剪切速率对聚苯乙烯／超临界CO2发泡体系的影响

在挤出发泡过程中聚合物／超临界CO2发泡体系的形成是气体在剪切混合作用下，通过对流扩散，完全溶解进聚合物形成物理性质均一的均相体系的过程。剪切作用对均相体系的形成具有重要的影响，为了研究剪切对均相体系形成的影响，成功设计了微孔发泡模拟实验机，研究了不同剪切速率作用下均相体系的形成。研究结果表明，随着剪切速率的增加，聚合物和气体的混合程度明显增强，泡孔分布变得均匀，泡孔密度增大。     

纳米TiO2光催化的活性碳纤维滤网产品性能研究

以纤维状活性碳滤网为原料,测试了经过纳米TiO2整理的活性碳纤维滤网与未经纳米TiO2整理的活性碳纤维滤网吸附甲醛的情况,得出了经纳米TiO2整理的活性碳纤维滤网吸附甲醛的性能得到增强的结论,并且测试了纳米整理前后活性碳纤维滤网的各种性能,并对结果作了分析比较。     

大型煤制油项目排放的CO2对空分装置安全性影响分析

分析大型煤化工项目中各装置区排放的二氧化碳对空分装置进气环境的影响。     

超临界CO2和植物油脱臭馏出物相平衡研究

研究了植物油脱臭馏出物在超临界CO2中的相平衡问题。基于组分的相似性把含有复杂组分的植物油脱臭馏出物简化为两种虚拟组分,用改进的混合规则和超临界组分的能量参数计算式,结合PR状态方程进行计算：理论计算与实验数据相吻合,为间歇式或连续逆流式超临界CO2萃取分离的设计提供了依据。     

高密度Ralstonia eutropha细胞培养过程中二氧化碳的生成及其抑制作用

测定了高密度R．eutropha细胞培养过程中二氧化碳的生成量。当通气量维持在1．0vvm时,出口气体中二氧化碳的最大浓度高达15％。为了了解高密度细胞培养过程中二氧化碳对细胞生长代谢可能产生的抑制作用,通过施加不同浓度、不同持续时间的二氧化碳脉冲,模拟测试了5升发酵罐内二氧化碳对R.eutropha细胞生长代谢的抑制作用。实验发现,二氧化碳对细胞生长的抑制作用随着二氧化碳脉冲时间的增长和浓度的增高而增强。当在细胞指数生长初期施加6小时浓度为22％的二氧化碳脉冲,最终细胞浓度降低了31％。     

The Effects of High CO2 and Strigolactones on Shoot Branching and Aphid–Plant Compatibility Control in Pea

Elevated atmospheric CO₂ concentrations (eCO₂) regulate plant architecture and susceptibility to insects. We explored the mechanisms underpinning these responses in wild type (WT) peas and mutants defective in either strigolactone (SL) synthesis or signaling. All genotypes had increased shoot height and branching, dry weights and carbohydrate levels under eCO₂, demonstrating that SLs are not required for shoot acclimation to eCO₂. Since shoot levels of jasmonic acid (JA) and salicylic acid (SA) tended to be lower in SL signaling mutants than the WT under ambient conditions, we compared pea aphid performance on these lines under both CO₂ conditions. Aphid fecundity was increased in the SL mutants compared to the WT under both ambient and eCO₂ conditions. Aphid infestation significantly decreased levels of JA, isopentenyladenine, trans-zeatin and gibberellin A4 and increased ethylene precursor ACC, gibberellin A1, gibberellic acid (GA₃) and SA accumulation in all lines. However, GA₃ levels were increased less in the SL signaling mutants than the WT. These studies provide new insights into phytohormone responses in this specific aphid/host interaction and suggest that SLs and gibberellins are part of the network of phytohormones that participate in host susceptibility.     

