General Control Scheme Research Articles

How Screening plays role in Covid-19 management? Results of a Cross-Sectional Study on Covid-19 patients signs and symptoms

Background and objective: Today, COVID-19 outbreak has become a global alert. So, lots of medical complications and socioeconomic and mental burdens have arisen following the outbreak of the disease. There is no adequate general strategy for total control of the virus’s widespread. According to this, preventive or early diagnostic measures are crucial. In this study, we designed a questionnaire in the context of the 4030 telephonic platform to assess the most common symptoms of COVID-19 in Iran. 
 Materials and Methods: A questionnaire that had been designed with 20 common and rare symptoms of COVID-19 was filled out by 115 operators of 4030, a 24-hour call center to answer the Iranians' questions associated with COVID-19 and screen probable COVID-19 cases.
 Results: Common COVID-19 symptoms among people included cough, dyspnea, sore throat, myalgia, headache, anosmia, fever, dysgeusia, chilling, lethargy, and fatigue. Also, less common symptoms were rhinorrhea, sneeze, vomiting, diarrhea, nasal congestion, eyesore, stomach ache, jaw pain, dry mouth, and abdominal cramps. 
 Discussion and Conclusion: Our study showed that the most common symptoms of COVID-19 in Iran include cough, dyspnea, sore throat, myalgia, headache, anosmia, fever, dysgeusia, chilling, lethargy, and fatigue. Some symptoms may incident due to over-use of disinfectants, or aggravated by fear of infection, or misdiagnosed with other issues such as food poisoning, flu, panic attacks, and allergies. Consequently, It seems that screening can help find new cases who haven’t refered to hospitals and health care centres, and this can result in COVID-19 improving, Covid-19 management, and decreasing the costs of patients and health systems.

Quasi-convex feasibility problems: Subgradient methods and convergence rates

The feasibility problem is at the core of the modeling of many problems in various areas, and the quasi-convex function usually provides a precise representation of reality in many fields such as economics, finance and management science. In this paper, we consider the quasi-convex feasibility problem (QFP), that is to find a common point of a family of sublevel sets of quasi-convex functions, and propose a unified framework of subgradient methods for solving the QFP. This paper is contributed to establish the quantitative convergence theory, including the iteration complexity and the convergence rates, of subgradient methods with the constant/dynamic stepsize rules and several general control schemes, including the α-most violated constraints control, the s-intermittent control and the stochastic control. An interesting finding is disclosed by iteration complexity results that the stochastic control enjoys both advantages of low computational cost requirement and low iteration complexity. More importantly, we introduce a notion of Hölder-type error bound property for the QFP, and use it to establish the linear (or sublinear) convergence rates for subgradient methods to a feasible solution of the QFP. Preliminary numerical results to the multiple Cobb-Douglas productions efficiency problem indicate the powerful modeling capability of the QFP and show the high efficiency and stability of subgradient methods for solving the QFP.

Update Atrial Fibrillation - Current Management strategies

Atrial fibrillation (AF) is the most common arrhythmia. The European Society of Cardiology released a new version of the guideline to streamline AF-management and current studies highlight the importance of early treatment.Oral anticoagulation to prevent thromboembolic events remains essential in AF-management for patients at risk. NOAK therapy, if possible, is recommend as first line treatment. In general rhythm or rate control strategies are available. Symptomatic patients and patients with heart failure should be offered an early rhythm control. Catheter ablation is effective for rhythm control and and should be offered early in AF treatment additional to treatment of risk factors and comorbidities.

Rhipicephalus Tick: A Contextual Review for Southeast Asia.

