(concentrate: roughage 50 ∶50, group Ⅰ) and Ⅱ(concentrate: roughage 45∶55, group Ⅱ), respectively. The test lasted 45 d.[Result] The final weight, daily gain and feed intake of rams in experimental group Ⅰ were significantly higher than those of control group and experimental group Ⅱ(P<0.05);the final weight and daily gain of rams in experimental group Ⅰ were also markedly higher than those of experimental group Ⅱ(P<0.05);the feed/gain of rams in experimental group Ⅰ was significantly lower than those in control group and experimental group Ⅱ(P<0.05). The feed gain cost of rams in experimental group Ⅰ was markedly lower than that in experimental group Ⅱ( P<0.05), but was significantly higher than that in experimental group Ⅰ(P<0.05);the gross profit of rams in experimental group Ⅰ was significantly higher than those in control group and experimental group Ⅱ(P<0.05). Compared with control group and experimental group Ⅱ, the serum total protein and glucose lev-els in experimental group Ⅱ increased significantly(P<0.05), but the urea nitrogen content reduced(P>0.05).[Conclusion] When the concentrateroughage ratio of pelleted total mixed ration was 50∶50, the fattening effect of Hainan black goat was better, and the serum total protein and glucose levels were evidently improved.

Optimization Analysis of the Mixing Chamber and Diffuser of Ejector Based on Fano Flow Model

An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model,and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward.The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature.Variations in the length of the mixing chamber L_(m) and length of the diffuser L_(d) with respect to variations in the outlet temperature of the ejector T_(c),outlet pressure of the ejector p_(c),and the expansion ratio of the pressure of the primary flow to that of the secondary flow p_(g)/p_(e) were investigated.Moreover,variations in L_(m) and L_(d) with respect to variations in the ratio of the diameter of the throat of the motive nozzle to the diameter of the mixing chamber d_(g0)/d_(c3) and ratio of the outlet diameter of the diffuser to the diameter of themixing chamber d_(c)/d_(c3) were investigated.The distribution of flow fields in the ejector was simulated.Increasing L_(m) and d_(c3) reduced T_(c) and p_(c).Moreover,reducing p_(g)/p_(e) or d_(g0)/d_(c3) reduced T_(c) and p_(c).The length of the mixed section L_(m2),which was determined on the basis of the Fano flow model,increased as pg increased and decreased as d_(c3) increased.The mixing length L_(m1),which was considered the primary flow expansion,showed the opposite trend with that of L_(m2).Moreover,Ld increased as p_(g)/p_(e) and d_(c)/d_(c3) increased.When the value of d_(c) was 1.8 to 2.0 times as high as that of dc3,the semi-cone angle of the diffuser ranged between 6°and 12°.At a constant dc/dc3,decreasing T_(c) and pc increased Ld.

Experimental research on the mixed sand ratio and initial dry density of weathered sand improved expansive soil free load swelling rate

In this paper, through the indoor free load swelling rate test, expansive soil in a section of a first- class highway reconstruction project in Yichang City was studied. It emphatically analyzed the interrelations among free load swelling rate, non-load time, the proportion of mixed sand and initial dry density. Experimen- tal studies have shown that： Free load swelling deformation is mainly divided into three stages of rapid expan- sion, slow expansion and final stability; when the initial dry density is constant, free load swelling rate of the weathered sand modified soil will reduce rapidly before they slow down with the increase of sand proportion, and weathered sand modified soil free load swelling rate is not sensitive to the large amount of sand mixed; in the same mixed sand ratio, weathered sand modified soil free load swelling rate increases rapidly with the in- crease of initial dry density, there is a good linear correlation between them. To take appropriate control of the initial dry density during the expansive soil subgrade construction helps to reduce its swelling deformation and ensures the stability of the embankment.

Effect of Hole Size on Flow Structure and Mixing Characteristic in a Multi-Hole Baffled Micro Combustor

Flow structure and mixing properties by the baffle shape are numerically studied for a baffled micro combustor. The baffle shape is changed by various fuel and hole sizes. The numerical simulations based on different geometric conditions are performed by using the Reynolds Stress Model. The fuel-air mixing is greatly affected by flow recirculations. The centrally located flow recirculation has an important role for the entire mixing performance. The results show that this feature depends on the baffle configurations, and the baffle with small air holes represents efficient characters.

