The Gaoligong Mountains(GLGM),located in southwestern China,extend north to south along the western border of the Hengduan Mountains,spanning approximately 600 km.In this study,we consolidated findings from 17 bird su...The Gaoligong Mountains(GLGM),located in southwestern China,extend north to south along the western border of the Hengduan Mountains,spanning approximately 600 km.In this study,we consolidated findings from 17 bird surveys conducted in the GLGM between 2010 and 2022.We found that the GLGM harbors tremendous bird diversity,with a total of 796 documented bird species in the region.Nearly a quarter(23.0%)of these species are listed as state key protected species or as Chinese and global threatened species.Analysis of species richness at the county level showed a decreasing trend with increasing latitude,with the greatest diversity in Yingjiang(661 species).Observations indicated that the GLGM belongs to the Oriental realm,primarily composed of bird species from southern and southwestern China.The GLGM plays an important role in avian conservation by sheltering exceptional bird diversity,providing corridors and flyways for bird migration and dispersal,and mitigating the effects of climate change.In response to the conservation needs of birds and other wildlife,the Chinese government has established numerous protected areas within the GLGM.Despite these efforts,avian conservation still faces considerable challenges in the GLGM due to limitations in the protected area network,transboundary nature of the regions,and existing gaps in monitoring and research.展开更多
Fractal theory offers a powerful tool for the precise description and quantification of the complex pore structures in reservoir rocks,crucial for understanding the storage and migration characteristics of media withi...Fractal theory offers a powerful tool for the precise description and quantification of the complex pore structures in reservoir rocks,crucial for understanding the storage and migration characteristics of media within these rocks.Faced with the challenge of calculating the three-dimensional fractal dimensions of rock porosity,this study proposes an innovative computational process that directly calculates the three-dimensional fractal dimensions from a geometric perspective.By employing a composite denoising approach that integrates Fourier transform(FT)and wavelet transform(WT),coupled with multimodal pore extraction techniques such as threshold segmentation,top-hat transformation,and membrane enhancement,we successfully crafted accurate digital rock models.The improved box-counting method was then applied to analyze the voxel data of these digital rocks,accurately calculating the fractal dimensions of the rock pore distribution.Further numerical simulations of permeability experiments were conducted to explore the physical correlations between the rock pore fractal dimensions,porosity,and absolute permeability.The results reveal that rocks with higher fractal dimensions exhibit more complex pore connectivity pathways and a wider,more uneven pore distribution,suggesting that the ideal rock samples should possess lower fractal dimensions and higher effective porosity rates to achieve optimal fluid transmission properties.The methodology and conclusions of this study provide new tools and insights for the quantitative analysis of complex pores in rocks and contribute to the exploration of the fractal transport properties of media within rocks.展开更多
Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caus...Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.展开更多
Artificial intelligence(AI)has emerged as a transformative force with the potential to positively impact every facet of society.One of its most profound applications lies in its ability to empower individuals within c...Artificial intelligence(AI)has emerged as a transformative force with the potential to positively impact every facet of society.One of its most profound applications lies in its ability to empower individuals within communities by leveraging their strengths,promoting independence,and aiding them in achieving their goals.Human uses for AI have grown across every aspect of society;from language generation to molecular synthesis,AI has begun to permeate every aspect of our lives.展开更多
In this paper,we study the global existence of BV solutions of the initial value problem for the isentropic p-system,where the state equation of the gas is given by P=Av^(-γ).Forγ>1,the general existence result f...In this paper,we study the global existence of BV solutions of the initial value problem for the isentropic p-system,where the state equation of the gas is given by P=Av^(-γ).Forγ>1,the general existence result for large initial data has not been obtained.By using the Glimm scheme,Nishida,Smoller and Diperna successively obtained the global existence results for(γ-1)TV(v_(0)(x),u_(0)(x))being small.In the present paper,by adopting a rescaling technique,we improve these results and obtain the global existence result under the condition that(γ-1)^(γ+1)(TV(v_(0)(x)))~(γ-1)(TV(u_(0)(x)))^(2) is small,which implies that,for fixedγ>1,either TV(v_(0)(x))or TV(u_(0)(x))can be arbitrarily large.展开更多
The low-cost RFID tags have very limited computing and storage resources and this makes it difficult to completely solve their security and privacy problems. Lightweight authentication is considered as one of the most...The low-cost RFID tags have very limited computing and storage resources and this makes it difficult to completely solve their security and privacy problems. Lightweight authentication is considered as one of the most effective methods to ensure the security in the RFID system. Many light-weight authentication protocols use Hash function and pseudorandom generator to ensure the anonymity and confidential communication of the RFID system. But these protocols do not provide such security as they claimed. By analyzing some typical Hash-based RFID authentication protocols, it is found that they are vulnerable to some common attacks. Many protocols cannot resist tracing attack and de-synchronization attack. Some protocols cannot provide forward security. Gy?z? Gódor and Sándor Imre proposed a Hash-based authentication protocol and they claimed their protocol could resist the well-known attacks. But by constructing some different attack scenarios, their protocol is shown to be vulnerable to tracing attack and de-synchronization attack. Based on the analysis for the Hash-based authentication protocols, some feasible suggestions are proposed to improve the security of the RFID authentication protocols.展开更多
