液氮洗工艺模拟分析与改造研究

应用ASPENPLUS模拟软件，采用具有预测性的RK-ASPEN热力学模型，在成功完成某厂液氮洗装置设计工况模拟分析的基础上，针对原料气发生较大变化情况进行了原工艺流程可行性研究。提出2种改造方案，为工厂改造提供了必要的技术支持和理论指导，同时对各类装置改造也具有借鉴意义。     

Allelochemical effects of eudesmane and eremophilane sesquiterpenes on Tribolium castaneum larvae

Eight eudesmane and eremophilane sesquiterpenes administered to Tribolium castaneum larvae caused different allelochemical effects. Topical application of 3-oxo--costic acid produced the greatest lengthening in the duration of the pupal stage. Morphological deformities were found, specifically when ilicic, costic, and -costic acids and costic aldehyde were used. Ilicic acid exhibited the major toxicity 72 hr following topical application. All compounds were significantly toxic at the end point of the experiment (60 days). Treated surface toxicity was lower than when topical assays were carried out. Responses to tessaric acid in choice bioassays had the highest attractive effect. Maximum repellency was caused by the 3-oxo--costic acid. However, experimental series carried out using -costic acid, eremophilan-1(10),2,11(13)-trien-12-oic acid, costic aldehyde, and ilicic aldehyde showed no clear response.     

Plant Dependence on Rhizobia for Nitrogen Influences Induced Plant Defenses and Herbivore Performance

Symbiotic rhizobia induce many changes in legumes that could affect aboveground interactions with herbivores. We explored how changing the intensity of Bradyrhizobium japonicum, as modulated by soil nitrogen (N) levels, influenced the interaction between soybean (Glycine max) and herbivores of different feeding guilds. When we employed a range of fertilizer applications to manipulate soil N, plants primarily dependent on rhizobia for N exhibited increased root nodulation and higher levels of foliar ureides than plants given N fertilizer; yet all treatments maintained similar total N levels. Soybean podworm (Helicoverpa zea) larvae grew best on plants with the highest levels of rhizobia but, somewhat surprisingly, preferred to feed on high-N-fertilized plants when given a choice. Induction of the defense signaling compound jasmonic acid (JA) by H. zea feeding damage was highest in plants primarily dependent on rhizobia. Differences in rhizobial dependency on soybean did not appear to affect interactions with the phloem-feeding soybean aphid (Aphis glycines). Overall, our results suggest that rhizobia association can affect plant nutritional quality and the induction of defense signaling pathways and that these effects may influence herbivore feeding preferences and performance—though such effects may vary considerably for different classes of herbivores.     

Integrated Proteomics and Metabolomics Analysis of Nitrogen System Regulation on Soybean Plant Nodulation and Nitrogen Fixation

The specific mechanisms by which nitrogen affects nodulation and nitrogen fixation in leguminous crops are still unclear. To study the relationship between nitrogen, nodulation and nitrogen fixation in soybeans, dual-root soybean plants with unilateral nodulation were prepared by grafting. At the third trifoliate leaf (V3) to fourth trifoliate leaf (V4) growth stages (for 5 days), nitrogen nutrient solution was added to the non-nodulated side, while nitrogen-free nutrient solution was added to the nodulated side. The experiment was designed to study the effects of exogenous nitrogen on proteins and metabolites in root nodules and provide a theoretical reference for analyzing the physiological mechanisms of the interaction between nitrogen application and nitrogen fixation in soybean root nodules. Compared with no nitrogen treatment, exogenous nitrogen regulated the metabolic pathways of starch and sucrose metabolism, organic acid metabolism, nitrogen metabolism, and amino acid metabolism, among others. Additionally, exogenous nitrogen promoted the synthesis of signaling molecules, including putrescine, nitric oxide, and asparagine in root nodules, and inhibited the transformation of sucrose to malic acid; consequently, the rhizobia lacked energy for nitrogen fixation. In addition, exogenous nitrogen reduced cell wall synthesis in the root nodules, thus inhibiting root nodule growth and nitrogen fixation.     

