Extracting condition and the activity admeasurement for pectinesterase in achenes of Ficus awkeotsang Makino

研究了爱玉子果胶酯酶的优化提取方法,并测定了不同条件下爱玉子果胶酯酶的活性及热稳定性。结果表明:爱玉子果胶酯酶抽提液中NaCl的最佳浓度是5%,最佳抽提温度是30℃,最佳抽提时间是24 h,最佳保存时间24 h;酶活测定时作用液中NaCl最适浓度范围为0.6%~1.0%,作用液的最适pH为7.0,温度30~50℃,爱玉子果胶酯酶的热稳定性良好。A method of extraction and assay for the pectinesterase were investigated and proposed as follows: the best concentration of NaCl in extracting mixtrure is 5%,the best extracting temperature is 30℃,the best extracting time is 24 hours,the best conservating time is 24 hours,the best concentration of NaCl in mixture is 0.6% to 1.0%,and maintain the pH on 7.0.Between 30-50℃,the pectinesterase in achenes of Ficus awkeotsang has a good thermal stability.福建省教育厅基金资助项目(K04029);; 福建省科技厅重点资助项目(2007S0015

Do Fleeting Orders Improve Liquidity?

台湾股市为集合竞价、散户为主的市场,异于欧美股市为连续竞价、机构法人为主的市场。通过采用60秒内之删单和改单作为快速删单,实证结果发现:全市场、散户、外资和其他本土法人的快速删单比例增加时,价差缩小,市场流动性增加;自营商的快速删单对价差无显著的影响,这可能源于其快速删单的定价积极度;其中,小型股票的流动性对快速删单更加敏感。进一步的实证发现,价差缩小源于各类型投资者观察到买(卖)单快速删单后,虽然投资者提交的同向买(卖)单变得消极,但反向的卖(买)单积极度增加更多,使得价差缩小,市场流动性增加。Taiwan stock market is organized as a call auction system and the majority participants are retail investors, which is different from European and American stock markets characterized by continuous auction and institutional legal persons. Fleeting orders are defined as those cancelled or updated within 60 seconds. The empirical results show that an increase in fleeting order ratios of the overall market, retail investors, foreign institutions and other domestic institutions will contribute to narrowing the spread, thus increasing market liquidity. However, the proprietary traders' fleeting orders have no significant effect on the spread, and this may results from aggressive pricing of their fleeting orders. In addition, the liquidity of small cap stocks is more sensitive to fleeting orders. Further study finds that the narrowed spread is the net effect of more aggressive selling(purchasing) orders on the ask side and less aggressive purchasing(selling) orders when all types of investors observe a purchasing fleeting order, thus increasing market liquidity.国家自然科学基金青年项目“投资者风险偏好:度量与应用”(71101121);国家自然科学基金项目“波动率微笑:隐含信息与动态建模”(71471155);国家自然科学基金项目“资产价格中隐含通货膨胀信息的提取、分析与应用”(71371161);国家自然科学基金青年项目“限价指令簿的信息内涵研究:基于市场微观结构的视角”(71301137

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors