Two novel hierarchical homogeneous nanoarchitectures of TiO2 nanorods branched and P25-coated TiO2 nanotube arrays and their photocurrent performances

We report here for the first time the synthesis of two novel hierarchical homogeneous nanoarchitectures of TiO2 nanorods branched TiO2 nanotube arrays (BTs) and P25-coated TiO2 nanotube arrays (PCTs) using two-step method including electrochemical anodization and hydrothermal modification process. Then the photocurrent densities versus applied potentials of BTs, PCTs, and pure TiO2 nanotube arrays (TNTAs) were investigated as well. Interestingly, at -0.11 V and under the same illumination condition, the photocurrent densities of BTs and PCTs show more than 1.5 and 1 times higher than that of pure TNTAs, respectively, which can be mainly attributed to significant improvement of the light-absorbing and charge-harvesting efficiency resulting from both larger and rougher surface areas of BTs and PCTs. Furthermore, these dramatic improvements suggest that BTs and PCTs will achieve better photoelectric conversion efficiency and become the promising candidates for applications in DSSCs, sensors, and photocatalysis

Case-control study on fragility fractures in coal miners: A comparison between surface and underground workers

BackgroundThe prevalence of osteoporosis and osteopenia is higher among underground coal miners than surface workers. The special underground work environment and unhealthy habits such as smoking, drinking, and a high-salt diet may lead to changes in bone metabolism, increasing the risk of fragility fractures and placing a heavy economic burden on individuals and society. ObjectiveTo identify potential factors influencing fragility fractures among coal miners in different working environments and to provide a basis for targeted preventive measures to reduce the occurrence of fragility fractures.MethodsMale participants who attended at least one of the physical examinations in Kailuan Group between June 2006 and December 2020 were included in the study. The participants were divided into two groups based on their working environment: surface or underground. A case-control study was conducted, where patients with new fragility fractures served as the case group and participants without fragility fractures served as the control group. The two groups were matched with a case:control ratio of 1:4 by age (±1 year) and the same year of physical examination. The matching process was repeated twice, once for the surface working population and once for the underground working population. The analysis of risk factors was conducted using conditional logistic regression models.ResultsAmong a total of 113138 employees in Kailuan Group, 82631 surface workers and 30507 underground workers were included, respectively. The number of individuals who suffered fragility fractures was 1375, accounting for 1.22% of the total population. The incidence of fragility fractures in underground workers was significantly higher than that in surface workers (1.63%>1.07%, P<0.001). The results of conditional logistic regression model showed that current smoking (OR=1.26, 95%CI: 1.05, 1.51), manual labor (OR=1.37, 95%CI: 1.06, 1.78), diabetes (OR=1.26, 95%CI: 1.04, 1.54), sinus tachycardia (OR=1.81, 95%CI: 1.23, 2.66), history of stroke (OR=1.51, 95%CI: 1.09, 2.09), education at college and above (OR=0.65, 95%CI: 0.45, 0.95), high income level (OR=0.69, 95%CI: 0.54, 0.90), elevated hemoglobin (OR=0.91, 95%CI: 0.85, 0.98), and elevated total cholesterol (OR=0.90, 95%CI: 0.82, 0.99) were associated with fragility fractures in the surface working population of coal mines; current smoking (OR=1.48, 95%CI: 1.17, 1.87), current drinking (OR=1.26, 95%CI: 1.01, 1.56), manual labor (OR=2.64, 95%CI: 1.41, 4.94), history of dust exposure (OR=1.28, 95%CI: 1.03, 1.58), and obesity (OR=0.72, 95%CI: 0.52, 0.96) were associated with fragility fractures in the underground working population of coal mines.ConclusionIn preventing fragility fractures, special attention should be paid to the bone health of underground workers engaged in manual labor or having a history of dust exposure. It is important to correct their unhealthy behaviors in a timely manner, such as smoking and drinking, and to appropriately increase body weight to prevent fragility fractures. For surface workers, particular attention should be given to the high-risk group for fragility fractures, such as low family income per capita, manual labor, and having a history of stroke or diabetes; in addition, close monitoring of their resting heart rate, hemoglobin levels, and total cholesterol levels may help prevent fragility fractures

An Improved Convergence Condition of the MMS Iteration Method for Horizontal LCP of <i>H</i>₊-Matrices

In this paper, inspired by the previous work in (Appl. Math. Comput., 369 (2020) 124890), we focus on the convergence condition of the modulus-based matrix splitting (MMS) iteration method for solving the horizontal linear complementarity problem (HLCP) with H+-matrices. An improved convergence condition of the MMS iteration method is given to improve the range of its applications, in a way which is better than that in the above published article

Homogeneity of isosceles orthogonality and related inequalities

Abstract We study the homogeneity of isosceles orthogonality, which is one of the most important orthogonality types in normed linear spaces, from two viewpoints. On the one hand, we study the relation between homogeneous direction of isosceles orthogonality and other notions including isometric reflection vectors and L 2-summand vectors and show that a Banach space X is a Hilbert space if and only if the relative interior of the set of homogeneous directions of isosceles orthogonality in the unit sphere of X is not empty. On the other hand, we introduce a geometric constant NH X to measure the non-homogeneity of isosceles orthogonality. It is proved that 0 &#8804; NH X &#8804; 2, NH X = 0 if and only if X is a Hilbert space, and NH X = 2 if and only if X is not uniformly non-square. Mathematics Subject Classification (2010): 46B20; 46C15</p

Relaxed Modulus-Based Matrix Splitting Methods for the Linear Complementarity Problem

In this paper, we obtain a new equivalent fixed-point form of the linear complementarity problem by introducing a relaxed matrix and establish a class of relaxed modulus-based matrix splitting iteration methods for solving the linear complementarity problem. Some sufficient conditions for guaranteeing the convergence of relaxed modulus-based matrix splitting iteration methods are presented. Numerical examples are offered to show the efficacy of the proposed methods

Scheduling of deteriorating jobs with release dates to minimize the maximum lateness

AbstractIn this paper, we consider the problem of scheduling n deteriorating jobs with release dates on a single (batching) machine. Each job’s processing time is a simple linear function of its starting time. The objective is to minimize the maximum lateness. When the machine can process only one job at a time, we first show that the problem is NP-hard even if there are only two distinct release dates. Then we present a 2-approximation algorithm for the case where all jobs have negative due dates. Furthermore, we prove that the earliest due date (EDD) rule provides an optimal solution to the case where all jobs have agreeable release dates, due dates and deteriorating rates, and that the EDD rule gives the worst order for the general case, respectively. When the machine can process up to b(b=∞) jobs simultaneously as a batch, i.e., the unbounded parallel-batch scheduling model, we show that the problem is NP-hard and present one property of the optimal schedule for the case where all jobs have agreeable release dates and due dates

A Distributed Conjugate Gradient Online Learning Method over Networks

In a distributed online optimization problem with a convex constrained set over an undirected multiagent network, the local objective functions are convex and vary over time. Most of the existing methods used to solve this problem are based on the fastest gradient descent method. However, the convergence speed of these methods is decreased with an increase in the number of iterations. To accelerate the convergence speed of the algorithm, we present a distributed online conjugate gradient algorithm, different from a gradient method, in which the search directions are a set of vectors that are conjugated to each other and the step sizes are obtained through an accurate line search. We analyzed the convergence of the algorithm theoretically and obtained a regret bound of OT, where T is the number of iterations. Finally, numerical experiments conducted on a sensor network demonstrate the performance of the proposed algorithm