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排序方式: 共有4180条查询结果,搜索用时 203 毫秒
31.
以甲酚紫培养基中加入乙醇作为分离培养基,从5种水果样品中分离得到20种醋酸菌,然后通过产酸量的测定,筛选出了一株产醋酸度高的醋酸菌AAB13.探讨了乙醇浓度、菌株接种量、发酵液有效体积对醋酸发酵的影响,并在优化的条件下制备了苹果梨醋. 相似文献
32.
Virginie Boy Wajdi Ben Khalifa Lucie Drvillon Yves Leme Thomas Lendormi Jean‐Louis Lanoisell 《加拿大化工杂志》2021,99(1):120-134
An original drying process combining air impingement and intermittent drying was studied on apple slices and mango cubes. The influence of four operating parameters (air velocity, drying/tempering periods, upper height, and air temperature) on the drying time and on the drying rate was evaluated. Continuous and intermittent drying were compared. The intermittency α = 1/7 (τon = 10 seconds and τoff = 60 seconds) gave the best results. A time savings of 54% for apple and 67% for mango was reached. In continuous drying, a time savings of 4620 seconds was observed by increasing the air velocity from 6 to 40 m s?1 for apple. Air temperatures of 328 K for apple and of 328 K or 338 K for mango were determined as optimum to prevent case‐hardening. Experimental results were fitted with the analytical solution of Fick's second law and the modified Page equation (average values R2 = 0.985 and 0.961, for apple and mango, respectively). For both products, the apparent moisture diffusivity Dapp, the drying constant k, the drying coefficient n, and the activation energy Ea, were identified. Activation energies calculated from the analytical solution were 30.3 and 36.8 kJ mol?1 and were 25.4 and 30.0 kJ mol?1 using the modified Page equation for apple and mango, respectively. Mango has an increased temperature sensitivity and thus will need less energy for drying than apple. 相似文献
33.
针对果蝇优化算法( FOA)收敛速度快但寻优精度低的缺点,为了改善果蝇算法的优化性能,提出一种混合果蝇优化算法( HFOA)。HFOA采用分段优化的思想,在优化过程后期采用收敛稳定性较好的粒子群优化( PSO)算法优化果蝇算法中果蝇个体飞行距离和味道浓度的判定值,采用误差性能指标积分准则ITAE作为适应度函数,并将优化方案应用于一类不稳定系统的PID控制。Matlab仿真验证表明:HFOA计算高效,具有良好的稳定性,收敛精度高,进而验证了HFOA应用于PID控制参数优化是可行而有效的。 相似文献
34.
David G. James Robert J. Bartelt Richard J. Faulder 《Journal of chemical ecology》1994,20(11):2805-2819
Synthetic aggregation pheromones ofCarpophilus hemipterus (L.) andCarpophilus mutilatus Erichson were field tested during a 10-month period in southern New South Wales stone fruit orchards to determineCarpophilus spp. phenology and the effect of two pheromone doses on attraction. Aggregation pheromones synergize the attraction of host volatiles toCarpophilus spp. Four major species,C. hemipterus, C. mutilatus, C. davidsoni Dobson andC. (Urophorus) humeralis (F.), were trapped, with greater numbers of each species inC. hemipterus pheromone/fermenting whole-wheat breaddough-baited traps, than in dough-only-traps. InC. mutilatus pheromone/ fermenting-dough-baited traps, onlyC. mutilatus andC. davidsoni responded in greater numbers than to dough-only traps. Beetles first appeared in traps in late September (early spring) when daily maximum temperatures averaged 17.5C. Trappings reached a peak during October and declined to very low levels in November–December (late spring-early summer). Numbers trapped of all species increased during February–March (late summer–early autumn), presumably due to the presence of abundant host resources (ripening and fallen fruit), and continued at high levels until May (late autumn). An 18-week study demonstrated significantly greater responses byCarpophilus spp. to 5000-g than to 500-g doses of C.hemipterus andC. mutilatus pheromones. Greatest responses to 5000g were recorded forC. hemipterus andC. mutilatus responding to their own pheromones (increased attraction over dough alone of 259x and 21.2x respectively). Implications of the study and the potential for using synthetic aggregation pheromones for managingCarpophilus spp. populations in Australian stone fruit are discussed. 相似文献
35.
