Bayesian-optimized lithology identification has important basic geological research significance and engineering application value,and this paper proposes a Bayesian-optimized lithology identification method based on ...Bayesian-optimized lithology identification has important basic geological research significance and engineering application value,and this paper proposes a Bayesian-optimized lithology identification method based on machine learning of rock visible and near-infrared spectral data.First,the rock spectral data are preprocessed using Savitzky-Golay(SG)smoothing to remove the noise of the spectral data;then,the preprocessed rock spectral data are downscaled using Principal Component Analysis(PCA)to reduce the redundancy of the data,optimize the effective discriminative information,and obtain the rock spectral features;finally,a Bayesian-optimized lithology identification model is established based on rock spectral features,optimize the model hyperparameters using Bayesian optimization(BO)algorithm to avoid the combination of hyperparameters falling into the local optimal solution,and output the predicted type of rock,so as to realize the Bayesian-optimized lithology identification.In addition,this paper conducts comparative analysis on models based on Artificial Neural Network(ANN)/Random Forest(RF),dimensionality reduction/full band,and optimization algorithms.It uses the confusion matrix,accuracy,Precison(P),Recall(R)and F_(1)values(F_(1))as the evaluation indexes of model accuracy.The results indicate that the lithology identification model optimized by the BO-ANN after dimensionality reduction achieves an accuracy of up to 99.80%,up to 99.79%and up to 99.79%.Compared with the BO-RF model,it has higher identification accuracy and better stability for each type of rock identification.The experiments and reliability analysis show that the Bayesian-optimized lithology identification method proposed in this paper has good robustness and generalization performance,which is of great significance for realizing fast,accurate and Bayesian-optimized lithology identification in tunnel site.展开更多
Imaging hyperspectral technology has distinctive advantages of non-destructive and non-contact measurement,and the integration of spectral and spatial data.These characteristics present new methodologies for intellige...Imaging hyperspectral technology has distinctive advantages of non-destructive and non-contact measurement,and the integration of spectral and spatial data.These characteristics present new methodologies for intelligent geological sensing in tunnels and other underground engineering projects.However,the in situ acquisition and rapid classification of hyperspectral images in underground still faces great challenges,including the difficulty in obtaining uniform hyperspectral images and the complexity of deploying sophisticated models on mobile platforms.This study proposes an intelligent lithology identification method based on partition feature extraction of hyperspectral images.Firstly,pixel-level hyperspectral information from representative lithological regions is extracted and fused to obtain rock hyperspectral image partition features.Subsequently,an SG-SNV-PCA-DNN(SSPD)model specifically designed for optimizing rock hyperspectral data,performing spectral dimensionality reduction,and identifying lithology is integrated.In an experimental study involving 3420 hyperspectral images,the SSPD identification model achieved the highest accuracy in the testing set,reaching 98.77%.Moreover,the speed of the SSPD model was found to be 18.5%faster than that of the unprocessed model,with an accuracy improvement of 5.22%.In contrast,the ResNet-101 model,used for point-by-point identification based on non-partitioned features,achieved a maximum accuracy of 97.86%in the testing set.In addition,the partition feature extraction methods significantly reduce computational complexity.An objective evaluation of various models demonstrated that the SSPD model exhibited superior performance,achieving a precision(P)of 99.46%,a recall(R)of 99.44%,and F1 score(F1)of 99.45%.Additionally,a pioneering in situ detection work was carried out in a tunnel using underground hyperspectral imaging technology.展开更多
L-Theanine(LTA)is a non-protein amino acid mainly found in tea plants with many beneficial effects.Exercise exerts a wide range of benefits in metabolic health.Here,we show that exercise or gastric lavage intervention...L-Theanine(LTA)is a non-protein amino acid mainly found in tea plants with many beneficial effects.Exercise exerts a wide range of benefits in metabolic health.Here,we show that exercise or gastric lavage intervention on mice with LTA improves diet-induced nonalcoholic steatohepatitis(NASH)in mice.Meanwhile,combinatory therapy shows that exercise and LTA synergistically improve obesity-related metabolic disorders and NASH phenotypes,including hepatic steatosis,inflammation,cell death and oxidative stress.In vivo studies indicate that LTA inhibits free fatty acid(FFA)-induced hepatocyte injury,including steatosis,oxidative stress and apoptosis.Knockdown of Nrf2 blunts the role of LTA in inhibiting FFA-induced hepatocyte oxidative stress and dysfunction.Mechanistically,LTA increases theα-ketoglutarate(α-KG)level in hepatocytes,which increases the transcription of Nrf2 by inducing active DNA demethylation on its promoter.Moreover,LTA promote the aboveα-KG/Nrf2 axis in synergy with exercise,thereby more efficiently inhibiting hepatic oxidative stress and ameliorating diet-induced NASH in mice.Our results suggest that,through promoting theα-KG/Nrf2 axis-mediated anti-oxidative pathway,the combination of LTA and exercise may provide an effective measure for the prevention and control of NASH.展开更多
Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resul...Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resulted in lengthy molding durations but also compromised the mechanical strength.In this work,silica(SiO--_2)ceramic cores,with fine complex geometric shapes,were fabricated using 65vol.%ceramic slurry by digital light processing(DLP)with different printing angles.Printing angles significantly impact the surface accuracy,shrinkage,printing efficiency of green bodies,as well as the microstructure and mechanical properties of sintered ceramic core samples.As the printing angle in the green body increases,the bonding area decreases,surface roughness on the XY plane worsens,shrinkage in the Z direction becomes more pronounced,and the printing efficiency declines.Similarly,an increase in the printing angle in the sintered body leads to a reduction in bending strength.At a printing angle of 30°,the printing time is reduced to half of that at 90°,which improves the molding efficiency.Meanwhile,the obtained bulk density of 1.71 g·cm~(-3),open porosity of 24%,and fiexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores.Therefore,designing and optimizing the printing angles can achieve the balance between shrinkage,printing efficiency,and fiexural strength.展开更多
