分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-11-10
摘要： In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Speci cally, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we nd its derivative to the temperature is discontinuous at critical points. We also ropose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-05-08
摘要： We discuss a class of matrix models describing cosmology with a light-like singularity, generalizing the model proposed by Craps et al. in hep-th/0506180.
分类： 计算机科学 >> 自然语言理解与机器翻译 提交时间： 2024-02-20
摘要： OpenAI's Generative Pre-trained Transformer 4 (GPT-4) is a powerful large language model with a certain degree of intelligence in understanding and generating coherent text. We are exploring whether GPT-4 is capable of acting as a die, i.e. generating random numbers. We show that GPT-4 does not appear to generate independent and identically distributed random numbers. Examples imply that GPT-4 tries to compensate for the uniformity of random numbers by sacrificing independence when acting as a die.
分类： 电子与通信技术 >> 通信技术 提交时间： 2025-02-28
Zhiqi Li
Xianlei Yang
Lei Zhang
Xiaozhou Ye
Dajiang Du
Zhigang Wang
Guanghui Zhang
Hehe Chen
Xinjian Li
Yang Bai
Yue Zhang
Yan Lu
Duozhi Zhu
Ye OUyang
Yunxin Liu
Xianyuan Zhan
Yuanchun Li
Yuanzhe Li
Weijun Wang
Ce Zhang
摘要： This report integrates the business needs of high - value scenarios in Autonomous Networks and evaluates the technical capabilities of DeepSeek and several typical large models from multiple dimensions such as semantic parsing, intent recognition, and reasoning ability. This is the first evaluation report focusing on the empowerment of large models in the field of Autonomous Networks. It aims to provide scientific basis and technical references for the advanced evolution of Autonomous Networks to L4/L5, and to promote the intelligent transformation and sustainable development of the communication industry.
分类： 生物学 >> 生物物理学 >> 生物力学与生物流变学 提交时间： 2016-05-12
Hua Sha
Liu Mi
Wu AiPing
Jiang TaiJiao
Hua Sha
Liu Mi
Li XiYan
Cheng YanHui
Huang WeiJuan
Tan MinJu
Wei HeJiang
Guo JunFeng
Wang DaYan
Shu YueLong
Peng YouSong
Jiang TaiJiao
Wu AiPing
Jiang TaiJiao
Wu AiPing
Jiang TaiJiao
摘要： The human influenza A (H3N2) virus dominated the 2014-2015 winter season in many countries and caused massive morbidity and mortality because of its antigenic variation. So far, very little is known about the antigenic patterns of the recent H3N2 virus. By systematically mapping the antigenic relationships of H3N2 strains isolated since 2010, we discovered that two groups with obvious antigenic divergence, named SW13 (A/Switzerland/9715293/2013-like strains) and HK14 (A/Hong Kong/5738/2014-like strains), co-circulated during the 2014-2015 winter season. HK14 group co-circulated with SW13 in Europe and the United States during this season, while there were few strains of HK14 in mainland China, where SW13 has dominated since 2012. Furthermore, we found that substitutions near the receptor-binding site on hemagglutinin played an important role in the antigenic variation of both the groups. These findings provide a comprehensive understanding of the recent antigenic evolution of H3N2 virus and will aid in the selection of vaccine strains.
