板蓝根水溶性多糖的提取纯化工艺条件研究

目的研究板蓝根水溶性多糖的提取纯化工艺条件。方法通过正交实验,考察液料比、提取时间、提取温度、醇沉时间、醇液比对多糖得率的影响。结果液料比是影响提取工艺的主要因素,最佳工艺条件为：液料比30：1,提取温度90℃,提取时间6h。三氯乙酸法脱蛋白,葡聚糖凝胶柱层析纯化分离。结论板蓝根多糖得率25．63％,多糖含量76．42％。纯化后的板蓝根多糖为分子大小均一的单一组分多糖,不含核酸和蛋白质。     

荸荠多糖的超声波辅助提取工艺

为提高荸荠多糖的得率,采用超声波辅助法提取荸荠多糖。通过单因素试验研究超声波功率、料液比、提取温度、超声处理时间、乙醇浓度对荸荠多糖得率的影响,确定荸荠多糖的最佳提取工艺。单因素试验结果表明,在本试验条件下,超声波功率为300W、料液比1：10、提取温度为50℃、超声时间25min时荸荠多糖得率最高。     

基于响应曲面法的桑叶萃余物多糖提取工艺优化

以提取生物碱和黄酮的桑叶萃余物为原料,采用响应曲面分析法(RSM)优化桑叶萃余物多糖的超声提取工艺。在单因素实验的基础上,选取对实验结果影响较大的因素:提取时间、提取温度、水料比,根据中心组合(BoxBenhnken)实验设计原理对桑叶多糖的超声提取工艺进行优化,苯酚-硫酸比色法测定桑叶多糖的含量。在分析各个因素的显著性和交互作用的基础上,得到最佳提取工艺条件为:提取温度79.29℃、超声波时间35.90min、水料比8.78mL/g。采用该工艺条件,桑叶多糖的提取得率达到2.97%。与模型预测值相符。     

响应面法优化河套蜜瓜皮水溶性膳食纤维提取工艺的研究

以河套蜜瓜皮为原料,采用化学法对原料中水溶性膳食纤维的制备工艺进行了研究。在单因素实验的基础上,采用响应面法对影响水溶性膳食纤维得率的四个因素pH、料液比、温度和时间进行工艺优化。结果表明,化学法提取河套蜜瓜皮水溶性膳食纤维的最佳提取工艺条件为pH12、料液比1∶40（g/mL）、温度80℃,时间30min。在此条件下,河套蜜瓜皮水溶性膳食纤维得率可达25.03%,与模型高度拟合。     

黄精多糖的提取工艺对比研究

目的以黄精为原料,对比不同提取工艺对黄精多糖提取率的影响,以确定黄精多糖的最佳提取工艺。方法对黄精多糖的水提醇沉法和复合酶解法等2种提取方法进行对比分析。结果得到了水提醇沉法最佳的实验条件,料液比(g/mL)为1∶25,pH值为6,温度为80℃,提取时间为2 h,乙醇的体积分数为70%,在该最佳条件下多糖的提取率为8.84%;得到了复合酶解法提取黄精多糖最佳复合酶组合条件,纤维素酶与木瓜蛋白酶的质量比为3∶7,pH值为5.0,酶解温度为50℃,料液比(g/mL)为1∶20,加酶量(质量分数)为5%,酶解2 h,在该条件下,黄精多糖的提取率可达22%。结论采用复合酶解法得到的多糖得率远高于采用水提醇沉法得到的多糖得率;实验提供了黄精多糖的最优提取工艺,为其开发利用提供了理论参考。     

罗汉松种子总黄酮提取工艺优化及抗氧化活性

目的 采用响应面法优化罗汉松种子总黄酮超声提取工艺，并考查总黄酮的抗氧化活性。方法 基于单因素试验，以料液比、超声时间、超声温度为自变量，以总黄酮得率和DPPH自由基的清除率为因变量，采用三因素三水平的响应面分析法，确定最佳提取工艺条件。结果 得到最佳工艺参数：在超声频率为40 kHz、超声功率为200 W时，料液比（g/mL）为1∶50、超声温度为70℃、超声时间为2.7 h，其理论预测值总黄酮得率为27.54mg/g(n=3，相对标准偏差为1.63%)。当添加稀释10倍的总黄酮提取液0.50mL时，对DPPH自由基的清除率达到87.2%、对Ce（Ⅳ）还原率达到84.2%；当添加稀释10倍的总黄酮提取液0.90mL时，对OH自由基的清除率为88.1%。结论 采用响应面法优化得到的超声波辅助提取工艺稳定、可靠，可用于罗汉松种子总黄酮的提取。罗汉松种子总黄酮可作为优良的天然抗氧化剂资源。     