The SOCS1/JAK2/STAT3 axis is strongly associated with tumor growth and progression,and participates in cytokine secretion in many diseases.However,the effects of the SOCS1/JAK2/STAT3 axis in experimental subarachnoid ...The SOCS1/JAK2/STAT3 axis is strongly associated with tumor growth and progression,and participates in cytokine secretion in many diseases.However,the effects of the SOCS1/JAK2/STAT3 axis in experimental subarachnoid hemorrhage remain to be studied.A subarachnoid hemorrhage model was established in rats by infusing autologous blood into the optic chiasm pool.Some rats were first treated with JAK2/STAT3 small interfering RNA(Si-JAK2/Si-STAT3)or overexpression plasmids of JAK2/STAT3.In the brains of subarachnoid hemorrhage model rats,the expression levels of both JAK2 and STAT3 were upregulated and the expression of SOCS1 was downregulated,reaching a peak at 48 hours after injury.Simultaneously,the interactions between JAK2 and SOCS1 were reduced.In contrast,the interactions between JAK2 and STAT3 were markedly enhanced.Si-JAK2 and Si-STAT3 treatment alleviated cortical neuronal cell apoptosis and necrosis,destruction of the blood-brain barrier,brain edema,and cognitive functional impairment after subarachnoid hemorrhage.This was accompanied by decreased phosphorylation of JAK2 and STAT3 protein,decreased total levels of JAK2 and STAT3 protein,and increased SOCS1 protein expression.However,overexpression of JAK2 and STAT3 exerted opposite effects,aggravating subarachnoid hemorrhage-induced early brain injury.Si-JAK2 and Si-STAT3 inhibited M1-type microglial conversion and the release of pro-inflammatory factors(inducible nitric oxide synthase,interleukin-1β,and tumor necrosis factor-α)and increased the release of anti-inflammatory factors(arginase-1,interleukin-10,and interleukin-4).Furthermore,primary neurons stimulated with oxyhemoglobin were used to simulate subarachnoid hemorrhage in vitro,and the JAK2 inhibitor AG490 was used as an intervention.The in vitro results also suggested that neuronal protection is mediated by the inhibition of JAK2 and STAT3 expression.Together,our findings indicate that the SOCS1/JAK2/STAT3 axis contributes to early brain injury after subarachnoid hemorrhage both in vitro and in vivo by inducing inflammatory responses.This study was approved by the Animal Ethics Committee of Anhui Medical University and the First Affiliated Hospital of University of Science and Technology of China(approval No.LLSC-20180202)on March 1,2018.展开更多
Recently a new clustering algorithm called 'affinity propagation' (AP) has been proposed, which efficiently clustered sparsely related data by passing messages between data points. However, we want to cluster ...Recently a new clustering algorithm called 'affinity propagation' (AP) has been proposed, which efficiently clustered sparsely related data by passing messages between data points. However, we want to cluster large scale data where the similarities are not sparse in many cases. This paper presents two variants of AP for grouping large scale data with a dense similarity matrix. The local approach is partition affinity propagation (PAP) and the global method is landmark affinity propagation (LAP). PAP passes messages in the subsets of data first and then merges them as the number of initial step of iterations; it can effectively reduce the number of iterations of clustering. LAP passes messages between the landmark data points first and then clusters non-landmark data points; it is a large global approximation method to speed up clustering. Experiments are conducted on many datasets, such as random data points, manifold subspaces, images of faces and Chinese calligraphy, and the results demonstrate that the two ap-proaches are feasible and practicable.展开更多
Background: Understanding the changes in population dynamics, including demographics, distribution and threats is essential for species status assessing.The endangered Green Peafowl (Povo muticus) has experienced s...Background: Understanding the changes in population dynamics, including demographics, distribution and threats is essential for species status assessing.The endangered Green Peafowl (Povo muticus) has experienced sharp population declines and d stribution range diminishing both in China and Southeast Asia. Field population surveys have not been conducted in China since the 1990s, which hindered conservation planning and decision-making.Methods: With interview and line transects methods, we figured out the population and distribution changes of Green Peafowl across its historical ranges over the past three decades in China during 2014-2017.Results: The Green Peafowl once habituated in 54 counties in China. Nearly 60% of the distribution counties were lost in the past three decades, with the left 22 counties distributed in central, southern and western Yunnan, SW China. Population decrease detected in all distribution areas except for Shuangbai and Xinping county where more than 60% of the total population is located. Only about 30% of the former bird population were recorded with the same interviewing method as 20 years ago.Three birds, 1 carcass, 6 calls and 12 footprints were detected along the 865 km line transects, indicating extremely low encounter rate of Green Peafowl in field. Sharp decreases in flock sizes were also detected, from 8-20 birds per flock in the 1990s to 3-5 birds at present. Poaching and habitat conversion are two widespread and long-lasting threats, while poison tion affect regional population's survival. Large flocks of 18 ng caused mortality in the past and hydropower construc -27 birds were discovered in the field, which increases our confidence of population recovery of this endangered pheasant in China.Conclusions: Only interviewed bird number and counts based on line transects were presented in this study, without further population estimation due to limitation of the data sets. Although the actual population of this cryptic bird must be underestimated, dramatic population declines and distribution concentrations of the endangered Green Peafowl occurred over the past 30 years in China undoubtedly.展开更多
Stratum corneum is the main obstacle for drugs to pass through the skin. Microneedles are composed of arrays of micro-projections formed with different materials, generally ranging from 25-2000 μm in height. Micronee...Stratum corneum is the main obstacle for drugs to pass through the skin. Microneedles are composed of arrays of micro-projections formed with different materials, generally ranging from 25-2000 μm in height. Microneedles straightly pierce the skin with its short needle arrays to overcome this barrier. Microneedles can be divided into several categories, for instance, solid microneedles, coated microneedles, and hollow microneedles and so on. However, all these types have their weak points related to corresponding mechanisms.In recent years, pioneering scientists have been working on these issues and some possible solutions have been investigated. This article will focus on the microneedle arrays consisting of hydrogels. Hydrogels are commonly used in drug delivery field. Hydrogel microneedles can be further divided into dissolving and degradable microneedles and phase transition microneedles. The former leaves drug with matrix in the skin. The latter has the feature that drugs in the matrix are delivered while the remaining ingredients can be easily removed from the skin after usage. For drugs which are required to be used every day, the phase transition microneedles are more acceptable. This article is written in order to summarize the advantages of these designs and summarize issues to be solved which may hinder the development of this technology.展开更多
