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Nano electro discharge machining (nano EDM), as a frontier processing method in the research stage of exploration, has an important application prospect in the machining of metal and alloy materials for achieving nanoscale removal resolution. A pulsed power supply used in nano EDM is expected to limit a single pulse energy to nJ order of magnitude for improving the removal resolution of single pulsed discharge even to nanoscale. One developing direction is to decrease pulsewidth of the pulsed power supply. Conventional pulsed power supplies hardly output a single pulse and continuous pulses with nanosecond (ns) pulsewidth, resulting in too large single pulsed energy of μJ order of magnitude usually. In this research, a novel pulsed power supply is designed for realizing the ns-pulsewidth with controllable pulsewidth and peak voltage. The key novelty lies in a cascaded circuit with two triodes working in the state of ultra-fast avalanche conduction, where pF capacitors are applied to adjust the pulsewidth and pulsed energy precisely. Performance tests verified that a single pulse of 5 ns pulsewidth or continuous pulses up to 9 MHz can be outputted. Furthermore, nano EDM experiments of single pulsed discharge are carried out under the conditions of nanometer (nm) discharge gap and nm-tip tool electrode based on an atomic force microscope (AFM) system. The special results are achieved: a single pulsed energy can reach down to 1.75 nJ by outputting a pulsewidth of 10 ns, and a nano-EDM crater is only about 182 nm in diameter with regular shape and little recasting. Those results verify the possibility of AFM-tip-based nano EDM for machining nanostructures. [ABSTRACT FROM AUTHOR]

BACKGROUND: HD-Zip genes encode several large and highly conserved protein families of transcription factors that play important roles in plant development and responses to environmental stress. To date, information about the involvement of HD-Zip in grape to drought response is limited. OBJECTIVE: The production of grapes is limited by a range of biotic and abiotic stresses, which cause significant losses in yield every year as well as a reduction in fruit quality. Identification and analysis of stress related genes in grapes are very important for cultivating more robust varieties with environmental stress resistance METHODS: We isolated a homeodomain-leucine zipper gene (HD-Zip), VvHDZ4, from grape, Vitis vinifera L. "Yatomi Rose", and characterized VvHDZ4 based on analyses of its expression patterns, subcellular localization, transcription activity, and overexpression. RESULTS: We found that VvHDZ4 was highly expressed in roots and leaves, localized to nucleus, and activated the expression of reporter genes in yeast. The overexpression (OE) of VvHDZ4 led to enhanced drought stress tolerance in Solanum lycopersicum L. "Ailsa Craig" (tomato). The drought-tolerant phenotypes of the OE lines exhibited decreases in electrolyte leakage and rate of water loss, higher photosynthetic production and net photosynthesis rate, and showed up-regulation of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), all of which are key antioxidant enzymes known to be activated during drought stress. Moreover, we observed the up-regulation of four additional drought stress indicator genes, SIDREB2A, SIAREB, SIRD29 and SIERD10, in the OE lines. VvHDZ4 improved drought tolerance in tomato, and the modes of action possibly consist of reducing membrane damage, increasing photosynthetic productivity, and modulating the expression of stress defense genes. CONCLUSIONS: This work increases our understanding of the important roles HD-Zip transcription factors in the responses of plants to the environment, especially abiotic stress. [ABSTRACT FROM AUTHOR]

Background & Objective: The results of epidemiologic studies on the relationship between the coffee consumption and pancreatic cancer risk were inconsistent. Thus, we performed an update meta-analysis of cohort studies to quantitatively summarize the association between coffee consumption and pancreatic cancer risk. Methods: We searched CBM (China Biology Medicine disc) and MEDLINE for studies of coffee consumption and pancreatic cancer risk up to June 2015. A total of 20 cohort studies were identified in this metaanalysis, and we analyzed these studies using random effects model. The dose-response analysis was conducted too. Results: The overall relative risk (RR) for highest coffee consumption versus lowest coffee consumption was 0.75 (95% Confidence Interval (CI), 0.63-0.86). Statistic significant heterogeneity was found among these studies (I² =37.8%, P for heterogeneity =0.045). The pooled RR for increment of 1 cup/day of coffee consumption was 0.99 (95%CI, 0.96-1.03) for the nine studies, without statistically significant. Conclusions: High coffee consumption is associated with a reduced pancreatic cancer risk. However, the result should be accepted with caution, due to the potential confounder and bias could not be excluded. Further well designed studies are needed to confirm the finding. [ABSTRACT FROM AUTHOR]

This paper presents an improved priority list and neighborhood search (IPL-NS) method for ramp rate constrained unit commitment (RUC). The IPL-NS consists of two steps. At the first step, an IPL based on a mixed integer linear programming (MILP) formulation for UC is proposed to get unit status for UC without ramp rate constraints. At the second step, a neighborhood search (NS) algorithm based on three neighborhoods is produced to get unit status for RUC. The IPL-NS approach is applied to solve several popular test systems of up to 1000 units and the simulation results confirm the superiority of the proposed method. At the same time, the numerical results show that the proposed IPL can commit the most economic unit first much better than other existing PL methods. The results also indicate that the presented NS can handle the ramp rate constraints efficiently. [ABSTRACT FROM AUTHOR]