Effects of Allelochemical Stress Produced by Sicyos deppei on Seedling Root Ultrastructure of Phaseolus vulgaris and Cucurbita ficifolia

The allelopathic potential of the cucurbit Sicyos deppei has been reported. Aqueous leachates (1% w/v) of S. deppei significantly inhibited the radicle growth of several test plants. Root tips of treated plants were thicker, with a brownish color as compared to control roots. Light microscope observations of treated root tips of Phaseolus vulgaris showed that cells around the quiescent center appeared compressed. Tissues were disorganized and lacked evident cell differentiation. Cucurbita ficifolia did not show these differences in root morphology. Scanning and electron microscope observations showed that treated roots of both P. vulgaris and C. ficifolia had ultrastructural alterations of certain organelles, the plasma membrane, and cell walls. Root cap cells of treated roots showed amorphous and inactivated (nondividing) nuclei, mitochondria, and endoplasmic reticulum. Vacuoles in treated cells showed invaginations that may correspond to engulfing of damaged cellular components.     

Pyrolytic Deposition of Carbon Films Containing Nitrogen and/or Boron

Carbon films containing nitrogen and/or boron were prepared in a closed system by the pyrolysis of appropriate precursor materials. The decomposition products of the pyrolysis were identified and the resulting films were characterized by chemical and physical means. The electrical conductivity of the heteroatom-containing films is similar to that of pure amorphous carbon films. Boron nitride was present in the C-N-B film as revealed by XPS and IR spectroscopy. Oxygen appeared to have a role in the adherence of the films to the silica substrate.     

Effects of Operational Variables on Nitrogen Removal Performances and Its Control in a Pre‐Denitrification Plant

The aim of this work is to study the effects of six operational variables, i.e., dissolved oxygen (DO), nitrate recirculation flow, sludge recycle flow, sludge wastage flow, external carbon dosage, and anoxic volume fraction, on the performance of nitrogen removal and its control in a pre‐denitrification plant. The results obtained show that the six operational variables have a significant influence on nitrogen removal in such a system, while the utilization of the control strategies can improve the situation to a significant extent. The control of DO concentration should be correlated with the influent ammonia load, the effluent requirement and nitrification type. The anoxic effluent nitrate concentration should be controlled at ca. 2 mg/L or the ORP value at the end of the anoxic zone should be controlled at ca. –90 mV. The control of the sludge recycling flow by online monitoring of the sludge blanket height (SBH), is an alternative to the conventional control of the constant sludge recycle flow. It may be possible to achieve the automatic control of sludge wastage flow by online measuring of the ammonia concentration and the nitrification capacity of the sludge. The recirculation of nitrate and external carbon dosage should be simultaneously controlled to optimize nitrogen removal. The anoxic volume fraction should also be optimized, to ensure a good balance between nitrification and denitrification.     

Characterization of CdTe Films Deposited at Various Bath Temperatures and Concentrations Using Electrophoretic Deposition

CdTe film was deposited using the electrophoretic deposition technique onto an ITO glass at various bath temperatures. Four batch film compositions were used by mixing 1 to 4 wt% concentration of CdTe powder with 10 mL of a solution of methanol and toluene. X-ray Diffraction analysis showed that the films exhibited polycrystalline nature of zinc-blende structure with the (111) orientation as the most prominent peak. From the Atomic Force Microscopy, the thickness and surface roughness of the CdTe film increased with the increase of CdTe concentration. The optical energy band gap of film decreased with the increase of CdTe concentration, and with the increase of isothermal bath temperature. The film thickness increased with respect to the increase of CdTe concentration and bath temperature, and following, the numerical expression for the film thickness with respect to these two variables has been established.     

基于沉积法的氮掺杂碳磷复合材料制备与性能研究

活性碳是重要的碳基体材料,利用沉积法制备氮掺杂碳磷复合材料,基于性能检测结果可以得知,碳纳米球型颗粒数量较多,均匀分散至活性碳上,改善了与电解液的接触效果,在创建的温室环境中,针对氮掺杂碳磷复合材料性能加以分析,得知其电化学性能更为良好。     

Synthesis of Highly Loaded Highly Dispersed Nickel on Carbon Nanofibers by Homogeneous Deposition–Precipitation

Highly loaded (45 wt%) Ni on graphitic carbon nanofiber (diameter 50nm) catalysts were prepared by means of homogeneous deposition–precipitation (HDP) from an aqueous solution. The obtained Ni metal particles were small (9nm). This shows clearly that HDP can be used for the preparation of catalysts based on inert supports, like carbon nanofibers, which cannot form surface co-precipitates between the catalyst support and the metal precursor. The latter is known to be a crucial step in the preparation of metal-on-oxidic support catalysts. The oxygen-containing groups on the surface of the carbon nanofiber act as nucleation and anchoring sites in the deposition of highly dispersed Ni.     