Background: The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurat...Background: The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, dicjestible energy (DE) and metabolizable enercjy (ME) content, and apparent ileal digestibility (AID) and standardized ileal dicjestibility (SID) of amino acids (AA) for growincj pigs. Thirteen solvent-extracted double-low rapeseed meal (DLIRSM) samples were obtained from the main double-low rapeseed producing areas in China. Methods: The DE and ME contents of the 13 DLRSM samples were measured in cjrowin9 pigs (six pigs per DLRSM sample, average initial body weicjht (BW) =48.3 kg). The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows (average initial BW = 35.3 kcj) by using two 6 x 6 Latin square designs. Each Latin square comprised one N-flee diet and 5 DLRSM test diets. Results: The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than ]0 % for ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), and total 91ucosinolates. The AA content of DLRSM varied among samples especially for lysine (Lys) and methionine (Met). On a dry matter (DM) basis, the apparent total tract digestibility (ATFD) of gross energy (GE), the DE and ME and the ME:DE ratio of DLRSM averaged 62.39 %, 2862 kcal/k9 and 2723 kcal/kcj, and 94.95 %, respectively. The mean value of S1D of Lys was 70.52 % which varied from 66.54-76.54 %. The SID of crude protein (CP), Met, and threonine (Thr) averaged 72.81%, 82.41%, and 69.76 %, respectively. Conclusions: There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLIRSM samples were observed. In addition, the AID and SID of all AA were relatively similar amoncj DLRSM samples except for that of Lys.展开更多
The response characteristics of the warhead under thermal stimuli conditions are important to the safety improvement.The goal of this study is to obtain data on the warhead in the fast cook-off process.In this paper,a...The response characteristics of the warhead under thermal stimuli conditions are important to the safety improvement.The goal of this study is to obtain data on the warhead in the fast cook-off process.In this paper,a numerical calculation method is proposed,whose reliability is supported by comparison with experimental results.Through the numerical calculation,the temperature distribution,temperature change,and ignition time are acquired.The numerical results show that the ignition time is 76 s after the warhead started to burn and that the maximum temperature of the explosive’s outer surface is 238.3℃ at the ignition time.The fast cook-off experiment of the warhead is implemented so as to get the flame temperature and reaction grades that are not available through numerical calculation.The experimental results show that the overpressure fails to reach the preset minimumvalue which is equivalent to 6 kg of TNT and that the reaction grade is deflagration.The research results have reference value for the design of the warhead and the reduction of detonation risks.展开更多
After the first Earth Orientation Parameters Prediction Comparison Campaign(1 st EOP PCC),the traditional method using least-squares extrapolation and autoregressive(LS+AR)models was considered as one of the polar mot...After the first Earth Orientation Parameters Prediction Comparison Campaign(1 st EOP PCC),the traditional method using least-squares extrapolation and autoregressive(LS+AR)models was considered as one of the polar motion prediction methods with higher accuracy.The traditional method predicts individual polar motion series separately,which has a single input data and limited improvement in prediction accuracy.To address this problem,this paper proposes a new method for predicting polar motion by combining the difference between polar motion series.The X,Y,and Y-X series were predicted separately using LS+AR models.Then,the new forecast value of X series is obtained by combining the forecast value of Y series with that of Y-X series;the new forecast value of Y series is obtained by combining the forecast value of X series with that of Y-X series.The hindcast experimental comparison results from January 1,2011 to April 4,2021 show that the new method achieves a maximum improvement of 12.95%and 14.96%over the traditional method in the X and Y directions,respectively.The new method has obvious advantages compared with the differential method.This study tests the stability and superiority of the new method and provides a new idea for the research of polar motion prediction.展开更多
DEAR EDITOR,The green peafowl (Pavo muticus) is one of the most threatened pheasants in the world. In China, it is widely appreciated for its beauty as well as historical and cultural value, but current populations nu...DEAR EDITOR,The green peafowl (Pavo muticus) is one of the most threatened pheasants in the world. In China, it is widely appreciated for its beauty as well as historical and cultural value, but current populations number less than 500 individuals. Recently, Tang and colleagues reported in Science that the green peafowl is likely to become extinct due to the construction of the Jiasajiang Level 1 Hydropower Station within the Red River Upstream District (RRUD) and thus called for a stop to this project (Tang et al., 2019). According to our recent surveys, however, this species is still extant in 22 counties of Yunnan Province, China, among which, only two within the RRUD have been predicted to be affected by floods from the hydropower station. Therefore, the conclusion that the species will likely go extinct in China upon completion of the dam is unwarranted. In fact, construction of the Jiasajiang Level 1 Hydropower Station was stopped in August 2017. The main challenge for green peafowl conservation is that over 65% of the population occurs outside of protected reserves in China. Fortunately, the Chinese government has adopted an Ecological Redline (ERL) strategy to achieve ecological civilization plans, thus bringing new hope to the conservation of green peafowls both inside and outside of protected reserves. As a top conservation priority for China, the government is fully committed to conserving this peafowl.展开更多