Highlights: [•] A tighter relaxation method is proposed for unit commitment based on SOCP and VIs. [•] All the MCIs for minimum on/off time constraints are obtained by simple formulas. [•] The proposed method has good convergence properties. [Copyright &y& Elsevier]

Due to the high randomness and volatility of renewable energy sources such as wind energy, the traditional thermal unit commitment (UC) model is no longer applicable. In this paper, in order to reduce the possible negative effects of an inaccurate wind energy forecast, the chance-constrained programming (CCP) method is used to study the UC problem with uncertainty wind power generation, and chance constraints such as power balance and spinning reserve are satisfied with a predetermined probability. In order to effectively solve the CCP problem, first, we used the sample average approximation (SAA) method to transform the chance constraints into deterministic constraints and to obtain a mixed-integer quadratic programming (MIQP) model. Then, the quadratic terms were incorporated into the constraints by introducing some auxiliary variables, and some second-order cone constraints were formed by combining them with the output characteristics of thermal unit; therefore, a tighter mixed-integer second-order cone programming (MISOCP) formulation was obtained. Finally, we applied this method to some systems including 10 to 100 thermal units and 1 to 2 wind units, and we invoked MOSEK in MATLAB to solve the MISOCP formulation. The numerical results obtained within 24 h confirm that not only is the MISOCP formulation a successful reformulation that can achieve better suboptimal solutions, but it is also a suitable method for solving the large-scale uncertain UC problem. In addition, for systems of up to 40 units within 24 h that do not consider wind power and pollution emissions, the numerical results were compared with those of previously published methods, showing that the MISOCP formulation is very promising, given its excellent performance. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, by means of “working set” technique for determining the active set and the idea of primal–dual interior-point method, a new feasible QP-free algorithm for solving inequality constrained optimization problems is presented. At each iteration, the algorithm solves only three reduced systems of linear equations with common coefficient matrix. Moreover, the initial iteration point can be at constraint boundary and the coefficient matrix is uniformly nonsingular without the strict complementarity. We also prove that the proposed algorithm obtains global and superlinear convergence. At last, preliminary numerical results are reported. [Copyright &y& Elsevier]

Abstract: In this paper, the nonlinear minimax problems with inequality constraints are discussed, and a sequential quadratic programming (SQP) algorithm with a generalized monotone line search is presented. At each iteration, a feasible direction of descent is obtained by solving a quadratic programming (QP). To avoid the Maratos effect, a high order correction direction is achieved by solving another QP. As a result, the proposed algorithm has global and superlinear convergence. Especially, the global convergence is obtained under a weak Mangasarian–Fromovitz constraint qualification (MFCQ) instead of the linearly independent constraint qualification (LICQ). At last, its numerical effectiveness is demonstrated with test examples. [Copyright &y& Elsevier]

Abstract: In this work, combining the generalized projection techniques with the idea of a strongly sub-feasible direction method, a new algorithm for solving systems of nonlinear inequalities is presented. At each iteration of the proposed algorithm, the search direction is yielded by just one new explicit formula. The proposed algorithm is proved not only to possess global and strong convergence but also to be able to produce a solution in a finite number of iterations. Finally, some interesting numerical results are reported. [Copyright &y& Elsevier]

The equilibrium solubility of cesium chloride + europium trichloride + hydrogen chloride (0.11) + water (298.15 K) quaternary system at T=298.15 K was investigated and the corresponding phase diagram was constructed. The two new compounds Cs5EuCl8·14H2O and Cs2EuCl5·4H2O were formed and obtained from the complicated system, both were characterized by X-ray, thermal analysis method of TG-DTG, DSC, ultra-violet absorption spectrometry and fluorescence spectrum. The fluorescence excitation and emission spectra of Cs5EuCl8·14H2O and Cs2EuCl5·4H2O were measured. The results show that upconversion spectra exhibit at 590 nm and 610 nm exited at 790 nm, and the upconversion intensity increase with the EuCl3 ratio increasing in CsCl. [Copyright &y& Elsevier]

Abstract: A new norm-relaxed sequential quadratic programming algorithm with global convergence for inequality constrained problem is presented in this paper, and the quadratic programming subproblem can be solved at each iteration. Without the boundedness assumptions on any of the iterative sequences, the global convergence can be guaranteed by line search with penalty function and under some mild assumptions. [Copyright &y& Elsevier]

Equilibrium phase relations and the solubility data for the rare earth trichloride RECl3·nH2O (RE La, n7; RE Nd, Sm, Eu, n6) and cadmium chloride CdCl2·2.5H2O in the aqueous system were investigated. The corresponding equilibrium phase diagrams in the ternary system CdCl2−RECl3−H2O at 303 K were constructed. The results showed that these systems were complicated and consisted of four stable equilibrium solid phases CdCl2·H2O, CdCl2·2.5H2O, Cd4RECl11·nH2O (n12, 14, 4:1 type), RECl3·7H2O and a metastable phase Cd8RECl19·16H2O (8:1 type). The new compounds Cd4RECl11·nH2O and Cd8RECl19·16H2O were found to be incongruently soluble in the systems. The 4:1 type compounds obtained were identified and characterized by the method of X-ray diffraction, thermogravimetry, and differential thermogravimetry (TG, DTG). [ABSTRACT FROM AUTHOR]