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排序方式: 共有436条查询结果,搜索用时 15 毫秒
11.
区分服务是目前网络支持多样化服务质量保障的重要手段,现有交换结构和调度算法在支持多样化服务方面存在不足.文章提出了一种支持多样化服务的交换结构,该结构通过分离业务类为每类业务提供专一和定制化的服务.针对复用器内部竞争输出端口的问题,提出了一种新的复用器调度算法,该算法采用带宽分配指示向量和队列长度计数器,能够有效地保障各类业务在输出端口的服务质量和业务类之间的公平性.仿真实验表明,该交换系统能够保证各类业务都获得较为满意的服务质量性能. 相似文献
12.
煤是含碳量最高的化石能源。煤炭利用导致大量CO2排放的问题已引起高度重视。为此,本文提出了以低碳理念指导的我国煤化工产业的发展思路。基于我国的实际情况,高能效的多联产路线以及煤化工和石化、冶金等产业的共生路线是实现煤的分级和高效利用的必然选择;在高附加值煤化工产品方面,应该大力发展三烯、三苯、天然气、乙炔等产品替代石油化工,尽可能减少对石油进口的依赖,并降低单位GDP煤化工的碳排放强度;为此必须加强相关关键工艺技术以及煤炭组分定向剪裁和转化等新技术的研发。 相似文献
13.
介绍了我国甲醇市场的生产和消费情况以及下游产品的产业发展趋势。指出:经历过高速增长期后,我国甲醇产能扩张趋于放缓,装置规模化和产业集中度明显提升;甲醇下游呈多元格局,传统消费领域甲醇需求趋于平稳增长,甲醇燃料渐成规模,甲醇制烯烃成为新兴的主力消费市场,甲醇制芳烃、甲醇制汽油、甲醇制聚碳酸酯、甲醇蛋白等高附加值产品领域消费潜力凸显;大力发展甲醇产业,对于优化和调整我国石油化工产业结构、提高化工产品国际市场竞争力具有十分重要的意义。最后指出,我国甲醇市场要保持平稳向好的发展态势,仍需延伸产业链条,发展有竞争力的衍生物产品,同时,要加快甲醇下游衍生物标准化体系建设,推动先进技术产业示范进程。 相似文献
14.
This study was carried out to investigate the ability of an artificial microalgal–bacterial consortium to remediate an oilfield wastewater using laboratory-scale fluidized bed reactors (FBRs) under lighting. The consortium consists of an oil-degrading bacterial community and a microalgae, Scenedesmus obliquus GH2. The microbes were immobilized onto Ca-alginate beads and filled to the FBRs. The influence of hydraulic retention time (HRT) on the removal of chemical oxygen demand (COD), total nitrogen, NH3-N and oil concentration was investigated over 40 operational days. The synergistic relationship in the algal–bacterial microcosm was clearly demonstrated, since for the four parameters tested, the highest removal was recorded in the system inoculated with both algae and bacteria. In the algal–bacterial FBR, at 16 h HRT, the average effluent concentrations of COD, NH3-N and oil were 92, 24 and 4.8 mg/L, respectively, corresponding to removal efficiencies of 70.8%, 61.2% and 84.2%, respectively. The effluent could meet the grade 2 as required by the national discharge standard of China. However, the effluent quality of the bacterial- or algal-only case could not satisfy the grade 3 discharge standard at 16 h HRT. The algal–bacterial biomass exhibits lowest effluent microtoxicity and highest dehydrogenase activity in comparison with bacterial-only and algal-only cases. This study reveals that the consortium containing dual microbial species has potential for microbial remediation of oilfield wastewater. 相似文献
15.
吴丽萍 《延边大学学报(自然科学版)》2022,(1):30-36
研究一类具有反馈控制变量和出生率具有密度制约的偏利共生模型的平衡点稳定性.首先通过分析系统的平衡点,得到系统正平衡点和边界平衡点存在的条件;其次通过构造适当的Lyapunov函数,得到在一定条件下系统的正平衡点和边界平衡点是全局稳定的;最后利用数值模拟验证了所得结果的正确性. 相似文献
16.
