纤维素酶协同高压热水提取香菇多糖的研究

为提高香菇多糖提取率及质量,本研究通过单因素及正交试验研究了高压热水浸提协同纤维素酶对香菇多糖提取的影响。结果表明:纤维素酶协同高压热水提取香菇多糖的最佳工艺条件为:纤维素酶酶浓度为2%,提取液p H为5.5,温度40℃,时间0.5h,该条件下香菇多糖的提取率为4.16%,提取率分别比高压热水和纤维素酶单一条件下提高了21.64%和17.85%。

高压热水-复合酶提取香菇多糖工艺研究

为提高香菇多糖提取率及质量,采用高压热水协同纤维素酶、果胶酶、菠萝蛋白酶的方法对香菇多糖进行提取。通过单因素及正交试验,研究了复合酶浓度、酶解温度、酶解时间、酶解pH四个因素对香菇多糖提取率的影响。研究显示:复合酶(1∶1∶1)浓度为3.25%,酶解温度40℃,酶解时间2.0h,酶解pH 4.5,在此条件下,香菇多糖的提取达到3.78%。

高压热水浸提法提取香菇多糖工艺优化

采用单因素试验及正交试验探讨了提取香菇多糖的最适工艺条件,结果表明,高压热水浸提香菇多糖的最佳工艺条件为:料液比为1 g∶60 mL,高压浸提温度为108℃,高压浸提时间为100 min。在此条件下,香菇多糖的提取率为7.83%。

微波协同高压热水浸提法提取金针菇多糖的研究

为了研究微波协同高压热水浸提法提取金针菇多糖的最佳工艺条件,试验通过单因素试验和正交试验,探讨了料液比、微波功率、微波处理时间、高压热水浸提温度、高压热水浸提时间对金针菇多糖提取率的影响。结果表明:此法提取金针菇多糖的最佳条件是料液比为1∶50,微波功率为640 W,微波处理时间为6 min,高压热水浸提温度为108℃,高压热水浸提时间为80 min。在此条件下,金针菇多糖提取率为12.43%。

利用高压热水法提取厚朴的有效精油成分

为了提高厚朴中厚朴酚与和厚朴酚的提取率及残渣的有效利用率,对厚朴进行了高压热水提取。高压热水提取法有提取时间短、效率高,能提取材料中的难挥发性成分,并且能把残渣挤压成型为高密度板材等优点。在常压(101.325 Pa)、1.0 MPa、1.5 MPa等不同压力条件下对厚朴进行了热水提取。在1.0 MPa的高压热水提取中得到了常压热水提取8倍的得率,并且厚朴酚与和厚朴酚的转移率分别提高了2倍和34%。试验结果表明,在高温高压条件下短时间内得到了高提取率的厚朴酚与和厚朴酚,同时提取到了难挥发的成分。高压热水法提取只使用水蒸气,确保把提取残渣压缩成型为不含任何化学药品的高密度压缩板。

高压热水循环泵密封设计计算及改造

针对高温热水循环泵出现的密封泄漏问题,分析了高温高压下机械密封泄漏的原因,提出了双级串联机械密封的改造方案,调整孔板,加大回流量,同时增加换热器面积,使通入密封腔的介质温度下降,避免密封腔内介质汽化,从而改善了机械密封的运行环境。应用API610密封流程系统方案,对高压热水机械密封进行了设计计算,选择合理的波纹管回弹率(刚度)、弹簧比压、载荷系数及密封端面比压。对设计的机械密封进行实际工业运转验证,经过4000 h的运转,提高了机械密封的使用寿命,消除了高温热水循环泵的密封事故,取得了良好的经济效益。

高压热水浸提法提取金针菇中游离氨基酸的优化研究

研究了采用高压热水浸提法从金针菇中提取游离氨基酸的最适条件。通过单因素试验和正交试验,探讨了料液比、高压热水浸提时间及高压热水浸提温度对金针菇中游离氨基酸提取率的影响。试验结果表明,此法提取金针菇中游离氨基酸的最适条件为:料液比为1∶35(g/m L)、高压热水浸提温度为108℃、高压热水浸提时间为50min。在此条件下,金针菇中游离氨基酸的提取率为3.37%。

高压热水浸提牛至香芹酚及其抗氧化性研究

为了提高牛至高压热水浸提液中香芹酚含量及其抗氧化活性,通过单因素试验和正交试验,以香芹酚含量和ABTS自由基半数抑制率为评价指标,优化提取工艺,探讨环糊精含量、高压热水浸提时间及高压热水浸提温度对牛至浸提液的影响。试验结果显示:高压热水浸提牛至的最适条件为环糊精浓度1%、高压热水浸提温度为112℃、高压热水浸提时间为20 min,在此条件下,浸提液香芹酚含量为13.545 mg/m L,ABTS自由基IC;为80.45μL。