Rhipicephalus species are distributed globally with a notifiable presence in Southeast Asia (SEA) within animal and human populations. The Rhipicephalus species are highly adaptive and have established successful coexistence within human dwellings and are known to be active all year round, predominantly in tropical and subtropical climates existing in SEA. In this review, the morphological characteristics, epidemiology, and epizootiology of Rhipicephalus tick species found in SEA are reviewed. There are six commonly reported Rhipicephalus ticks in the SEA region. Their interactions with their host species that range from cattle, sheep, and goats, through cats and dogs, to rodents and man are discussed in this article. Rhipicephalus-borne pathogens, including Anaplasma species, Ehrlichia species, Babesia species, and Theileria species, have been highlighted as are relevant to the region in review. Pathogens transmitted from Rhipicepahalus ticks to host animals are usually presented clinically with signs of anemia, jaundice, and other signs of hemolytic changes. Rhipicephalus ticks infestation also account for ectoparasitic nuisance in man and animals. These issues are discussed with specific interest to the SEA countries highlighting peculiarities of the region in the epidemiology of Rhipicephalus species and attendant pathogens therein. This paper also discusses the current general control strategies for ticks in SEA proffering measures required for increased documentation. The potential risks associated with rampant and improper acaricide use are highlighted. Furthermore, such practices lead to acaricide resistance among Rhipicephalus species are highlighted.

CFD Simulation of the Airborne Transmission of COVID-19 Vectors Emitted during Respiratory Mechanisms: Revisiting the Concept of Safe Distance.

The airborne transmission of the COVID-19 virus has been suggested as a major mode of transmission in recent studies. In this context, we studied the spatial transmission of COVID-19 vectors in an indoor setting representative of a typical office room. Computational fluid dynamics (CFD) simulations were performed to study the airborne dispersion of particles ejected due to different respiratory mechanisms, i.e., coughing, sneezing, normal talking, and loud talking. Number concentration profiles at a distance of 2 m in front of the emitter at the ventilation rates of 4, 6, and 8 air changes per hour (ACH) were estimated for different combinations of inlet–outlet positions and emitter–receptor configurations. Apart from respiratory events, viz., coughing and sneezing characterized by higher velocity and concentration of ejected particles, normal as well as loud talking was seen to be carrying particles to the receptor for some airflow patterns in the room. This study indicates that the ″rule of thumb based safe distance approach″ cannot be a general mitigation strategy for infection control. Under some scenarios, events with a lower release rate of droplets such as talking (i.e., asymptomatic transmission) can lead to a high concentration of particles persisting for long times. For better removal, the study suggests ″air curtains″ as an appropriate approach, simultaneously highlighting the pitfalls in the ″higher ventilation rate for better removal″ strategy. The inferences for talking-induced particle transmissions are crucial considering that large populations of COVID-19-infected persons are projected to be asymptomatic transmitters.

Screening and band bending effects in the Stark control of electrons at interfaces (SCELI)

Recently, we developed a general laser control scheme, i.e., the Stark control of electrons at interfaces (SCELI), based on Stark shifts, that is able to manipulate the electron dynamics at material interfaces [A. J. Garz\'on-Ram\'{\i}rez and I. Franco, Phys. Rev. B 98, 121305 (2018)]. Here, we investigate how SCELI is influenced by the band bending effects introduced by interfacial dipoles and by the laser screening due to the polarization response of the material. For this, we follow the quantum dynamics of a model one-dimensional tight-binding semiconductor-semiconductor heterojunction driven by nonresonant few-cycle laser pulses of intermediate intensity. Band bending effects are introduced through an interfacial electrostatic potential term dictated by the depletion approximation of a neutral $p\text{\ensuremath{-}}n$ junction. In turn, screening effects are captured through the general boundary conditions of the field vectors at interfaces dictated by Maxwell's equations. For field amplitudes where SCELI dominates (${E}_{0}\ensuremath{\le}0.55$ V/\AA{} in the model), laser screening leads to a 46% reduction of the effect that can be partially compensated by increasing the intensity of the incident field. Surprisingly, band bending mildly affects SCELI. When both band bending and screening are considered simultaneously, the charge transfer is reduced, on average, 40% for ${E}_{0}\ensuremath{\le}0.46$ V/\AA{}. Overall, we observe that screening and band bending change the magnitude of SCELI but leave the underlying mechanism for electron transfer intact.

