Reduced-Order GPIO Based Dynamic Event-Triggered Tracking Control of a Networked One-DOF Link Manipulator Without Velocity Measurement

In networked robot manipulators that deeply integrate control, communication and computation, the controller design needs to take into consideration the limited or costly system resources and the presence of disturbances/uncertainties. To cope with these requirements, this paper proposes a novel dynamic event-triggered robust tracking control method for a onedegree of freedom(DOF) link manipulator with external disturbance and system uncertainties via a reduced-order generalized proportional-integral observer(GPIO). By only using the sampled-data position signal, a new sampled-data robust output feedback tracking controller is proposed based on a reduced-order GPIO to attenuate the undesirable influence of the external disturbance and the system uncertainties. To save the communication resources, we propose a discrete-time dynamic event-triggering mechanism(DETM), where the estimates and the control signal are transmitted and computed only when the proposed discrete-time DETM is violated. It is shown that with the proposed control method, both tracking control properties and communication properties can be significantly improved. Finally, simulation results are shown to demonstrate the feasibility and efficacy of the proposed control approach.

Only Sunda and Chinese pangolin(Pholidota)are naturally distributed in China

INTRODUCTION Pangolin is the common name for animals in the Family Pholidota,Mammalia,which consists of eight extant species.All pangolin species have been listed as critically endangered(CR),endangered(EN),or vulnerable(VU)species in the International Union for Conservation of Nature(IUCN)Red List of Threatened Species(Challender et al.2020).In June 2020,the Chinese government upgraded the Chinese pangolin(Manis pentadactyla Linnaeus,1758)from a national second-class protected animal to a national first-class protected animal.In February 2021,the Sunda pangolin(Manis javanica Desmarest,1822)and the Indian pangolin(Manis crassicaudata Geoffroy,1803)were added to the list of national first-class protected animals.However,the number of species of pangolins naturally distributed in China varies in the literature:Some sources have recorded only one species,namely the Chinese pangolin(Nowak&Paradiso 1983;Sheng 1999),while most have recorded two species,namely the Chinese pangolin and Indian pangolin(Allen 1938;Zhang 1997;Wang 2003;Wu et al.2005a;Hu&Hu 2017).

Transferable Features from 1D-Convolutional Network for Industrial Malware Classification

With the development of information technology,malware threats to the industrial system have become an emergent issue,since various industrial infrastructures have been deeply integrated into our modern works and lives.To identify and classify new malware variants,different types of deep learning models have been widely explored recently.Generally,sufficient data is usually required to achieve a well-trained deep learning classifier with satisfactory generalization ability.However,in current practical applications,an ample supply of data is absent in most specific industrial malware detection scenarios.Transfer learning as an effective approach can be used to alleviate the influence of the small sample size problem.In addition,it can also reuse the knowledge from pretrained models,which is beneficial to the real-time requirement in industrial malware detection.In this paper,we investigate the transferable features learned by a 1D-convolutional network and evaluate our proposed methods on 6 transfer learning tasks.The experiment results show that 1D-convolutional architecture is effective to learn transferable features for malware classification,and indicate that transferring the first 2 layers of our proposed 1D-convolutional network is the most efficient way to reuse the learned features.

植物氮形态利用策略及对外来植物入侵性的影响

氮是影响外来植物入侵性的重要因素之一,但相关研究多关注土壤氮水平的效应,较少考虑氮形态的作用。为从土壤氮形态利用的角度阐释外来植物的入侵机制,本文在植物氮形态利用策略分析的基础上,综述了外来植物氮形态利用的偏好性及其对入侵性的影响。植物的氮形态利用策略有偏好性和可塑性两种,这可能与植物对土壤氮形态特性的长期适应有关;植物不仅可以对土壤氮形态做出响应,而且还能改造土壤氮形态,并对改变后的土壤氮形态做出反馈响应。很多外来植物入侵硝态氮占优势的干扰生境,偏好硝态氮的外来植物与本地植物竞争硝态氮;而偏好铵态氮的外来植物通过抑制土壤硝化作用,营造铵态氮环境,促进自身生长,同时抑制偏好硝态氮的本地植物生长。然而,植物氮形态利用策略不是一成不变的,而是受多种生物和非生物因素共同作用影响的复杂过程,今后应加强多因素交互作用对外来入侵植物氮形态利用策略的影响及机制研究,更好地揭示氮形态利用策略,尤其是氮形态利用的可塑性与外来植物入侵性的关系。

120 mm Single-crystalline perovskite and wafers： towards viable applications

As the large single-crystalline silicon wafers have revolutionized many industries including electronics and solar cells, it is envisioned that the availability of large single-crystalline perovskite crystals and wafers will revolutionize its broad applications in photovoltaics, optoelectronics, lasers, photodetectors, light emitting diodes(LEDs), etc. Here we report a method to grow large single-crystalline perovskites including single-halide crystals: CH3NH3PbX3(X=I, Br, Cl), and dual-halide ones:CH3NH3Pb(ClxBr1.x)3 and CH3NH3Pb(BrxI1.x)3, with the largest crystal being 120 mm in length. Meanwhile, we have advanced a process to slice the large perovskite crystals into thin wafers. It is found that the wafers exhibit remarkable features:(1)its trap-state density is a million times smaller than that in the microcrystalline perovskite thin films(MPTF);(2) its carrier mobility is 410 times higher than its most popular organic counterpart P3HT;(3) its optical absorption is expanded to as high as910 nm comparing to 797 nm for the MPTF;(4) while MPTF decomposes at 150 °C, the wafer is stable at high temperature up to270 °C;(5) when exposed to high humidity(75% RH), MPTF decomposes in 5 h while the wafer shows no change for overnight;(6) its photocurrent response is 250 times higher than its MPTF counterpart. A few electronic devices have been fabricated using the crystalline wafers. Among them, the Hall test gives low carrier concentration with high mobility. The trap-state density is measured much lower than common semiconductors. Moreover, the large SC-wafer is found particularly useful for mass production of integrated circuits. By adjusting the halide composition, both the optical absorption and the light emission can be fine-tuned across the entire visible spectrum from 400 nm to 800 nm. It is envisioned that a range of visible lasers and LEDs may be developed using the dual-halide perovskites. With fewer trap states, high mobility, broader absorption, and humidity resistance, it is expected that solar cells with high stable efficiency maybe attainable using the crystalline wafers.