高压热水提取灵芝多糖及对其抗氧化活性的影响

以灵芝子实体超微粉为原料,研究了提取温度、提取时间和料液比在高压热水条件下对灵芝多糖提取以及多糖提取液对DPPH自由基清除率的影响,并采用正交试验优化了灵芝多糖高压热水提取工艺。确定较优工艺条件为料液比1∶50 g/m L、提取温度125℃下提取30 min,一次高压热水提取灵芝多糖提取率达到4.54%。抗氧化实验结果表明,灵芝多糖对DPPH自由基有一定的清除能力,且与多糖质量浓度存在一定的量效关系。

高温高压热水条件下的引水隧洞施工

黑白水三级电站是丽江地区第一座地下厂房水电站。引水隧洞总长2311.70m,其中800m穿越高温高压热水塘区。文章介绍了隧洞施工实践,总结和探讨了在高温高压热水条件下隧道综合降温措施,为类似地质条件的隧洞施工提供可借鉴的经验。

高压电极热水锅炉发生高压速断的原因分析

新疆大学博达校区位于乌鲁木齐市水磨沟区东部河马泉新区,一期占地164.33 hm^(2),总建筑面积约71×10^(4)m^(2),建有两座蓄热式电锅炉房,装机72 MW,2021年10月(投入使用时间)至2022年10月期间高压电极热水锅炉先后发生高压速断 17 次,均致突发停炉,严重影响供暖质量。通过分析、查找原因,将空气压缩机充压缩空气改为制氮机充氮气后,电极热水常压锅炉未发生过高压速断问题。

高压热水-酶法分段提取香菇多糖的研究

首先采用高压热水对香菇样品进行浸提,然后再分别采用纤维素酶、果胶酶、菠萝蛋白酶对香菇样本进行酶解,提取香菇多糖,经单因素试验及正交试验获得各种酶的最佳工艺;然后在获得的各种酶的最佳工艺条件下依次分段用高压热水、纤维素酶、果胶酶及菠萝蛋白酶提取香菇多糖.结果表明:高压热水→纤维素酶→果胶酶→菠萝蛋白酶分段提取香菇多糖的提取率高达5.27%,比单独采用高压热水法提高了101.15%.

高压热水浸提法提取金针菇黄酮的纯化及活性测定

为了获知高压热水浸提法所提取金针菇黄酮的抑菌和抗氧化活性以及聚酰胺树脂纯化金针菇黄酮的最优条件,利用聚酰胺树脂对高压热水浸提法所提取的金针菇黄酮进行纯化,并对纯化条件进行了优化研究,而后对纯化后黄酮抑制大肠杆菌、枯草芽孢杆菌、沙门氏菌和金黄色葡萄球菌的能力进行了检测;又以抗坏血酸(Vc)为对照,对黄酮清除1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、超氧阴离子自由基(O2—·)、羟基自由基(OH·)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS·)的能力进行了测定。结果表明,聚酰胺树脂纯化金针菇黄酮的最适条件为:采用浓度为1.0 mg/mL、pH值为4的上样液,在上样流速为0.5 mL/min的条件下进行吸附;吸附饱和后用80%的乙醇70 mL以1 mL/min洗脱。在此条件下得到的黄酮纯度是纯化前的5.95倍。高压热水浸提法所提取金针菇黄酮对4种菌均有不同程度的抑制作用,其抑菌程度大小顺序为:金黄色葡萄球菌>大肠杆菌>沙门氏菌>枯草芽孢杆菌。金针菇黄酮对DPPH·、O2—·、OH·和ABTS·均具有一定的清除能力,但弱于Vc。研究表明,高压热水浸提法所提取的金针菇黄酮具有抑菌及抗氧化活性,聚酰胺树脂纯化金针菇黄酮效果较好。

模糊神经网络滑模控制在高压电极热水锅炉液位控制系统中的应用

针对某公司生产的高压电极热水锅炉在工作过程中的高阶性、非线性及强耦合等特性以及用户对高压电极热水锅炉在电网侧调频调峰应用中的功率稳定性、响应快速性的严苛要求,而现有的控制策略难以满足精确控制(主要指功率)要求的实际情况,提出了一种将模糊神经网络控制与滑模变结构控制相结合的先进PID控制器,使其应用在高压电极热水锅炉的液位控制系统中。实验结果显示,将该控制器应用到高压电极热水锅炉的液位控制系统中,可有效克服上述系统的不良特性且有较好的稳定性和响应快速性,能够满足电网侧对电极锅炉在调频调峰中功率稳定性、响应快速性的要求。