基于响应面法优化无子刺梨总皂苷提取条件

目的 优化超声辅助提取无子刺梨总皂苷的条件,以提高总皂苷的提取效率.方法 通过单因素试验评估乙醇体积分数、超声时间、料液比和提取次数对总皂苷得率的影响,结合响应面法的中心组合实验设计,确定其最佳提取条件.结果 在超声时间为40 min、乙醇体积分数为60％、料液比(g/mL)为1:30、提取4次的条件下,总皂苷的得率为9.15％,与模型预测值9.18％较为接近,表明了响应面法优化无子刺梨总皂苷的超声辅助提取方法的可行性.结论 此研究为无子刺梨资源在食品贮藏、医药等方面的进一步开发利用提供参考依据.     

对锁阳中黄酮最佳提取工艺的研究

目的优选锁阳中黄酮的最佳提取工艺。方法分别以总黄酮含量、浸膏得率、儿茶素含量和抗自由基活性为评价指标,选择物料比（A）,提取时间（B）和提取次数（C）为考察因素,采用正交实验L9（34）优选锁阳中黄酮的最佳提取工艺。结果锁阳中黄酮的最佳提取工艺条件为：以60％的乙醇为提取溶剂,物料比为1：14,提取时间3．0h,共提取1次。结论优选工艺条件可为新药研究和工业化生产提供参考。     

响应面法优化蛋壳膜硫酸软骨素提取工艺

目的 以鸡蛋壳膜为原材料,采用碱盐法提取硫酸软骨素。方法 以多糖提取率为指标研究提取时间、提取温度、碱盐比和液料比对试验的影响。在单因素实验基础上,用响应曲面法分析优化试验的各种条件。结果 得到了提取蛋壳膜硫酸软骨素的最佳工艺参数,提取时间为8 h,提取温度为65 ℃,碱盐比为6∶1,液料比为15∶1。在此条件下,硫酸软骨素的提取率为74.0%。结论 通过响应曲面设计试验及验证试验证明该最佳反应条件具有一定的可靠性与可行性。     

纤维素酶预处理玉米秸杆转化燃料乙醇的效果研究

以玉米秸杆为原料,采用纤维素酶进行预处理,然后发酵制备燃料乙醇.探讨了预处理温度、时间、酶解液用量及原料粒度对乙醇得率的影响.采用响应面法建立二次回归模型,并对预处理工艺进行了优化.研究结果表明:预处理能有效的促进玉米秸杆的降解,提高乙醇的得率.在当预处理温度为55.7℃、预处理时间为10.47h,酶解液用量为30.5...     

基于废弃印刷线路板中非金属的复合板材制备

随着废弃电子电器产品的快速增长带来的环境问题日趋严重,废弃印刷线路板的资源化问题一直成为关注的焦点。着重研究了气流分选后得到的废弃印刷线路板非金属粉碎料的资源化再生制板材的可行性,探讨了不同填料粒径、投加量和改性剂下所得复合材料拉伸强度、弯曲和冲击强度的变化。研究表明以马来酸酐接枝聚丙烯（MAH-g-PP）作为改性剂,聚丙烯S700为基体树脂,在粒径范围为0.125～0.3mm的非金属粉碎料添加量为20%的条件下,板材力学性能较优,具有广泛的应用前景。     

Preparation of Pure Copper Powder from Acidic Copper Chloride Waste Etchant

The method for the recycling of copper from copper chloride solution was developed. This process consists of extraction of copper, purification and particle size reduction. In the first step, reductive metal scraps were added to acidic copper chloride waste enchants produced in the PCB industry to obtain copper powder. Composition analysis showed that this powder contained impurities such as Fe, Ni, and water. So, drying and purification were carried out by using microwave and a centrifugal separator. Thereby the copper powder had a purity of higher than 99% and spherical form in morphology. The copper powder size was decreased by ball milling.     

