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Interrelationships between Length of the Day, Moon Distance, Phanerozoic Geodynamic Cycles, Tidal Dissipation and Earth’s Core: Review and Analysis
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作者 Heinz-Jürgen Brink 《International Journal of Geosciences》 CAS 2024年第5期396-415,共20页
The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around... The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around the rotation axis of the spinning Earth during the growth of the core the rotation should have been accelerated. Controversially the tidal dissipation by the Moon, which is mainly dependent on the availability of open shallow seas and the kind of Moon escape from a nearby position, acts towards a deceleration of the rotating Earth. Measurements of LOD for Phanerozoic and Precambrian times open ways to solve questions concerning the geodynamical history of the Earth. These measurements encompass investigations of growth patterns in fossils and depositional patterns in sediments (Cyclostratigraphy, Tidalites, Stromatolites, Rhythmites). These patterns contain information on the LOD and on the changing distance between Earth and Moon and can be used as well for a discussion about the growth of the Earth’s core. By updating an older paper with its simple approach as well as incorporating newly published results provided by the geoscientific community, a moderate to fast growth of the core in a hot early Earth will be favored controversially to the assumption of a delayed development of the core in an originally cold Earth. Core development with acceleration of Earth’s rotation and the contemporaneous slowing down due to tidal dissipation during the filling of the ocean may significantly interrelate. 展开更多
关键词 length of the Day Moon Distance Phanerozoic Geodynamic Cycles Tidal Dissipation Earth’s Core
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Planck Scale Fluid Mechanics: Measuring the Planck Length from Fluid Mechanics Independent of G
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作者 Espen Gaarder Haug 《Open Journal of Fluid Dynamics》 2023年第S1期250-261,共12页
We demonstrate how to extract the Planck length from hydrostatic pressure without relying on any knowledge of Newton’s gravitational constant, G. By measuring the pressure from a water column, we can determine the Pl... We demonstrate how to extract the Planck length from hydrostatic pressure without relying on any knowledge of Newton’s gravitational constant, G. By measuring the pressure from a water column, we can determine the Planck length without requiring knowledge of either G or the Planck constant. This experiment is simple to perform and cost-effective, making it not only of interest to researchers studying gravity but also suitable for low-budget educational settings. Despite its simplicity, this has never been demonstrated to be possible before, and it is achievable due to new theoretical insights into gravity and its connection to quantum gravity and the Planck scale. This provides new insights into fluid mechanics and the Planck scale. We are also exploring initial concepts related to what we are calling “Planck fluid”, which could potentially play a central role in quantum gravity and quantum fluid mechanics. 展开更多
关键词 Planck length Hydrostatic Pressure Pascal’s Law GRAVITY Planck Fluid
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Analysis of Hops Length in Wireless Sensor Networks 被引量:4
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作者 Mekkaoui Kheireddine Rahmoun Abdellatif 《Wireless Sensor Network》 2014年第6期109-117,共9页
Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy... Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy is distributed over the nodes especially during transmitting and receiving data. Each node may route messages to destination nodes either through short hops or long hops. Optimizing the length of these hops may save energy, and therefore extend the lifetime of WSNs. In this paper, we propose a theorem to optimize the hop’s length so to make WSN power consumption minimal. The theorem establishes a simple condition on hop’s length range. Computer simulation when performing such condition on Mica2 sensors and Mica2dot sensors reveals good performance regarding WSNs energy consumption. 展开更多
关键词 Wireless sensor NETWORKs Energy Efficiency MULTI-HOP ROUTING HOP length Network’s Life Time
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Evaluation of axial length/total corneal refractive power ratio as a potential marker for ocular diagnosis of Marfan’s syndrome in children 被引量:1
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作者 Tian-Hui Chen Ai-Zhu Miao +6 位作者 Yu-Liang Wang Min Zhang Jia-Hui Chen Jia-Lei Zheng Michael Deng Ying-Hong Ji Yong-Xiang Jiang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2021年第8期1218-1224,共7页