The efficiency of tunnel excavation,rock strength,stability of surrounding rock,and underground engineering disasters are closely related to lithology.Accurately identifying lithology is a necessary prerequisite for i...The efficiency of tunnel excavation,rock strength,stability of surrounding rock,and underground engineering disasters are closely related to lithology.Accurately identifying lithology is a necessary prerequisite for intelligent,safe,and efficient tunnel construction.The design of conventional recognition models heavily relies on experience and extensive calculations.To develop a model suitable for deployment on construction sites and capable of accurate lithology identification,a fast search method for lithology identification models is proposed.This method integrates geological knowledge,apparent feature extraction techniques,and search algorithms.An efficient feature extraction super network using multi-scale geological features of rock surface is constructed,a model evaluation method that comprehensively considers accuracy and latency is developed,and differential evolution algorithm is used to search for the optimal model parameters.Experiments demonstrate that the proposed method enables the model to evolve faster and more accurately,and eventually a model(LithoNet)suitable for lithological classification is found.It only takes 2.10 ms to infer an image of 224×224,which is 57.25%faster than MobileNet v3 and 62.83%faster than ShuffleNet V2.The F1-score of LithoNet is 0.9874,surpassing classical models such as EfficientNetV2-S.LithoNet can be easily deployed on portable devices,effectively promoting the intelligence and accuracy of lithology identification at engineering sites.展开更多
In this paper,we study anti-derivations and anti-left multipliers.For a class of algebras,which contains triangular algebras,matrix algebras,embedded algebras,Cuntz algebras,nest algebras,P-lattice algebras,and linear...In this paper,we study anti-derivations and anti-left multipliers.For a class of algebras,which contains triangular algebras,matrix algebras,embedded algebras,Cuntz algebras,nest algebras,P-lattice algebras,and linear transformation algebras L(X),we show that every anti-left multiplier on these algebras is zero.Furthermore,let A be a zero product determined algebra andδbe a linear mapping from A into itself,satisfying that for any a,b in A,ab=0 impliesδ(b)a+bδ(a)=0.We show thatδ(x)=D(x)+δ(1)x,where D is an anti-derivation andδ(1)∈Z(A).展开更多
Cytotoxic lymphocytes are key players in the orchestration of immune response and elimination of defective cells. We have previously reported that natural killer （NK） cells enter target tumor ceils, leading to eithe...Cytotoxic lymphocytes are key players in the orchestration of immune response and elimination of defective cells. We have previously reported that natural killer （NK） cells enter target tumor ceils, leading to either target cell death or self-destruction within tumor cells. However, it has remained elusive as to the fate of NK cells after internalization and whether the heterotypic cell-in-cell process is different from that of the homotypic cell-in-cell event recently named entosis. Here, we show that NK cells undergo a cell-in-cell process with the ultimate fate of apoptosis within tumor cells and reveal that the internalization process requires the actin cytoskeletal regulator, ezrin. To visualize how NK cells enter into tumor cells, we carried out real-time dual color imaging analyses of NK cell internalization into tumor cells. Surprisingly, most NK cells commit to programmed cell death after their entry into tumor cells, which is distinctively different from entosis observed in the homotypic cell-in-cell process. The apoptotic cell death of the internalized NK cells was evident by activation of caspase 3 and DNA fragmentation. Furthermore, NK cell death after internalization is attenuated by the caspase inhibitor, Z-VAD-FMK, confirming apoptosis as the mode of NK cell death within tumor cells. To determine protein factors essential for the entry of NK cells into tumor cells, we car- ried out siRNA-based knockdown analysis and discovered a critical role of ezrin in NK cell internalization. Impor- tantly, PKA-mediated phosphorylation of ezrin promotes the NK cell internalization process. Our findings suggest a novel regulatory mechanism by which ezrin governs NK cell internalization into tumor cells.展开更多
To analyze the degree and pattern of phenotypic variation in leaves of Tetracentron sinense Oliv from the perspective of genetic and environmental adaptation and thus contribute to effective evidence-based conservatio...To analyze the degree and pattern of phenotypic variation in leaves of Tetracentron sinense Oliv from the perspective of genetic and environmental adaptation and thus contribute to effective evidence-based conservation and management strategies for germplasm resources,we measured 17 morphological and epidermal micromorphological leaf traits from 24 natural populations of T.sinense.Nested analysis of variance,multiple comparison,principal component analysis(PCA),cluster analysis,and correlation analysis were used to explore phenotypic leaf variation among and within populations and potential correlations with geographic and environmental factors.There were significant differences in 17 leaf phenotypic traits among and within populations.The mean phenotypic differentiation coefficient of the 17 traits was 56.34%,and the variation among populations(36.4%)was greater than that within populations(27.2%).The coefficient of variation(CV)of each trait ranged from 4.6 to 23.8%,and the mean was 11.8%.Phenotypic variation of leaves was related to environmental factors such as average annual sunshine hours,average July temperature,and average annual rainfall.The variation changed along gradients of longitude,latitude,and altitude.The PCA clustered the 24 natural populations into four groups.Our study suggests that phenotypic variation in T.sinense occurred primarily among populations,with moderate levels of phenotypic differentiation among populations and low levels of phenotypic variation within populations.The plant’s poor adaptability to the environment is likely an important contributor to its endangerment.Accordingly,conservation strategies are proposed to protect and manage the natural populations of T.sinense.展开更多
BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy....BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy.The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.METHODS:A sepsis mouse model was constructed by the cecal ligation and puncture(CLP)method,and AML12 cells were pretreated with lipopolysaccharide(LPS)(1μg/mL)to establish a sepsis cell model.Forty mice were divided into four groups,namely control group,TSA group,CLP group,and CLP+TSA group,with 10 mice in each group.Cells were divided into control group,TSA group,LPS group,and LPS+TSA group.Hematoxylin-eosin(H&E)staining and biochemical methods were used to evaluate liver tissue injury.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of proinflammatory cytokines,and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.RESULTS:Compared with the CLP group(mice),the proinflammatory cytokines(interleukin-β[IL-β]2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL;interleukin-6[IL-6]399.01±60.98 pg/mL to 221.90±46.89 pg/mL)and the hepatocyte injury markers(aspartate transaminase[AST]from 198.18±27.07 U/L to 128.42±20.55 U/L;alanine aminotransferase[ALT]from 634.98±74.10 U/L to 478.60±32.56 U/L)were notably decreased after TSA intervention.Moreover,LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group.Cell experiment results showed the similar trend.After Fox O3a gene was knocked down in AML12 cells,the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.CONCLUSION:TSA may improve the inflammatory response and liver injury in septic mice through Fox O3a/autophagy.展开更多
The yield ratios of neutron/proton(R(n/p)) and ~3H=~3He(R(t/~3He)) with reduced rapidity from 0 to 0.5 are investigated for 50 MeV/u ^(42;44;46;48;50;52;54;56)Ca+^(40)Ca.This was conducted at whole reduced impact para...The yield ratios of neutron/proton(R(n/p)) and ~3H=~3He(R(t/~3He)) with reduced rapidity from 0 to 0.5 are investigated for 50 MeV/u ^(42;44;46;48;50;52;54;56)Ca+^(40)Ca.This was conducted at whole reduced impact parameters using the isospin-dependent quantum-molecular-dynamics model in which the initial neutron and proton densities are sampled within the Skyrme–Hartree–Fock model, using which the neutron skin thickness(△R_(np)) is determined for different neutron-rich Ca isotopes. The results show that both R(n/p) and R(t/~3He) have strong linear correlations with △R_(np) of different Ca isotopic projectiles from five different centralities. It is suggested that R(n/p) and R(t/~3He), from the same centrality, could be treated as possible experimental observables to extract the neutron skin or halo thickness for neutron-rich isotopic nuclei,including the nuclei near the neutron drip line.展开更多
Caspase-1-mediated IL-1β production is generally controlled by two pathways. Toll-like receptors （TLRs） recognize pathogen-derived products and induce NF-KB-dependent pro-IL-1β transcription; NOD-like receptors （...Caspase-1-mediated IL-1β production is generally controlled by two pathways. Toll-like receptors （TLRs） recognize pathogen-derived products and induce NF-KB-dependent pro-IL-1β transcription; NOD-like receptors （NLRs） assemble caspase-l-activating inflammasome complexes that sense bacterial products/danger signals. Through a targeted chemical screen, we identify bromoxone, a marine natural product, as a specifc and potent inhibitor of the caspase-1 pathway. Bromoxone is effective over diverse inflammatory stimuli including TLR ligands plus ATP/nigeri- cin, cytosolic DNA, flagellin and Bacillus anthracis lethal toxin. Bromoxone also efficiently suppresses easpase-1 acti- vation triggered by several types of bacterial infection. Bromoxone acts upstream or at the level of the inflammasome in a transcription-independent manner. Bromoxone also inhibits pro-IL-1β expression by targeting components up- stream of IKK in the TLR-NF-kB pathway. The unique dual activities of bromoxone are shared by the known TAK1 inhibitor that specifically blocks Nalp3 inflammasome activation. Hinted from the mechanistic and pharmacological properties of bromoxone, we further discover that several known NF-KB inhibitors that act upstream of IKK, but not those targeting IKK or IKK downstream, are potent blockers of different NLRs-mediated caspase-1 activation. Our study uncovers a possible non-transcriptional molecular link between the NLR （Nalp3）-mediated inflammasome pathway and TLR-NF-kB signaling, and suggests a potential strategy to develop new anti-inflammatory drugs.展开更多
Osteoarthritis （OA） is a common joint degenerative disease affecting the whole joint structure, including articular cartilage, subchondral bone and synovial tissue. Although extensive work has been done in recent ye...Osteoarthritis （OA） is a common joint degenerative disease affecting the whole joint structure, including articular cartilage, subchondral bone and synovial tissue. Although extensive work has been done in recent years to explore the molecular mechanism underlying this disease, the pathogenesis of OA is still poorly understood and currently, there is no effective disease-modifying treatment for OA. Recently, both in vitro an, in vivo studies suggest that confirmed （TGF-β）/SMAD pathway plays a critical role during OA development This short review will focus on the function and signaling mechanisms of TGF-β/SMAD pathway in articula chondrocytes, mesenchymal progenitor cells of subchondral bone and synovial lining cells during OA development.展开更多
Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and poi...Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting （HRM） analysis. Pooled rice （Oryza sativa） samples mixed at a 1：7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ, ray-induced mutants in rice. For demonstration, a γ, ray-mutagenized M2 rice population （n=4560） was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution （G→A） and one single nucleotide insertion （A） were identified in OsLCT1, and one tdnucleotide （TTC） deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ, ray mutagenesis to the breeding of rice and other seed crops.展开更多
