Temperature Dependent Piezoelectric Properties of Lead-Free (1-x)K0.6Na0.4NbO3–xBiFeO3 Ceramics

(1-x)K0.4Na0.6NbO3–xBiFeO3 lead-free piezoelectric ceramics were successfully prepared in a single perovskite phase using the conventional solid-state synthesis. Relative permittivity (εr) as a function of temperature indicated that small additions of BiFeO3 not only broadened and lowered the cubic to tetragonal phase transition (TC) but also shifted the tetragonal to orthorhombic phase transition (TO–T) toward room temperature (RT). Ceramics with x = 1 mol.% showed optimum properties with small and large signal piezoelectric coefficient, d33 = 182 pC/N and d∗33 = 250 pm/V, respectively, electromechanical coupling coefficient, kp = 50%, and TC = 355°C. kp varied by ∼5% from RT to 90°C, while d∗33 showed a variation of ∼15% from RT to 75°C, indicating that piezoelectric properties were stable with temperature in the orthorhombic phase field. However, above the onset of TO–T, the properties monotonically degraded in the tetragonal phase field as TC was approached

What is China doing in policy-making to push back the negative aspects of the nutrition transition?

OBJECTIVE: To review the nutrition policies and efforts related to nutrition transition in China. DESIGN AND SETTING: This paper reviews the nutrition policy and activities of China to prevent and control diet-related non-communicable diseases (DR-NCDs). Data came from the Ministry of Health, the Ministry of Agriculture, the State Council and some cross-sectional surveys. RESULTS: China is undergoing a remarkable, but undesirable, rapid transition towards a stage of the nutrition transition characterised by high rates of DR-NCDs in a very short time. Some public sector Chinese organisations have combined their efforts to create the initial stages of systematic attempts to reduce these problems. These efforts, which focus on both under- and overnutrition, include the new Dietary Guidelines for Chinese Residents and the Chinese Pagoda and The National Plan of Action for Nutrition in China, issued by the highest body of the government, the State Council. There are selected agricultural sector activities that are laudable and few other systematic efforts that are impacting behaviour yet. In the health sector, efforts related to reducing hypertension and diabetes are becoming more widespread, but there is limited work in the nutrition sector. This paper points to some unique strengths from past Chinese efforts and to an agenda for the next several decades. CONCLUSIONS: China is trying in its efforts to prevent and control the development of DR-NCDs but effects are limited. Systematic multi-sector co-operation is needed to effectively prevent and control DR-NCDs inside and outside the health sector

Enhancing Graph Neural Networks with Structure-Based Prompt

Graph Neural Networks (GNNs) are powerful in learning semantics of graph data. Recently, a new paradigm "pre-train, prompt" has shown promising results in adapting GNNs to various tasks with less supervised data. The success of such paradigm can be attributed to the more consistent objectives of pre-training and task-oriented prompt tuning, where the pre-trained knowledge can be effectively transferred to downstream tasks. However, an overlooked issue of existing studies is that the structure information of graph is usually exploited during pre-training for learning node representations, while neglected in the prompt tuning stage for learning task-specific parameters. To bridge this gap, we propose a novel structure-based prompting method for GNNs, namely SAP, which consistently exploits structure information in both pre-training and prompt tuning stages. In particular, SAP 1) employs a dual-view contrastive learning to align the latent semantic spaces of node attributes and graph structure, and 2) incorporates structure information in prompted graph to elicit more pre-trained knowledge in prompt tuning. We conduct extensive experiments on node classification and graph classification tasks to show the effectiveness of SAP. Moreover, we show that SAP can lead to better performance in more challenging few-shot scenarios on both homophilous and heterophilous graphs

BiFeO3-BaTiO3: A new generation of lead-free electroceramics

Lead-based electroceramics such as Pb(Zr.Ti)O3 (PZT) and its derivatives have excellent piezoelectric, pyroelectric and energy storage properties and can be used in a wide range of applications. Potential lead-free replacements for PZT such as potassium sodium niobate (KNN) and sodium bismuth titanate (NBT) have a much more limited range of useful properties and have been optimized primarily for piezoelectric applications. Here, we review the initial results on a new generation of lead-free electroceramics based on BiFeO3-BaTiO3 (BF-BT) highlighting the essential crystal chemistry that permits a wide range of functional properties. We demonstrate that with the appropriate dopants and heat treatment, BF-BT can be used to fabricate commercially viable ceramics for applications, ranging from sensors, multilayer actuators, capacitors and high-density energy storage devices. We also assess the potential of BF-BT-based ceramics for electrocaloric and pyroelectric applications

LawBench: Benchmarking Legal Knowledge of Large Language Models

Large language models (LLMs) have demonstrated strong capabilities in various aspects. However, when applying them to the highly specialized, safe-critical legal domain, it is unclear how much legal knowledge they possess and whether they can reliably perform legal-related tasks. To address this gap, we propose a comprehensive evaluation benchmark LawBench. LawBench has been meticulously crafted to have precise assessment of the LLMs' legal capabilities from three cognitive levels: (1) Legal knowledge memorization: whether LLMs can memorize needed legal concepts, articles and facts; (2) Legal knowledge understanding: whether LLMs can comprehend entities, events and relationships within legal text; (3) Legal knowledge applying: whether LLMs can properly utilize their legal knowledge and make necessary reasoning steps to solve realistic legal tasks. LawBench contains 20 diverse tasks covering 5 task types: single-label classification (SLC), multi-label classification (MLC), regression, extraction and generation. We perform extensive evaluations of 51 LLMs on LawBench, including 20 multilingual LLMs, 22 Chinese-oriented LLMs and 9 legal specific LLMs. The results show that GPT-4 remains the best-performing LLM in the legal domain, surpassing the others by a significant margin. While fine-tuning LLMs on legal specific text brings certain improvements, we are still a long way from obtaining usable and reliable LLMs in legal tasks. All data, model predictions and evaluation code are released in https://github.com/open-compass/LawBench/. We hope this benchmark provides in-depth understanding of the LLMs' domain-specified capabilities and speed up the development of LLMs in the legal domain

miRNA-544a Regulates the Inflammation of Spinal Cord Injury by Inhibiting the Expression of NEUROD4

