A novel stability criterion and precise control for linear time delay systems based on regional configuration of the poles.

This paper presents the concept of region stability and provides criteria for region stability of linear time delay systems, which can reveal the dynamic and steady-state performance of the systems more precisely. Corresponding design schemes for stabilization and tracking control that can accurately control various performance of time delay systems have also been explored. First, in the light of the connection between the poles and the dynamic properties of the system, the concept of region stability is given to describe the finer dynamic behavior of time delay systems. The criteria for the region stability are also presented. Second, the region stabilization methods are investigated, which can ensure that the system satisfies a certain dynamic performance by setting the eigenvalues in a certain convex region. Third, a precise tracking control of the linear time delay systems is addressed as an application of region stabilization. It can control the steady state performance and transient response of the tracking signal more precisely. Finally, three instances are provided to display the superiority of the new method for the performance indexes of the linear time delay systems.

Precise Tuning of Hollow and Pore Size of Bimetallic MOFs Derivate to Construct High-Performance Nanoscale Materials for Supercapacitors and Sodium-Ion Batteries.

Precise control of pore volume and size of carbon nanoscale materials is crucial for achieving high capacity and rate performances of charge/discharge. In this paper, starting from the unique mechanism of the role of In, Zn combination, and carboxyl functional groups in the formation of the lumen and pore size, the composition of InZn-MIL-68 is regulated to precisely tune the diameter and wall pore size of the hollow carbon tubes. The hollow carbon nanotubes (CNT) with high-capacity storage and fast exchange of Na+ ions and charges are prepared. The CNT possess ultra-high specific capacitance and ultra-long cycle life and also offer several times higher Na+ ion storage capacity and rate performance than the existing CNTs. Density functional theory calculations and tests reveal that these superior characteristics are attributed to the spacious hollow structure, which provides sufficient space for Na+ storage and the tube wall's distinctive porosity of tube wall as well as open ends for facilitating Na+ rapid desorption. It is believed that precise control of sub-nanopore volume and pore size by tuning the composition of the carbon materials derived from bimetallic metal-organic frameworks (MOFs) will establish the basis for the future development of high-energy density and high-power density supercapacitors and batteries.

Precise Control of Single-Crystal Perovskite Nanolasers.

Efficient control of integrated light sources is crucial to advancing practical applications of nanophotonics. Despite the success of microlasers, their sophisticated nanostructures are not applicable in nanolasers. The situation for bottom-up-synthesized nanolasers becomes more challenging due to the constraints of fixed cavity shapes and fragile material stability. Here, the physics of exceptional points (EPs) is employed, and a strategy is demonstrated to precisely tune the lasing actions in lead halide perovskite nanorods. By placing a nanoparticle to the boundary of a square nanocavity, it is shown that EPs regularly and controllably emerge as a function of the nanoparticle position. Consequently, both the internal lasing actions and their far-field radiation can be completely reversed with a tiny displacement of <100 nm. The new strategy for controlling lasing actions in nanocavities is confirmed with numerical simulations and lasing experiments. This research can also bring new avenues for ultrasensitive position sensing.

Development and application of an smart emergency respirator with open airway / 中华危重病急救医学

To solve the problems of insufficient airway opening, insufficient or excessive ventilation, ventilation interruption, and the rescuer's physical strength during the process of cardiopulmonary resuscitation (CPR) outside the hospital and in the hospital, and to ensure the accuracy of ventilation frequency rate and tidal volume. Zhongnan Hospital and School of Nursing, Wuhan University, jointly designed and developed a smart emergency respirator with open airway function, that has been granted National Utility Model Patent of China (ZL 2021 2 1557989.8). The device is structured of pillow, pneumatic booster pump and mask. It can be used simply by plugging the pillow under the patient's head and shoulder, turning on the power supply and wearing the mask. The smart emergency respirator can quickly and effectively open the patient's airway and give accurate ventilation with adjustable ventilation parameters. The default settings are 10 times/min in respiratory rate and 500 mL in tidal volume. The whole operation does not require the operator have professional operation ability, which can be independently applied used in any cases without oxygen source or power supply, therefore, the application scenario has no limit. The device has the advantages of small size, simple operation and low production cost, which can reduce human source, save physical strength and significantly improve the quality of CPR. The device is suitable for respiratory support in multiple scenes outside and inside the hospital, and can significantly improve the success rate of treatment.

A Multi-Stage Planning Method for Distribution Networks Based on ARIMA with Error Gradient Sampling for Source-Load Prediction.

