半干法制备千克量级α-半水石膏粉及工艺能耗计算

以磷石膏、脱硫石膏为原料,采用半干法工艺实现α-半水石膏粉千克量级制备试验,采用SEM场发射扫描电镜和马尔文激光粒度仪分析α-半水石膏粉形貌和粒径分布,对两种α-半水石膏粉物相组成分析和力学性能强度进行对比。结果表明:两种α-半水石膏粉中半水石膏相转化率在90%左右,晶体长径比接近于1,磷石膏基α-半水石膏粉力学性能最佳,其2 h抗折强度2.6 MPa,绝干抗压强度13.6 MPa。计算半干法工艺能耗,与传统煅烧法对比能耗降低约29.5%,工艺简单、绿色化,证明半干法工艺量产制备α-半水石膏粉在工业上可行性,为大规模消耗利用化学石膏提供科学基础。

Optimization of Process Parameters of Continuous Microwave Drying Raspberry Puree Based on RSM and ANN-GA

To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexes(average temperature,average moisture content,average retention rate of the total anthocyanin content,temperature contrast value,and moisture dispersion value)were investigated via the response surface method(RSM)and the artificial neural network(ANN)with genetic algorithm(GA).The results showed that the microwave intensity and drying time dominated the changes of evaluation indexes.Overall,the ANN model was superior to the RSM model with better estimation ability,and higher drying uniformity and anthocyanin retention rate were achieved for the ANN-GA model compared with RSM.The optimal parameters were microwave intensity of 5.53 W•g^(-1),air velocity of 1.22 m·s^(-1),and drying time of 5.85 min.This study might provide guidance for process optimization of microwave drying berry fruits.

壳聚糖-刺玫果提取物复配涂膜对半干型风干牛肉贮藏品质的影响

在25℃贮藏条件下,以未涂膜的半干型风干牛肉为对照组,用1.5%壳聚糖、0.5%、1.0%、1.5%刺玫果提取物和1.0%2,6-二叔丁基对甲酚(butylated hydroxytoluene,BHT)复配涂膜的半干型风干牛肉为处理组,利用水分含量、色度、过氧化值、pH值、硫代巴比妥酸反应物(thiobarbituric reactive substances,TBARS)值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、菌落总数表征半干型风干牛肉在贮藏第0,3,6,9,12天时的品质变化。结果表明,与对照组相比,涂膜处理组均能较好地保持半干型风干牛肉的贮藏品质,其中1.5%刺玫果提取物复配壳聚糖涂膜显著优于其他涂膜(P<0.05),可减缓半干型风干牛肉色泽褐变和水分损失,有效抑制微生物生长以及过氧化值、TBARS值和TVB-N值的上升。

Effect of <i>Monascus</i>Fermentation on Aroma Patterns of Semi-Dried Grass Carp

The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor substances present in fresh fish, semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer (GC-MS). The results showed that alcohols, aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap. Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp. Moreover, the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish, but also make up for the defect of the pickled flavor of semi-dried fish. Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value (ROAV), as follows: 1-octene-3-ol, phenylethanol, hexanal, heptanal, nonanal, (E)-2-octenal, 3-Methyl-1-butanal, benzaldehyde, (E)-2-nonenal, (E,E)-2,4-heptadienal, (E)-2-Decenal, phenylacetaldehyde, (E,E)-2.4-decadienal, tetradecanal, 2,3-butanone, 2,3-octanedione, alpha-pinene, 2-pentane furan.

Effects of process parameters on pore structure of semi-coke prepared by solid heat carrier with dry distillation

The semi-coke was prepared by solid heat carrier with dry distillation in single factor method. The pore structures of raw coal and semi-coke were characterized by Brunauer-Emmett-Teller (BET) and scanning electron microscope (SEM). The results show that the adsorption and desorption isotherm of semi-coke are not coincident. There was a wide pore distribution on the semi-coke, in which mesopores and micropores account for a considerable proportion. Also there are many more secondary pores. With the increase of the final temperature of heat carrier and constant temperature, as well as the decrease of volume ratio of coal and hot carrier reactor, specific surface area and pore volume of semi-coke increased rapidly first and then decreased and finally increased, along with the rapidly reduction of average pore size. SEM photos show that the surface of semi-coke becomes increasingly rough and glossy.