Background: To investigate the effects of dietary crude protein(CP) restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing p...Background: To investigate the effects of dietary crude protein(CP) restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs(62.30 ± 0.88 kg)were allotted to 3 groups and fed with the recommended adequate protein(AP, 16 % CP) diet, moderately restricted protein(MP, 13 % CP) diet and low protein(LP, 10 % CP) diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle(LDM), psoas major muscle(PMM) and biceps femoris muscle(BFM) were collected and analyzed.Results: Results showed that growing-finishing pigs fed the MP or AP diet improved(P 〈 0.01) the average daily gain and feed: gain ratio compared with those fed the LP diet, and the MP diet tended to increase(P = 0.09) the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated(P 〈 0.05) muscular m RNA expression of all the selected key genes, except that myosin heavy chain(My HC) IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1(m TORC1) pathway was stimulated(P 〈 0.05) in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion: The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.展开更多
Proteins therapy is of great importance in the treatment of protein deficiency disease. Most human diseases are related to the malfunctioning of one or more proteins. The most effective and direct approach is protein ...Proteins therapy is of great importance in the treatment of protein deficiency disease. Most human diseases are related to the malfunctioning of one or more proteins. The most effective and direct approach is protein therapy, which delivers the proteins into the target cell to replace the dysfunction protein and maintain the balance of organism. However, clinical application is frequently hampered by various biological barriers to their successful delivery. This review aims to discuss the recent advances about microparticles and nanoparticles fabricated using micro and nanotechnology for intracellular delivery therapy protein and give some suggestions about the promising delivery system.展开更多
1.Introduction Artificial intelligence(AI)is committed to the realization of machine-borne intelligence.The technologies underpinning AI have made huge leaps in the past decade,bringing exciting applications such as l...1.Introduction Artificial intelligence(AI)is committed to the realization of machine-borne intelligence.The technologies underpinning AI have made huge leaps in the past decade,bringing exciting applications such as language understanding,vision recognition,and intelligent digital assistants.However,contemporary AI systems are good at specific predefined tasks and are unable to learn by themselves from data or from experience,intuitive reasoning,and adaptation.展开更多
Cross-media retrieval is an interesting research topic,which seeks to remove the barriers among different modalities.To enable cross-media retrieval,it is needed to find the correlation measures between heterogeneous ...Cross-media retrieval is an interesting research topic,which seeks to remove the barriers among different modalities.To enable cross-media retrieval,it is needed to find the correlation measures between heterogeneous low-level features and to judge the semantic similarity.This paper presents a novel approach to learn cross-media correlation between visual features and auditory features for image-audio retrieval.A semi-supervised correlation preserving mapping(SSCPM)method is described to construct the isomorphic SSCPM subspace where canonical correlations between the original visual and auditory features are further preserved.Subspace optimization algorithm is proposed to improve the local image cluster and audio cluster quality in an interactive way.A unique relevance feedback strategy is developed to update the knowledge of cross-media correlation by learning from user behaviors,so retrieval performance is enhanced in a progressive manner.Experimental results show that the performance of our approach is effective.展开更多
The optic nerve is a viscoelastic solid-like biomaterial.Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury.We hypothesized that stress relaxation a...The optic nerve is a viscoelastic solid-like biomaterial.Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury.We hypothesized that stress relaxation and creep properties of the optic nerve change after injury.Moreover,human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal.To validate this hypothesis,a rabbit model of optic nerve injury was established using a clamp approach.At 7 days after injury,the vitreous body received a one-time injection of 50 μg human brain-derived neurotrophic factor or 1 × 106 human umbilical cord blood-derived stem cells.At 30 days after injury,stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly,with pathological changes in the injured optic nerve also noticeably improved.These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves,and thereby contributes to nerve recovery.展开更多
基金supported by the National Key R&D Program of China(2022YFC2602500,2022YFC2602502)Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment,China,Second Xizang Plateau Scientific Expedition and Research Program(STEP,2019QZKK0501)+3 种基金Major Science and Technique Programs in Yunnan Province(202102AA310055)National Natural Science Foundation of China(32070435)Science and Technology Basic Resources Investigation Program of China“Wild germplasm collection and preservation in Great Gaoligong Mountain”(2021FY100200)Project for Talent and Platform of Science and Technology in Yunnan Province Science and Technology Department(202205AM070007)。
文摘The Gaoligong Mountains(GLGM),located in southwestern China,extend north to south along the western border of the Hengduan Mountains,spanning approximately 600 km.In this study,we consolidated findings from 17 bird surveys conducted in the GLGM between 2010 and 2022.We found that the GLGM harbors tremendous bird diversity,with a total of 796 documented bird species in the region.Nearly a quarter(23.0%)of these species are listed as state key protected species or as Chinese and global threatened species.Analysis of species richness at the county level showed a decreasing trend with increasing latitude,with the greatest diversity in Yingjiang(661 species).Observations indicated that the GLGM belongs to the Oriental realm,primarily composed of bird species from southern and southwestern China.The GLGM plays an important role in avian conservation by sheltering exceptional bird diversity,providing corridors and flyways for bird migration and dispersal,and mitigating the effects of climate change.In response to the conservation needs of birds and other wildlife,the Chinese government has established numerous protected areas within the GLGM.Despite these efforts,avian conservation still faces considerable challenges in the GLGM due to limitations in the protected area network,transboundary nature of the regions,and existing gaps in monitoring and research.