Objective:This study was aimed at analyzing the efficacy and safety of an injectable form of chlorogenic acid(CGA)in patients with recurrent high-grade glioma after standard of care treatments,through a first-in-human...Objective:This study was aimed at analyzing the efficacy and safety of an injectable form of chlorogenic acid(CGA)in patients with recurrent high-grade glioma after standard of care treatments,through a first-in-human,open-label,dose-escalation phase I trial.Methods:A total of 26 eligible patients were enrolled,received intramuscular CGA injections at 5 dose levels,and were followed up for 5 years.CGA was well tolerated,and the maximum tolerated dose was 5.5 mg/kg.Results:The most common treatment-related adverse events occurred at the sites of injection.No grade 3 or 4 adverse events(e.g.,drug allergy)were reported for these patients except for induration at the injection sites.A clinical pharmacokinetic study showed that CGA was rapidly eliminated from the plasma,with a t_(1/2)of 0.95–1.27 h on day 1 and 1.19–1.39 h on day 30,and no detectable CGA was observed on days 9,11,13,23,25,27,and 29 before CGA administration.After the first treatment cycle,52.2%of patients(12 of 23)achieved stable disease.Long-term follow-up indicated an estimated median overall survival of 11.3 months for all 23 evaluable patients.Of the 18 patients with grade 3 glioma,the median overall survival was 9.5 months.Two patients remained alive at the cutoff day.Conclusions:This phase I study demonstrated that CGA has a favorable safety profile(with no severe toxicity),and provides preliminary clinical benefits for patients with high grade glioma relapsing after prior standard therapies,thus shedding light on the potential clinical application of CGA for recurrent grade 4 glioma.展开更多
The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(...The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(28)Si and ^(32)S+^(28)Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model.The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton,~3H and ~3He from ^(28)S+^(28)Si collisions.The differences in directed flows for neutrons and protons and ~3H–~3He from a proton-rich nucleus ^(28)S- induced collisions are noticeably larger than those from a stable nucleus ^(32)S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ~3H–~3He under medium impact parameters are proposed as possible observable items for studying isospin physics.展开更多
To date,the benchmark Bi_(2)Te_(3)-based alloys are still the only commercial material system used for ther-moelectric solid-state refrigeration.Nonetheless,the conspicuous performance imbalance between the p-type Bi_...To date,the benchmark Bi_(2)Te_(3)-based alloys are still the only commercial material system used for ther-moelectric solid-state refrigeration.Nonetheless,the conspicuous performance imbalance between the p-type Bi_(2-x)Sb_(x)Te_(3)and n-type Bi_(2)Te_(3-x)Se_(x) legs has become a major obstacle for the improvement of cooling devices to achieve higher efficiency.In our previous study,novel n-type Bi_(2-x)Sb_(x)Te_(3)alloy has been pro-posed via manipulating donor-like effect as an alternative to mainstream n-type Bi_(2)Te_(3-x)Se_(x).However,the narrow bandgap of Bi_(2-x)Sb_(x)Te_(3)provoked severe bipolar effect that constrained the further improvement of zT near room temperature.Herein,we have implemented band gap engineering in n-type Bi_(1.5)Sb_(0.5)Te_(3)by employing isovalent Se substitution to inhibit the undesired intrinsic excitation and achieve the dis-tinguished room-temperature zT.First,the preferential occupancy of Se at Te^(2)site appropriately enlarges the band gap,thereby concurrently improving the Seebeck coefficient and depressing the bipolar thermal conductivity.In addition,the Se alloying mildly suppresses the compensation mechanism and essentially preserves the already optimized carrier concentration,which maintains the peak zT near room tempera-ture.Moreover,the large strain field and mass fluctuation generated by Se alloying leads to the remark-able reduction of lattice thermal conductivity.Accordingly,the zT value of Bi_(1.5)Sb_(0.5)Te_(2.8)Se_(0.2)reaches 1.0 at 300 K and peaks 1.1 at 360 K,which surpasses that of most well-known room-temperature n-type thermoelectric materials.These results pave the way for n-type Bi_(2-x)Sb_(x)Te_(3)alloys to become a new and promising top candidate for large-scale solid-state cooling applications.展开更多
Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China,and its components,which include ultrafine particles(UFPs),volatile organic compounds(VOCs),and other reactive gases,su...Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China,and its components,which include ultrafine particles(UFPs),volatile organic compounds(VOCs),and other reactive gases,such as NH3and NOx,are the most harmful to human health.China has released various regulations and standards to address pollution from mobile and stationary sources.Thus,it is urgent to develop online monitoring technology for atmospheric pollution source emissions.This study provides an overview of the main progress in mobile and stationary source monitoring technology in China and describes the comprehensive application of some typical instruments in vital areas in recent years.These instruments have been applied to monitor emissions from motor vehicles,ships,airports,the chemical industry,and electric power generation.Not only has the level of atmospheric environment monitoring technology and equipment been improving,but relevant regulations and standards have also been constantly updated.Meanwhile,the developed instruments can provide scientific assistance for the successful implementation of regulations.According to the potential problem areas in atmospheric pollution in China,some research hotspots and future trends of atmospheric online monitoring technology are summarized.Furthermore,more advanced atmospheric online monitoring technology will contribute to a comprehensive understanding of atmospheric pollution and improve environmental monitoring capacity.展开更多
The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,...The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,the intrinsically p-type Mg3Sb2 shows low figure of merit（z T = 0.23 at 723 K） for its poor electrical conductivity.In this study,a series of Mg（3-x）LixSb2 bulk materials have been prepared by high-energy ball milling and spark plasma sintering（SPS） process.Electrical transport measurements on these materials revealed significant improvement on the power factor with respect to the undoped sample,which can be essentially attributed to the increased carrier concentration,leading to a maximum z T of0.59 at 723 K with the optimum doping level x = 0.01.Additionally,the engineering z T and energy conversion efficiency are calculated to be 0.235 and 4.89%,respectively.To our best knowledge,those are the highest values of all reported p-type Mg3Sb2-based compounds with single element doping.展开更多
基金support from the National Natural Science Foundation of China(Grant Nos:52379103 and 52279103)the Natural Science Foundation of Shandong Province(Grant No:ZR2023YQ049).