MOLECULAR BEAM STUDIES ON OXIDATION OF CO ON Pd WITH DIFFERENT MIXED RATIOS OF P_(CO) TO P_(O2) ~*

Here some steady-state experiments on oxidation of CO on Pd were performed on a molecular beam apparatus. It is found that the characteristics of the rate of CO_2 formation r versus substrate temperature T are dependent on the ratio P=P_(CO)/P_(O2) in the mixed beam. These characteristics are related to the complicated interactions of co-adsorbed CO and O particles on Pd surface.

Equal Volumes of Sand and Gravel Concrete Mix Ratios in Cameroon and Its Effect on Concrete Compressive Strength

In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of this study is therefore to investigate if the concrete produced with rationalized mix ratio can be adopted as conventional mix ratio in terms of minimum required compression strength of concrete for buildings. Specifically this work compared the conventional mix ratio of 350 kg of cement: 400 liters of sand: 800 liters of gravel for a cubic meter and the rationalized batch of 350 kg of cement: 600 liters of sand: 600 liters of 5/15 gravel, 15/25 gravel and a combination of 5/15 + 15/25 gravel. Average compressive tests’results for both the conventional and the rationalized mix ratios were found to meet the minimum compressive strength of 65% at 7 days, 90% at 14 days and 99% at 28 days for gravel size combination 5/15 + 15/25. Single size gravel of 5/15 and 15/25 did not meet the minimum required compressive strength of 20 N/mm2 for the rationalized mix ratio at 28 days curing based on the minimum compressive strength required, this study arrives at the conclusion that the equal volumes of sand and gravel mix ratio of 350 kg/m3 of cement: 600 liters of sand: 600 liters of gravel mix ratio can be adopted as a conventional concrete mix ratio for gravel size 5/15 + 15/25.

Preparation and Optimization of Mix ratio for C50T Girder Manufactured Sand and Concrete

Considering actual construction conditions of Binchuan-Heqing Highway,this paper provides the C50 mix ratio conforming to engineering requirements by strictly controlling the quality of raw materials,optimizing the design of mix ratio scientifically,preparing superior C50 concrete 0 with manufactured sand,and optimizing the concrete mix ratio based on the adjustment of fly ash replacement,water-cement ratio,polycarboxylate-type water reducer mixing amount,sand ratio,etc.The result indicates that,the water-cement ratio has a great influence on the concrete strength,and if the ratio of coal ash is high in the binding material,the early compressive strength of the concrete will increase slowly.

Identification of Mixtures of Two Types of Body Fluids Using the Multiplex Methylation System and Random Forest Models

Objective Body fluid mixtures are complex biological samples that frequently occur in crime scenes,and can provide important clues for criminal case analysis.DNA methylation assay has been applied in the identification of human body fluids,and has exhibited excellent performance in predicting single-source body fluids.The present study aims to develop a methylation SNaPshot multiplex system for body fluid identification,and accurately predict the mixture samples.In addition,the value of DNA methylation in the prediction of body fluid mixtures was further explored.Methods In the present study,420 samples of body fluid mixtures and 250 samples of single body fluids were tested using an optimized multiplex methylation system.Each kind of body fluid sample presented the specific methylation profiles of the 10 markers.Results Significant differences in methylation levels were observed between the mixtures and single body fluids.For all kinds of mixtures,the Spearman’s correlation analysis revealed a significantly strong correlation between the methylation levels and component proportions(1:20,1:10,1:5,1:1,5:1,10:1 and 20:1).Two random forest classification models were trained for the prediction of mixture types and the prediction of the mixture proportion of 2 components,based on the methylation levels of 10 markers.For the mixture prediction,Model-1 presented outstanding prediction accuracy,which reached up to 99.3%in 427 training samples,and had a remarkable accuracy of 100%in 243 independent test samples.For the mixture proportion prediction,Model-2 demonstrated an excellent accuracy of 98.8%in 252 training samples,and 98.2%in 168 independent test samples.The total prediction accuracy reached 99.3%for body fluid mixtures and 98.6%for the mixture proportions.Conclusion These results indicate the excellent capability and powerful value of the multiplex methylation system in the identification of forensic body fluid mixtures.

