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As a typical synergistic minimal quantity lubrication (MQL) technology, oils on water（OoW） has almost the same cooling performance as a large amount of pouring cooling oil and excellent lubrication performance. Based on the technical mechanism of OoW, the MQL products with advanced functions are developed for gear hobbing production, and the processing parameters are optimized in practice. The product application results show that： the MQL of gear hobbing has excellent properties such as reducing machining oil fume, improving tool life, expanding the machining modulus range of dry cutting machine tool and reducing carbon dioxide emission. It is of great significance to upgrade the traditional gear industry, develop new types of near dry cutting machine tools, and build green factories.

As a typical synergistic MQL technology， OoW（oils on water） has almost the same cooling performance as a large amount of pouring cooling oil and excellent lubrication performance. Based on the technical mechanism of OoW， the MQL products with advanced functions are developed for gear hobbing production， and the processing parameters are optimized in practice. The product application results show that： the MQL of gear hobbing has excellent properties such as reducing machining oil fume， improving tool life， expanding the machining modulus range of dry cutting machine tool and reducing carbon dioxide emission. It is of great significance to upgrade the traditional gear industry， develop new types of near dry cutting machine tools， and build green factories.

This paper builds upon the results in the article “G-matrices, J-orthogonal matrices, and their sign patterns", Czechoslovak Math. J. 66 (2016), 653-670, by Hall and Rozloznik. A number of further general results on the sign patterns of the J-orthogonal matrices are proved. Properties of block diagonal matrices and their sign patterns are examined. It is shown that all 4 × 4 full sign patterns allow J-orthogonality. Important tools in this analysis are Theorem 2.2 on the exchange operator and Theorem 3.2 on the characterization of J-orthogonal matrices in the paper “J-orthogonal matrices: properties and generation", SIAM Review 45 (3) (2003), 504-519, by Higham. As a result, it follows that for n ≤4 all n×n full sign patterns allow a J-orthogonal matrix as well as a G-matrix. In addition, the 3 × 3 sign patterns of the J-orthogonal matrices which have zero entries are characterized.

A sign pattern (matrix) is a matrix whose entries are from the set {+, −, 0} and a sign vector is a vector whose entries are from the set {+, −, 0}. A sign pattern or sign vector is full if it does not contain any zero entries. The minimum rank of a sign pattern matrix A is the minimum of the ranks of the real matrices whose entries have signs equal to the corresponding entries of A. The notions of essential row sign change number and essential column sign change number are introduced for full sign patterns and condensed sign patterns. By inspecting the sign vectors realized by a list of real polynomials in one variable, a lower bound on the essential row and column sign change numbers is obtained. Using point-line confiurations on the plane, it is shown that even for full sign patterns with minimum rank 3, the essential row and column sign change numbers can differ greatly and can be much bigger than the minimum rank. Some open problems concerning square full sign patterns with large minimum ranks are discussed.

Analogical reasoning is central to thought and learning, with a key focus on similarities where the same relations hold across different sets of elements. The current research investigated analogical reasoning in first-order and second-order relations, represented in word-like symbols following syntactic rules. Since most previous studies in this field have focused on visuospatial and semantic analogy, the primary goal of this paper was to specify the neural substrates for analogical reasoning based on syntactic rules. We found the activation locates in both anterior and posterior MFG, and these two regions correspond to parts of rlPFC and dlPFC respectively. The results reveal that although analogical reasoning with syntactic rules recruits similar brain regions as those in visuospatial and semantic analogy, their activation patterns are not the same. The role of rlPFC, the core area for analogical reasoning, needs to be reconsidered, and the complexity of syntactic-related activation is worth more attention.