New control strategy for suppressing the local vibration of sandwich beams based on the wave propagation method

The general vibration control strategy of beam structures is a global vibration control method based on the principle of modal superposition. However, the vibration wave control of beams can achieve local control of the vibration energy. This paper presents a wave control method for the local vibration control of fractional viscoelastic composite beams based on the operating principle of a piezoelectric sheet. To obtain better control performance, a particle swarm optimization algorithm was adopted to optimize the parameters of the piezoelectric sheet. A linear quadratic regulator control algorithm was designed to verify the validity of the proposed method. In addition, the effects of the piezoelectric sheet number and fractional order on the amplitude response and optimization parameters were investigated. We observed that the proposed method has a good control effect on the local area vibration, and it can control the flow direction of the vibration power. The proposed method can be used to directly design the voltage and phase of a piezoelectric sheet without real-time feedback computation. This method is suitable for reducing local vibration under single repetitive operating conditions in engineering and can provide a theoretical basis for a follow-up study on the acoustic black hole phenomenon.

Hierarchical task-based formation control and collision avoidance of UAVs in finite time

This work addresses the problem of distributedly controlling the position of a group of Unmanned Aerial Vehicles (UAVs), that are considered as holonomic three-dimensional agents, to achieve a desired formation while collisions are avoided. We propose a generic control scheme computed by the adaptive convex combination of two control laws dealing with two, possibly conflicting, tasks, which are formation control and obstacle avoidance. The main contributions of the paper are threefold: First, the whole proposed scheme is distributed by nature, since the formation control is formulated as a consensus problem of virtual agents and the collision avoidance strategy is reactive, valid for unknown environments. Second, two control protocols are proposed to guarantee convergence to the desired formation in finite or predefined time; in the last case, the formation is achieved in a constant time independently of the initial UAVs positions. And finally, the control scheme generates continuous control signals in spite of activation and deactivation of the obstacle avoidance task, and stability is proved even in the transition of tasks. The effectiveness of the proposed approach is shown through realistic simulations and real experiments for a group of quadrotors.

A generalized control scheme for system uncertainty estimation and cancellation

This paper addresses the control of a continuous-time system with possibly large uncertainty of unknown internal dynamics or external disturbance. A novel control scheme is proposed to estimate and cancel the system uncertainty effectively so as to enhance disturbance rejection (DR) performance. Unlike asymptotic analysis with infinite gain in the literature, the estimation transient analysis is carried out for the proposed scheme with a finite estimator gain and the precise error formulas are derived, based on a classical low-order plant description. The control performance associated with a realizable gain is quantified by tight bounds with respect to the ideal case, which enables easy parameter tuning. The necessary and sufficient condition for the internal stability of the control system is established, along with a D-decomposition method for determining the complete set of the gain intervals that could internally stabilize the plant. In the presence of measurement noise, a low-pass filter is introduced to attenuate its adverse effect. Simulations and semi-realistic experiments are performed to demonstrate the effectiveness of the proposed scheme, which shows evident improvement on DR performance over the well-known active DR control.

A General Control Strategy to Micropattern Topological Defects in Nematic Liquid Crystals Using Ionically Charged Dielectric Surface

AbstractTailoring self‐organized nano/microstructures in soft materials is crucial for exploiting intrinsic functional properties toward emerging applications. Engineered topological defects in liquid crystals are interesting for electro‐optical devices as well as for soft actuators morphing surface. Despite the promising potential, there are currently few bottom‐up methods for positioning a large number of defects periodically over a large area. It is highly challenging to develop essential techniques for achieving high‐throughput fabrication with simple procedure. Using ultraviolet/ozone treatment, herein we present a general and robust strategy to produce the surface that can be a platform for a self‐organized micropattern of topological defects in nematic liquid crystals, irrespective of the chemical structure of compounds including polymerizable monomers. The micropattern formation is controllable by applying area‐selective surface modification, which dramatically improves the fabrication efficiency. By low frequency impedance spectroscopy, the distinctive frequency dependence of the apparent threshold voltage at the micropattern formation is experimentally assigned to a unique reorientational response which occurs when a dielectric surface is charged by ionic additives. This characterization provides crucial guidance in further engineering self‐organized topological defects in liquid crystals.

Master-Slave Synchronization of Delayed Neural Networks With Time-Varying Control.

This brief investigates the master-slave synchronization problem of delayed neural networks with general time-varying control. Assuming a linear feedback controller with time-varying control gain, the synchronization problem is recast into the stability problem of a delayed system with a time-varying coefficient. The main theorem is established in terms of the time average of the control gain by using the Lyapunov-Razumikhin theorem. Moreover, the proposed framework encompasses some general intermittent control schemes, such as the switched control gain with external disturbance and intermittent control with pulse-modulated gain function, while some useful corollaries are consequently deduced. Interestingly, our theorem also provides a solution for regaining stability under control failure. The validity of the theorem and corollaries is further demonstrated with numerical examples.