As the scale of distributed renewable energy represented by wind power and photovoltaic continues to expand and load demand gradually changes, the future evolution of the smart distribution network will be directly driven by both distributed generation and user demand. The smart distribution network contains a wide range of flexible resources, and its flexibility and uncertainty will bring great challenges to grid data acquisition and control feedback. To adapt to the precise control and feedback of smart distribution network access equipment under the high proportion of new energy access and to ensure the safe operation of the system, it is urgent to accelerate the study of the evolution of the future distribution grid based on the existing distribution grid. Hence, a multi-stage planning method for distribution networks based on source-load prediction is proposed in this paper. Firstly, a distribution network source-load prediction method based on the autoregressive integrated moving average model (ARIMA) and error gradient sampling is proposed, using ARIMA to predict the scale of source-load development and error gradient sampling based on the generation of source-load scenarios with error intervals. K-means is further used for scenario reduction, to explore multiple operating scenarios of China's distribution network source-load, and the unit's output forecast interval and load demand from 2021 to 2030 for typical regions are derived using rolling forecasts by combining the unit's output, end-demand and clean energy share over the years. Secondly, the planning model of distribution grid evolution in different stages is constructed to analyze the future evolution form of the distribution grid considering the distribution network's load cross-section, respectively, and to provide a development path reference for the future construction of distribution grid form in China.

Unimolecular Nanoparticles toward More Precise Regulations of Self-Assembled Superlattices in Soft Matter.

The hierarchical self-assembly process opens up great potential for the construction of nanostructural superlattices. Precise regulation of self-assembled superlattices, however, remains a challenge. Even when the primary molecules are precise, the supramolecular motifs (or secondary building blocks) can vary dramatically. In the present work, we propose the concept of unimolecular nanoparticles (UMNPs). The UMNPs act as the supramolecular motif and directly pack into the superlattices. A highly branched giant molecule is presented. We systematically explore its conformations and the superlattice of this giant molecule. Moreover, intriguing complex phases are discovered when blending this UMNP with other conventional giant molecules. These binary mixtures provide direct evidence to support our previously proposed self-sorting process in the self-assembly of "soft alloys". The concept of UMNPs offers a unique approach toward more precise regulation of self-assembled superlattices in soft matter.

Sidechain Metallopolymers with Precisely Controlled Structures: Synthesis and Application in Catalysis.

Inspired by the cooperative multi-metallic activation in metalloenzyme catalysis, artificial enzymes as multi-metallic catalysts have been developed for improved kinetics and higher selectivity. Previous models about multi-metallic catalysts, such as cross-linked polymer-supported catalysts, failed to precisely control the number and location of their active sites, leading to low activity and selectivity. In recent years, metallopolymers with metals in the sidechain, also named as sidechain metallopolymers (SMPs), have attracted much attention because of their combination of the catalytic, magnetic, and electronic properties of metals with desirable mechanical and processing properties of polymeric backbones. Living and controlled polymerization techniques provide access to SMPs with precisely controlled structures, for example, controlled degree of polymerization (DP) and molecular weight dispersity (D), which may have excellent performance as multi-metallic catalysts in a variety of catalytic reactions. This review will cover the recent advances about SMPs, especially on their synthesis and application in catalysis. These tailor-made SMPs with metallic catalytic centers can precisely control the number and location of their active sites, exhibiting high catalytic efficiency.

Seleno-Amino Acids in Vegetables: A Review of Their Forms and Metabolism.

Seleno-amino acids are safe, health-promoting compounds for humans. Numerous studies have focused on the forms and metabolism of seleno-amino acids in vegetables. Based on research progress on seleno-amino acids, we provide insights into the production of selenium-enriched vegetables with high seleno-amino acids contents. To ensure safe and effective intake of selenium, several issues need to be addressed, including (1) how to improve the accumulation of seleno-amino acids and (2) how to control the total selenium and seleno-amino acids contents in vegetables. The combined use of plant factories with artificial lighting and multiple analytical technologies may help to resolve these issues. Moreover, we propose a Precise Control of Selenium Content production system, which has the potential to produce vegetables with specified amounts of selenium and high proportions of seleno-amino acids.

How to control the spatiotemporal spread of Omicron in the region with low vaccination rates.

Currently, finding ways to effectively control the spread of Omicron in regions with low vaccination rates is an urgent issue. In this study, we use a district-level model for predicting the COVID-19 symptom onset risk to explore and control the whole process of spread of Omicron in South Africa at a finer spatial scale. We found that in the early stage of the accelerated spread, Omicron spreads rapidly from the districts at the center of human mobility to other important districts of the human mobility network and its peripheral districts. In the subsequent diffusion-contraction stage, Omicron rapidly spreads to districts with low human mobility and then mainly contracts to districts with the highest human mobility. We found that increasing daily vaccination rates 10 times mainly reduced the symptom onset risk in remote areas with low human mobility. Implementing Alert Level 5 in the three districts at the epicenter, and Alert Level 1 in the remaining 49 districts, the spatial spread related to human mobility was effectively restricted, and the daily onset risk in districts with high human mobility also decreased by 20-80%.

