Rapidly in situ forming adhesive hydrogels are promising candidates for efficient hemostasis due to their easy administration and minimal invasion. However, development of biocompatible and high-performance hemostatic hydrogels without any additional toxic agents remains a challenge. Herein, a series of novel injectable adhesive hydrogels based on N-hydroxysuccinimide (NHS) modified γ-poly(glutamic acid) (γPGA-NHS) and tetra-armed poly(ethylene glycol) amine (Tetra-PEG-NH2) were developed. Among all samples, PGA10-PEG15 and PGA10-PEG20 hydrogels with higher PEG contents exhibited rapid gelation time (<20 s), strong mechanical strength (compression modulus up to ∼75 kPa), good adhesive properties (∼15 kPa), and satisfactory burst pressure (∼18-20 kPa). As a result, PGA10-PEG15 and PGA10-PEG20 hydrogels showed a remarkable reduction in hemostasis time and blood loss compared with gauze and fibrin glue. More importantly, the PGA10-PEG20 hydrogel was also successfully used to seal femoral arterial trauma. Subcutaneous implantation experiments indicated a good biocompatibility of the hydrogels in vivo. All these results strongly support that the developed PGA-PEG hydrogels could serve as promising hemostatic agents in emergency and clinical situations.
Forests are composed of landscape spatial units (patches) of different sizes, shapes, and characteristics. The forest landscape pattern and its trends are closely related to resistance to disturbance, restoration, stability, and the biodiversity of the forest landscape and directly influence the benefits and sustainable exploitation of forest landscape resources. Therefore, forest landscape patterns and the driving forces have increasingly attracted the attention of researchers. The present study analyzed the spatial and temporal dynamics of woodland landscape patterns in typical hilly mountainous areas in southern China using ArcGIS, landscape pattern index, and morphological spatial pattern analysis. Meanwhile, a logistic regression model was used to analyze the drivers of woodland change in Anyuan County from three aspects: natural, geographic location, and socio-economic conditions. The total area of woodland decreased during the 10-year study period, with a net decrease of 4959.27 ha, mainly due to conversion into cultivated land, garden land, and construction land. Patch density, edge density, and aggregation index of woodlands increased over time, indicating enhanced fragmentation, stable and complex patch edges, and increased patch connectivity. Conversely, the highest patch index values exhibited decreasing trends, indicating decreases in the dominant patch type. Morphological spatial pattern analysis results showed that the core area was dominant and the islet area increased over time, which also indicates enhanced fragmentation. Forest landscape change is the result of environmental change, ecological processes, and human disturbance, with geographical location and social economy having greater influences on forest landscape change. Human activities such as navel orange cultivation, returning cultivated land to forest, and land occupation for construction were the major factors driving woodland change. The results provide reference that could facilitate forest management and sustainable forest resource utilization.
An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
To effectively address the key issue of clean and low carbon building distribution network, which is how to increase the amount of distributed renewable energy generation and effectively consume renewable energy generation. Through the analysis of the development trend of building electrification, this paper takes a public building in Xiong'an New Area as an example to study the method of increasing the building new energy power generation and balancing the new energy volatility, and designs the PEDF (Photovoltaics, Energy storage, Direct current and Flexibility) low-voltage DC lighting power supply system that integrates clean energy, distributed energy storage and DC power supply technologies. The system uses photovoltaic power generation and energy storage devices to provide clean power, and realizes efficient power supply for lighting equipment through flexible low-voltage DC technology to reduce energy conversion losses, which realizes clean electrification of lighting in this building and promotes coordinated control of multiple energy sources and comprehensive energy efficiency management. It achieves the purpose of coordinating and complementing the source, network, load and storage, and reducing electrical energy consumption, making the building a near-zero carbon clean building on the electricity consumption side.
In this study, BNBT-KNN-xTa 2 O 5 was designed and synthesized, successfully achieving a reduction in the relaxor-ferroelectric phase transition temperature. Synergy between temperature-dependent ferroelectric testing and dielectric spectroscopy confirmed that the depoling temperature gradually decreased with increasing doping concentration. Fitting of the relaxation parameter and freezing temperature substantiated that the incorporation of Ta 2 O 5 increased the degree of relaxation in BNBT-KNN-xTa 2 O 5 , thereby effectively lowering the relaxor-ferroelectric phase transition temperature.
Selective catalytic reduction (SCR) is an effective way to deal with the flue gas at the outlet of coal-fired boiler. The working process of SCR systems is to use the ammonia (NH3) adsorbed on the catalyst to react with nitrogen oxide (NOx) to generate nitrogen and water. This paper presents an observer based dynamic output feedback control for SCR systems. Since NH3 coverage ratio cannot be measured directly, a reduced order observer is designed first. And then it is proved that the error of observer tends to 0 by using Lyapunov function. Furthermore, the dynamic equation of the composite including the observer state is obtained. Finally, the controller is designed to adjust the rate of NH3 injection in order to satisfy the industrial demand.
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