超临界水流动传热特性影响因素数值模拟研究

以计算流体力学(CFD)商业软件FLUENT为计算平台,通过进行网格敏感性分析和湍流模型比较,选取最优化的网格和最佳湍流模型,对圆管和圆环通道内超临界水流动传热特性进行数值模拟,研究通道的几何结构、特征距离lT以及水物性对超临界水流动传热特性的影响。结果表明,热力学当量直径对流动传热特性影响不大,可以忽略;水力学当量直径、特征距离lT以及水的物性都对超临界水流动传热特性有很大的影响。

跨临界瞬态数值模拟中的高精度拟临界温度计算

根据拟临界温度的定义,结合IAPWS-IF97水物性公式,迭代计算获得了不同压力下的拟临界温度数据,在此基础上拟合出拟临界温度与压力的关系式.基于该关系式计算构建了拟临界温度计算模块,用于热工水力系统程序的跨临界计算改造.应用修改后的热工水力系统程序,针对简单的模型进行了跨临界瞬态计算.结果表明,拟临界温度与压力拟合关系式能够用于超临界压力系统的跨临界瞬态计算.

基于朗肯循环和卡琳娜循环的中低温余热动力循环分析

中低温朗肯循环、Kalina循环、氨吸收式动力循环和槽式太阳能Kalina发电循环系统都是低温余热动力循环的主要方式,对其热力学原理以及Kalina循环的影响因素进行分析,认为研究推广中低温朗肯循环及Kalina循环和多种应用形式的Kalina循环对提高中低温余热循环效率更加有效,而且Kalina循环技术相比其它热力循环具有更加光明的发展前景和更加广泛的工业应用范围。

Anti-tumor Effect and Protective Effect on Chemotherapeutic Damage of Water Soluble Extracts from Hedyotis diffusa

Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic material, promoting blood circulation and removing blood stasis'.It is a well known Chinese folk-medicine used for the treatment of appendicitis, sore throat, mumps,acne, sebo-rheic dermatitis and various kinds of tumors, such as tumors of digestive tract,carcinoma of liver. It was reported that the MeOH extract of H. diffusa demonstrated a significantantitumor activity and ursolic acid succeeded in being isolated from the MeOH extract as an activecomponent . Shan BN, et al suggested that the direct aqueous extract of H. diffusa hadimmuno-modulating activity and antitumor activity in vitro through stimulating the immune system tokill or engulf tumor cells. But regarding anti-tumor activity in vivo of water soluble extracts fromH. diffusa, no detail was reported. Therefore, we prepared water soluble extracts (H_1 and H_2)from H. diffusa and evaluated their anti-tumor property in vivo experiments as well as protectiveeffect on chemo-therapeutic damage.

Optimization of Hydrolysis Conditions for Corn Gluten Meal

[Objective] To investigate the optimal enzyme for the hydrolysis of corn gluten meal and the optimal hydrolysis conditions for the enzyme. [Method] Nine kinds of enzymes were used to hydrolyze the corn gluten meal, using the formaldehyde titration method for the determination of hydrolysis degree, and orthogonal test was used to determine the optimal hydrolysis conditions for double enzymes hydrol- ysis of corn gluten meal. [Result] The optimal pretreatment condition for corn gluten meal is heating at 121 ~C for 30 min. The double enzyme hydrolysis for the pro- treated corn gluten meal using 2709 alkaline protease and flavourzyme showed that the degree of hydrolysis could reach 32.4% with enzyme addition amount of 4%, hy- drolysis time of 4 h at 45℃ and pH=7.0. [Conclusion] This study laid the foundation for the study on the preparation of bioactive peptides such as oligopeptide with high F value and antihypertensive peptides, further improving the corn intensive process- ing industrial chain.

Study on the Floating Plant Climatic Adaptation of Undercurrent Constructed Wetland in North China

[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.

Genetic Relationships Among Soluble Carbohydrates, Anthocyanins and Growth Characteristics in Leymus (Gramineae) Detected with Molecular Markers