基金supported by the National Natural Science Foundation of China (Nos.52374078 and 52074043)the Fundamental Research Funds for the Central Universities (No.2023CDJKYJH021)。
文摘Fractal theory offers a powerful tool for the precise description and quantification of the complex pore structures in reservoir rocks,crucial for understanding the storage and migration characteristics of media within these rocks.Faced with the challenge of calculating the three-dimensional fractal dimensions of rock porosity,this study proposes an innovative computational process that directly calculates the three-dimensional fractal dimensions from a geometric perspective.By employing a composite denoising approach that integrates Fourier transform(FT)and wavelet transform(WT),coupled with multimodal pore extraction techniques such as threshold segmentation,top-hat transformation,and membrane enhancement,we successfully crafted accurate digital rock models.The improved box-counting method was then applied to analyze the voxel data of these digital rocks,accurately calculating the fractal dimensions of the rock pore distribution.Further numerical simulations of permeability experiments were conducted to explore the physical correlations between the rock pore fractal dimensions,porosity,and absolute permeability.The results reveal that rocks with higher fractal dimensions exhibit more complex pore connectivity pathways and a wider,more uneven pore distribution,suggesting that the ideal rock samples should possess lower fractal dimensions and higher effective porosity rates to achieve optimal fluid transmission properties.The methodology and conclusions of this study provide new tools and insights for the quantitative analysis of complex pores in rocks and contribute to the exploration of the fractal transport properties of media within rocks.
基金supported by the General Program of Chongqing Natural Science Foundation(CSTB2022NSCQMSX1227 and CSTB2022NSCQ-MSX0459)the supports from the Fundamental Research Funds for the Central Universities(SWU-XDJH202314)。
文摘Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.
文摘Artificial intelligence(AI)has emerged as a transformative force with the potential to positively impact every facet of society.One of its most profound applications lies in its ability to empower individuals within communities by leveraging their strengths,promoting independence,and aiding them in achieving their goals.Human uses for AI have grown across every aspect of society;from language generation to molecular synthesis,AI has begun to permeate every aspect of our lives.
基金partially the NSFC(11671193)Fangqi Chen was partially the NSFC(12172166,11872201)。
文摘In this paper,we study the global existence of BV solutions of the initial value problem for the isentropic p-system,where the state equation of the gas is given by P=Av^(-γ).Forγ>1,the general existence result for large initial data has not been obtained.By using the Glimm scheme,Nishida,Smoller and Diperna successively obtained the global existence results for(γ-1)TV(v_(0)(x),u_(0)(x))being small.In the present paper,by adopting a rescaling technique,we improve these results and obtain the global existence result under the condition that(γ-1)^(γ+1)(TV(v_(0)(x)))~(γ-1)(TV(u_(0)(x)))^(2) is small,which implies that,for fixedγ>1,either TV(v_(0)(x))or TV(u_(0)(x))can be arbitrarily large.
文摘The low-cost RFID tags have very limited computing and storage resources and this makes it difficult to completely solve their security and privacy problems. Lightweight authentication is considered as one of the most effective methods to ensure the security in the RFID system. Many light-weight authentication protocols use Hash function and pseudorandom generator to ensure the anonymity and confidential communication of the RFID system. But these protocols do not provide such security as they claimed. By analyzing some typical Hash-based RFID authentication protocols, it is found that they are vulnerable to some common attacks. Many protocols cannot resist tracing attack and de-synchronization attack. Some protocols cannot provide forward security. Gy?z? Gódor and Sándor Imre proposed a Hash-based authentication protocol and they claimed their protocol could resist the well-known attacks. But by constructing some different attack scenarios, their protocol is shown to be vulnerable to tracing attack and de-synchronization attack. Based on the analysis for the Hash-based authentication protocols, some feasible suggestions are proposed to improve the security of the RFID authentication protocols.
基金This study was supported by the National Natural Science Foundation of China,No.81500375(to XQK)the Fundamental Research Funds for the Central Universities,No.WK9110000112(to YW)+1 种基金the Anhui Provincial Natural Science Foundation of China,No.1508085QH184(to YW)Shandong Provincial Natural Science Foundation of China,No.ZR2015HQ001(to XQK).