分类： 生物学 >> 生态学 提交时间： 2017-11-17
Lai, YX (Lai, Yunxin)
Wei, XR (Wei, Xinru)
Lin, SH (Lin, Shouheng)
Qin, L (Qin, Le)
Cheng, L (Cheng, Lin)
Li, P (Li, Peng)
摘要： Cancers remain a major public health problem worldwide, which still require profound research in both the basic and preclinical fields. Patient-derived xenograft(PDX) models are created when cancerous cells or tissues from patients' primary tumors are implanted into immunodeficient mice to simulate human tumor biology in vivo, which have been extensively used in cancer research. The routes of implantation appeared to affect the outcome of PDX research, and there has been increasing applications of patient-derived orthotopic xenograft (PDOX) models. In this review, we firstly summarize the methodology to establish PDX models and then go over recent application and function of PDX models in basic cancer research on the areas of cancer characterization, initiation, proliferation, metastasis, and tumor microenvironment and in preclinical explorations of anti-cancer targets, drugs, and therapeutic strategies and finally give our perspectives on the future prospects of PDX models.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-11-10
摘要： Future Higgs factories can reach impressive precision on Higgs property measurements.In this paper, instead of conventional focus of Higgs precision in certain interaction bases, we explored its sensitivity to new physics models at the electron-positron colliders. In particular, we studied two categories of new physics models, Standard Model (SM) with a real scalar singlet extension, and Two Higgs Double Model (2HDM) as examples of weaklyinteracting models, Minimal Composite Higgs Model (MCHM) and three typical patterns of the more general operator counting for strong nteracting models as examples of strong dynamics. We performed a global t to various Higgs search channels to obtain the 95% C.L.constraints on the model parameter space. In the SM with a singlet xtension, we obtained the limits on the singlet-doublet mixing angle sin , as well as the more general Wilson coe cients of the induced higher dimensional operators. In the 2HDM, we analyzed tree level e ects in tan vs. cos(β-α) plane, as well as the one-loop contributions from the heavy Higgs bosons in the alignment limit to obtain the constraints on heavy Higgs masses for di erent types of 2HDM. In strong dynamics models, we obtained lower limits on the strong dynamics scale. In addition, once deviations of Higgs couplings are observed, they can be used to distinguish di erent models. We also compared the sensitivity of various future Higgs factories,namely Circular Electron Positron Collider (CEPC), Future Circular Collider (FCC)-ee and International Linear Collider (ILC).
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-05-09
摘要： We study the structure of the phase space in Horava-Lifshitz theory. With the constraints derived from the action, the phase space is described by five fields, thus there is a lack of canonical structure. The Poisson brackets of the Hamiltonian density do not form a closed structure, resulting in many new constraints. Taking these new constraints into account, it appears that there is no degree of freedom left, or the phase space is reduced to one with an odd number of fields.
分类： 地球科学 >> 大气科学 提交时间： 2025-05-19
摘要： The magnitude of El Niño determines the level of its global impact. Yet, how well our state-of-the-art models simulate this key aspect of El Niño is not well documented. Previous studies tend to ignore ENSO asymmetry and equate the variance of ENSO to the magnitude of El Niño. Moreover, previous evaluations are more focused on the surface manifestation of El Niño. Here, we quantify the magnitudes of El Niño and La Niña separately, both at the surface and subsurface levels. At the surface, we find that while the magnitude of La Niña events in most models is generally stronger than observed, the magnitude of El Niño is more diverse to observations. In fact, in many models, El Niño is weaker than observed. This bias in the magnitude of El Niño is more pronounced in the subsurface. We attribute this weakness in the subsurface to the generally weaker coupling strength and the apparent stronger ENSO at the surface to a lack of sufficiently strong negative feedback from the surface heat flux in the models. When normalized by the variance of ENSO, the lack of exceptionally strong El Niño events in the models is more common and pronounced. The consequences of a generally weaker El Niño in the models are discussed.