Suppression method of industrial Al alloy powder explosion in dry and humid environment: A low-cost intrinsic safety technology

During the production and processing of Al alloy, a large number of small particle size powders will be produced. If the concentration of these Al alloy dust is too high under dry conditions, it will lead to dry powder explosion, and if hydrogen is produced in contact with water under wet conditions, it will lead to hydrogen explosion. This work is intended to develop a simple, cost effective technology that inerts waste Al alloy dust and minimizes its explosion hazards in different environments. Dihydrogen phosphates (KH₂PO₄, NH₄H₂PO₄, Ca(H₂PO₄)₂) are used to test the explosion flame propagation, explosion pressure, and hydrogen evolution, of waste Al alloy dust. The results show that dihydrogen phosphate can significantly reduce the flame propagation distance, speed, explosion pressure and hydrogen evolution performance of Al alloy dust, and inhibit the explosion of Al alloy dust in dry and humid environment to varying degrees. In different experiments, Ca(H₂PO₄)₂ has the best inerting effect, low cost and simple operation, which realizes the intrinsic safety of metal dust processing process. The phosphating film on the surface of Al alloy particles blocks the generation of Al(OH)₃ and retains the metal body to the greatest extent, which provides a possibility for the recycling of waste metal dust.     

Yields, solids loss and effluents generation during blanching and cooling of asparagus spears

Blanching and cooling of asparagus spears (two sizes) were compared for overall product yield, total solids loss, effluents generation and chemical oxygen demand (COD). Blanching was done using steam followed by cold water (2°C) cooling or air (static or forced) cooling. Steam blanching of 1 cm diameter asparagus produced a total solids loss of 1.04%, an effluent of 9.50 g/100 g of fresh asparagus, a COD of 0.061 g/100 g of fresh asparagus and a yield of 99.20%. Yields for cold water cooling, static air cooling and forced air cooling were, respectively, 99.8, 94.7 and 96.0%. Since cold water cooling produced a total solids loss similar to steam blanching, the combination steam blanching (IQB)-cold water cooling appears to be convenient for obtaining an excellent yield with low total solids loss of a high price vegetable like asparagus.     

双介质喷嘴雾化特性数值模拟研究

目的 双介质喷嘴雾化效果直接影响烟卷加料工艺的进一步提升，通过对雾化过程进行数值模拟，方便对雾化特性进行透彻的分析，提升雾化效果。方法 采用数值模拟方法构建两相流连续相流场与DPM离散态双向耦合的数值模型，研究蒸汽压力、液体流量以及双介质喷嘴结构对喷嘴雾化特性的影响。结果 适当增加蒸汽压力，可以在不影响最大流速、颗粒粒径均匀度及颗粒中值粒径的情况下，减小雾化扩散角，小幅度地增加喷射距离，雾化细度变好，进而提高雾化效果。随着有机液流量的增加，雾化扩散角增大，喷射距离增加，雾化粒径均匀度变好，从而使雾化效果变好。液体路通流面积越大喷雾的贯穿距离越小，气路通流面积越大喷雾的雾化扩散角度越大。若需要得到较好的雾化效果，需要保证较小的蒸汽路通流面积，与此同时液路侧保持正常开度。结论 适当地提高有机液流量或者蒸汽压力，以及采用较小蒸汽路通流面积，同时液路侧保持正常开度的结构，有利于提高料液喷洒的均匀性，减少了料液的浪费，提高了烟丝制备的工艺水平。     

Kinetics of Silver Dissolution in Nitric Acid from Ag-Au0:04-Cu0:10 and Ag-Cu0:23 Scraps