文摘Bayesian-optimized lithology identification has important basic geological research significance and engineering application value,and this paper proposes a Bayesian-optimized lithology identification method based on machine learning of rock visible and near-infrared spectral data.First,the rock spectral data are preprocessed using Savitzky-Golay(SG)smoothing to remove the noise of the spectral data;then,the preprocessed rock spectral data are downscaled using Principal Component Analysis(PCA)to reduce the redundancy of the data,optimize the effective discriminative information,and obtain the rock spectral features;finally,a Bayesian-optimized lithology identification model is established based on rock spectral features,optimize the model hyperparameters using Bayesian optimization(BO)algorithm to avoid the combination of hyperparameters falling into the local optimal solution,and output the predicted type of rock,so as to realize the Bayesian-optimized lithology identification.In addition,this paper conducts comparative analysis on models based on Artificial Neural Network(ANN)/Random Forest(RF),dimensionality reduction/full band,and optimization algorithms.It uses the confusion matrix,accuracy,Precison(P),Recall(R)and F_(1)values(F_(1))as the evaluation indexes of model accuracy.The results indicate that the lithology identification model optimized by the BO-ANN after dimensionality reduction achieves an accuracy of up to 99.80%,up to 99.79%and up to 99.79%.Compared with the BO-RF model,it has higher identification accuracy and better stability for each type of rock identification.The experiments and reliability analysis show that the Bayesian-optimized lithology identification method proposed in this paper has good robustness and generalization performance,which is of great significance for realizing fast,accurate and Bayesian-optimized lithology identification in tunnel site.
基金support from the National Natural Science Foundation of China(Grant Nos.52379103,52279103)the Natural Science Foundation of Shandong Province(Grant No.ZR2023YQ049).
文摘Imaging hyperspectral technology has distinctive advantages of non-destructive and non-contact measurement,and the integration of spectral and spatial data.These characteristics present new methodologies for intelligent geological sensing in tunnels and other underground engineering projects.However,the in situ acquisition and rapid classification of hyperspectral images in underground still faces great challenges,including the difficulty in obtaining uniform hyperspectral images and the complexity of deploying sophisticated models on mobile platforms.This study proposes an intelligent lithology identification method based on partition feature extraction of hyperspectral images.Firstly,pixel-level hyperspectral information from representative lithological regions is extracted and fused to obtain rock hyperspectral image partition features.Subsequently,an SG-SNV-PCA-DNN(SSPD)model specifically designed for optimizing rock hyperspectral data,performing spectral dimensionality reduction,and identifying lithology is integrated.In an experimental study involving 3420 hyperspectral images,the SSPD identification model achieved the highest accuracy in the testing set,reaching 98.77%.Moreover,the speed of the SSPD model was found to be 18.5%faster than that of the unprocessed model,with an accuracy improvement of 5.22%.In contrast,the ResNet-101 model,used for point-by-point identification based on non-partitioned features,achieved a maximum accuracy of 97.86%in the testing set.In addition,the partition feature extraction methods significantly reduce computational complexity.An objective evaluation of various models demonstrated that the SSPD model exhibited superior performance,achieving a precision(P)of 99.46%,a recall(R)of 99.44%,and F1 score(F1)of 99.45%.Additionally,a pioneering in situ detection work was carried out in a tunnel using underground hyperspectral imaging technology.
基金supported by the National Natural Science Foundation of China(82571021,32070751 and 31871435)the Shanghai Natural Science Foundation(25ZR1401328)the Program for Overseas High-level talents at Shanghai Institutions of Higher Learning(TP2022100)。
文摘L-Theanine(LTA)is a non-protein amino acid mainly found in tea plants with many beneficial effects.Exercise exerts a wide range of benefits in metabolic health.Here,we show that exercise or gastric lavage intervention on mice with LTA improves diet-induced nonalcoholic steatohepatitis(NASH)in mice.Meanwhile,combinatory therapy shows that exercise and LTA synergistically improve obesity-related metabolic disorders and NASH phenotypes,including hepatic steatosis,inflammation,cell death and oxidative stress.In vivo studies indicate that LTA inhibits free fatty acid(FFA)-induced hepatocyte injury,including steatosis,oxidative stress and apoptosis.Knockdown of Nrf2 blunts the role of LTA in inhibiting FFA-induced hepatocyte oxidative stress and dysfunction.Mechanistically,LTA increases theα-ketoglutarate(α-KG)level in hepatocytes,which increases the transcription of Nrf2 by inducing active DNA demethylation on its promoter.Moreover,LTA promote the aboveα-KG/Nrf2 axis in synergy with exercise,thereby more efficiently inhibiting hepatic oxidative stress and ameliorating diet-induced NASH in mice.Our results suggest that,through promoting theα-KG/Nrf2 axis-mediated anti-oxidative pathway,the combination of LTA and exercise may provide an effective measure for the prevention and control of NASH.
基金the Youth Innovation Promotion Association of Chinese Academy of Science(No.2021160)the National Natural Science Foundation of China(No.51802319)the Technology and Engineering Center for Space(No.CSU-QZKT-2019-04)。
文摘Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resulted in lengthy molding durations but also compromised the mechanical strength.In this work,silica(SiO--_2)ceramic cores,with fine complex geometric shapes,were fabricated using 65vol.%ceramic slurry by digital light processing(DLP)with different printing angles.Printing angles significantly impact the surface accuracy,shrinkage,printing efficiency of green bodies,as well as the microstructure and mechanical properties of sintered ceramic core samples.As the printing angle in the green body increases,the bonding area decreases,surface roughness on the XY plane worsens,shrinkage in the Z direction becomes more pronounced,and the printing efficiency declines.Similarly,an increase in the printing angle in the sintered body leads to a reduction in bending strength.At a printing angle of 30°,the printing time is reduced to half of that at 90°,which improves the molding efficiency.Meanwhile,the obtained bulk density of 1.71 g·cm~(-3),open porosity of 24%,and fiexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores.Therefore,designing and optimizing the printing angles can achieve the balance between shrinkage,printing efficiency,and fiexural strength.
基金financial support from the National Natural Science Foundation of China(Grant Nos.52279103 and 52379103)the Natural Science Foundation of Shandong Province(Grant No.ZR2023YQ049).