分类： 物理学 >> 核物理学 提交时间： 2025-04-26
Li, Mr. Junfeng
Yang, Mr. Jiawei
Wang, Mr. Mou
Zhao, Dr. Pengcheng
Wang, Mr. Da
Yokoyama, Dr. Ryo
WANG, Dr. KAI
Zhang, Dr. Guangwei
Zhou, Dr. Wenzhong
Zhou, Mr. Lijun
摘要： In this paper, we propose an artificial intelligence (AI)-driven framework for predicting fission gas release (FGR) in liquid metal-cooled reactors. Three AI models are trained on a comprehensive FGR database comprising 10,065 data points generated from multi-physics simulations. The results reveal that Random Forest (RF) achieves superior prediction accuracy, with a mean error (ME) of 3.96% for the optimal parameter combination (p_lin0, a_grain0, po, and t). While RF excels in database predictions, the Transformer model demonstrates exceptional capability in capturing parameter-effect trends, such as the positive correlation between FGR and fuel linear power or time. This study underscores the potential of AI models, particularly RF and Transformer, in advancing FGR forecasting for reactor safety analysis. This work can provide a replicable methodological paradigm for the FGR prediction of nuclear reactors and reliable technical support for the safety margin assessment of liquid metal-cooled reactors.
分类： 计算机科学 >> 计算机科学的集成理论 提交时间： 2022-11-25 合作期刊: 《数据智能（英文）》
摘要： We study the problem of the unsupervised learning of graphical models in mixed discrete-continuous domains. The problem of unsupervised learning of such models in discrete domains alone is notoriously challenging, compounded by the fact that inference is computationally demanding. The situation is generally believed to be significantly worse in discrete-continuous domains: estimating the unknown probability distribution of given samples is often limited in practice to a handful of parametric forms, and in addition to that, computing conditional queries need to carefully handle low-probability regions in safety-critical applications. In recent years, the regime of tractable learning has emerged, which attempts to learn a graphical model that permits efficient inference. Most of the results in this regime are based on arithmetic circuits, for which inference is linear in the size of the obtained circuit. In this work, we show how, with minimal modifications, such regimes can be generalized by leveraging efficient density estimation schemes based on piecewise polynomial approximations. Our framework is realized on a recent computational abstraction that permits efficient inference for a range of queries in the underlying language. Our empirical results show that our approach is effective, and allows a study of the trade-off between the granularity of the learned model and its predictive power.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-06-30
摘要： We construct a general class of pseudo-Goldstone composite Higgs models, within the minimal SO(5)/SO(4) coset structure, that are not necessarily of moose-type. We characterize the main properties these models should have in order to give rise to a Higgs mass around 125 GeV. We assume the existence of relatively light and weakly coupled spin 1 and 1/2 resonances. In absence of a symmetry principle, we introduce the Minimal Higgs Potential (MHP) hypothesis: the Higgs potential is assumed to be one-loop dominated by the SM fields and the above resonances, with a contribution that is made calculable by imposing suitable generalizations of the first and second Weinberg sum rules. We show that a 125 GeV Higgs requires light, often sub-TeV, fermion resonances. Their presence can also be important for the models to successfully pass the electroweak precision tests. Interestingly enough, the latter can also be passed by models with a heavy Higgs around 320 GeV. The composite Higgs models of the moose-type considered in the literature can be seen as particular limits of our class of models.
分类： 计算机科学 >> 计算机软件 提交时间： 2024-04-23
摘要： We propose a method to guide Large Language Models (LLMs) in generating structured content adhering to specific conventions without fine-tuning. By utilizing coroutine-based content generation constraints through a pre-agreed context-free grammar (CFG), LLMs are directed during decoding to produce formal language compliant outputs. This enhances stability and consistency in generating target data structures, types, or instructions, reducing application development complexities. Experimentally, error rates of GPT-2 and Gemma exceed 95% for DSLs longer than 36 and 282 tokens, respectively. We introduce YieldLang, a coroutine-based DSL generation framework, and evaluate it with LLMs on various tasks including JSON and Mermaid flowchart generation. Compared to benchmarks, our approach improves accuracy by 1.09 to 11.6 times, with LLMs requiring only about 16.5% of the samples to generate JSON effectively. This enhances usability of LLM-generated content for computer programs.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-07-11
摘要： We explore the possibility that the right-handed top quark is composite. We examine the consequences that compositeness would have on t (t) over bar production at the Tevatron, and derive a weak constraint on the scale of compositeness of order a few hundred GeV from the t (t) over bar inclusive cross section. More detailed studies of differential properties of t (t) over bar production could potentially improve this limit. We find that a composite top can result in an enhancement of the t (t) over bart (t) over bar production rate at the LHC (of as much as 10(3) compared to the Standatd Model four top rate). We explore observables which allow us to extract the four top rate from the backgrounds, and show that the LHC can either discover or constrain top compositeness for wide ranges of parameter space.