AIM:To investigate whether the axial length(AL)/total corneal refractive power(TCRP)ratio is a sensitive and simple factor that can be used for the early diagnosis of Marfan’s syndrome(MFS)in children.METHODS:The rel... AIM:To investigate whether the axial length(AL)/total corneal refractive power(TCRP)ratio is a sensitive and simple factor that can be used for the early diagnosis of Marfan’s syndrome(MFS)in children.METHODS:The relationship between the AL/TCRP ratio and the diagnosis of MFS for 192 eyes in 97 children were evaluate.The biological characteristics,including age,sex,AL,and TCRP,were collected from medical records.Receiver operating characteristic(ROC)curve analysis was performed to investigate whether the AL/TCRP ratio effectively distinguishes MFS from other subjects.The Youden index was used to re-divide the whole population into two groups according to an AL/TCRP ratio of 0.59.RESULTS:Of 96 subjects(mean age 7.46±3.28 y)evaluated,56(110 eyes)had a definite diagnosis of MFS in childhood based on the revised Ghent criteria,41(82 eyes)with diagnosis of congenital ectopia lentis(EL)were included as a control group.AL was negatively correlated with TCRP,with a linear regression coefficient of-0.36(R2=0.08).A significant correlation was found between age and the AL/TCRP ratio(P=0.023).ROC curve analysis showed that the AL/TCRP ratio distinguished MFS from the other patients at a threshold of 0.59.MFS patients were present in 24/58(41.38%)patients with an AL/TCRP ratio of≤0.59 and in 34/39(87.18%)patients with an AL/TCRP ratio of>0.59.CONCLUSION:An AL/TCRP ratio of>0.59 is significantly associated with the risk of MFS.The AL/TCRP ratio should be measured as a promising marker for the prognosis of children MFS.Changes in the AL/TCRP ratio should be monitored over time. 展开更多
关键词 axial length total corneal refractive power ratio DIAGNOsIs Marfan’s syndrome CHILDREN
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Diversity of Microflora in Colonic Mucus from Severe Ulcerative Colitis Patients Analyzed by Terminal Restriction Fragment Length Polymorphism and Clone Libraries of Bacterial 16S rRNA Gene Sequences 被引量:1
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作者 I-Nung Huang Yuri Sato +8 位作者 Mitsuo Sakamoto Moriya Ohkuma Shinobu Ohnuma Takeshi Naitoh Chikashi Shibata Akira Horii Junko Nishimura Haruki Kitazawa Tadao Saito 《Advances in Microbiology》 2014年第13期857-870,共14页
Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microf... Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microflora distribution;however, here we analyzed the bacterial diversity in colonic mucus from UC patients receiving colectomy surgery and control patients. The diversity of microflora was investigated using a combination of terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses of the 16S rRNA gene sequences. In the T-RFLP analysis, the number of terminal restriction fragments (T-RFs) decreased significantly in UC patients when compared to control samples. Also in the clone library analysis, the number of operational taxonomic units (OTU) and the Shannon diversity index were reduced significantly in UC patients. These molecular analyses reveal an overall dysbiosis in UC patients. No specific pathogen was found, and a strong negative correlation in relative abundance of bacterial populations was observed between the phyla Bacteroidetes and Firmicutes in the UC patients. This is the first report showing a significant correlation between these two phyla, which may be important characteristics in the pathogenesis of UC. 展开更多
关键词 ULCERATIVE Colitis MICROFLORA Terminal Restriction Fragment length Polymorphism 16s rRNA Gene CLONE Library
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Length polymorphisms for intergenic spacer regions of 16S-23S rDNA in members of the new hydrogen-producing bacteria
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作者 李永峰 徐菁利 +1 位作者 杨传平 任南琪 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第5期691-694,共4页
A method based on PCR amplification of the 16S rRNA gene (rDNA)-23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes o... A method based on PCR amplification of the 16S rRNA gene (rDNA)-23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes of the PCR products varied from 1264 to 398 bp. Strain of isolate Rennanqilyf 3 was characterized as having products of 1262,398,638,437 and 436 bp. The isolate Rennanqilyf 1 had product of 1264 bp. The isolate Rennanqilyf 13 had products of 1261,579 and 485 bp. Of the 3 species of the novel group hydrogen-producing anaerobes examined, no one was indistinguishable. Two environmental isolates were identified as hydrogen-producing bacteria, which were new species in present taxon. Rennanqilyf 3 could not be associated with any Clostridium sp. studied. Rennanqilyf 1 could be classified into Clostridium genus. The combination between 16S rDNA equencing and length polymorphisms of IRS in 16S-23S rDNA is a better method for determining species of the hydrogen-producing bacteria. 展开更多
关键词 Biohydrogen production Hydrogen-producing Anaerobes IsR of 16s-23s rDNA length polymorphisms
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Hospital costs, length of stay and prevalence of hip and knee arthroplasty in patients with inflammatory bowel disease
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作者 Eli D Ehrenpreis Ying Zhou 《World Journal of Gastroenterology》 SCIE CAS 2017年第26期4752-4758,共7页