超临界CO2萃取辣椒素最优工艺参数的研究及含量HPLC分析

采用超临界二氧化碳萃取技术从辣椒粉中提取辣椒素,通过正交试验,确定出最佳工艺条件为分离釜Ⅰ压力17 Mpa,温度35℃;分离釜Ⅱ压力15 Mpa, 温度36℃,夹带剂流速0.1 L·h-1.回收率为0.20%,纯度为12.0%,辣椒素含量的线性回归方程为y=2.280600×105x + 7.486209×106,线性相关系数为0.862143.     

二氧化碳对发电机内冷水pH与电导率的影响

应用热力学方法,导出了空气中的CO2对用氨水和NaOH做碱化剂时,在开放内冷水体系及封闭内冷水体系的pH和电导率的影响的多个关系式,并用计算机作图展示了这些关系;得出了空气中的CO2对除盐水的pH和电导率影响很大,开放内冷水体系不能满足电导率和pH值同时达标的要求,以及用碱化法抑制发电机铜导线腐蚀时用NaOH做碱化剂比用氨水更适宜等三点结论;提出了加强内冷水体系的密闭性,或在内冷水箱上加装防污呼吸器的建议。     

Effects of Elevated Carbon Dioxide and Ozone on Foliar Proanthocyanidins in Betula platyphylla, Betula ermanii, and Fagus crenata Seedlings

Proanthocyanidins (PAs) or condensed tannins are a major group of phenolic compounds in the leaves of birch trees and many other woody and herbaceous plants. These compounds constitute a significant allocation of carbon in leaves and are involved in plant responses to environmental stress factors, such as pathogens or herbivores. In some plants, PA concentrations are affected by atmospheric carbon dioxide (CO₂) and ozone (O₃) levels that may influence, for example, species fitness, community structure, or ecosystem nutrient cycling. Therefore, a study on the quantitative response of PAs to elevated concentrations of carbon dioxide (CO₂) and ozone (O₃) was undertaken in seedlings of Betula platyphylla, Betula ermanii, and Fagus crenata. Seedlings were exposed to ambient or elevated O₃ and CO₂ levels during two growing seasons in the Kanto district in Japan. Ten open-top chambers were used for five different treatments with two replicates: filtered air (FA), ambient air (ambient O₃, 43 ppb; ambient CO₂, 377 ppm), elevated O₃ (1.5 × ambient O₃, 66 ppb), elevated CO₂ (1.5 × ambient CO₂, 544 ppm), and elevated O₃ and CO₂ combined. In addition, seedlings growing in natural conditions outside of chambers were studied. Leaf samples were analyzed for total PA concentrations by butanol–HCl assay and for polymeric PA concentrations by normal-phase high-performance liquid chromatography. Total PA concentrations in leaves of all species were similarly affected by different treatments. They were significantly higher in seedlings treated with elevated CO₂ and O₃ combined, and in seedlings growing outside chambers compared with the FA controls. F. crenata contained only traces of polymeric PAs, but significant species × treatment interaction was observed in the polymeric PA concentrations in B. ermanii and B. platyphylla. In B. platyphylla, leaves treated with elevated CO₂ + O₃ differed significantly from all other treatments. It was suggested that the strongest effect of elevated CO₂ and O₃ combined on leaf PA contents resulted from the additive effect of these environmental factors on phenolic biosynthesis.     

Studies on the Effects of Certain Non‐dimensional Groups on Dynamic Simultaneous Adsorption Behaviour of Carbon Dioxide and Moisture in Molecular Sieve, 5A

A non‐isothermal model based on linear driving force approximation for a system like CO₂ – moisture – N₂ – molecular sieve, 5A predicted the experimental results satisfactorily for simultaneous adsorption of CO₂ and moisture in a fixed bed. Moisture being the strongly adsorbed component forces carbon dioxide (weakly adsorbed component) to be rolled up. The thermophysical and transport properties of moisture mainly governs the dynamics of the process, control or manipulation of which could give better separation by adsorption of one component from the other lying together in a stream. The major parameters are inlet adsorbate concentration, particle Reynolds number, bed diameter to bed length ratio, Schmidt number, Equilibrium Distribution coefficient, Sherwood number, and Kutateladze number.     