分类： 生物学 >> 生物物理学 提交时间： 2016-05-12
Liu, Mi
Wu, Aiping
Jiang, Taijiao
Liu, Mi
Wu, Aiping
Jiang, Taijiao
Liu, Mi
Wu, Aiping
Jiang, Taijiao
Liu, Mi
Hua, Sha
Wu, Aiping
Jiang, Taijiao
Zhao, Xiang
Li, Xiyan
Lan, Yu
Wang, Dayan
Shu, Yuelong
Hua, Sha
Du, Xiangjun
摘要： The influenza A (H1N1) virus causes seasonal epidemics that result in severe illnesses and deaths almost every year. A deep understanding of the antigenic patterns and evolution of human influenza A (H1N1) virus is extremely important for its effective surveillance and prevention. Through development of antigenicity inference method for human influenza A (H1N1), named PREDAC-H1, we systematically mapped the antigenic patterns and evolution of the human influenza A (H1N1) virus. Eight dominant antigenic clusters have been inferred for seasonal H1N1 viruses since 1977, which demonstrated sequential replacements over time with a similar pattern in Asia, Europe and North America. Among them, six clusters emerged first in Asia. As for China, three of the eight antigenic clusters were detected in South China earlier than in North China, indicating the leading role of South China in H1N1 transmission. The comprehensive view of the antigenic evolution of human influenza A (H1N1) virus can help formulate better strategy for its prevention and control.
分类： 地球科学 >> 地理学 提交时间： 2021-12-03 合作期刊: 《干旱区科学》
摘要： The water resources of the Nadhour-Sisseb-El Alem Basin in Tunisia exhibit semi-arid and arid climatic conditions. This induces an excessive pumping of groundwater, which creates drops in water level ranging about 1–2 m/a. Indeed, these unfavorable conditions require interventions to rationalize integrated management in decision making. The aim of this study is to determine a water recharge index (WRI), delineate the potential groundwater recharge area and estimate the potential groundwater recharge rate based on the integration of statistical models resulted from remote sensing imagery, GIS digital data (e.g., lithology, soil, runoff), measured artificial recharge data, fuzzy set theory and multi-criteria decision making (MCDM) using the analytical hierarchy process (AHP). Eight factors affecting potential groundwater recharge were determined, namely lithology, soil, slope, topography, land cover/use, runoff, drainage and lineaments. The WRI is between 1.2 and 3.1, which is classified into five classes as poor, weak, moderate, good and very good sites of potential groundwater recharge area. The very good and good classes occupied respectively 27% and 44% of the study area. The potential groundwater recharge rate was 43% of total precipitation. According to the results of the study, river beds are favorable sites for groundwater recharge.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-06-30
摘要： We address the possibility that CP violation in B-s-(B) over bar (s) mixing may help explain the origin of the cosmic baryon asymmetry. We propose a new baryogenesis mechanism-"electroweak beautygenesis"-explicitly showing that these two CP-violating phenomena can be sourced by a common CP phase. As an illustration, we work in the two-Higgs-doublet model. Because the relevant CP phase is flavor off diagonal, this mechanism is less severely constrained by null results of electric dipole moment searches than other scenarios. We show how measurements of flavor observables by the D0, CDF, and LHCb collaborations test this scenario.
