超临界CO2对酵母菌生长状况影响的研究

为将超临界CO2作为生物转化的介质,考察了其对微生物生长特性的影响。以酵母菌为对象,研究了其种子液经不同压力的超临界CO2处理和处理不同时间后,接种培养的糖利用状况,以及在不同培养条件下的生长状况。结果表明,超临界CO2对酵母菌的生长有明显影响,主要表现为处理后的酵母总的糖利用与细胞生长速率减慢,代谢性能也有所变化,并随超临界CO2的压力及处理时间的不同而不同。     

几株酵母菌对纤维板废水生长适应性研究

本文研究了酵母菌和白地霉在纤维板废水中的生长情况，选出２株适于在该废水中生长的菌株及其最适生长条件。     

几株酵母菌对纤维板废水生长适应性研究

本文研究了酵母菌和白地霉在纤维板废水中的生长情况，选出２株适于在该废水中生长的菌株及其最适生长条件。     

常用微生物培养有机质对小球藻生长的影响

为探求小球藻快速生长所需营养条件,选用3种实验室常用的微生物培养有机质蛋白胨、酵母提取物、牛肉膏,在一定的光照强度和温度下,比较其对小球藻生长的影响。结果表明,蛋白胨对小球藻生长的促进作用最大,其次是牛肉膏,酵母提取物几乎不能促进小球藻生长;在蛋白胨质量浓度为1.00%时,小球藻的生物累积量达到最高;考虑到经济成本,蛋白胨的质量浓度以0.60%为宜。     

烯唑醇对植物生长调节活性的研究

本文以甜菜为试材，研究了烯唑醇对植物的生长调节活性。并以试验证明，该活性受供试药剂的施用浓度、剂量和处理时间等因素的影响。田间试验证明，烯唑醇对甜菜有明显的增产和增糖作用。     

不同硫源对小球诺卡氏菌R-9生长和脱硫活性的影响

用氯化钡沉淀结合傅里叶变换红外光谱法，证明小球诺卡氏菌（Nocardia globerula）R-9从二苯并噻吩中脱除的含硫产物以硫酸盐的形式存在于水相.比较了R-9分别以二苯并噻吩、硫酸钠和二甲基亚砜作为惟一硫源时的生长和脱硫活性.结果表明，二苯并噻吩、硫酸钠和二甲基亚砜均可以作为R-9的生长硫源，且高浓度（25 mmol•L^-1）硫酸钠和二甲基亚砜对细胞的生长不产生抑制作用.2 mmol•L^-1左右的硫酸钠或二甲基亚砜作为硫源时培养的细胞脱硫活性最高.提高硫源和碳源浓度可以提高R-9在发酵罐中的比生长速率和细胞浓度(OD600).     

Pyrabactin的合成及植物生长调节活性

以1-溴代萘为起始原料,经过多步反应制得目标产物pyrabactin.目标化合物的结构通过1H NMR和MS确证后进行了植物生长调节活性测试.结果表明:pyrabactin对小麦和绿豆种子萌发具有双重性效应,低剂量的pyrabactin可促进2种种子萌发,而高剂量的pyrabactin则抑制2种种子的萌发,小麦和绿豆对一定剂量pyrabactin处理的反应效果存在差异.     

合成氨催化剂活性与还原压力关系的研究

通过实验测定表明:合成氨催化剂在常压、低压下进行还原,可达到低温活性高、稳定性好的效果。     

不同生长年限铁皮石斛叶主要功效成分及抗氧化活性分析

铁皮石斛是一种以茎入药的药食两用中药,为了开发铁皮石斛叶资源,以不同生长年限铁皮石斛叶为试验材料,分析其主要功效成分及抗氧化活性.结果表明:不同年限的铁皮石斛叶中均含有较丰富多糖、总黄酮和总酚类以及生物碱类,其中三年生铁皮石斛叶中多糖的含量最高,为146.6 mg/g;一年生铁皮石斛叶中含量最少,仅为119.7mg/g...     

