排序方式： 共有17条查询结果，搜索用时 15 毫秒
1.
2.
3.
4.
在大类招生形势下,不少高校力学专业出现了修读生源减少、生源质量下降的情况,不利于力学学科的整体发展。针对此问题,从力学专业招生面临的形势、力学学科的优势、以及大类分流工作的实践三个方面,探讨如何做好力学专业大类分流工作。 相似文献
5.
本文从形成产业集群的竞争成势理论出发,运用多元统计中的主成分分析和聚类分析方法,阐明形成产业集群量化的一般原理,并对河南省18个地区的经济水平进行了区域分类,据此进行综合评价,提出产业集群的培育和区域经济的发展对策。 相似文献
6.
Ying Li 《European Journal of Operational Research》2011,214(2):273-283
Suppliers often make proactive investments to strategically position themselves to win contracts with a large buyer. Such investments reduce the suppliers’ variable costs of serving the buyer’s demand. We show that an auction mechanism does not always benefit the buyer, the supply chain, or the society. We identify scenarios where the buyer can implement the supply chain and socially optimal solution by committing to a bilateral relationship with fair reimbursement, and forgoing the benefits of competition altogether. We explore the role of commitment by the buyer (to a procurement mechanism) and by the suppliers (to an investment level) by analyzing different timing games under symmetric and asymmetric information about suppliers’ types. We show that it never benefits anyone for the suppliers to commit first. Equilibrium investments and cost structures depend upon the buyer’s bargaining power (opportunity cost). However, the winning supplier’s investments are almost always below the supply chain optimal level. 相似文献
7.
8.
Dr. Muhammad Mansha Asif Ayub Ibad Ali Khan Dr. Shahid Ali Dr. Atif Saeed Alzahrani Dr. Majad Khan Dr. Muhammad Arshad Dr. Abdul Rauf Dr. Safyan Akram Khan 《Chemical record (New York, N.Y.)》2024,24(1):e202300284
In recent years, aqueous organic redox flow batteries (AORFBs) have attracted considerable attention due to advancements in grid-level energy storage capacity research. These batteries offer remarkable benefits, including outstanding capacity retention, excellent cell performance, high energy density, and cost-effectiveness. The organic electrolytes in AORFBs exhibit adjustable redox potentials and tunable solubilities in water. Previously, various types of organic electrolytes, such as quinones, organometallic complexes, viologens, redox-active polymers, and organic salts, were extensively investigated for their electrochemical performance and stability. This study presents an overview of recently published novel organic electrolytes for AORFBs in acidic, alkaline, and neutral environments. Furthermore, it delves into the current status, challenges, and prospects of AORFBs, highlighting different strategies to overcome these challenges, with special emphasis placed on their design, composition, functionalities, and cost. A brief techno-economic analysis of various aqueous RFBs is also outlined, considering their potential scalability and integration with renewable energy systems. 相似文献
9.
《Journal of Chemometrics》2017,31(6)
Several curve resolution techniques have been developed to analyze higher‐order data structures, among which one can name parallel profiles with linear dependencies (PARALIND). The PARALIND is a variant of the Parallel Factor Analysis (PARAFAC) to cope with linear dependencies. Applying a PARAFAC model with different random initializations to a noisy three‐way data with linearly dependent loadings always converges to a best‐fitted noisy solution. Since PARAFAC maximally fits the noise part of the data, rank‐deficiency is broken, and it causes a noise‐induced unique decomposition. The uniqueness due to the presence of noise in rank‐deficient cases is an artificial phenomenon called “surface uniqueness.” The PARALIND model causes non‐uniqueness to be revealed, ie, it leads to a different set of profiles in each run. However, it might not give us all the possible solutions. Therefore, there is still a demand for determining all and every possible solution. The aim of this paper is 3‐fold: (1) A method is developed for determining feasible regions using the PARALIND model. (2) The surface uniqueness phenomenon is clarified. (3) The effect of interaction matrices in PARALIND as an active constraint is emphasized and discussed in detail using simulated noisy and noise‐free two‐ and three‐component data arrays. 相似文献
10.
A. S. Said 《Journal of separation science》1980,3(10):507-515
Different methods for producing a pre-assigned gradient in liquid chromatography are presented. A systematic approach to the calculations involved is given. The derived equations are mostly Poisson and Poisson summation distributions which are tabulated in the literature. The incremental method of gradient elution developed by Scott has been modified. In the modified apparatus two mixing chambers are used instead of one. This leads to an appreciable decrease in the number of reservoirs needed for the same precision in fitting a desired gradient. The application of the derived equations, together with other Varigrad modifications, will be given in Part 2 of this paper (to be published shortly in this Journal). 相似文献