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91.
For seasonal products,the retailers usually launch various marketing efforts,like advertising and promotion,to promote them in a selling season.While facing large demand from the customers,one should take the capacity constraint and outsourcing into consideration.Considering the shorten life cycles of most products,in this paper we adopt the traditional newsvendor model to investigate the optimal marketing effort along with optimal order quantity.We address the risk aversion issue and characterize the influence of the sellers’ risk propensity with CVaR criterion,and we develop an effective algorithm to obtain the optimal strategy.The impact of sellers’ risk propensity on the performance of the system is illustrated via numerical examples.The innovation of this paper is threefold.First,the optimal joint strategy of the marketing effort and order quantity is investigated and an efficient algorithm to find the optimal strategy is developed.Second,the capacity constraint option and an outsourcing strategy are studied jointly for excess products.Finally,the risk propensity of the seller and its influence are investigated by using the CVaR criterion,through which we obtain some new managerial insights.  相似文献   
92.
Intergenric protoplast fusion between Aspergillus terreus CA99 and Monascus anka M-3, the high and low producers of monacolin K respectively,was performed for enhancement of monacolin K production. The 24-hour-old mycelia of A. terreus CA99 and M. anka M-3 were treated with 0.5% lywallzyme, 0.3% snailase and 0.3% cellulase at 34℃ for 5 h and at 30℃ for 3.5 h, and their protoplasts formation reached 1.76×107/mL and 1.68×107/mL respectively. Parental protoplasts were irradiated with a 30 W UV light away from 30 cm for 3 min and then mixed. The mixture was incubated with 30% PEG 6000 for 15 min. The reviving fusants were isolated on the regeneration plates. Of the 363 fusants isolated, over 100 showed enhanced monacolin K production compared with the parental strain M. anka M-3. Ten of them produced monacolin K about 1.6-fold of that M.anka M-3 does and the monacolin K titer of two fusants (F49 and F104) increased by about 1-fold. The monacolin K yields of F49 and F104 were 460 μg/mL and 457 μg/mL respectively. In optimized fermentation medium, the monacolin K titer of F49 reached 1216 μg/mL.  相似文献   
93.
The SMART/ASTC dynamic soft reduction technology of VAI and its application on the 6-strand bloom continuous caster at Pangang, China are presented. The operation results show that soft reduction technology is effective to improve the inner quality of continuously cast blooms. At Pangang, both the central porosity and the central segregation ratings are no more than 1.0, the central shrinkage cavity rating is no more than 0.5, and the central segregation index of carbon is no more than 1.05. Rails made from the blooms have excellent quality and are used for high-speed tracks.  相似文献   
94.
Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program was introduced since 2000 to reduce soil erosion by converting slope-cultivated land into forestry and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the loess plateau. The results indicate that the soil conservation program to convert slope fields into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit of land use activity of slope fields before their conversion into forest and pasture is needed to encourage farmers to join the conservation program. A policy measure to encourage and assist farmers to develop sedentary livestock by using crops produced from fields as well as fodder and forage grass from the converted slope fields might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage households to reduce cultivation in slope fields. That implies a policy measure to encourage rural urbanization might contribute to combat soil erosion.  相似文献   
95.
方向包围盒(Oriented bounding box:OBB)的构造以及包围盒的相交测试的计算量都比较大,严重影响了在模拟、仿真的应用,尤其是有变形物体的场景。引入近似凸包的思想提出一种快速构造方向包围盒算法,很大程度上减少了构造方向包围盒(0BB)层次结构的顶点数,改进后的算法在降低构造层次结构时间的同时,对方向包围盒的紧密性代价几乎没有影响,在有些时候还提高了包围盒的紧密性。在包围盒相交测试方面,提留了一种基于筒单羽以爱的相交须刿方击,该算法在检测过程中省去了大量包围盒的相交测试计算,提高了相交测试的速度。最后将两种改进算法联合的碰撞检测框架与常用的基于均值和协方差矩阵的包围盒构造和基于分裂轴的算法进行比较,证明了算法具有高效性。  相似文献   
96.
The preparation of ferronickel alloy from the nickel laterite ore with low Co and high MgO contents was studied by using a pre-reduction-smelting method. The effects of reduction time, calcination temperature, quantity of reductant and calcium oxide (CaO), and pellet diameter on the reduction ratio of Fe and on the pellet strength were investigated. The results show that, for a roasting temperature >800℃, a roasting time >30 min, 1.5wt% added anthracite coal, 5wt% added CaO, and a pellet size of~10 mm, the reduction ratio of Fe exceeds 70% and the compressive strength of the pellets exceeds 10 kg per pellet. Reduction smelting experiments were performed by varying the smelting time, temperature, quantity of reductant and CaO, and reduction ratio of Fe in the pellets. Optimal conditions for the reduction smelting process are as follows:smelting time, 30-45 min; smelting temperature, 1550℃; quantity of reductant, 4wt%-5wt%; and quantity of CaO, 5wt%; leading to an Fe reduction ratio of 75% in the pellets. In addition, the mineral composition of the raw ore and that during the reduction process were investigated by process mineralogy.  相似文献   
97.