Characterization of new yeast lipases

Previously, we used a simple, sensitive agar plate method to screen lipase activity from 1229 selected cultures, including 508 bacteria, 479 yeasts, 230 actinomycetes and 12 fungi, that covered many genera and species. About 25% of the cultures tested were lipase-positive. We also expanded our screening method to focus specifically on the pH dependence and thermostability of these lipase activities. In this report, we have characterized 25 yeast lipases, obtained from our screening program, on the basis of their positional specificity against triglycerides. Lipase was produced by growing cultures on nutrient medium in the presence of vegetable oil at 25°C for 4 d. Of the 25 new yeast lipases analyzed, 19 showed 1,3-positional specificity and 6 showed random specificity. No 2-positional specific lipases were found. Among those cultures with highest lipase activity are: Candida silvicola NRRL YB-2846 (random); Candida sp. 55 (random); Candida sp. 125 (random); Pichia americana NRRL Y-2156 (1,3-specific); P. muscicola NRRL Y-7005 (random); P. petersanii NRRL YB-3808 (1,3-specific); and Yarrowia lipolytica NRRL YB-423 (random). Characterization of Candida sp. strain 55 lipase on its substrate preference showed that this enzyme hydrolyzed soybean oil triglyceride species LLLn, LLL, LLO, and LLP more readily than LOO, LOP, OOO, LOS, and POO, where L=linoleic, Ln=linolenic, O=oleic, P=palmitic, and S=stearin.     

实验室耐硫变换催化剂高压活性评价方法

为研究耐硫变换催化剂在高压和高汽气比工况条件下的活性、稳定性评价方法,模拟工况建立了实验室活性评价装置。通过正交试验,确定活性评价条件,并对评价装置的稳定性和评价方法的适用性进行考察。结果表明,在催化剂装填量30 mL（原粒度）、CO体积分数48%、硫化空速750 h^-1、硫化压力为常压、硫化时H₂S浓度17 g·m^-3、活性测定空速3 000 h^-1、汽气比1.5、活性测定温度350 ℃和活性测定压力8.0 MPa条件下,装置的平行性＜1.0%、复现性＜2.0%;在此条件下,测得的催化剂活性和稳定性与催化剂工业应用结果存在较好的一致性。     

Effect of pressure and temperature on viscosity of a borosilicate glass

During industrial glass production processes, the actual distribution of stress components in the glass during scribing remains, to date, poorly quantified, and thus continues to be challenging to model numerically. In this work, we experimentally quantified the effect of pressure and temperature on the viscosity of SCHOTT N‐BK7^® glass, by performing in situ deformation experiments at temperatures between 550 and 595°C and confining pressures between 100 and 300 MPa. Experiments were performed at constant displacement rates to produce almost constant strain rates between 9.70 × 10^?6 and 4.98 × 10^?5 s^?1. The resulting net axial stresses range from 81 to 802 MPa, and the finite strains range from 1.4% to 8.9%. The mechanical results show that the SCHOTT N‐BK7^® glass is viscoelastic near the glass transition temperature at 300 MPa of confining pressure. To elucidate the data, we incorporated both 1‐element and 2‐element generalized Maxwell viscoelastic models in an inversion approach, for which we provide MATLAB scrips. Results show that the 2‐element Maxwell model fits the experimental data well. The stress decreases with increasing temperature at 300 MPa and the temperature dependence yields a similar activation energy (601 ± 10 kJ mol^?1 or ?H/R = 7.2 × 10⁴ K) to a previously reported value at 1‐atm (615 kJ mol^?1 or ?H/R = 7.4 × 10⁴ K). The SCHOTT N‐BK7^® glass shows a limited linear increase in viscosity with increasing pressure of ~0.1 log₁₀ (Pa·s)/100 MPa, which is in agreement with the most recent 2‐internal‐parameter relaxation model (based on experiments).     