文摘The SOCS1/JAK2/STAT3 axis is strongly associated with tumor growth and progression,and participates in cytokine secretion in many diseases.However,the effects of the SOCS1/JAK2/STAT3 axis in experimental subarachnoid hemorrhage remain to be studied.A subarachnoid hemorrhage model was established in rats by infusing autologous blood into the optic chiasm pool.Some rats were first treated with JAK2/STAT3 small interfering RNA(Si-JAK2/Si-STAT3)or overexpression plasmids of JAK2/STAT3.In the brains of subarachnoid hemorrhage model rats,the expression levels of both JAK2 and STAT3 were upregulated and the expression of SOCS1 was downregulated,reaching a peak at 48 hours after injury.Simultaneously,the interactions between JAK2 and SOCS1 were reduced.In contrast,the interactions between JAK2 and STAT3 were markedly enhanced.Si-JAK2 and Si-STAT3 treatment alleviated cortical neuronal cell apoptosis and necrosis,destruction of the blood-brain barrier,brain edema,and cognitive functional impairment after subarachnoid hemorrhage.This was accompanied by decreased phosphorylation of JAK2 and STAT3 protein,decreased total levels of JAK2 and STAT3 protein,and increased SOCS1 protein expression.However,overexpression of JAK2 and STAT3 exerted opposite effects,aggravating subarachnoid hemorrhage-induced early brain injury.Si-JAK2 and Si-STAT3 inhibited M1-type microglial conversion and the release of pro-inflammatory factors(inducible nitric oxide synthase,interleukin-1β,and tumor necrosis factor-α)and increased the release of anti-inflammatory factors(arginase-1,interleukin-10,and interleukin-4).Furthermore,primary neurons stimulated with oxyhemoglobin were used to simulate subarachnoid hemorrhage in vitro,and the JAK2 inhibitor AG490 was used as an intervention.The in vitro results also suggested that neuronal protection is mediated by the inhibition of JAK2 and STAT3 expression.Together,our findings indicate that the SOCS1/JAK2/STAT3 axis contributes to early brain injury after subarachnoid hemorrhage both in vitro and in vivo by inducing inflammatory responses.This study was approved by the Animal Ethics Committee of Anhui Medical University and the First Affiliated Hospital of University of Science and Technology of China(approval No.LLSC-20180202)on March 1,2018.
基金the National Natural Science Foundation of China (Nos. 60533090 and 60603096)the National Hi-Tech Research and Development Program (863) of China (No. 2006AA010107)+2 种基金the Key Technology R&D Program of China (No. 2006BAH02A13-4)the Program for Changjiang Scholars and Innovative Research Team in University of China (No. IRT0652)the Cultivation Fund of the Key Scientific and Technical Innovation Project of MOE, China (No. 706033)
文摘Recently a new clustering algorithm called 'affinity propagation' (AP) has been proposed, which efficiently clustered sparsely related data by passing messages between data points. However, we want to cluster large scale data where the similarities are not sparse in many cases. This paper presents two variants of AP for grouping large scale data with a dense similarity matrix. The local approach is partition affinity propagation (PAP) and the global method is landmark affinity propagation (LAP). PAP passes messages in the subsets of data first and then merges them as the number of initial step of iterations; it can effectively reduce the number of iterations of clustering. LAP passes messages between the landmark data points first and then clusters non-landmark data points; it is a large global approximation method to speed up clustering. Experiments are conducted on many datasets, such as random data points, manifold subspaces, images of faces and Chinese calligraphy, and the results demonstrate that the two ap-proaches are feasible and practicable.
基金the financial supports from the Biodiversity Conservation Fund from Yunnan Environmental Protection DepartmentSpecial Funds for Green Peafowl Investigation from State Forestry Administration of the People’s Republic of Chinasupported by the Key Laboratory of Special Biological Resource Development and Utilization of Universities in Yunnan Province
文摘Background: Understanding the changes in population dynamics, including demographics, distribution and threats is essential for species status assessing.The endangered Green Peafowl (Povo muticus) has experienced sharp population declines and d stribution range diminishing both in China and Southeast Asia. Field population surveys have not been conducted in China since the 1990s, which hindered conservation planning and decision-making.Methods: With interview and line transects methods, we figured out the population and distribution changes of Green Peafowl across its historical ranges over the past three decades in China during 2014-2017.Results: The Green Peafowl once habituated in 54 counties in China. Nearly 60% of the distribution counties were lost in the past three decades, with the left 22 counties distributed in central, southern and western Yunnan, SW China. Population decrease detected in all distribution areas except for Shuangbai and Xinping county where more than 60% of the total population is located. Only about 30% of the former bird population were recorded with the same interviewing method as 20 years ago.Three birds, 1 carcass, 6 calls and 12 footprints were detected along the 865 km line transects, indicating extremely low encounter rate of Green Peafowl in field. Sharp decreases in flock sizes were also detected, from 8-20 birds per flock in the 1990s to 3-5 birds at present. Poaching and habitat conversion are two widespread and long-lasting threats, while poison tion affect regional population's survival. Large flocks of 18 ng caused mortality in the past and hydropower construc -27 birds were discovered in the field, which increases our confidence of population recovery of this endangered pheasant in China.Conclusions: Only interviewed bird number and counts based on line transects were presented in this study, without further population estimation due to limitation of the data sets. Although the actual population of this cryptic bird must be underestimated, dramatic population declines and distribution concentrations of the endangered Green Peafowl occurred over the past 30 years in China undoubtedly.