The carbon deposition behavior on nickel particles was observed within the temperature range from 400 to 800℃ in a pure methane atmosphere. The topography, properties, and molecular structure of the deposited carbon were investigated using field-emission scanning electron microscopy (FESEM), temperature-programmed oxidation (TPO) technology, X-ray diffraction (XRD), and Raman spectroscopy. The deposited carbon is present in the form of a film at 400-450℃, as fibers at 500-600℃, and as particles at 650-800℃. In addition, the structure of the deposited carbon becomes more ordered at higher temperatures because both the TPO peak temperature of deposited carbon and the Raman shift of the G band increase with the increase in experimental temperature, whereas the intensity ratio between the D bands and the G band decreases. An interesting observation is that the carbon deposition rate is suppressed in the medium-temperature range (M-T range) and the corresponding kinetic mechanism changes. Correspondingly, the FWHM of the G and D1 bands in the Raman spectrum reaches a maximum and the intensities of the D2, D3, and D4 bands decrease to low limits in the M-T range. These results indicate that carbon structure parameters exhibit two different tendencies with respect to varying temperature. Both of the two group parameters change dramatically as a peak function with increasing reaction temperature within the M-T range.  相似文献   
98.
高孝裕  Zhou  Yong  Chen  Ji'  an  Lei  Chong  Zhao  Xiaolin 《高技术通讯(英文版)》2006,12(3):260-262
0 IntroductionThere has been a great demand on micro DC/DCconverter for the applications of the portable electronicproducts such as mobile communication product CDMA(Code Division Multiple Access) ,portable notebookcom-puter ,microprocessor ,digital camcorder andso on.Mag-netic components such as inductors and transformers arethe essential components in constructingthe power supplytransformer ,filter , oscillator , amplifier and micro DC/DCconverter ,andthe miniaturization of inductor an…  相似文献   
99.
In standard near-field scanning optical microscopy (NSOM), a subwavelength probe acts as an optical 'stethoscope' to map the near field produced at the sample surface by external illumination. This technique has been applied using visible, infrared, terahertz and gigahertz radiation to illuminate the sample, providing a resolution well beyond the diffraction limit. NSOM is well suited to study surface waves such as surface plasmons or surface-phonon polaritons. Using an aperture NSOM with visible laser illumination, a near-field interference pattern around a corral structure has been observed, whose features were similar to the scanning tunnelling microscope image of the electronic waves in a quantum corral. Here we describe an infrared NSOM that operates without any external illumination: it is a near-field analogue of a night-vision camera, making use of the thermal infrared evanescent fields emitted by the surface, and behaves as an optical scanning tunnelling microscope. We therefore term this instrument a 'thermal radiation scanning tunnelling microscope' (TRSTM). We show the first TRSTM images of thermally excited surface plasmons, and demonstrate spatial coherence effects in near-field thermal emission.  相似文献   
100.
Active terahertz metamaterial devices   总被引:1,自引:0,他引:1  
Chen HT  Padilla WJ  Zide JM  Gossard AC  Taylor AJ  Averitt RD 《Nature》2006,444(7119):597-600
The development of artificially structured electromagnetic materials, termed metamaterials, has led to the realization of phenomena that cannot be obtained with natural materials. This is especially important for the technologically relevant terahertz (1 THz = 10(12) Hz) frequency regime; many materials inherently do not respond to THz radiation, and the tools that are necessary to construct devices operating within this range-sources, lenses, switches, modulators and detectors-largely do not exist. Considerable efforts are underway to fill this 'THz gap' in view of the useful potential applications of THz radiation. Moderate progress has been made in THz generation and detection; THz quantum cascade lasers are a recent example. However, techniques to control and manipulate THz waves are lagging behind. Here we demonstrate an active metamaterial device capable of efficient real-time control and manipulation of THz radiation. The device consists of an array of gold electric resonator elements (the metamaterial) fabricated on a semiconductor substrate. The metamaterial array and substrate together effectively form a Schottky diode, which enables modulation of THz transmission by 50 per cent, an order of magnitude improvement over existing devices.  相似文献   
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