Kinetics of dissolution of silver present in precious metal 26～85℃. Dissolution rate of silver was much faster than scraps in HNO3 was studied in temperature range of that of copper at all temperatures. Effects of particle size, stirring speed, acid concentration and temperature on the rate of dissolving of silver were evaluated. Dissolution rate decreases with particle size and increases with temperature. Dissolving was accelerated with acid concentrations less than 10 mol/L. Concentrations greater than 10 mol/L resulted in slowing down of the dissolution rate. Shrinking core model with internal diffusion equation t/τ=1-3（1-x）^2/3＋2（1-x） could be used to explain the mechanism of the reaction. Silver extraction resulted in activation energies of 33.95 kJ/mol for Ag-Au0.04-Cu0.10 and 68.87 kJ/mol for Ag-Cu0.23 particles. Inter-diffusion of silver and nitrate ions through the porous region of the insoluble alloying layer was the main resistance to the dissolving process. Results were tangible for applications in recycling of the material from electronic silver-bearing scraps, dental alloys, jewelry, silverware and anodic slime precious metal recovery.     

超临界撞击流技术制备微胶囊工艺

将超临界流体与撞击流技术相结合,提出了一项新的包覆技术—超临界撞击流技术(SFIT)。以石蜡和玻璃微珠分别作为包覆模型材料的壁材和芯材,考察该技术的可行性和有效性;研究混合器内压力、温度、撞击釜内撞击距离以及膨胀前温度等因素对于微胶囊的表观包覆率和表观形态的影响。结果表明,在混合器内压力20MPa以上、温度75℃,且撞击距离70mm,膨胀前温度140℃时,得到的微胶囊团聚小,包覆均匀且效果较好。实验采用电子扫描电镜、激光粒度分布仪和差式扫描量热仪等检测方法从微胶囊的表观包覆率、粒径分布范围、表面形态等角度进行评价。从结果来看,超临界流体与撞击流技术相结合可以实现微胶囊的包覆且效果良好。     

Overall characterization of cork dust explosion

Explosibility and ignitability studies of air/cork dust mixtures were conducted in a near-spherical 22.7 L explosibility test chamber using pyrotechnic ignitors and in a furnace of 1.23 L. The suspension dust burned as air-dispersed dust clouds and the uniformity of the dispersion inside the chamber was evaluated through optical dust probes. The range of tested particle sizes went from a mass median diameter of 47.4 to 438.3 microm and the covered dust cloud concentration was up to 700-800 g/m(3). Measured explosion parameters included minimum explosible concentration, maximum explosion pressure, maximum rate of pressure rise and minimum autoignition temperature. The effect of dust particle size on flammability was evaluated and it was found that the minimum explosible concentration is around 40 g/m(3) and it is relatively independent of particle size below 180 microm. Maximum explosion pressure of 7.2 bar and maximum rate of pressure rise of 179 bar/s were detected for the smallest tested sizes. The limitations on the rates of devolatilization of the solid particles became rate controlling at high burning velocities, at high dust loadings and for large particle sizes. The effect of initial pressure on the characteristic parameters of the explosion was studied by varying the initial absolute pressure from 0.9 bar to 2.2 bar, and it was found that as initial pressure increases, there is a proportional increase of minimum explosion limit, maximum explosion pressure, and maximum rate of pressure rise. The influence of the intensity of the ignition energy on the development of the explosion was evaluated using ignition energies of 1000 J, 2500 J and 5000 J, and the experimental data showed that the value of 2500 J is the most convenient to use in the determination of minimum explosion concentration. The behavior of the cork dust explosion in hybrid methane air mixtures was studied for atmospheres with 2% and 3.5% (v/v) of methane. The effect of methane content on the characteristic parameters of the explosions was evaluated. The conclusion is that, the hazard and explosion danger rise with the increase of methane concentration, characterized by the reduction of the minimum dust explosion concentration. The minimum autoignition temperature obtained with the thermal ignition tests was 540 degrees C and the results have shown that this value is independent of particle size, for particles with mass median diameters below 80 microm.     

供热机组滑压运行曲线综合优化的研究与应用

针对华电能源哈尔滨第三发电厂机组供热改造的特点,研究分析了供热机组滑压运行的相关问题;比较供热与非供热工况的差异,提出了采用主蒸汽流量作为自变量来确定机组主蒸汽压力的滑压设定值,以抽汽机组的最优滑压运行曲线,综合考虑抽汽机组最优滑压运行曲线确定的各种影响因素,使机组在抽汽模式以及非抽汽模式都能获得良好的经济性,从而最大限度地挖掘经济运行的潜力,真正实现节能增效。