随着清洁能源的大力发展与智能电网技术的不断成熟,特高压技术解决了超远距离电力传输调度问题,在当今全球化进程中全球能源互联已成为现阶段急需解决的重大问题,也是实现全球经济与能源可持续发展的重要战略规划。全球能源互联需要世界各国在能源领域进行全方面合作,打破不同发展水平国家间的能源准入壁垒,将世界各国的资源及能源性企业联合起来,形成一套互信互惠的能源交易运行机制,并探索适用于全球能源互联的商业模式,以保障全球能源互联网的建设有序开展。通过现阶段“一带一路”发展战略对全球能源发展现状及全球能源互联网现阶段取得成果的分析,对全球能源互联网发展过程中的新型投融资机制、市场机制、协同创新机制以及组织保障机制的建设进行了探索,旨在提出全球能源互联运行当中面对的各种问题,为全球能源互联运行机制建设提供可行性方案,推动“一带一路”与构建全球能源互联网两大战略的耦合与互动。 相似文献
17.
Michael Martin 《Biomass & bioenergy》2011,35(5):1747-1755
In the production of biofuels for transport many critics have argued about the poor energy efficiency and environmental performance of the production industries. Optimism is thus set on the production of second generation biofuels, while first generation biofuels continue to dominate worldwide. Therefore it is interesting to consider how the environmental performance of first generation biofuel industries can be improved. The field of industrial symbiosis offers many possibilities for potential improvements in the biofuel industry and theories from this research field are used in this paper to highlight how environmental performance improvements can be accomplished. This comes in the form of by-product synergies and utility synergies which can improve material and energy handling. Furthermore, the processes and products can gain increased environmental performance improvements by the adaption of a renewable energy system which will act as a utility provider for many industries in a symbiotic network. By-products may thereafter be upcycled through biogas production processes to generate both energy and a bio-fertilizer. A case study of an actual biofuel industrial symbiosis is also reviewed to provide support for these theories. 相似文献
18.
The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO2 emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO2 emissions. 相似文献
19.
Active centers, catalytic behavior, symbiosis and redox properties of MoV(Nb,Ta)TeO ammoxidation catalysts 总被引:1,自引:0,他引:1
Robert K. Grasselli Douglas J. Buttrey James D. Burrington Arne Andersson Johan Holmberg Wataru Ueda Jun Kubo Claus G. Lugmair Anthony F. Volpe Jr 《Topics in Catalysis》2006,38(1-3):7-16
Selective as well as waste forming active centers were defined for MoVNbTeO and MoVTaTeO catalysts in the ammoxidation of
propane to acrylonitrile and all catalytic functionalities were assigned to specific elements at the respective active centers.
Symbiosis between M1 and M2 phases of these catalysts was observed, with phase cooperation being more extensive in the Nb than Ta containing compositions.
The difference in catalytic effectiveness arises most likely because contact and surface area exposure of the two respective,
cooperating phase pairs are not equal. The M1 phase of the catalysts is reducible by propane and ammonia in the absence of dioxygen and is regenerable to its original,
fully oxidized state by dioxygen (air). No structural collapse is observed even after 120 C3H8 + NH3 reduction pulses. The so induced reduction of the catalyst extends up to 70 layers deep. The product distribution over the
first few pulses is very similar to that under catalytic conditions, supporting the concept that lattice oxygen is involved
in the catalytic ammoxidation process. Therefore, the ammoxidation of paraffins is a redox process, as is of course the well-known
olefin ammoxidation process. 相似文献
20.
本课题为《黑龙江垦区中长期科技发展战略研究》的子课题之一,任务是研究农业自然资源的优势、劣势、开发利用现状和存在问题,产业发展现状和存在问题。从宏观上探求变资源优势为产品优势、经济优势的途径和主要措施,为垦区经济的振兴、发展服务。本课题的研究方法是在前人资料的基础上,通过整理分析和补充调查研究,提出报告和建议。 相似文献