水泥-石灰-干渣半刚性基层材料路用性能研究

结合某高速公路工程,对水泥-石灰-干渣半刚性基层材料路用性能进行研究。选择原材料,通过抗压强度、疲劳强度和抗弯拉强度确定水泥-石灰-干渣半刚性基层材料的掺量,最佳水泥、石灰、干渣掺量分别为4%、3%、70%,最后检测水泥-石灰-干渣半刚性基层路段平整度和压实度发现该路段具有较好的路用性能。

Semi-LC/MS技术快速定量分析黄芪样品中黄芪甲苷含量

为了测定黄芪中的黄芪甲苷含量,应用半高效液相色谱-质谱串联技术(Semi-LC/MS),以薯蓣皂苷为内标化合物,仅用一段色谱保护柱分离掉大部分干扰性成分,同时使目标化合物富集,采用Waters公司的多反应监测(MRM)扫描模式检测。结果表明:黄芪甲苷在2.85～57.0mg/L的范围内线性关系良好,稳定性和重复性实验RSD<3%,样品回收率达98.9%。Semi-LC/MS方法可以对黄芪样品中黄芪甲苷进行快速定量分析,是一种黄芪甲苷的简单、高效、灵敏的定量检测方法。

Progress in Semi-arid Climate Change Studies in China

This article reviews recent progress in semi-arid climate change research in China.Results indicate that the areas of semiarid regions have increased rapidly during recent years in China,with an increase of 33%during 1994-2008 compared to 1948-62.Studies have found that the expansion rate of semi-arid areas over China is nearly 10 times higher than that of arid and sub-humid areas,and is mainly transformed from sub-humid/humid regions.Meanwhile,the greatest warming during the past 100 years has been observed over semi-arid regions in China,and mainly induced by radiatively forced processes.The intensity of the regional temperature response over semi-arid regions has been amplified by land-atmosphere interactions and human activities.The decadal climate variation in semi-arid regions is modulated by oceanic oscillations,which induce land-sea and north-south thermal contrasts and affect the intensities of westerlies,planetary waves and blocking frequencies.In addition,the drier climates in semi-arid regions across China are also associated with the weakened East Asian summer monsoon in recent years.Moreover,dust aerosols in semi-arid regions may have altered precipitation by affecting the local energy and hydrological cycles.Finally,semi-arid regions in China are projected to continuously expand in the 21st century,which will increase the risk of desertification in the near future.

GC×GC-TOFMS结合化学计量学解析传统型半干黄酒的挥发性陈化标志物质

采用顶空固相微萃取结合全二维气相色谱-飞行时间质谱技术对不同年份传统型半干黄酒的挥发性组分进行解析,并结合化学计量学挖掘陈化标志物质。结果显示,6个年份黄酒中共鉴定出351个化合物,其中有40个首次在中国黄酒中被发现。挥发性物质总数随陈化时间延长呈增加趋势。单因素方差分析和相关性分析发现有107个化合物含量显著变化且与陈化时间相关性较强,其中2-乙酰基噻吩等55个化合物首次被发现与陈化时间显著相关。主成分分析和聚类分析发现传统型半干黄酒陈化进程可以分为短期陈化(1~3 a)、中期陈化(6~12 a)和长期陈化(15 a以上)3个阶段。偏最小二乘判别分析进一步筛选出37个陈化标志化合物,其中12个化合物陈化过程中含量显著减少,25个化合物含量显著增加。最终结合Pearson相关系数筛选出10个最具有代表性的陈化关键标志物质,其中丁酸异戊酯、丁酸、2-糠醇、2-乙酰基-5-甲基呋喃和邻甲酚5个物质首次被鉴定为黄酒的陈化关键标志物质。本研究为理解黄酒陈化过程、黄酒品质评估及酒龄鉴别提供了科学依据。

Green and efficient dry gel conversion synthesis of SAPO-34 catalyst with plate-like morphology

SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension containing nanosheet-like SAPO-34 seed. The latter played an important role in formation of SAPO-34 （CHA-type） with plate-like morphology. In addition, the yield of the product in the synthesis system containing seed suspension reached 97%, 15% higher than that obtained in the corre- sponding synthesis system without the seed suspension. Meanwhile, the plate-like SAPO-34 catalysts synthesized by this method exhibited higher selectivity to light olefins and longer lifetime in methanol-to-olefins （MTO） reaction than the traditional cubic SAPO-34 catalyst. This work provides a new technical route for green and efficient synthesis of SAPO-34 catalysts with improved MTO performance.

State of the art for dry tree semi technologies

Dry tree semi is a fast developing technology and becomes more and more appealing to the operators as a solution for producing deepwater reserves. Utilizing a dry tree semi means spending less cost on well mainte-nance and interventions,while the production platform can be integrated and commissioned at quayside. This paper presents a comprehensive overview of various technologies for dry tree semi,such as E-semi,T-semi,paired-column semi and long stroke tensioners. Each dry tree semi concept is briefed in terms of global performance,top tension riser (TTR) tensioner system,quayside integration and feasibility to environment.

Decomposition Theorems for Semi-order Fuzzy Supermartingales and Submartingales

Based on semi - order fuzzy supermaringales andsubmartingales, the semi- order fuzzy supermartingaleand submartingale theory is developed. The main resultis to generalize the Doob decomposition and the Riesz de-composition theorems of standard martingale theory tosemi - order fuzzy supermaringales and submartingales.The structure of semi - order fuzzy supermaringales andsubmartingales and the conditions of that they has Doobdecomposition (resp. Riesz decomposition) are discussedin detail.

Effect of Al Addition on Properties of Al_2O_3-SiC-C Dry Ramming Mixes for BF Trough

Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.

Screening of Semi-solid Culture Conditions of Armillaria mellea A9

[Objectives]This study was conducted to optimize the germplasm resources of Gastrodia elata and improve the condition of declining G.elata production.[Methods]A scientific and reasonable method was used to screen the optimum nutritional conditions(carbon sources,nitrogen sources,microelements,vitamins)and environmental conditions(pH,temperature,light)of Armillaria mellea A9 growth,so as to screen the medium suitable for the growth of A.mellea.[Results]Under the semi-solid culture condition,the suitable pH range of A.mellea mycelia was 4.0-9.0;the temperature was about 25℃;and the light condition was dark culture.Under the experimental conditions,the optimal carbon source was 25 g/L ethanol;the optimal nitrogen source was 2.5 g/L soy peptone;and the optimum microelement and vitamin were 0.5 g/L MnSO 4,0.5 g/L MgSO 4 and 20 mg/L vitamin B6,respectively.After screening,the growth rate of A.mellea rhizomorph was as high as 13.52 mm/d,and the dry weight of mycelium also reached 0.296 7 g.[Conclusions]This study not only omitted a lot of tedious experiments,but also obtained reliable and scientific experimental results,and achieved the purpose of rejuvenating A.mellea,which is conducive to the further development and utilization of G.elata and its symbiotic fungi.

基于压电纤维复合材料半主动干摩擦阻尼器的设计与实验研究

针对薄壁结构的振动问题,设计了一种铺设压电纤维复合材料(Macro-Fiber Composite,MFC)的波纹形柔性干摩擦阻尼器。介绍了波纹形半主动干摩擦阻尼器的结构形式和驱动原理。通过准静态试验探究了阻尼器在不同电压序列下输入电压与输出正压力的关系,揭示了MFC驱动变形的迟滞非线性,并据此提出了局部线性化的驱动方案,规避了迟滞非线性给正压力控制带来的挑战。在此基础上,对安装上述阻尼器的悬臂梁结构开展了振动试验。结果表明,在设计工况下该阻尼器的减振效果良好,质量占比仅为5%的阻尼器即可使振动峰值下降79%;该半主动干摩擦阻尼器显著拓宽了有效工作范围,当振动水平为设计工况的9倍时,通过MFC驱动调控正压力,减振比例仍可保持在约75%,避免了阻尼效果的大幅衰减。