香菇多糖提取工艺的优化

试验研究了超声波协同高压热水浸提法从香菇(Lentinus edodes)中提取活性多糖的最适条件。通过正交试验,探讨了料液比(g/mL,下同)、超声波功率、超声波处理时间、高压热水浸提时间及高压热水浸提温度对香菇多糖提取率的影响,并以香菇多糖提取率为评价指标,优化其提取工艺。结果表明,超声波协同高压热水浸提法提取香菇多糖的最适条件为:料液比1∶50,超声波功率250 W,超声波处理时间8 min,高压热水浸提温度108℃,高压热水浸提时间100 min。在此条件下,香菇多糖的提取率为27.2%。

Precipitation under Subtropical High Conditions:Evidence and Implications

The impact of the subtropical high (STH) on precipitation was investigated on a daily timescale using matched NCEP and the Global Precipitation Climatology Project (GPCP) datasets.Comparison of the conditional probability (intensity) of precipitation under STH condi-tions with that under non-STH conditions suggests that the presence of the STH conditions has a limited impact on local precipitation.In the West Pacific Subtropical High (WPSH) and the North Atlantic Subtropical High (NASH),precipitation was only 30% lower under STH conditions than under non-STH conditions.The STH conditions had somewhat more impact on precipitation intensity,but it was still 50% less than the intensity under non-STH conditions (mean of roughly 5 mm d 1).Pre-cipitation under STH conditions was found to be highly correlated with vertical motion.Active updrafts occurring even under STH conditions are essential for frequent oc-currences and moderate intensities of precipitation.

THE VARIATION OF THE SPRING PRECIPITATION IN GUANGZHOU AND ITS PRECURSORY SIGNALS

Guangzhou spring rainfall mainly exhibits interannual variation of Quasi-biannual and interdecadal variation of 30 yrs, and is in the period of weak rainfall at interdecadal time scale. SST anomalies （SSTA） of Nino3 are the strongest precursor of Guangzhou spring rainfall. They have significant positive correlation from previous November and persist stably to April. Nino3 SSTA in the previous winter affects Guangzhou spring rainfall through North Pacific subtropical high and low wind in spring. When Nino3 SSTA is positive in the previous winter, sprirg subtropical high is intense and westward, South China is located in the area of ascending airflow at the edge of the subtropical high, and water vapor transporting to South China is intensified by anticyclone circulation to the east of the Philippines. So Guangzhou spring rainfall is heavy. When Nino3 SSTA is negative, the subtropical high is weak and eastward, South China is far away from the subtropical high and is located in the area of descending airflow, and water vapor transportirg to South China is weak because low-level cyclonic circulation controls areas to the east of the Philippines and north wind prevails in South China. So Guangzhou spring rainfall is weak ard spring drought is resulted.

Combined impact of in-phase and out-of-phase variation between the northern East Asian low and western North Pacific subtropical high on East Asian summer rainfall

East Asian summer rainfall is affected by both the continental northern East Asian low （NEAL） and the western North Pacific subtropical high （WNPSH） in the lower troposphere. This study investigates the joint effect of the two circulation factors on East Asian summer rainfall. It is found that the rainfall in East Asia behaves differently in the years with in-phase and out-of-phase variation between the NEAL and WNPSH. When the NEAL and WNPSH vary in phase, i.e. when they are both stronger, the rainfall anomaly shows a dipole pattern in East Asia and displays opposite changes between north and south of 30°N. When the two circulation factors vary out of phase, the rainfall anomaly is concentrated in the Yangtze River valley.

Water vapor transport over China and its relationship with drought and flood in Yangtze River Basin

The characteristics of water vapor transport(WVT) over China and its relationship with precipitation anomalies in the Yangtze River Basin(YRB) are analyzed by using the upper-air station data in China and ECMWF reanalysis data in summer from 1981 to 2002.The results indicate that the first mode of the vertically integrated WVT is significant whose spatial distribution presents water vapor convergence or divergence in the YRB.When the Western Pacific Subtropical High(WPSH) is strong and shifts southward and westward, the Indian Monsoon Low Pressure(IMLP) is weak, and the northern part of China stands behind the middle and high latitude trough, a large amount of water vapor from the Bay of Bengal(BOB), the South China Sea(SCS) and the western Pacific forms a strong and steady southwest WVT band and meets the strong cold water vapor from northern China in the YRB, thus it is likely to cause flood in the YRB.When WPSH is weak and shifts northward and eastward, IMLP is strong, and there is nearly straight west wind over the middle and high latitude, it is unfavorable for oceanic vapor extending to China and no steady and strong southwest WVT exists in the region south of the YRB.Meanwhile, the cold air from northern China is weak and can hardly be transported to the YRB.This brings on no obvious water vapor convergence, and then less precipitation in the YRB.