基金supported by the Pro jects of National Science Foundation of China (No. 81373366 and 81173001)Funds for Interdisciplinary Pro jects of Medicine and Engineering by Shanghai Jiao Tong University (No. YG2013MS52 and YG2013MS62)
文摘Stratum corneum is the main obstacle for drugs to pass through the skin. Microneedles are composed of arrays of micro-projections formed with different materials, generally ranging from 25-2000 μm in height. Microneedles straightly pierce the skin with its short needle arrays to overcome this barrier. Microneedles can be divided into several categories, for instance, solid microneedles, coated microneedles, and hollow microneedles and so on. However, all these types have their weak points related to corresponding mechanisms.In recent years, pioneering scientists have been working on these issues and some possible solutions have been investigated. This article will focus on the microneedle arrays consisting of hydrogels. Hydrogels are commonly used in drug delivery field. Hydrogel microneedles can be further divided into dissolving and degradable microneedles and phase transition microneedles. The former leaves drug with matrix in the skin. The latter has the feature that drugs in the matrix are delivered while the remaining ingredients can be easily removed from the skin after usage. For drugs which are required to be used every day, the phase transition microneedles are more acceptable. This article is written in order to summarize the advantages of these designs and summarize issues to be solved which may hinder the development of this technology.
基金financially supported by the Modern Agricultural Industry Technology System(CARS-36)Special Public Sector Fund in Agriculture (200903006)
文摘Background: The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, dicjestible energy (DE) and metabolizable enercjy (ME) content, and apparent ileal digestibility (AID) and standardized ileal dicjestibility (SID) of amino acids (AA) for growincj pigs. Thirteen solvent-extracted double-low rapeseed meal (DLIRSM) samples were obtained from the main double-low rapeseed producing areas in China. Methods: The DE and ME contents of the 13 DLRSM samples were measured in cjrowin9 pigs (six pigs per DLRSM sample, average initial body weicjht (BW) =48.3 kg). The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows (average initial BW = 35.3 kcj) by using two 6 x 6 Latin square designs. Each Latin square comprised one N-flee diet and 5 DLRSM test diets. Results: The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than ]0 % for ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), and total 91ucosinolates. The AA content of DLRSM varied among samples especially for lysine (Lys) and methionine (Met). On a dry matter (DM) basis, the apparent total tract digestibility (ATFD) of gross energy (GE), the DE and ME and the ME:DE ratio of DLRSM averaged 62.39 %, 2862 kcal/k9 and 2723 kcal/kcj, and 94.95 %, respectively. The mean value of S1D of Lys was 70.52 % which varied from 66.54-76.54 %. The SID of crude protein (CP), Met, and threonine (Thr) averaged 72.81%, 82.41%, and 69.76 %, respectively. Conclusions: There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLIRSM samples were observed. In addition, the AID and SID of all AA were relatively similar amoncj DLRSM samples except for that of Lys.
文摘The response characteristics of the warhead under thermal stimuli conditions are important to the safety improvement.The goal of this study is to obtain data on the warhead in the fast cook-off process.In this paper,a numerical calculation method is proposed,whose reliability is supported by comparison with experimental results.Through the numerical calculation,the temperature distribution,temperature change,and ignition time are acquired.The numerical results show that the ignition time is 76 s after the warhead started to burn and that the maximum temperature of the explosive’s outer surface is 238.3℃ at the ignition time.The fast cook-off experiment of the warhead is implemented so as to get the flame temperature and reaction grades that are not available through numerical calculation.The experimental results show that the overpressure fails to reach the preset minimumvalue which is equivalent to 6 kg of TNT and that the reaction grade is deflagration.The research results have reference value for the design of the warhead and the reduction of detonation risks.
基金funded by the National Natural Science Foundation of China(Nos.42174011 and 41874001)Jiangxi Province Graduate Student Innovation Fund(No.YC2021-S614)+2 种基金Jiangxi Provincial Natural Science Foundation(No.20202BABL212015)the East China University of Technology Ph.D.Project(No.DNBK2019181)the Key Laboratory for Digital Land and Resources of Jiangxi Province,East China University of Technology(No.DLLJ202109)
文摘After the first Earth Orientation Parameters Prediction Comparison Campaign(1 st EOP PCC),the traditional method using least-squares extrapolation and autoregressive(LS+AR)models was considered as one of the polar motion prediction methods with higher accuracy.The traditional method predicts individual polar motion series separately,which has a single input data and limited improvement in prediction accuracy.To address this problem,this paper proposes a new method for predicting polar motion by combining the difference between polar motion series.The X,Y,and Y-X series were predicted separately using LS+AR models.Then,the new forecast value of X series is obtained by combining the forecast value of Y series with that of Y-X series;the new forecast value of Y series is obtained by combining the forecast value of X series with that of Y-X series.The hindcast experimental comparison results from January 1,2011 to April 4,2021 show that the new method achieves a maximum improvement of 12.95%and 14.96%over the traditional method in the X and Y directions,respectively.The new method has obvious advantages compared with the differential method.This study tests the stability and superiority of the new method and provides a new idea for the research of polar motion prediction.
文摘DEAR EDITOR,The green peafowl (Pavo muticus) is one of the most threatened pheasants in the world. In China, it is widely appreciated for its beauty as well as historical and cultural value, but current populations number less than 500 individuals. Recently, Tang and colleagues reported in Science that the green peafowl is likely to become extinct due to the construction of the Jiasajiang Level 1 Hydropower Station within the Red River Upstream District (RRUD) and thus called for a stop to this project (Tang et al., 2019). According to our recent surveys, however, this species is still extant in 22 counties of Yunnan Province, China, among which, only two within the RRUD have been predicted to be affected by floods from the hydropower station. Therefore, the conclusion that the species will likely go extinct in China upon completion of the dam is unwarranted. In fact, construction of the Jiasajiang Level 1 Hydropower Station was stopped in August 2017. The main challenge for green peafowl conservation is that over 65% of the population occurs outside of protected reserves in China. Fortunately, the Chinese government has adopted an Ecological Redline (ERL) strategy to achieve ecological civilization plans, thus bringing new hope to the conservation of green peafowls both inside and outside of protected reserves. As a top conservation priority for China, the government is fully committed to conserving this peafowl.
