Recent advances in heterojunction and interfacial engineering of perovskite solar cells (PSCs) have enabled great progress in developing highly efficient and stable devices. Nevertheless, the effect of halide choice on the formation mechanism, crystallography, and photoelectric properties of the low-dimensional phase still requires further detailed study. In this work, we present key insights into the significance of halide choice when designing passivation strategies comprising large organic spacer salts, clarifying the effect of anions on the formation of quasi-2D/3D heterojunctions. To demonstrate the importance of halide influences, we employ novel neo-pentylammonium halide salts with different halide anions (neoPAX, X=I, Br, or Cl). We find that regardless of halide selection, iodide-based (neoPA) 2 (FA) ( n -1) Pb n I (3 n +1) phases are formed above the perovskite substrate, while the added halide anions diffuse and passivate the perovskite bulk. In addition, we also find the halide choice has an influence on the degree of dimensionality ( n ). Comparing the three halides, we find that chloride-based salts exhibit superior crystallographic, enhanced carrier transport, and extraction compared to the iodide and bromide analogs. As a result, we report high power conversion efficiency in quasi-2D/3D PSCs, which are optimal when using chloride salts, reaching up to 23.35%, and improving long-term stability.

In this manuscript, a delayed Nicholson-type model with linear harvesting terms is investigated. Applying coincidence degree theory, we establish a sufficient condition which guarantees the existence of positive periodic solutions for the delayed Nicholson-type model. By constructing suitable Lyapunov functions, a new criterion for the uniqueness and global attractivity of the periodic solution of the Nicholson-type delay system is obtained. The derived results of this article are completely new and complement some previous investigations.

This paper analytically and numerically presents global dynamics of the generalized Boussinesq equation (GBE) with cubic nonlinearity and harmonic excitation. The effect of the damping coefficient on the dynamical responses of the generalized Boussinesq equation is clearly revealed. Using the reductive perturbation method, an equivalent wave equation is then derived from the complex nonlinear equation of the GBE. The persistent homoclinic orbit for the perturbed equation is located through the first and second measurements, and the breaking of the homoclinic structure will generate chaos in a Smale horseshoe sense for the GBE. Numerical examples are used to test the validity of the theoretical prediction. Both theoretical prediction and numerical simulations demonstrate the homoclinic chaos for the GBE.

The raw vibration signal carries a great deal of information representing the mechanical equipment's health conditions. However, in the working condition, the vibration response signals of faulty components are often characterized by the presence of different kinds of impulses, and the corresponding fault features are always immersed in heavy noises. Therefore, signal denoising is one of the most important tasks in the fault detection of mechanical components. As a time-frequency signal processing technique without the support of the strictly mathematical theory, empirical mode decomposition (EMD) has been widely applied to detect faults in mechanical systems. Kernel regression (KR) is a well-known nonparametric mathematical tool to construct a prediction model with good performance. Inspired by the basic idea of EMD, a new kernel regression residual decomposition (KRRD) method is proposed. Nonparametric Nadaraya–Watson KR and a standard deviation (SD) criterion are employed to generate a deep cascading framework including a series of high-frequency terms denoted by residual signals and a final low-frequency term represented by kernel regression signal. The soft thresholding technique is then applied to each residual signal to suppress noises. To illustrate the feasibility and the performance of the KRRD method, a numerical simulation and the faulty rolling element bearings of well-known open access data as well as the experimental investigations of the machinery simulator are performed. The fault detection results show that the proposed method enables the recognition of faults in mechanical systems. It is expected that the KRRD method might have a similar application prospect of EMD.

Based on the status quo of cultivated land, this paper analyzes the existing problems and builds a dynamic monitoring system for cultivated land protection. It works by using the Internet of Things technology and geographic and national conditions to realize the systematization, informatization, and socialization of cultivated land protection, thereby promoting the sustainable development of cultivated land and social stability and harmony. This paper puts forward relevant countermeasures and suggestions for the protection of cultivated land. This paper constructs the farmland protection dynamic monitoring system, proposes the goals of the system construction, points out the ideas of the system construction, and designs and analyzes the key points of the system composition. The system includes seven subsystems, and the functions and specific contents of the subsystems are explained, respectively, to build the entire system. Then, we put forward the financial, technical, and implementation problems of the system, and find out countermeasures, expand the system research, propose the development of the dynamic monitoring system of cultivated land protection in the direction of intelligence and convenience, and expand the application to food safety and disasters. In terms of forecasting, comprehensive evaluation of the existence and operation of the system is carried out by designing evaluation indicators and weights for the operation of the system.

Background: Obesity has a permanent effect on childrens’ health and acts as a major risk factor for chronic diseases. Therefore considering children BMI is a vital parameter at each visit. Objectives: This study was performed to assess the prevalence of obesity and its determinants in school children of Zahedan in Iran. Zahedan is the capital of Sistan-and-Balouchestan province known to have the highest prevalence of underweight in Iranian children. Patients and Methods: This cross-sectional study was performed on 3582 school children, among which 1786 were girls and 1796 boys in 2012. The students aged 6 to 13 years old and selected based on a stratified random method. The body mass index (BMI) was measured for each student and being overweight/obesity was determined based on CDC 2000 definitions. Prevalence proportions were estimated by weighing the sample. The study was performed at primary and guidance schools of Zahedan. Samples were stratified from two geographic regions of Zahedan (Zone 1 and 2). Results: In the sample, 78.9% were under 85th percentile, 11.8% were overweight (85th - 95th percentile) and 9.3% were obese (> 95th percentile). Weighted estimate for the prevalence of obesity/overweight in girls, boys and all 6 - 13 years old students were 16.2%, 18.4% and 17.4%, respectively. Presence of overweight/obesity was related to school type (private to public schools OR = 2.13, 1.80 - 2.52) and increasing age (OR = 1.12, 1.04 - 1.20). Conclusions: A high prevalence of obesity was found in Zahedan students. Concurrent high prevalence of obesity/overweight and underweight demonstrates amplitude of weight problems in school children. There is an urgent need for special health programs to conduct proper diagnosis and management of obesity in Zahedan.