文摘The efficiency of tunnel excavation,rock strength,stability of surrounding rock,and underground engineering disasters are closely related to lithology.Accurately identifying lithology is a necessary prerequisite for intelligent,safe,and efficient tunnel construction.The design of conventional recognition models heavily relies on experience and extensive calculations.To develop a model suitable for deployment on construction sites and capable of accurate lithology identification,a fast search method for lithology identification models is proposed.This method integrates geological knowledge,apparent feature extraction techniques,and search algorithms.An efficient feature extraction super network using multi-scale geological features of rock surface is constructed,a model evaluation method that comprehensively considers accuracy and latency is developed,and differential evolution algorithm is used to search for the optimal model parameters.Experiments demonstrate that the proposed method enables the model to evolve faster and more accurately,and eventually a model(LithoNet)suitable for lithological classification is found.It only takes 2.10 ms to infer an image of 224×224,which is 57.25%faster than MobileNet v3 and 62.83%faster than ShuffleNet V2.The F1-score of LithoNet is 0.9874,surpassing classical models such as EfficientNetV2-S.LithoNet can be easily deployed on portable devices,effectively promoting the intelligence and accuracy of lithology identification at engineering sites.
基金Supported by the General Program of Shanghai Natural Science Foundation(Grant No.24ZR1415600)the National Natural Science Foundation of China(Grant Nos.1232637412401157)。
文摘In this paper,we study anti-derivations and anti-left multipliers.For a class of algebras,which contains triangular algebras,matrix algebras,embedded algebras,Cuntz algebras,nest algebras,P-lattice algebras,and linear transformation algebras L(X),we show that every anti-left multiplier on these algebras is zero.Furthermore,let A be a zero product determined algebra andδbe a linear mapping from A into itself,satisfying that for any a,b in A,ab=0 impliesδ(b)a+bδ(a)=0.We show thatδ(x)=D(x)+δ(1)x,where D is an anti-derivation andδ(1)∈Z(A).
基金We thank members of our group for insightful discussion dur- ing the course of this study and Drs Haiming Wei and Zhigang Tian for NK92 cells. This work was supported by grants from National Natural Science Foundation of China （30972681 to XW 90508002 to XY+1 种基金 30872286 to LS）, Guangdong-NSFC Joint Key Program （to XW）, Chinese Academy of Sciences （KSCX1- YW-R65, KSCX2-YWH-10）, National Basic Research Program of China （973 Program） （2007CB512402 to XW 2007CB914503 and 2010CB912103 to XY）, Ministry of Science ＆ Technology of China International Collaboration Program （2009DFA31010 to XD）, China National Key Projects for Infectious Disease （2008ZX 10002-021 to XY）, 2007 National Undergraduate Innova- tive Research Program of China （PX） and KC Wong Education Foundation （ZG）.
文摘Cytotoxic lymphocytes are key players in the orchestration of immune response and elimination of defective cells. We have previously reported that natural killer （NK） cells enter target tumor ceils, leading to either target cell death or self-destruction within tumor cells. However, it has remained elusive as to the fate of NK cells after internalization and whether the heterotypic cell-in-cell process is different from that of the homotypic cell-in-cell event recently named entosis. Here, we show that NK cells undergo a cell-in-cell process with the ultimate fate of apoptosis within tumor cells and reveal that the internalization process requires the actin cytoskeletal regulator, ezrin. To visualize how NK cells enter into tumor cells, we carried out real-time dual color imaging analyses of NK cell internalization into tumor cells. Surprisingly, most NK cells commit to programmed cell death after their entry into tumor cells, which is distinctively different from entosis observed in the homotypic cell-in-cell process. The apoptotic cell death of the internalized NK cells was evident by activation of caspase 3 and DNA fragmentation. Furthermore, NK cell death after internalization is attenuated by the caspase inhibitor, Z-VAD-FMK, confirming apoptosis as the mode of NK cell death within tumor cells. To determine protein factors essential for the entry of NK cells into tumor cells, we car- ried out siRNA-based knockdown analysis and discovered a critical role of ezrin in NK cell internalization. Impor- tantly, PKA-mediated phosphorylation of ezrin promotes the NK cell internalization process. Our findings suggest a novel regulatory mechanism by which ezrin governs NK cell internalization into tumor cells.
基金funded by the Sichuan Science and Technology Program,Sichuan Province,China(No.2017JY0164)the Special Fund for the Fourth General Survey of Chinese Medicine Resources in China(No.2018PC001)+1 种基金Meritocracy Research Funds of China West Normal University(No.17YC325)the Fundamental Research Funds of China West Normal University(No.18B026).
文摘To analyze the degree and pattern of phenotypic variation in leaves of Tetracentron sinense Oliv from the perspective of genetic and environmental adaptation and thus contribute to effective evidence-based conservation and management strategies for germplasm resources,we measured 17 morphological and epidermal micromorphological leaf traits from 24 natural populations of T.sinense.Nested analysis of variance,multiple comparison,principal component analysis(PCA),cluster analysis,and correlation analysis were used to explore phenotypic leaf variation among and within populations and potential correlations with geographic and environmental factors.There were significant differences in 17 leaf phenotypic traits among and within populations.The mean phenotypic differentiation coefficient of the 17 traits was 56.34%,and the variation among populations(36.4%)was greater than that within populations(27.2%).The coefficient of variation(CV)of each trait ranged from 4.6 to 23.8%,and the mean was 11.8%.Phenotypic variation of leaves was related to environmental factors such as average annual sunshine hours,average July temperature,and average annual rainfall.The variation changed along gradients of longitude,latitude,and altitude.The PCA clustered the 24 natural populations into four groups.Our study suggests that phenotypic variation in T.sinense occurred primarily among populations,with moderate levels of phenotypic differentiation among populations and low levels of phenotypic variation within populations.The plant’s poor adaptability to the environment is likely an important contributor to its endangerment.Accordingly,conservation strategies are proposed to protect and manage the natural populations of T.sinense.