Low-temperature soluble carbohydrate accumulations are commonly associated with anthocyanin coloration, attenuated growth and cold adaptation of cool-season grasses. The vrn-1 gene has potent effects on vernalization requirement, growth, and soluble carbohydrate accumulations of the winter-annual Triticeae species. Two hundred and four unmapped AFLP markers and genome-specific DNA markers genetically linked to the vrn-1 gene were used to detect QTL controlling soluble carbohydrate accumulations, anthocyanin coloration and growth characteristics in a segregating population derived from open pollinated Leymus cinereus x L. triticoides hybrids. These perennial Triticeae grasses are distinguished by adaptation and growth habit. As expected, positive trait correlations and pleiotropic gene effects were detected for soluble carbohydrate accumulations and anthocyanin coloration. Likewise, positive trait correlations and pleiotropic gene effects were detected for tillering, leaf development, leaf growth, regrowth and rhizome spread. However, soluble carbohydrate accumulations were not associated with attenuated growth. In fact, several DNA marker alleles, including one near vrn-Ns1, had positive effects on soluble leaf carbohydrate concentrations and low temperature growth. The corresponding DNA marker near vrn-Ns1 had more specific effects on tillering. We speculate that vrn-1 exerts quantitative effects on low-temperature soluble leaf carbohydrate accumulations and growth habit of the perennial Leymus. However, a number of other DNA markers displayed highly significant effects on soluble carbohydrate accumulations and various growth characteristics. Findings indicate that anthocyanin coloration may be a useful phenotypic marker for soluble carbohydrate accumulation. Although variation for soluble carbohydrates was not associated with attenuated growth in this population, this trait was under genetic control.

Estimation of Digestible Energy Values of Plant Protein Supplement in Pig

[Objective] The aim of the study was to establish the effective and accurate formulas for estimating the digestible energy （DE） values of plant protein supplement in pig. [Method] By difference method with different amount of alternative feeds （20% -50%）, two4 x4 Latin- square-designed trials were taken on eight castrated male pigs [ Yorkshire x Landrace x Neijiang pig, initial body-weight： （46 ±2） kg ] to deter- mine the apparent digestible energy （ADE） of the eight kinds of plant protein supplement commonly used in China, that is, corn gluten meal （sol.）, soybean meal （ sol. ）, fababean, pea, rapeseed meal （ sol. ）, sesame meal （ sol. ）, rapeseed meal （ exp. ） and cotton seed meal （sol.）. [Resultl （1） Fiber was the most important factor to estimate the ADE of plant protein supplement in pigs, and ADF was the best one. （2） The most effective equations were as below： （ 1 ） OE （kJ/kg DM） = 14 741.86 - 185.01ADF＋54.01SCHO＋22.45CP （ R =0.988,RSD= 67.9,P〈0.01 ） ; （2） DE （kJ/kg DM） =22 223.26 -209.58ADF＋26.79SCHO-1.09GE （ Ff =0.989,RSD=66.9, P〈0.01 ） . [Conclusion] The accurate, practical and specific regression equations were established for DE prediction of plant protein supplement in pig.

Effects of Planting and Irrigation Patterns on Water Consumption Characteristics and Dry Matter Production in Winter Wheat

[Objective] This study aimed to investigate the effects of different planting and irrigation patterns on water consumption characteristics and dry matter produc- tion and allocation of winter wheat. [Method] With high-yield winter wheat cultivar Jimai 22 as the experimental material, field experiment was conducted during 2008- 2010. A total of 3 planting patterns were designed, uniform row, wide-narrow row and furrow. Under each planting pattern, total four irrigation patterns were designed, no irrigation （Wo）, irrigation at jointing state （Wl）, irrigation at jointing and anthesis stages （W2） and irrigation at jointing, anthesis and milking stages （W3）, and the irri- gation amount per treatment was all 60 mm. [Result] Under the three planting pat- terns, with the increased irrigation amount, the total water consumption of the exper- imental field increased; the proportion of irrigation in the total water consumption in- creased, and that of soil water consumption in the total water consumption de- creased significantly. Compared with W0 treatment, various irrigation treatments sig- nificantly increased the post-anthesis dry matter accumulation in wheat plants; with the increased irrigation amount, the grain yield under the three planting patterns all increased, while the water use efficiency （WUE） decreased. Under the same irriga- tion conditions, compared with other two planting patterns, furrow planting increased the total water consumption of the experimental field, increased the proportion of soil water consumption in the total water consumption, and improved the WUE and wheat grain yield. [Conclusion] Under the experimental conditions, considering both wheat grain yield and WUE, furrow planting with moderately deficit irrigation at joint- ing and anthesis stages is more suitable for the winter wheat production in North China Plain.