分类： 物理学 >> 基本粒子与场物理学 提交时间： 2016-05-09
摘要： We construct a holographic multi-band superconductor model with each complex scalar field in the bulk minimally coupled to a same gauge field. Taking into account the back reaction of matter fields on the background geometry and focusing on the two band case with two scalar order parameters, we find that depending on the strength of the back reaction and the charge ratio of the two bulk scalars, five different superconducting phases exist, and three of five phases exhibit some region where both orders coexist and are thermodynamically favored. The other two superconducting phases have only one scalar order. The model exhibits rich phase structure and we construct the full diagram for the five superconducting phases. Our analysis indicates that the equivalent attractive interaction mediated by gravity between the two order parameters tends to make the coexistence of two orders much more easy rather than more difficult.
分类： 地球科学 >> 地理学 提交时间： 2024-09-20 合作期刊: 《干旱区科学》
摘要： Protection and optimization of cultivated land resources are of great significance to national food security. Cultivated land conversion in northern China has increased in recent years due to the industrialization and urbanization of society. However, the assessment of cultivated land conversion in this area is insufficient, posing a potential risk to cultivated land resources. This study evaluated the evolution and spatiotemporal patterns of cultivated land conversion in Inner Mongolia Autonomous Region, China, and the driving factors to improve rational utilization and to protect cultivated land resources. The spatiotemporal patterns of cultivated land conversion in Inner Mongolia were analyzed using the cultivated land conversion index, kernel density analysis, a standard deviation ellipse model, and a geographic detector. Results showed that from 2000 to 2020, the trends in cultivated land conversion area and rate in Inner Mongolia exhibited fluctuating growth, with the total area of cultivated land conversion reaching 7307.59 km2 at a rate of 6.69%. Spatial distribution of cultivated land conversion was primarily concentrated in the Hetao Plain, Nengjiang Plain, Liaohe Plain, and the Hohhot-Baotou-Ordos urban agglomeration. Moreover, the standard deviational ellipse of cultivated land conversion in Inner Mongolia exhibited a directional southwest-northeast-southwest-northeast distribution, with the northeast-southwest direction identified as the main driving force of spatial change in cultivated land conversion. Meanwhile, cultivated land conversion exhibited an increase-decrease-increase change process, indicating that spatial distribution of cultivated land conversion in Inner Mongolia became gradually apparent within the study period. The geographic detector results further revealed that the main driving factors of cultivated land conversion in Inner Mongolia were the share of secondary and tertiary industries and per-unit area yield of grain, with explanatory rates of 57.00%, 55.00%, and 51.00%, respectively. Additionally, improved agricultural production efficiency and the coordinated development of population urbanization and industry resulted in cultivated land conversion. Collectively, the findings of this study indicated that, from 2000 to 2020, the cultivated land conversion in Inner Mongolia was significant and fluctuated in time, and had strong spatial heterogeneity. The primary drivers of these events included the effects of agriculture, population, and social economy.
分类： 生物学 >> 生物物理学 分类： 化学 >> 物理化学 分类： 生物学 >> 生物物理学 提交时间： 2024-04-16
摘要： Transcription factor (TF) are proteins that regulates the transcription of genetic information from DNA to messenger RNA by binding to a specific DNA sequence.Nucleic acid-protein interactions are crucial in regulating transcription in biological systems. This work presents a quick and convenient method for constructing tight-binding models and offers physical insights into the electronic structure properties of transcription factor complexes and DNA motifs. The tight binding Hamiltonian parameters are generated using the random forest regression algorithm, which reproduces the given ab-initiolevel calculations with reasonable accuracy. We present a library of residue-level parameters derived from extensive electronic structure calculations over various possible combinations of nucleobases and amino acid side chains from high-quality DNA-protein complex structures. As an example, our approach can reasonably generate the subtle electronic structure details for the orthologous transcription factors human AP-1 and Epstein-Barr virus Zta within a few seconds on a laptop. This method potentially enhances our understanding of the electronic structure variationsof gene-protein interaction complexes, even those involving dozens of proteins and genes. We hope this study offers a powerful tool for analyzing transcription regulation mechanisms at an electronic structural level.
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