Fixed-time adaptive general type-2 fuzzy logic control for air-breathing hypersonic vehicle

This paper proposes a novel fixed-time adaptive general type-2 fuzzy logical control (FAGT2FLC) scheme for an air-breathing hypersonic vehicle (AHV) with uncertainties. Firstly, the AHV dynamic model is transformed into a strict feedback form. Then, the FAGT2FLC is designed based on the transformed model to improve robustness and guarantee fixed-time convergence of the closed-loop system. The general type-2 fuzzy logic system (GT2FLS) is utilized to approximate the model uncertainties; for the purpose of designing adaptive laws, the [Formula: see text]-plane method is employed to represent the GT2FLS. A parameter projection operator is used to solve the possible singularity problem of parameter adaption. Besides, a fixed-time differentiator is used to deal with the “explosion of terms” inherent in backstepping method. Theoretical analysis based on relevant lemmas shows that the closed-loop system will converge into a small error band in fixed time. Lastly, detailed simulations are carried out to demonstrate the effectiveness and superiority of the proposed control scheme.

Model-free anti-swing control of complex-shaped payload with offshore floating cranes and a large number of lift wires

Being one of the most commonly used offshore operations, offshore lifting operations become increasingly challenging due to the gradually growing size and weight of payloads. The research on automatic control in lifting operations, e.g., anti-swing control and heave compensation, only considers simple-shaped payloads, such as lumped-mass rigid points. However, the sizes and orientations of many structures cannot be neglected. To lift heavy and large-scale payloads, larger and higher cranes are required. Alternatively, it is possible to share the total loads by enhancing the number of lift wires that may limit the tension on each lift wire. However, the complicated configuration introduces significant complexity into the design of the automatic anti-swing algorithm, especially to the control allocation module. This paper performs a preliminary study on the anti-swing control of a complex-shaped suspended payload lift using a floating crane vessel and a large number of lift wires. Inspired by the knowledge of inverse dynamics and range-based localization, a general model-free anti-swing control scheme is proposed. The controller has a simple form without considering state–space equations, but it can reduce the pendular payload motion regardless of the detailed system configuration. An offshore wind turbine tower–nacelle–rotor preassembly installation using floating crane vessel is adopted as a case study to verify the performance of the proposed control strategy.

A Multi-Input Single-Output iterative learning control for improved material placement in extrusion-based additive manufacturing

A major limitation in extrusion-based additive manufacturing (AM) is the lack of process monitoring and control tools in the material deposition frame. Iterative learning control (ILC) has been demonstrated to be an effective control strategy (Hoelzle et al., 2009; Bristow & Alleyne, 2003) due to the repetitive nature of manufacturing processes, but for much of the prior work of ILC in AM, the focus was on precise control of the machine components. To improve on fabricated part quality, we apply ILC directly to the material deposition to account for uncertainty in material behavior and imperfect coordination between the material flow and the machine axes. This paper presents a novel Multi-Input Single-Output (MISO) Iterative Learning Control (ILC) method that couples the extrusion input and axis speed to improve material width control along the trajectory. MISO ILC partitions the error to the different stages through frequency separation to avoid input saturation. MISO ILC uses process feedback in the material deposition frame to improve material placement. The stability and convergence properties for the MISO ILC system are presented in the lifted domain. Simulation and experimental system results on an extrusion printing system demonstrate that MISO ILC achieves improved material placement control along the path. While we apply the MISO ILC to a specific extrusion system, we present a general control strategy that can be implemented for other MISO applications.

Health, work performance, and risk of infection in office-like environments: The role of indoor temperature, air humidity, and ventilation.