Precise Control of Customized Macrophage Cell Robot for Targeted Therapy of Solid Tumors with Minimal Invasion.

Injecting micro/nanorobots into the body to kill tumors is one of the ultimate ambitions for medical nanotechnology. However, injecting current micro/nanorobots based on 3D-printed biocompatible materials directly into blood vessels for targeted therapy is often difficult, and mistakes in targeting can cause serious side effects, such as blood clots, oxidative stress, or inflammation. The natural affinity of macrophages to tumors, and their natural phagocytosis and ability to invade tumors, make them outstanding drug delivery vehicles for targeted tumor therapy. Hence, a magnetically controlled cell robot (MCR) based on a macrophage drug carrier is proposed. Here, living macrophages are converted into MCRs through endocytosis of specially-designed magnetic nanoparticles loaded with doxorubicin and indocyanine green. Following this, the MCRs can be transported to tumors through the blood vessels using external magnetic fields, and penetrate the blood vessels into the interior of the tumor due to their deformability. With the MCR's cascaded drug release, targeted killing of tumors in mice is demonstrated, with minimal effects on the normal surrounding tissue. The ability to impart precise drug doses onto natural cells, such as macrophages, and load various functional components into the MCRs, offers an efficient method for precise targeted therapy.

[Development Progress of Ventilator].

Ventilator is an indispensable emergency medical equipment in hospitals. The global outbreak of the coronavirus disease 2019 (COVID-19) has highlighted the importance of the ventilator, which has attracted the attention and research on ventilators of all countries in the world. This article reviews the development history of the ventilator, briefly introduces the main air circuit structure and working principle of the ventilator, and then deeply analyzes the key technologies of this device. In addition, it compares some major brands of ventilators from several aspects in the market. Finally, the development trend and perspective of ventilators are presented.

Precise Controlled Target Molecule Release through Light-Triggered Charge Reversal Bridged Polysilsesquioxane Nanoparticles.

Precise control of target molecule release time, site, and dosage remains a challenge in controlled release systems. We employed a photoresponsive molecule release system via light-triggered charge reversal nanoparticles to achieve a triggered, stepwise, and precise controlled release platform. This release system was based on photocleavage-bridged polysilsesquioxane nanoparticles which acted as nanocarriers of doxorubicin loaded on the surface via electrostatic interaction. The nanoparticles could reverse into positive charges triggered by 254 nm light irradiation due to the photocleavage of the o-nitrobenzyl bridged segment. The charge reversal property of the nanoparticles could release loaded molecules. Doxorubicin was selected as a positively charged model molecule. The as-prepared nanoparticles with an average size of 124 nm had an acceptable doxorubicin loading content up to 12.8%. The surface charge of the nanoparticles could rapidly reverse from negative (-28.20 mV) to positive (+18.9 mV) upon light irradiation for only 10 min. In vitro release experiments showed a cumulative release up to 96% with continuously enhancing irradiation intensity. By regulating irradiation parameters, precisely controlled drug release was carried out. The typical "stepped" profile could be accurately controlled in an on/off irradiation mode. This approach provides an ideal light-triggered molecule release system for location, timing, and dosage. This updated controlled release system, triggered by near-infrared or infrared light, will have greater potential applications in biomedical technology.

Shanghai mode of precise control of imported cold-chain food for during the COVID-19 epidemic / 上海预防医学

In order to strictly control and prevent the risk of the coronavirus disease 2019 （COVID-19） transmission through imported cold-chain foods， Shanghai has implemented many multiple countermeasures， including “Three PointsIntermediate Sites， One Transit Cold Storage” and “Four Drive Linkage”. Shanghai cold-chain information traceability system and other operating mechanisms have been established， according to the guidance of “One Single Plan”. The multilevel， overall， traceable， life cycle and whole processand closed-loop control regulatory system， called “Shanghai mode of control” for imported cold-chain food has been basically formed， which would facilitate precise regulation and management of create an accurate management system for imported cold-chain foods.

Development Progress of Ventilator / 中国医疗器械杂志

Ventilator is an indispensable emergency medical equipment in hospitals. The global outbreak of the coronavirus disease 2019 (COVID-19) has highlighted the importance of the ventilator, which has attracted the attention and research on ventilators of all countries in the world. This article reviews the development history of the ventilator, briefly introduces the main air circuit structure and working principle of the ventilator, and then deeply analyzes the key technologies of this device. In addition, it compares some major brands of ventilators from several aspects in the market. Finally, the development trend and perspective of ventilators are presented.

Precise Phase Control of Large-Scale Inorganic Perovskites via Vapor-Phase Anion-Exchange Strategy.