The Influence of the Ozonation Dosage on the Structure and Biodegradability of Pollutants in water,and its Effect on Activated Carbon Filtration

Laboratory tests underline the improvement which ozonation brings about in the removal of organic micropollutants in surface water with activated carbon filtration. Optimal ozone dosages correspond to the stabilization of the asymptotical diminution of UV absorption. HPLC analysis shows that, though ozone sometimes degrades organic compounds into more polar and less adsorbable products, improvement in GAC filtration is attained through increased bacterial activity, as revealed by measurements of ATP, of dehydrogenase and of oxygen consumed.     

超声波对新疆紫草悬浮培养细胞生长和紫草素合成的影响

探讨了超声波功率、超声波处理时间对新疆紫草细胞生长和紫草素合成的影响. 研究结果表明,超声波对悬浮培养的新疆紫草细胞生长有促进作用,低功率长时间或高功率短时间的超声处理对细胞生长比较有利. 在优化条件下(200 W超声处理1 min),培养结束时的生物量比对照提高61%. 超声波也可以提高新疆紫草悬浮培养细胞的紫草素含量和产量,接种后即进行超声波处理,超声波功率密度为39.9 mW/cm3、超声时间为3 min时,细胞紫草素含量和产量最高,达到2.72%和294 mg/L,分别比对照组提高了64%和135%. 超声波是通过提高细胞苯丙氨酸解氨酶的活力来强化紫草素的生物合成途径.     

Hydrogenation of Citral using Monometallic Pt and Bimetallic Pt‐Ru Catalysts on a Mesoporous Support in Supercritical Carbon Dioxide Medium

Supercritical carbon dioxide was shown to be a suitable reaction medium for the highly efficient hydrogenation of citral using monometallic Pt and bimetallic Pt‐Ru supported on a mesoporous material, MCM‐48, as catalyst. A remarkable change in the product distribution was observed after the addition of Ru to the monometallic Pt catalyst in supercritical carbon dioxide. The monometallic Pt catalyst was found to be highly selective to the unsaturated alcohol (geraniol+nerol) at a temperature of 323 K within 2 h whereas the bimetallic catalyst becomes selective to the partially saturated aldehyde (citronellal) under the same reaction conditions. Phase behavior plays an important role in the product distribution. Highest conversion and high selectivity to citronellal were achieved in the homogeneous phase for the Pt‐Ru catalyst while on the other hand the unsaturated alcohol (geraniol+nerol) was produced in the heterogeneous phase for the monometallic Pt catalyst. An XPS study offers strong evidence of the electronic modification of Pt after the addition of Ru in the bimetallic catalyst. The change in product distribution on the Pt‐Ru bimetallic catalyst may be explained by the appreciable interaction between the medium and the metal particles promoted by the presence of metallic Ru.     

Impact of Carbon Dioxide Pressurization on Liquid Phase Organic Reactions: A Case Study on Heck and Diels–Alder Reactions

Heck coupling reactions of methyl acrylate with various aryl bromides have been investigated using a Pd/TPP catalyst in toluene under pressurized CO₂ conditions up to 13 MPa. Although CO₂ is not a reactant, the pressurization of the reaction liquid phase with CO₂ has positive and negative impacts on the rate of Heck coupling depending on the structures of the substrates examined. In the case of either 2‐bromoacetophenone or 2‐bromocinnamate, the conversion has a maximum at a CO₂ pressure of about 3 MPa; for the former, it is much larger by a factor of 3 compared with that under ambient pressure. For 2‐bromobenzene, in contrast, the conversion is minimized at a similar CO₂ pressure, being half compared with that at ambient pressure. In the other substrates, including the other isomers of these three aryl bromides, the conversion simply decreases or does not change so much with the CO₂ pressure. To examine the factors responsible for the effects of CO₂ pressurization, the phase behavior and the molecular interactions with dense phase CO₂ have also been studied by visual observation and in situ high pressure FT‐IR spectroscopy. In addition, impact of CO₂ pressurization was also studied for the Diels–Alder reactions of isoprene with a few dienophiles like methyl acrylate, methyl vinyl ketone, and acrolein in the same solvent, toluene, but a heterogeneous silica‐alumina catalyst was used (the reaction system was liquid‐solid biphasic). When the CO₂ pressure is raised, the conversion monotonously decreases for the three dienophiles; however, the product selectivity changes with the pressure, in particular for acrolein. The FT‐IR spectroscopic measurements suggest that its reactivity is altered by interactions with CO₂ molecules under pressurized conditions.     