Epidemiological and experimental studies have revealed the effects of the room temperature, indoor air humidity, and ventilation on human health, work and cognitive performance, and risk of infection. In this overview, we integrate the influence of these important microclimatic parameters and assess their influence in offices based on literature searches. The dose-effect curves of the temperature describe a concave shape. Low temperature increases the risk of cardiovascular and respiratory diseases and elevated temperature increases the risk of acute non-specific symptoms, e.g., dry eyes, and respiratory symptoms. Cognitive and work performance is optimal between 22°C and 24°C for regions with temperate or cold climate, but both higher and lower temperatures may deteriorate the performances and learning efficiency. Low temperature may favor virus viability, however, depending on the status of the physiological tissue in the airways. Low indoor air humidity causes vulnerable eyes and airways from desiccation and less efficient mucociliary clearance. This causes elevation of the most common mucous membrane-related symptoms, like dry and tired eyes, which deteriorates the work performance. Epidemiological, experimental, and clinical studies support that intervention of dry indoor air conditions by humidification alleviates symptoms of dry eyes and airways, fatigue symptoms, less complaints about perceived dry air, and less compromised work performance. Intervention of dry air conditions by elevation of the indoor air humidity may be a non-pharmaceutical treatment of the risk of infection by reduced viability and transport of influenza virus. Relative humidity between 40 and 60% appears optimal for health, work performance, and lower risk of infection. Ventilation can reduce both acute and chronic health outcomes and improve work performance, because the exposure is reduced by the dilution of the indoor air pollutants (including pathogens, e.g., as virus droplets), and in addition to general emission source control strategies. Personal control of ventilation appears an important factor that influences the satisfaction of the thermal comfort due to its physical and positive psychological impact. However, natural ventilation or mechanical ventilation can become sources of air pollutants, allergens, and pathogens of outdoor or indoor origin and cause an increase in exposure. The "health-based ventilation rate" in a building should meet WHO's air quality guidelines and dilute human bio-effluent emissions to reach an acceptable perceived indoor air quality. Ventilation is a modifying factor that should be integrated with both the indoor air humidity and the room temperature in a strategic joint control to satisfy the perceived indoor air quality, health, working performance, and minimize the risk of infection.

Path Planning and Trajectory Tracking Strategy of Autonomous Vehicles

With the development of global urbanization and the construction of regional urbanization, residents around urban cities are increasingly making demands on urban public transportation system. A new kind of modern public transportation vehicle named Multi-Articulated Guided Vehicle based on Virtual Track (MAAV-VT) with the advantages of beautiful, smart energy conservation and environmental protection is proposed in this paper, which aims at optimizing the public transportation system between and within urban areas. Therefore, concentrating on the general design and control strategy, the main contents of this paper are as follows. At first, the design concepts and key technologies of MAAV-VT are introduced. It is the fusion of urban rail transit operation mode and advanced automotive technologies, which have the characteristics of 100% low-floor, medium to high velocity, medium to big capacity, and low construction cost. Then, as the core subsystem, to guarantee the properties of self-guiding and trajectory tracking of the new vehicle, this paper is focused on the control system based on the dynamics and kinematics model of the whole multi-articulated vehicle. The multi-trace-points cooperative trajectory tracking control strategy on the basis of the circulation of feasible path generation method is proposed and the lateral controller is designed for trajectory tracking. The process of feasible path generation is conducted once the tracking error exceeded. A simulation platform is built considering the mechanical properties of each vehicle element and the characteristic of articulated mechanism. Finally, the function of control system is validated. The tracking error of each vehicle elements would be reduced to make sure the whole multi-articulated vehicle moves along the preset virtual track.

Exponential Synchronization of Delayed Memristor-Based Uncertain Complex-Valued Neural Networks for Image Protection.

This article solves the exponential synchronization issue of memristor-based complex-valued neural networks (MCVNNs) with time-varying uncertainties via feedback control. Compared with the traditional control methods, a more practical and general control scheme with the available uncertain information of the parameters is newly developed for MCVNNs. Our approach considers the proposed neural networks as two dynamic real-valued systems. Then, the less conservative exponential synchronization criteria are proposed by incorporating the framework of the Lyapunov method and inequality techniques. Under the proposed algorithm, not only can the stability of MCVNNs be guaranteed but also the behavior of such a system is appropriate for image protection. Meanwhile, the sensitive measure of the encryption and decryption can be converted into synchronization error. When monitoring the secure mechanism as a whole, the influence of error feasible domain on image decryption is analyzed. Simulation examples are provided to verify the efficacy of the proposed synchronization criterion and the results of practical application on image protection.