Jet Noise Reduction of Double-Mixing Exhaust System

A jet noise reduction technique by using the external chevron nozzle with lobed mixer in the double-mixing exhaust system is investigated under cold conditions.The computations of jet field and the experiments of noise field are conducted with scaled model of high-bypass-ratio turbofan engine mixing exhaust system composed of external chevron nozzle with lobed mixer.The computational results indicate that comparing with the baseline nozzle with lobed mixer,the external chevron nozzle with lobed mixer increases mixing of jet and ambient air near the nozzle exit.The experimental results show that the external chevron nozzle with lobed mixer has better jet noise reduction at low frequencies,and this reduction rises with the increase of chevron bend angle.The experimental results also show that the external chevron nozzle with lobed mixer has sound pressure level(SPL)increase which is not obvious at high frequencies.With chevron bend angle increasing,SPL has relatively marked increase at 60°(directivity angle measured from upstream jet axis)and little fluctuations at 90°and 150°.The external chevron nozzle with lobed mixer has overall sound pressure level(OASPL)reduction in varying degrees at 60°and 150°,but it has little OASPL increase at 90°.

配合比参数对C30高性能混凝土抗碳化性能影响算法分析

基于配合比参数,对C30高性能混凝土抗碳化性能的影响进行了探讨,得出了随着矿粉用量的增加,21 d抗压强度随之提高;随着粉煤灰掺量的降低,21 d抗压强度随之提高;C30混凝土126 d的碳化深度明显小于21 d的碳化深度,C30各组试件的21 d的平均碳化深度为7.57 mm;126 d平均碳化深度为6.51 mm。随着矿物粉用量的增大,粉煤灰用量的减小,混凝土的抗碳化能力增强。以C30-07矿粉与水泥混合料的比例为38%时,C30水泥混合料的最佳混合比例为C30-07矿粉与水泥混合料的最佳混合比例。在龄期从21 d提高到126 d时,随粉煤灰掺量比例的下降,C30混凝土试件碳化深度下降值随之减小,从1.31 mm降低为0.91 mm。利用试验数据,对混凝土的碳化过程进行了预测,结果发现,影响粉煤灰混凝土的碳化的因素比较复杂,将各模型使用应和工程相结合,对混凝土的碳化深度更好预测。利用Matlab对水泥砂浆的碳化厚度进行了线性回归分析,得到了水泥砂浆21 d后碳化厚度的计算方法。

高强页岩轻骨料混凝土制备及微观结构研究

基于最紧密堆积理论和最小需水量法进行高强页岩轻骨料混凝土配合比设计与制备,研究了水胶比对抗压及劈裂抗拉强度影响,并借助SEM/EDS进行微观测试分析。结果表明:当粗细骨料体积分数比为5.5:4.5时,粗细骨料达到最紧密堆积状态;当硅灰、粉煤灰和水泥质量比为0.8:3.2:6时,需水量最少,粉体材料密实度最佳;依据优化配比所配混凝土的抗压强度和劈裂抗拉强度均随龄期增加而增加;随着水胶比增加,抗压强度和劈裂抗拉强度呈先增后减的趋势,且当水胶比为0.24时达到最大,分别为70.9、5.83MPa;硅灰和粉煤灰特有的形态效应和火山灰效应有效改善了浆体与骨料间界面的密实程度,微观结果显示浆体与骨料界面区域结构致密,陶粒区域为富Si、Al相,浆体一侧为富Ca相。

管式蒸发冷却下LiCl-CaCl_(2)混合溶液降膜除湿特性分析

针对绝热型溶液除湿器性能低下的问题,设计了一种管式蒸发冷却型溶液除湿器,并采用具有较高经济性的LiCl-CaCl_(2)混合溶液作为除湿剂.基于理论模型,数值模拟了混合溶液中LiCl、CaCl_(2)两组分混合质量比、溶液参数和空气参数对蒸发冷却及绝热工况下除湿器热湿传递特性的影响.结果表明,除湿器在蒸发冷却工况下的单位面积除湿率高于绝热工况,最高可提升41.5%,且溶液中LiCl质量分数越小,其性能优势越显著.蒸发冷却除湿优势受溶液温度影响显著,单位面积除湿率与除湿空气流量呈正相关,与溶液流量呈负相关.不同的LiCl-CaCl_(2)混合质量比下蒸发冷却除湿特性主要受溶液温度影响,且在溶液温度较低时降低LiCl质量分数对除湿性能影响较小.2种运行工况下空气流量对除湿器单位面积除湿率的正向提升率可达136.9%~168.1%,而溶液流量对其影响较弱.