Anion exchange offers great flexibility and high precision in phase control, compositional engineering, and optoelectronic property tuning. Different from previous successful anion exchange process in liquid solution, herein, a vapor-phase anion-exchange strategy is developed to realize the precise phase and bandgap control of large-scale inorganic perovskites by using gas injection cycle, producing some perovskites such as CsPbCl3 which has never been reported in thin film morphology. Ab initio calculations also provide the insightful mechanism to understand the impact of anion exchange on tuning the electronic properties and optimizing the structural stability. Furthermore, because of precise control of specific atomic concentrations, intriguing tunable photoluminescence is observed and photodetectors with tunable photoresponse edge from green to ultraviolet light can be realized accurately with an ultrahigh spectral resolution of 1 nm. Therefore, a new, universal vapor-phase anion exchange method is offered for inorganic perovskite with fine-tunable optoelectronic properties.

Graphene-Based Helical Micromotors Constructed by "Microscale Liquid Rope-Coil Effect" with Microfluidics.

Nature provides diverse inspirations for constructing mobile and functionalized micromachines. For example, artificial helical micro-/nanomotors inspired by bacteria flagella that can be precisely steered for various applications have been constructed by utilizing materials with excellent functions. Graphene-based materials show outstanding properties, and, to date, have not been considered to construct helical micromotors and investigate their potential applications. Here, we propose an interesting "microscale liquid rope-coil effect" strategy to stably and simply fabricate graphene oxide-based helical micromotors (GOFHMs) with high throughput by the capillary microfluidics technique. A range of desirable GOFHMs with different pitch, length, and linear diameter are tailored by smart parameter setting in microfluidic system (flow velocity, concentration, and so on). Afterward, graphene-based helical micromotors (GFHMs) are easily acquired by the reduction of GOFHMs and further drying. Actuated by rotating magnetic field, GFHMs show capability to conduct programmed locomotion in a microchannel. As a proof-of-concept demonstration, GFHMs and Ag modified GFHMs have been successfully applied to water remediation, which exhibits excellent removal efficiency of chemical and biological pollutants. Meanwhile, doxorubicin is modified onto GFHMs for the application of drug delivery. Accordingly, we believe that GFHMs have great potential in a variety of fields by modifying graphene with other nanoparticles or functional molecules.

Selective Digital Etching of Silicon-Germanium Using Nitric and Hydrofluoric Acids.

A digital etching method was proposed to achieve excellent control of etching depth. The digital etching characteristics of p+-Si and Si0.7Ge0.3 using a combination of HNO3 oxidation and buffered oxide etching oxide removal processes were investigated. Experimental results showed that oxidation saturates as time goes on because of low activation energy and its diffusion-limited characteristic. An oxidation model was developed to describe the wet oxidation process with nitric acid. The model was calibrated with experimental data, and the oxidation saturation time, final oxide thickness, and selectivity between Si0.7Ge0.3 and p+-Si were obtained. In Si0.7Ge0.3/p+-Si stacks, the saturated relative etched depth per cycle was 0.5 nm (four monolayers), and variation between experiments was about 4% after saturation. A corrected selectivity calculation formula was also proposed, and the calculated selectivity was 3.7-7.7 for different oxidation times, which was the same as the selectivity obtained from our oxidation model. The proposed model can be used to analyze process variations and repeatability, and it can provide credible guidance for the design of other wet digital etching experiments.

Application of Microfluidic Technology for Preparation of Nanoparticle Drug Carriers / 中国药学杂志

Microfluidic technology is a scientific technology that precisely controls and manipulates fluids in micro-nano-scale space, and has become one of the research hotspots in the field of nanomedicine. It has the ability to scale the basic functions of biological and chemical laboratories, including sample preparation, reaction, separation and detection, to a few square centimeters of chip. Compared with traditional approaches, microfluidic technology is equipped with many advantages in the development of nanomedicine carriers, such as controlling quality precisely, high reproducibility, fast and effective. Herein, this paper provides the brief introduction about the microfluidic technology and its application in the preparation of nanoparticulate drug carriers, which including polymer nanoparticles, lipid nanoparticles and hybrid nanoparticles. This review will provide ideas and references in utilization of microfluidic technology accurately and reasonably and also bring some prospects for its future development and challenges.

[Strengthening the research and application of spatial epidemiology to promote precise prevention and control of parasitic diseases in China].

Spatial epidemiology is a new branch of epidemiology, and is a subject that mainly analyzes the geographical distribution and changes of population health or diseases and its related impact factors. Recently, spatial epidemiology has been extensively applied in the prevention and control of parasitic diseases in China, and delightful results have been achieved. However, the research and application of theories and methods of spatial epidemiology are still needed to protect the people's health in China.