基金This study was supported by a grant from National Natural Science Foundation of China (81871600)
文摘BACKGROUND:Sepsis-induced liver injury is a fatal complication of sepsis.Trichostatin A(TSA)regulates inflammation and autophagy in some human diseases,and forkhead box O3a(FoxO3a)has been shown to regulate autophagy.The present study aims to investigate whether TSA exerts its effects on septic liver injury through the FoxO3a/autophagy signaling pathway.METHODS:A sepsis mouse model was constructed by the cecal ligation and puncture(CLP)method,and AML12 cells were pretreated with lipopolysaccharide(LPS)(1μg/mL)to establish a sepsis cell model.Forty mice were divided into four groups,namely control group,TSA group,CLP group,and CLP+TSA group,with 10 mice in each group.Cells were divided into control group,TSA group,LPS group,and LPS+TSA group.Hematoxylin-eosin(H&E)staining and biochemical methods were used to evaluate liver tissue injury.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the expression of proinflammatory cytokines,and Western blotting and immunofluorescence were used to measure autophagy-related protein expression.RESULTS:Compared with the CLP group(mice),the proinflammatory cytokines(interleukin-β[IL-β]2,665.27±324.90 pg/mL to 2,080.26±373.66 pg/mL;interleukin-6[IL-6]399.01±60.98 pg/mL to 221.90±46.89 pg/mL)and the hepatocyte injury markers(aspartate transaminase[AST]from 198.18±27.07 U/L to 128.42±20.55 U/L;alanine aminotransferase[ALT]from 634.98±74.10 U/L to 478.60±32.56 U/L)were notably decreased after TSA intervention.Moreover,LC3 II and FoxO3a showed an obvious increase and P62 showed an obvious decrease in the CLP+TSA group.Cell experiment results showed the similar trend.After Fox O3a gene was knocked down in AML12 cells,the promotion of autophagy and the improvement of liver enzyme index and inflammation by TSA were weakened.CONCLUSION:TSA may improve the inflammatory response and liver injury in septic mice through Fox O3a/autophagy.
基金supported by the National Natural Science Foundation of China(No.11405025)
文摘The yield ratios of neutron/proton(R(n/p)) and ~3H=~3He(R(t/~3He)) with reduced rapidity from 0 to 0.5 are investigated for 50 MeV/u ^(42;44;46;48;50;52;54;56)Ca+^(40)Ca.This was conducted at whole reduced impact parameters using the isospin-dependent quantum-molecular-dynamics model in which the initial neutron and proton densities are sampled within the Skyrme–Hartree–Fock model, using which the neutron skin thickness(△R_(np)) is determined for different neutron-rich Ca isotopes. The results show that both R(n/p) and R(t/~3He) have strong linear correlations with △R_(np) of different Ca isotopic projectiles from five different centralities. It is suggested that R(n/p) and R(t/~3He), from the same centrality, could be treated as possible experimental observables to extract the neutron skin or halo thickness for neutron-rich isotopic nuclei,including the nuclei near the neutron drip line.
文摘Caspase-1-mediated IL-1β production is generally controlled by two pathways. Toll-like receptors （TLRs） recognize pathogen-derived products and induce NF-KB-dependent pro-IL-1β transcription; NOD-like receptors （NLRs） assemble caspase-l-activating inflammasome complexes that sense bacterial products/danger signals. Through a targeted chemical screen, we identify bromoxone, a marine natural product, as a specifc and potent inhibitor of the caspase-1 pathway. Bromoxone is effective over diverse inflammatory stimuli including TLR ligands plus ATP/nigeri- cin, cytosolic DNA, flagellin and Bacillus anthracis lethal toxin. Bromoxone also efficiently suppresses easpase-1 acti- vation triggered by several types of bacterial infection. Bromoxone acts upstream or at the level of the inflammasome in a transcription-independent manner. Bromoxone also inhibits pro-IL-1β expression by targeting components up- stream of IKK in the TLR-NF-kB pathway. The unique dual activities of bromoxone are shared by the known TAK1 inhibitor that specifically blocks Nalp3 inflammasome activation. Hinted from the mechanistic and pharmacological properties of bromoxone, we further discover that several known NF-KB inhibitors that act upstream of IKK, but not those targeting IKK or IKK downstream, are potent blockers of different NLRs-mediated caspase-1 activation. Our study uncovers a possible non-transcriptional molecular link between the NLR （Nalp3）-mediated inflammasome pathway and TLR-NF-kB signaling, and suggests a potential strategy to develop new anti-inflammatory drugs.
基金supported by Grants R01 AR055915 and R01 AR054465 to DC from the National Institute of Health
文摘Osteoarthritis （OA） is a common joint degenerative disease affecting the whole joint structure, including articular cartilage, subchondral bone and synovial tissue. Although extensive work has been done in recent years to explore the molecular mechanism underlying this disease, the pathogenesis of OA is still poorly understood and currently, there is no effective disease-modifying treatment for OA. Recently, both in vitro an, in vivo studies suggest that confirmed （TGF-β）/SMAD pathway plays a critical role during OA development This short review will focus on the function and signaling mechanisms of TGF-β/SMAD pathway in articula chondrocytes, mesenchymal progenitor cells of subchondral bone and synovial lining cells during OA development.
基金Project supported by the National Key Research and Development Program of China(No.2016YFD0102103)
文摘Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting （HRM） analysis. Pooled rice （Oryza sativa） samples mixed at a 1：7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ, ray-induced mutants in rice. For demonstration, a γ, ray-mutagenized M2 rice population （n=4560） was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution （G→A） and one single nucleotide insertion （A） were identified in OsLCT1, and one tdnucleotide （TTC） deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ, ray mutagenesis to the breeding of rice and other seed crops.