Modelling and Transient Synchronization Stability Analysis for PLL-Based Renewable Energy Generator Considering Sequential Switching Schemes

The synchronization characteristics of phase-locked loop (PLL) based renewable energy generators (REG) are considerably sensitive to the grid condition and the inner sequential switching actions of their control system, especially suffered from grid faults. In this article, the general output characteristics of REG systems are investigated considering the nonlinear behaviour of PLL. In addition, general sequential switching control schemes for the entire grid fault process are introduced. Then, to physically determine and theoretically analyze the transient synchronization stability of REG systems, the synchronization model of a REG system for different fault stages is built and presented in the form of rotor swing equations, which are similar to those of a synchronous generator (SG). The proposed model was able to deduce the characteristics of virtual torque, virtual inertia, and virtual damping coefficient of the REG system, and identify the coupling relationship between the angular frequency/magnitude states of the terminal voltage of the REG system during the synchronization process. Thus, the synchronization stability criteria were proposed based on those of the SG, in which the transient instability phenomenon and mechanism for different fault stages is physically explained by the deduced equal area criteria. Finally, the analysis was verified by simulations and experiments.

Unified Fast-Dynamic Direct-Current Control Scheme for Intermediary Inductive AC-Link Isolated DC-DC Converters

The isolated dc-dc converters with middle inductive AC links dc-dc converter have been extensively studied in modern energy conversion applications for safety and reliability, especially those featuring intermediary inductive ac-link (I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL) configurations such as full-bridge dc-dc converter and dual-active-bridge (DAB). However, up to now, the dynamic equivalence in these I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL type converters has not been systematically revealed. To fill such a gap, in this paper, the existing I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL isolated dc-dc converters are reviewed thoroughly, including unidirectional type and bidirectional type. Then, the general current transferred features of these two groups are analyzed, respectively, and the transferred current during the transient process is just influenced by the middle inductance little. So, the I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL isolated dc-dc converter can be regarded as the first-order converter. Based on the discovered general characteristic, a unified fast-dynamic direct-current (FDDC) control scheme is proposed for improving the dynamic performance of these I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ACL isolated dc-dc converters. Such a scheme can also facilitate the uniform control design for existing or emerging new topologies with the same electrical equivalence. Moreover, the specialized design principles of the PI parameters in the unified FDDC control method are also presented. Finally, to verify the universality and feasibility of the proposed general FDDC control strategy, both simulation and experiment results are presented with demonstration examples, e.g., full-bridge type, DAB-type, and the three-phase DAB type dc-dc converters.

ZIF-8 derived ZnWO4 nanocrystals: Calcination temperature induced evolution of composition and microstructures, and their electrochemical performances as anode for lithium-ion batteries

Calcination temperature plays a key role in determining the phase purity, composition and microstructures for the zeolitic imidazolate frameworks (ZIFs) derived transition metal oxides materials, the investigation on the influences of the calcination temperature during ZIFs derivative process is helpful to dissect the reaction mechanism and the transformation process. The present work is aimed at constructing ZnWO4 nanocrystals derived from ZIF-8 via a facile strategy, and systematical study on the influences of calcination temperature during ZIFs derivative process on the microstructure, phase purity and composition of the final product. More importantly, the probable evolution mechanisms for the microstructure and the composition of the as-obtained final products are proposed. It is found that the crystallinity, composition, microstructure and electrochemical performances of the ZnWO4 samples strongly depend on the calcination temperature. When the calcination temperature is lower than 700 °C (500 and 600 °C), the ZnWO4/C composite nanocrystals can be obtained. Whereas the as-synthesized products are pure ZnWO4 nanocrystals featuring single crystalline under the higher calcination temperatures (700–900 °C). Due to the single crystalline structure and the optimal microstructures, the ZnWO4 sample obtained at 800 °C exhibits the superior electrochemical performances when applied as anode material for lithium-ion batteries such as excellent cyclic stability, higher capacity and better rate capability. The present work may provide the deep insight into the Zn-based materials derived from the ZIF-8, and paves a facile and general strategy for the precise control the microstructures and composition of the other transition metal oxides derived from ZIFs.