为了使微电网控制系统中PI控制器的参数能够更好地适应可再生能源的随机性和波动性,提出了基于自适应步长的四分区多策略果蝇优化算法(fruit fly optimization algorithm, FOA)对PI参数进行实时优化。首先,以风光燃储微电网不同微源控制系统中的变换器为控制对象,建立微电网整体控制系统模型,基于此模型实时调整PI参数。然后,根据不同果蝇个体的适应度值将果蝇种群分为4个区,同时考虑4个区果蝇收敛性以及多样性的差异,设计不同的自适应更新策略。最后,采用所提算法对各微源控制过程中的PI参数进行寻优,与其他3种智能算法进行对比,验证了所提算法的可行性和优越性。仿真结果表明,所提算法可以使系统变换器响应速度更快,输出更加稳定。 相似文献
36.
Recently, the fundamental problem with Hybrid Mobile Ad-hoc Networks (H-MANETs) is to find a suitable and secure way of balancing the load through Internet gateways. Moreover, the selection of the gateway and overload of the network results in packet loss and Delay (DL). For optimal performance, it is important to load balance between different gateways. As a result, a stable load balancing procedure is implemented, which selects gateways based on Fuzzy Logic (FL) and increases the efficiency of the network. In this case, since gateways are selected based on the number of nodes, the Energy Consumption (EC) was high. This paper presents a novel Node Quality-based Clustering Algorithm (NQCA) based on Fuzzy-Genetic for Cluster Head and Gateway Selection (FGCHGS). This algorithm combines NQCA with the Improved Weighted Clustering Algorithm (IWCA). The NQCA algorithm divides the network into clusters based upon node priority, transmission range, and neighbour fidelity. In addition, the simulation results tend to evaluate the performance effectiveness of the FFFCHGS algorithm in terms of EC, packet loss rate (PLR), etc. 相似文献
37.
针对混合流水车间调度问题(HFSP),本文提出了一种新的基于果蝇算法和变邻域搜索的混合优化方法.首先,将关键块内的工序与同阶段其他机器上的工序进行交换,提出了一种基于关键路径的HFSP新邻域结构.其次,针对HFSP的阶段式解码特性,提出了一种邻域解的快速评估方法,并验证了快速评估方法的高效性.然后,基于提出的新邻域结构,并将N7和K-insertion邻域结构引入HFSP,设计了基于上述3种邻域结构的变邻域搜索方法,以此为基础提出了一种针对HFSP的混合优化方法.最后,通过对Carlier和Liao等经典测试集进行测试,验证了所提新邻域结构的可行性和有效性,并将该方法与其他文献的方法进行了对比,验证了所提方法的优越性. 相似文献
38.
39.
利用赌博机赌博案件的作案手段隐蔽、发现查处难度大、涉及人员多、社会危害性大,是群众反响强烈的难点问题。本文从分析现场取得百家乐1号赌博机的电子证据入手,通过电子数据检验鉴定,从而全面掌握涉案赌博机的非法所得情况。 相似文献
40.
基于Web的亚热带水果产品质量安全追溯系统关键技术研究 总被引:5,自引:0,他引:5
徐龙琴 《计算机工程与设计》2011,32(4):1174-1177,1189
为了实现对亚热带水果"从果园到餐桌"全方位的跟踪和追溯,分析了水果产品生产流程并确定了影响其质量的关键点,以产品生产批次作为"身份标识",采用UCC/EAN-128编码方式结合流程编码、RFID和二维码等编码技术进行了追溯编码,并采用任务与角色相结合的权限分配策略,构建了一个多层次多用户权限动态管理的亚热带水果生产加工全过程的质量跟踪与追溯系统,为生产者、质检部门和消费者提供一个集产品生产加工诸环节的信息交流平台,并以网络、语音、短信、触摸屏向公众提供追溯查询和防伪服务,具有应用推广价值。 相似文献