基金funded by Sichuan Jiuzhang Biological Science and Technology Co.,Ltd.the Drug Innovation Major Project in China(Grant No.2016ZX09101017)the National Nature Science Foundation(Grant No.81972338)。
文摘Objective:This study was aimed at analyzing the efficacy and safety of an injectable form of chlorogenic acid(CGA)in patients with recurrent high-grade glioma after standard of care treatments,through a first-in-human,open-label,dose-escalation phase I trial.Methods:A total of 26 eligible patients were enrolled,received intramuscular CGA injections at 5 dose levels,and were followed up for 5 years.CGA was well tolerated,and the maximum tolerated dose was 5.5 mg/kg.Results:The most common treatment-related adverse events occurred at the sites of injection.No grade 3 or 4 adverse events(e.g.,drug allergy)were reported for these patients except for induration at the injection sites.A clinical pharmacokinetic study showed that CGA was rapidly eliminated from the plasma,with a t_(1/2)of 0.95–1.27 h on day 1 and 1.19–1.39 h on day 30,and no detectable CGA was observed on days 9,11,13,23,25,27,and 29 before CGA administration.After the first treatment cycle,52.2%of patients(12 of 23)achieved stable disease.Long-term follow-up indicated an estimated median overall survival of 11.3 months for all 23 evaluable patients.Of the 18 patients with grade 3 glioma,the median overall survival was 9.5 months.Two patients remained alive at the cutoff day.Conclusions:This phase I study demonstrated that CGA has a favorable safety profile(with no severe toxicity),and provides preliminary clinical benefits for patients with high grade glioma relapsing after prior standard therapies,thus shedding light on the potential clinical application of CGA for recurrent grade 4 glioma.
基金supported by the National Natural Science Foundation of China(No.11405025)
文摘The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(28)Si and ^(32)S+^(28)Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model.The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton,~3H and ~3He from ^(28)S+^(28)Si collisions.The differences in directed flows for neutrons and protons and ~3H–~3He from a proton-rich nucleus ^(28)S- induced collisions are noticeably larger than those from a stable nucleus ^(32)S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ~3H–~3He under medium impact parameters are proposed as possible observable items for studying isospin physics.
基金The work is supported by the National Natural Science Foundation of China(No.52071218)Shenzhen Science and Technology Innovation Commission(Nos.20200731215211001,20200814110413001)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515012492).The authors also appreciate the Instrumental Analysis Center of Shenzhen University.
文摘To date,the benchmark Bi_(2)Te_(3)-based alloys are still the only commercial material system used for ther-moelectric solid-state refrigeration.Nonetheless,the conspicuous performance imbalance between the p-type Bi_(2-x)Sb_(x)Te_(3)and n-type Bi_(2)Te_(3-x)Se_(x) legs has become a major obstacle for the improvement of cooling devices to achieve higher efficiency.In our previous study,novel n-type Bi_(2-x)Sb_(x)Te_(3)alloy has been pro-posed via manipulating donor-like effect as an alternative to mainstream n-type Bi_(2)Te_(3-x)Se_(x).However,the narrow bandgap of Bi_(2-x)Sb_(x)Te_(3)provoked severe bipolar effect that constrained the further improvement of zT near room temperature.Herein,we have implemented band gap engineering in n-type Bi_(1.5)Sb_(0.5)Te_(3)by employing isovalent Se substitution to inhibit the undesired intrinsic excitation and achieve the dis-tinguished room-temperature zT.First,the preferential occupancy of Se at Te^(2)site appropriately enlarges the band gap,thereby concurrently improving the Seebeck coefficient and depressing the bipolar thermal conductivity.In addition,the Se alloying mildly suppresses the compensation mechanism and essentially preserves the already optimized carrier concentration,which maintains the peak zT near room tempera-ture.Moreover,the large strain field and mass fluctuation generated by Se alloying leads to the remark-able reduction of lattice thermal conductivity.Accordingly,the zT value of Bi_(1.5)Sb_(0.5)Te_(2.8)Se_(0.2)reaches 1.0 at 300 K and peaks 1.1 at 360 K,which surpasses that of most well-known room-temperature n-type thermoelectric materials.These results pave the way for n-type Bi_(2-x)Sb_(x)Te_(3)alloys to become a new and promising top candidate for large-scale solid-state cooling applications.
基金supported by the National Key Research and Development Program of China(Nos.2016YFC0201000 and 2016YFC0201100)the Plan for Anhui Major Provincial Science&Technology Project(Nos.202203a07020004 and 202003a07020005)+1 种基金the National Natural Science Foundation of China(Nos.U2133212 and 42005108)the Science and Technological Fund of Anhui Province for Outstanding Youth(No.1808085J19)。
文摘Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China,and its components,which include ultrafine particles(UFPs),volatile organic compounds(VOCs),and other reactive gases,such as NH3and NOx,are the most harmful to human health.China has released various regulations and standards to address pollution from mobile and stationary sources.Thus,it is urgent to develop online monitoring technology for atmospheric pollution source emissions.This study provides an overview of the main progress in mobile and stationary source monitoring technology in China and describes the comprehensive application of some typical instruments in vital areas in recent years.These instruments have been applied to monitor emissions from motor vehicles,ships,airports,the chemical industry,and electric power generation.Not only has the level of atmospheric environment monitoring technology and equipment been improving,but relevant regulations and standards have also been constantly updated.Meanwhile,the developed instruments can provide scientific assistance for the successful implementation of regulations.According to the potential problem areas in atmospheric pollution in China,some research hotspots and future trends of atmospheric online monitoring technology are summarized.Furthermore,more advanced atmospheric online monitoring technology will contribute to a comprehensive understanding of atmospheric pollution and improve environmental monitoring capacity.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1601213 and 51572287)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH013)
文摘The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,the intrinsically p-type Mg3Sb2 shows low figure of merit（z T = 0.23 at 723 K） for its poor electrical conductivity.In this study,a series of Mg（3-x）LixSb2 bulk materials have been prepared by high-energy ball milling and spark plasma sintering（SPS） process.Electrical transport measurements on these materials revealed significant improvement on the power factor with respect to the undoped sample,which can be essentially attributed to the increased carrier concentration,leading to a maximum z T of0.59 at 723 K with the optimum doping level x = 0.01.Additionally,the engineering z T and energy conversion efficiency are calculated to be 0.235 and 4.89%,respectively.To our best knowledge,those are the highest values of all reported p-type Mg3Sb2-based compounds with single element doping.