乙烯装置初分馏系统模拟计算和系统分析

对乙烯装置初分馏系统作了全面的模拟和分析，讨论了各参数对热量回收的影响。     

Simultaneous Phenomenon of Particle Deposition and Reentrainment: Effects of Surface Roughness on Deposition Layer of Striped Pattern

Formation of particle deposition layers on rough wall surfaces was studied as a simultaneous phenomenon of particle deposition and reentrainment. The test powders used were alumina of micron sizes and the experiments were conducted under turbulent aerosol flows. After particle deposition and reentrainment reached an equilibrium state, deposition layer of a striped pattern was formed. The striped pattern was characterized by the interval and the thickness, which decreased when the roughness of the wall surface increased. Further, the striped deposition layers moved slowly downstream, and the velocity of the moving deposition layers decreased with the increase of the surface roughness. A moment balance model was used to explain the effect of the surface roughness on the velocity of the moving deposition layers.     

Plant Antimicrobial Agents and Their Effects on Plant and Human Pathogens

To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the bioactivity of several phytoalexins and phytoanticipins defending plants against fungal and bacterial aggressors and those with antibacterial activities against pathogens affecting humans such as Pseudomonas aeruginosa and Staphylococcus aureus involved in respiratory infections of cystic fibrosis patients. The utility of plant products as “antibiotic potentiators” and “virulence attenuators” is also described as well as some biotechnological applications in phytoprotection.     

MAP沉淀法同步脱除水中氮磷的影响因素

采用磷酸铵镁沉淀法(MAP法),以MgCl2.6H2O为沉淀剂同步脱除水中氮磷。结果表明pH对氮磷的去除效果影响较大,当pH为10.5时,氮磷的去除效果达到最佳;致浊物质的存在对氨氮的去除有促进作用,低浊条件有利于磷的去除,而高浊条件对磷的去除无明显影响;较低浓度的HCO3-促进氮磷的去除,而浓度较高时抑制氮磷的去除;SO42-的存在不利于氨氮的去除,而对磷的去除略有促进作用;钙离子对氮磷的去除影响较大,当钙离子和镁离子的浓度相当时,会抑制MAP沉淀的生成。     

施镀工艺参数对化学镀沉积速率的影响

各种工艺参数对化学镀沉积速度影响的研究是化学镀中的关键问题之一,文献尚无系统的研究,本文全面总结研究了金属盐浓度,还原剂浓度,络合剂浓度,ＰＨ值,施镀温度与时间对化学镀沉积速度的影响和原因。     

磷酸铵镁沉淀法去除垃圾渗滤液氨氮的研究

为了有效地去除垃圾渗滤液中高浓度氨氮,本实验以磷酸氢二钠和氯化镁为沉淀剂,通过正交试验方法,确定了磷酸铵镁沉淀去除垃圾渗滤液中氨氮的最佳工艺条件。实验结果表明,在pH为10.0,反应时间为10 min,n（Mg）∶n（P）∶n（N）=1.2∶1.1∶1的条件下,采用磷酸铵镁沉淀法可实现垃圾渗滤液中氨氮的去除率达到92.25%,为后续生化处理创造良好的反应条件。本研究对于垃圾渗滤液氨氮的去除具有一定的参考价值。     

Study of the Effects of LAS and Zein Concentrations on Protein Solubilization

The effects of both linear alkylbenzene sulfonate (LAS) and zein protein concentrations on protein solubilization were investigated to better understand the influence of increasing concentration of the surfactant on protein denaturation and skin irritation. Different methods have been used for the determination of the amount of protein dissolved. A wide range of LAS concentrations and zein amounts were used. The results confirm that protein solubilization increases with LAS concentration increase and demonstrate that a minimum LAS/Zein ratio exists for all the zein to be dissolved.