Photooxidation in Leaves of Facultative CAM Plant Sedum spectabile at C_3 and CAM Mode

The switch from C-3 to CAM pathway was induced by water stress in a C-3/CAM intermediate plant Sedum spectabile Boreau. Typical CAM criteria were observed upon 15 d of withholding water. Leaf delta(13)C value (-%) and water content showed a linear correlation fashion. Chlorophyll fluorescence parameters and antioxidative capacity were altered by water stress. Phi(PSII) and q(P) were reduced by 50% and 34% of the control, respectively, while NPQ rose ca. 180%. SOD activity and ability to scavenge DPPH. free radical went down but membrane permeability changed slightly. However, when an additional photooxidation by MV with high PPFD was carried out with leaf discs from watered (C-3 mode) and drought plants (CAM mode), q(P) and Phi(PSII) in leaves at induced CAM mode stage continuously decreased to a very low level. High 1 - q(P) value (0.86) and 1 - q(P)/NPQ ratio (>1) indicated the presence of high reduction state and unbalance of light energy budget. Together with the marked loss of membrane integral, it was evidenced that photooxidative damage was more serious in the induced CAM mode than in the C-3 mode. No advantage of photooxidation tolerance was found at the induced CAM expression stage of the facultative CAM plant, as compared with its C-3 mode stage, and also with the constitutive CAM plants reported previously. The differences in photooxidation sensitivity between the inducible CAM expressing plant and the constitutive CAM plant were discussed.

DNA Damage and Repair of Two Ecotypes of Phragmites communis Subjected to Water Stress

In order to thoroughly understand the mechanism Of drought resistance in plants at DNA level, the DNA damage of two ecotypes of reeds (Phragmites communis T.) stressed by PEG 6000 was analyzed by means of fluorescence analysis of DNA unwinding (FADU). The results showed that the residual double strand DNA percentages (dsDNA%) in dune reed (DR) were significantly higher than those in swamp reed (SR) treated with either 20% or 30% PEG 6000. This meant that the DNA of DR was less damaged in comparison with SR. Similarly, DR resisted DNA damage more strongly than SR as reactive oxygen species (ROS) increased by adding ROS producers diethyldithio carbamate (DDC), H2O2 and Fe2+ of different concentrations. Meanwhile, treating PEG stressed SR with ROS scavengers such as dimethyl sulphoxide (DMSO) and ascorbic acid (Vc) resulted in the reduction of DNA damage, suggesting that ROS could cause DNA damage. In addition, the DNA repair for water-stressed reeds indicated that DR repaired DNA damage much faster and more completely. This might be the first indication that drought stress led to DNA damage in plants and that drought resistance of plants was closely related to DNA damage and repair.

STUDY AND SIMULATION OF AN ACTIVATED SLUDGE TREATMENT FOR METHYL VIOLET WASTE WATER

This paper researched a promising biological treatment of methyl violet waste water by methods of activated sludge.Effects of temperature and pH were studied on this process.Kinetic equation of the substrate biodegradation was investigated in the experimental range.It was studied and simulated that flow within the bubble region of this bioreactor according to the κ ε two fluid equation.Simulation results agree well with experimental data.

Detection of gas hydrate sediments using prestack seismic AVA inversion

Bottom-simulating reflectors (BSRs) in seismic profile always indicate the bottom of gas hydrate stability zone, but is difficult to determine the distribution and features of gas hydrate sediments (GHS). In this study, based on AVA forward modeling and angle-domain common-image gathers we use prestack AVA parameters consistency inversion in predicting gas hydrate sediments in the Shenhu area at northern slope of South China Sea, and obtain the vertical and lateral features and saturation of GHS.

Photosynthesis of Resurrection Angiosperms

Resurrection plants which are able to quickly reactivate after falling into a period of anabiosis caused by dehydration have been very rare among angiosperms, especially among dicotyledons whose chlorophyll content and chloroplast structure little changed in the course of desiccation, therefore has been called homoiochlorophyllous desiccation-tolerant plants (HDTs). Another type of resurrection angiosperms that lost its chlorophyll dining desiccation is called poikilochlorophyllous desiccation-tolerant plants (PDTs). HDTs have been received more attention because of simplicity of protection mechanism which is much easy to the study and utilization of the desiccation tolerance of resurrection angiosperms. Recent advances in studies of photosynthesis of resurrection angiosperms indicate that photochemical activities are sensitive indicators for the study of physiological state of resurrection angiosperms during desiccation and rehydration. Photochemical activities of resurrection angiosperms are inhibited with loss of water similar to those of general plants, however, the magic thing is that they could reactivate rapidly during rehydration even losing more than 95% water. Up-regulations in xanthophyll cycle and antioxidative systems as well as preservation in integrity and stability of photosynthetic membranes during desiccation may be very important to desiccation tolerance of resurrection angiosperms. The fact that phosphate treatment in rehydration stage also strongly influences resurrection indicated importance of studies on rehydration stages of resurrection angiosperms.