基金financially supported by the National Basic Research Program of China(2013CB127305)the Nature Science Foundation of Hunan Province(S2014J504I)+1 种基金the Major Project of Hunan Province(2015NK1002)the National Science and Technology Ministry(2014BAD08B11)
文摘Background: To investigate the effects of dietary crude protein(CP) restriction on muscle fiber characteristics and key regulators related to protein deposition in skeletal muscle, a total of 18 growing-finishing pigs(62.30 ± 0.88 kg)were allotted to 3 groups and fed with the recommended adequate protein(AP, 16 % CP) diet, moderately restricted protein(MP, 13 % CP) diet and low protein(LP, 10 % CP) diet, respectively. The skeletal muscle of different locations in pigs, including longissimus dorsi muscle(LDM), psoas major muscle(PMM) and biceps femoris muscle(BFM) were collected and analyzed.Results: Results showed that growing-finishing pigs fed the MP or AP diet improved(P 〈 0.01) the average daily gain and feed: gain ratio compared with those fed the LP diet, and the MP diet tended to increase(P = 0.09) the weight of LDM. Moreover, the ATP content and energy charge value were varied among muscle samples from different locations of pigs fed the reduced protein diets. We also observed that pigs fed the MP diet up-regulated(P 〈 0.05) muscular m RNA expression of all the selected key genes, except that myosin heavy chain(My HC) IIb,My HC IIx, while m RNA expression of ubiquitin ligases genes was not affected by dietary CP level. Additionally, the activation of mammalian target of rapamycin complex 1(m TORC1) pathway was stimulated(P 〈 0.05) in skeletal muscle of the pigs fed the MP or AP diet compared with those fed the LP diet.Conclusion: The results suggest that the pigs fed the MP diet could catch up to the growth performance and the LDM weight of the pigs fed the AP diet, and the underlying mechanism may be partly due to the alteration in energy status, modulation of muscle fiber characteristics and m TORC1 activation as well as its downstream effectors in skeletal muscle of different locations in growing-finishing pigs.
基金supported by the program of Ma jor scientific and technological specialized project for "significant new formulation of new drugs" (No. 2009ZX09310-007 and No. 2009ZX09301007)National Science Foundation of China Committee (No. 30873180)+2 种基金Foundation of Ministry of Education of China (No. 20090073120085)the Shanghai Science and Technology Committee (No. 0952nm03700 and No. 0952nm03700)The authors thank the Analytical Center of Shanghai JiaoTong University for Technical Support
文摘Proteins therapy is of great importance in the treatment of protein deficiency disease. Most human diseases are related to the malfunctioning of one or more proteins. The most effective and direct approach is protein therapy, which delivers the proteins into the target cell to replace the dysfunction protein and maintain the balance of organism. However, clinical application is frequently hampered by various biological barriers to their successful delivery. This review aims to discuss the recent advances about microparticles and nanoparticles fabricated using micro and nanotechnology for intracellular delivery therapy protein and give some suggestions about the promising delivery system.
文摘1.Introduction Artificial intelligence(AI)is committed to the realization of machine-borne intelligence.The technologies underpinning AI have made huge leaps in the past decade,bringing exciting applications such as language understanding,vision recognition,and intelligent digital assistants.However,contemporary AI systems are good at specific predefined tasks and are unable to learn by themselves from data or from experience,intuitive reasoning,and adaptation.
基金Project supported by the National Natural Science Foundation of China (Nos. 60533090 and 60773051)the Natural Science Foundation of Zhejiang Province (No. Y105395),China
文摘Cross-media retrieval is an interesting research topic,which seeks to remove the barriers among different modalities.To enable cross-media retrieval,it is needed to find the correlation measures between heterogeneous low-level features and to judge the semantic similarity.This paper presents a novel approach to learn cross-media correlation between visual features and auditory features for image-audio retrieval.A semi-supervised correlation preserving mapping(SSCPM)method is described to construct the isomorphic SSCPM subspace where canonical correlations between the original visual and auditory features are further preserved.Subspace optimization algorithm is proposed to improve the local image cluster and audio cluster quality in an interactive way.A unique relevance feedback strategy is developed to update the knowledge of cross-media correlation by learning from user behaviors,so retrieval performance is enhanced in a progressive manner.Experimental results show that the performance of our approach is effective.
基金supported by a grant from High-Tech Research and Development Program of Jilin Province of China,No.20110492
文摘The optic nerve is a viscoelastic solid-like biomaterial.Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury.We hypothesized that stress relaxation and creep properties of the optic nerve change after injury.Moreover,human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal.To validate this hypothesis,a rabbit model of optic nerve injury was established using a clamp approach.At 7 days after injury,the vitreous body received a one-time injection of 50 μg human brain-derived neurotrophic factor or 1 × 106 human umbilical cord blood-derived stem cells.At 30 days after injury,stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly,with pathological changes in the injured optic nerve also noticeably improved.These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves,and thereby contributes to nerve recovery.