米制粉方式及影响因素研究进展

我国是稻谷生产大国。近年来,随着饮食结构的不断升级,米制食品消费量剧增,拥有广阔的前景。这些米制食品大多由大米粉制成,而大米粉在制粉时不同的制粉方式对大米粉的品质影响很大,它能够决定制得米粉的品质及其加工适用性。目前,常用的制粉方式主要有干法制粉、湿法制粉和半干法制粉。文章对3种制粉方式的研究现状进行综述,并论述了影响制粉工艺的主要因素,以期为米制粉产业提供一定的参考。

喷雾-喷动床半干法烟气脱硫实验研究

实验采用 Ca( OH) 2 做脱硫剂 ,考察了 n( Ca)∶ n( S)、入口 SO2 质量浓度、进气温度、绝热饱和温差、表观气速、静床层高度、喷动粒子直径等对脱硫率的影响。结果表明 ,脱硫率随着 n( Ca)∶ n( S)、入口 SO2 质量浓度、静床层高度的增大而增大 ;随进气温度、绝热饱和温差、表观气速、喷动粒子直径的增大而减小。当 n( a)∶n( S) >1.0 0 ,绝热饱和温差为 7℃时 ,脱硫效率可高达 90 %以上。此脱硫技术具有流态化性能好 ,传热传质效率高 ,脱硫效果好等优点 。

多孔性水泥-聚苯颗粒材料的吸声性能研究

水泥-聚苯颗粒材料被广泛用作外墙外保温材料,通过特殊制备工艺可形成多孔性结构,从而同时具备吸声功能,改善建筑环境.以水泥为胶凝材料,以聚苯颗粒为骨料,以聚丙烯纤维和可再分散乳胶粉为增韧材料,采用半干料压缩工艺成型制备吸声材料,分析了水泥用量和蒸汽养护对材料吸声性能的影响.结果表明:水泥掺量越高,在高频段的吸声系数越低,但水泥掺量过低对低频声的吸收不利;蒸汽养护使材料表面形成了空腔共振吸声结构,对提高一定频率下的吸声性有利,根据理论计算了空腔共振吸声结构提高吸声性的频率范围,结果与实测结果一致,分析认为通过调整聚苯颗粒粒径可实现在相对较宽频率范围的高效吸声;纤维提高了抗折强度,可在保障强度的前提下降低水泥用量以提高吸声性.

添加剂对喷雾-喷动床半干法烟气脱硫性能的影响

研究了3种添加剂(NaOH、CaCl2、NaCl)对喷雾-喷动床半干法烟气脱硫性能的影响, 并分析了添加剂增进脱硫效果的机理。试验结果表明:3种添加剂都能显著提高脱硫率, NaOH的效果最佳,CaCl2次之,NaCl较差。

n(Na^＋)/n(Cl^-)对烟气脱氯及脱硫废水零排放的影响

半干法脱氯是通过碱基物质将燃煤烟气中的大部分HCl固定到飞灰中,同时将大幅度减少的脱硫(flue gas desulfurization,FGD)废水作为碱基溶剂回喷烟道,从而可实现脱硫废水零排放.通过搭建实验台对碱基物质与烟气中HCl和SO_2的反应效率随n(Na^+)/n(Cl^-)的变化进行了实验研究.结果表明:碱基物质与HCl的反应效率与n(Na^+)/n(Cl^-)呈正相关,且随n(Na^+)/n(Cl^-)的增大,其增长趋势逐渐变缓,在n(Na^+)/n(Cl^-)为4.8时,反应效率已经达到70%以上.针对一台660 MW燃煤机组进行计算,采用半干法烟气脱氯后,脱硫废水量显著下降,由8.01m^3/h降为2.31m^3/h;利用脱硫废水作为碱基溶剂回喷空气预热器后烟道,烟气温降较小,仅为2.49℃.半干法脱氯系统简单,运行成本较低,不会对粉煤灰的综合利用造成显著的不利影响.