Architectural Plasticity in Response to Soil Moisture in the Stoloniferous Herb, Duchesnea indica

Architectural plasticity of clonal plants may enhance exploitation of soil moisture heterogeneity by the plants. The plasticity of clonal architecture in response to soil moisture in the stoloniferous herb, Duchesnea indica Focke, was investigated in an experiment with different soil moisture contents as treatments, i.e. 40%, 60%, 80%, 100% of the maximum moisture content of soil (MMCS). As soil moisture content increased, the spacer length, ramet density, branching intensity and branching angle of D. indica plants changed by quadratic curve. And the optimum habitat for the plants was at 80% of the MMCS. This architectural plasticity in D. indica was simulated through the Dynamic Logistic Model. The imitative effect was statistically satisfactory. Its architectural plasticity observed here may allow the species to show foraging behavior in its habitat where soil moisture is patchily distributed.

Ozonation and Biodegradability of Lignin in Water

To convert the non biodegradable sodium lignin sulfonate into biodegradable substances, the sodium lignin sulfonate in the water was ozonized and the pH value, dissolved organic carbon(DOC), ultraviolet absorbency at λ =254 nm(UVA) and the biodegradability of the ozonation effluent were measured. The non biodegradable sodium lignin sulfonate can be partly converted into biodegradable substances by ozonation (about 38 76%). In the ozonation process, there is little DOC decrease, but much UVA decrease and obvious pH drop.

pH Stability of Defibrase_ in Aqueous Solution Determined by En-zyme-linked Immunosorbent Assay

Stability of Defibrase in various pH buffer solutions was investigated. Enzyme-linked immuno-sorbent assay (ELISA) and coagulating time method were used to assess antigenic stability and coagulating stability, respectively. The change of antigenic activities and coagulating activities of Defibrase in the same buffer solutions (pH 6, 7 and 8, with the exception of pH 3.6) showed similar tendency to decline with the time. Concentrated Defi-brase was relatively stable at neutral pH 6~7, more than 95% of its initial activities (100BUmL-1) was kept after a 10-day storage at 40 oC, whereas in pH 3.6 and pH 9 buffer solutions, diluted Defibrase was very labile. Addition of Triton X-100 or bovine serum albumin could effectively prevent loss of Defibrase by minimizing adsorption of De-fibrase to plastic surface (P<0.005). Concentration of Defibrase could also affect its stability in aqueous solutions.

Effect of thatch on water-soluble phosphorus of pasture soil fertilized with broiler litter

The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory study to evaluate the effect of a thatch layer on the dynamics of water-soluble P in undisturbed cores taken from a pasture. Cores with and without a thatch layer received a surface application of broiler litter (5 thm-2) and were incubated at 25 oC for 56 d. The result showed that on the soil surface the contents of water soluble-P (39 kghm-2) of the cores with the thatch layer was higher than that (20 kghm-2) of the cores without the thatch layer. Therefore on well-established pastures fertilized with broiler litter, the presence of a thatch layer might lead to high concentrations of water-soluble P on the soil surface.

Water holding effect of subalpine dark coniferous forest soil in Gongga Mountain, China

Because of the distinction of soil property and humus content, soil water content is not ideal to indicate whether it is suitable to the growth of plant. Mainly based on the PF-a numerical value denoting the water regime of soil and connected with the growth of plant, the study combined the moisture percentage of soil with PF to research in quantity the interrelation between the moisture percentage and PF in different succession phases of subalpine dark coniferous forest in Gongga Mountain. The results showed that: (1) In the same PF value, the moisture percentage in humus horizon increased gradually with the devel-opment of the succession of the dark coniferous forest; The moisture percentage of over-mature forest was the highest and>mature forest>half-mature forest>young growth forest; (2) With the increase of soil depth, the soil bulk density increased and the moisture percentage decreased, but the difference in the percentage of moisture was not notable in different succession phases. (3) In different succession series, the vegetation affected the soil water characteristics by increasing the soil organic matter, improving the soil construction, receding the soil bulk density and enhancing the soil porosity; (4) The humus horizon of the dark coniferous forest soil has the highest water holding capability in this region.

Preliminary Study on the Accumulation Characteristics of Mineral Elements in Potted Poa crymophila under Drought and Water Stress

[Objective] This study was conducted to explain the mechanism of the accumulation characteristics of mineral elements in alpine grassland plants. [Method] Cultivated alpine grassland plant, Poa crymophila, was treated with drought and wa- ter stress, and then the samples were collected and analyzed. [Result] Compared with the control group, under drought and water stress, multiple mineral elements tended to accumulate and increase, and there were significant differences in the contents of Cu, Mn, Ni and P （P〈0.05）. [Conclusion] Under drought and water stress, mineral elements in potted Poa crymophila tended to accumulate and in- crease, which is the adaption and response of Poa crymophila to drought and water stress, as well as the re-verification of the starvation effect hypothesis of mineral effects. The starvation effect of mineral elements is one of the endogenic forces for the accumulation and differentiation of mineral elements in grassland plants.