Background/Aims: To explore the potential role of miR-544a in spinal cord injury and the possible mechanism involved. Methods: We established a mouse model with spinal cord injury to examine the changes in grip force recovery of the forelimb or the posterior limb of the mouse. Microarray was performed to achieve differentiated miRNAs in the mice. The expressions of miR-544a, MCP-1, IL36B and IL17B after spinal cord injury were detected by qRT-PCR. Subsequently, miR-544a was overexpressed to observe changes in inflammation and grip strength after spinal cord injury. Target gene of miR-544a was then predicted using bioinformatics technology. Finally, dual luciferase reporter gene assay was used to verify the binding of miR-544a to its target gene. Results: Using mice models with spinal cord injury, we found that the strength of their four limbs began to recover 7 days after injury. The results of microarray and qRT-PCR confirmed that mir-544a level in mice with spinal cord injury decreased with increase of injury time, while the levels of inflammatory genes MCP-1 (monocyte chemoattractant protein-1), IL1 (interleukin-1) and TNF-α (tumor necrosis factor alpha) IL36B (interleukin-36 beta) and IL17B (interleukin-17 beta) were significantly increased. However, overexpression of miR-544a in the mice significantly reduced the level of inflammation and restored their grip strength in their four limbs. Finally, we found that miR-544a can bind to the NEUROD4 (Neurogenic differentiation 4) 3’UTR (Untranslated Region) region through bioinformatics website prediction, which was further confirmed by dual luciferase reporter assay. NEUROD4 level was significantly reduced following the overexpression of miR-544a. Conclusion: The expression of miR-544a was significantly decreased after spinal cord injury. High expression of miR-544a could alleviate the inflammation caused by spinal cord injury and promote the recovery of spinal cord via the inhibition of NEUROD4

Lead Free Multilayer Piezoelectric Actuators by Economically New Approach

The replacement of lead zirconate titanate ceramics (PZTs), with a lead-oxide (PbO)-free alternative is the subject of intense investigation worldwide. In this research, a cheap reliable methodology for the fabrication of multilayers (MLs) of lead-free potassium sodium niobate (KNN)-based ceramics is presented without the need for vacuuming and/or hot isostatic pressing of the tape. The thickness per active layer was 193 μm and 102 μm for the 10 and 16 layer MLs actuators, respectively. Effective d33 (piezoelectric coefficient), effective d33∗ (electrostrain coefficient), bi-polar strain (Smax), max displacement, dielectric constant (ϵr) and loss (tanδ) are 2500 pC/N, 4604 pm/V, 0.17%, 2.2 μm, 1812 and 2% at 1 kHz, respectively, where the effective d33 or d33∗ is the total output of all layers together. The ultimate target materials for potential substitution with KNN-based ceramics and MLs are commercial PZT-4 and PZT-8

Quality Changes of Pre-fried Fish during Frozen and Reheating Process

To solve the problem of taste loss of new retail prepared fish after freezing and reheating. The changes of moisture content, water holding capacity, water distribution, and microstructure in pre-fried fish were analyzed during frying, freezing and reheating processes. The results showed that with the increase of freezing-thawing cycles, a significant decrease of the moisture content (P<0.05) and water holding capacity of pre-fried fish were observed, while the degree of fat oxidation, protein degradation, and muscle fiber destruction were increased significantly (P<0.05)，as well as the flavor changes were displayed in all the samples. After reheating, the taste of pre-fried fish at 1 freezing-thawing cycle was similar to the unfrozen group. However, lower sensory scores were gained after 2 freezing-thawing cycles. Also, in comparation with the samples without freezing, the contents of myofibrillar fragmentation index, TBARS and TCA-soluble peptide increased by 24.44%, 225.84% and 52.85%, respectively. In conclusion, the edible quality and consumer acceptance of the pre-fried fish are significantly reduced when the number of freezing-thawing cycles are more than 2 times in the process of storage and transportation

Crystal Structure, Phase Transitions and Photoferroelectric Properties of KNbO3-Based Lead-Free Ferroelectric Ceramics: A Brief Review

Ferroelectric KNbO3 (KN) ceramics were first fabricated in the 1950s, however, their use in commercial technical applications has been hampered by inherently challenging processing difficulties. In the early 1990s, the interest in KN ceramics was revived by the pursuit of Pb-free piezoceramics. More recently the search for inexpensive photovoltaic materials alternative to Si prompted bandgap engineering studies in KN-based solid solutions. If the ferroelectric and piezoelectric properties of KN-based ceramics are now well established, the understanding of chemical doping on the bandgap of KN-based ceramics is still in its infancy. Here we provide a brief review on the current understanding of the structure-property relationships in this class of materials, which successively covers crystal structures, structural phase transitions, lattice dynamics, polarization, solid solutions and bandgap engineering of KN