The Effects of Material Properties on the Activity of Sol‐Gel Entrapped Perruthenate under Supercritical Conditions

Silica gels organically modified and doped with the ruthenium species tetra‐n‐propylammonium perruthenate (TPAP) are leach‐proof, selective catalysts for the aerobic oxidation of alcohols to carbonyl compounds with dioxygen at low pressure in compressed carbon dioxide. The catalytic sol‐gels are recyclable and the correlation between the reactivity of the materials and their surface polarity and textural properties suggests valuable information on the chemical behaviour of sol‐gel entrapped silica catalysts in oxidation catalysis which is of relevant interest considering the importance of heterogeneous oxidative dehydrogenation of alcohols in fine chemistry. An explanation of the structure‐activity relationship is proposed to provide guidelines for the further development of efficient solid oxidation catalysts for conversions in supercritical carbon dioxide.     

Ciprofloxacin and Levofloxacin as Potential Drugs in Genitourinary Cancer Treatment—The Effect of Dose–Response on 2D and 3D Cell Cultures

Introduction: Introducing new drugs for clinical application is a very difficult, long, drawn-out, and costly process, which is why drug repositioning is increasingly gaining in importance. The aim of this study was to analyze the cytotoxic properties of ciprofloxacin and levofloxacin on bladder and prostate cell lines in vitro. Methods: Bladder and prostate cancer cell lines together with their non-malignant counterparts were used in this study. In order to evaluate the cytotoxic effect of both drugs on tested cell lines, MTT assay, real-time cell growth analysis, apoptosis detection, cell cycle changes, molecular analysis, and 3D cultures were examined. Results: Both fluoroquinolones exhibited a toxic effect on all of the tested cell lines. In the case of non-malignant cell lines, the cytotoxic effect was weaker, which was especially pronounced in the bladder cell line. A comparison of both fluoroquinolones showed the advantage of ciprofloxacin (lower doses of drug caused a stronger cytotoxic effect). Both fluoroquinolones led to an increase in late apoptotic cells and an inhibition of cell cycle mainly in the S phase. Molecular analysis showed changes in BAX, BCL2, TP53, and CDKN1 expression in tested cell lines following incubation with ciprofloxacin and levofloxacin. The downregulation of topoisomerase II genes (TOP2A and TOP2B) was noticed. Three-dimensional (3D) cell culture analysis confirmed the higher cytotoxic effect of tested fluoroquinolone against cancer cell lines. Conclusions: Our results suggest that both ciprofloxacin and levofloxacin may have great potential, especially in the supportive therapy of bladder cancer treatment. Taking into account the low costs of such therapy, fluoroquinolones seem to be ideal candidates for repositioning into bladder cancer therapeutics.     

灌溉周期对工业大麻秆部分理化性能的影响Ⅱ.灌溉周期对纤维素相对结晶度和晶胞尺寸的影响

为更好利用生物质材料,研究纤维素的相对结晶度和晶胞尺寸及其影响因素,用广角X射线衍射仪,研究了不同灌溉周期（3天浇一次水、14天浇一次水、不浇水）对工业大麻秆纤维素相对结晶度和晶胞尺寸的影响。结果表明在整个生长期中,随着生长期延长纤维素的相对结晶度呈增加趋势,晶胞尺寸呈减小趋势;不同灌溉周期对纤维素相对结晶度和晶胞尺寸影响显著（P≤0.05）;纤维素的物理结构在纤维细胞壁不同层次中是不同的。