表面活性剂在红土镍矿高压酸浸中的抑垢作用

研究了红土镍矿浸出过程中高压釜结垢与抑垢问题。采用XRD和SEM分析研究了表面活性剂十二烷基苯磺酸钠对结垢物相和形貌的影响,并考察了表面活性剂对矿浆性质的影响。研究发现十二烷基苯磺酸钠可以减小矿浆表面张力和黏度,添加量为70 mg·L^-1时抑垢效果显著,对镍浸出率影响不明显,可以缓解红土镍矿高压酸浸过程中反应器结垢问题。     

Effect of high pressure on mass transfer kinetics of granny smith apple

The mass transfer kinetics during osmotic dehydration of granny smith apple slices in 60 Brix fructose and sucrose solution was studied at atmospheric pressure and at elevated pressure of 200–600?MPa at 40°C. The moisture and solute fractions in apple slices during osmotic dehydration under high pressure were predicted by Weibull frequency distribution model. The calculated effective moisture diffusivity values of apple slices suspended in fructose and sucrose solution during high-pressure treatment (0.1–600?MPa) were in the range of 6.35?×?10^?10 to 3.60?×?10^?9?m²/s and 7.96?×?10^?10 to 4.32?×?10^?9?m²/s, respectively.     

Effect of combined high pressure and thermal treatment on myofibrillar proteins solubilization of beef muscle

The effects of high pressure (to 600 MPa) at different temperatures (20 to 60 °C) for 20 min on protein solubilization and electrophoretic pattern in beef post-rigor longissimus dorsi muscle were studied. The results showed that protein solubilization increased with increasing temperature, especially from 40 °C to 60 °C. A regular trend of protein solubilization was found when isolated myofibrils were subjected to high pressure at different temperatures, an increase was observed with increasing pressure up to about 400 MPa, solubility then decreasing to 600 MPa. Electrophoretic profiles showed that myosin light chains and actin thin filaments were sensitive to pressure, and were released from myofibrils subjected to 100 MPa and higher pressures at the different temperatures.     

高压水射流喷射枪具

介绍高压水射流喷射枪具构造特点及其应用经验.     

Effect of high pressure pretreatment on drying kinetics and oleoresin extraction from ginger

The present study reports for the first time the effect of high pressure pretreatment (100–400?MPa, 10?min) on drying kinetics of ginger and its oleoresin extraction. High pressure pretreated samples were dried, powdered and solvent extracted. The increase in drying temperature (55–85°C) increased the moisture diffusivity (2.03–4.87?×?10^?9?m²/s) but resulted in decrease in 6-gingerol (53.98%) and oleoresin yield (57.31%). However, high pressure pretreatment followed by dehydration (55°C) resulted in higher moisture diffusivity (2.84–6.09?×?10^?9?m²/s) as well as enhanced extraction yield of 6-gingerol (34.05%) and oleoresin (28.29%).     

Highly sensitive pressure sensor based on structurally modified tissue paper for human physiological activity monitoring

Pressure sensor has become an important part of physiological condition monitoring system because it can respond to small pressure in human activities. Tissue paper has been studied as a carrier of sensitive unit layer for pressure sensors in recent years due to its internal pore structure and wrinkle morphology of surface. In this work, the pore structure of the tissue paper is improved by the principle of hydration and destruction of hydrogen bonds. Based on flexible substrate of NaOH modified tissue paper (NMTP) with enhanced pore structure, combined with dip-coating composite conductive filler, the pressure sensor is fabricated by sandwiching the sensitive unit between the interdigital electrode and the microdome elastomer through layer-by-layer assembly method. Thanks to the excellent interfacial resistance effect of porous NMTP under pressure, the sensitivity of NMTP-based pressure sensor is as high as 37.5 kPa⁻¹ in a pressure range of 0–2 kPa. Finally, the follow-up studies on pressure sensors have been proven to be applicable to a variety of physiological activity such as pulse detection, respiration detection and voice recognition. The NMTP-based sensitive unit provides alternative strategy to improve performance of pressure sensors and extends potential applications in monitoring human physiological activities. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48973.     

PTA装置高压催化燃烧反应单元压差变化影响分析及处理

PTA装置中PX氧化反应尾气利用高压催化燃烧反应单元(HPCCU)将尾气中的有机物和CO等转化为CO2,以达到环保排放标准。该单元系统压差高易造成催化燃烧反应器催化剂床层的损坏,也有对尾气透平运行的潜在隐患。根据装置运行特点,对该单元压差变化产生的原因加以排查和分析,通过合理调整参数,降低压差,避免危害,并在确定原因后对缺陷部位实施材质升级变更,彻底解决了该系统压差高的问题,消除了设备隐患。