To examined the prevalence of hip and knee arthroplasty in patients with inflammatory bowel disease (IBD) by comparing the diagnostic codes for these procedures in patients with IBD and a control group of patients. ME... To examined the prevalence of hip and knee arthroplasty in patients with inflammatory bowel disease (IBD) by comparing the diagnostic codes for these procedures in patients with IBD and a control group of patients. METHODSThe National Inpatient Sample database (NIS) is part of the Healthcare Cost and Utilization Project (HCUP), the largest publicly available inpatient healthcare database in the United States. The NIS samples about 20% of discharges from all community hospitals participating in HCUP, representative of more than 95% of the United States population, with approximately 7000000 hospitalizations reported annually. NIS contains data on diagnoses, procedures, demographics, length of stay (LOS), co-morbidities and outcomes. ICD-9-CM diagnostic codes for primary hospitalizations for arthroplasty of the hip or knee with a co-diagnosis of IBD [combining both Crohn’s disease (CD) and ulcerative colitis (UC)] were used to identify study subjects for cost and LOS analysis for NIS from 1999-2012. Statistical analysis: 1: 2 propensity score matching between IBD vs a control group based on following factors: Patient age, gender, race, total co-morbidities, # of procedures, admission type, insurance, income quartiles, and hospital bed size, location and hospital teaching status. Categorical variables were reported as frequency and compared by χ<sup>2</sup> tests or Fisher’s exact tests. Individual 1:3 matching was also performed for patients carrying diagnostic codes for CD and for patients with the diagnostic code for UC. After matching, continuous variables were rcompared with Wilcoxon signed rank or Paired T-tests. Binary outcomes were compared with the McNemar’s test. This process was performed for the diagnosis of hip or knee arthroplasty and IBD (CD and UC combined). Prevalence of the primary or secondary diagnostic codes for these procedures in patients with IBD was determined from NIS 2007. RESULTSCosts and mortality were similar for patients with IBD and controls, but LOS was significantly longer for hip arthroplasties patients with IBD, (3.85 +/-2.59 d vs 3.68 +/-2.54 d, respectively, P = 0.009). Costs, LOS and survival from the procedures was similar in patients with CD and UC compared to matched controls. These results are shown in Tables 1-10. The prevalence of hip arthroplasty in patients with IBD was 0.5% in 2007, (170/33783 total patients with diagnostic codes for IBD) and was 0.66% in matched controls (P = 0.0012). The prevalence of knee arthroplasty in patients with IBD was 1.36, (292/21202 IBD patients) and was 2.22% in matched controls (P < 0.0001). CONCLUSIONCosts and mortality rates for hip and knee arthroplasties are the same in patients with IBD and the general population, while a statistical but non-relevant increase in LOS is seen for hip arthroplasties in patients with IBD. Compared to the general population, arthroplasties of the hip and knee are less prevalent in hospitalized patients with IBD. 展开更多
关键词 Ulcerative colitis OUTCOMEs Inflammatory bowel disease Hip arthroplasty Knee arthroplasty Hospital length of stay MORTALITY Crohn’s disease
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Inverse Length Biased Maxwell Distribution:Statistical Inference with an Application
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作者 Amer Ibrahim Al-Omari Ayed R.A.Alanzi 《Computer Systems Science & Engineering》 SCIE EI 2021年第10期147-164,共18页
In this paper,we suggested and studied the inverse length biased Maxell distribution(ILBMD)as a new continuous distribution of one parameter.The ILBMD is obtained by considering the inverse transformation technique of... In this paper,we suggested and studied the inverse length biased Maxell distribution(ILBMD)as a new continuous distribution of one parameter.The ILBMD is obtained by considering the inverse transformation technique of the Maxwell length biased distribution.Statistical characteristics of the ILBMD such as the moments,moment generating function,mode,quantile function,the coefficient of variation,coefficient of skewness,Moors and Bowley measures of kurtosis and skewness,stochastic ordering,stress-strength reliability,and mean deviations are obtained.In addition,the Bonferroni and Lorenz curves,Gini index,the reliability function,the hazard rate function,the reverse hazard rate function,the odds function,and the distributions of order statistics for the ILBMD,are presented.The ILBMD parameter is estimated using the maximum likelihood method,the method of moments,the maximum product of spacing technique,the ordinary and weight least square procedures,and the Cramer-Von-Mises methods.The Fishers information,as well as the Rényi and q-entropies,are derived.To investigate the usefulness of the proposed lifetime distribution and to illustrate the purpose of the study,a real dataset of the relief times of 20 patients receiving an analgesic is used. 展开更多
关键词 Maxell distribution inverse length biased Maxwell distribution Fisher’s information methods of estimation goodness of fit tests
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Comparative study on atomic ionization in bicircular laser fields by length and velocity gauges S-matrix theory
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作者 Hong Xia Xin-Yan Jia +4 位作者 Xiao-Lei Hao Li Guo Dai-He Fan Gen-Bai Chu Jing Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第2期254-261,共8页
Ionization of atoms in counter-rotating and co-rotating bicircular laser fields is studied using the S-matrix theory in both length and velocity gauges.We show that for both the bicircular fields,ionization rates are ... Ionization of atoms in counter-rotating and co-rotating bicircular laser fields is studied using the S-matrix theory in both length and velocity gauges.We show that for both the bicircular fields,ionization rates are enhanced when the two circularly polarized lights have comparable intensities.In addition,the curves of ionization rate versus the field amplitude ratio of the two colors for counter-rotating and co-rotating fields coincide with each other in the length gauge case at the total laser intensity 5×10^14 W/cm^2,which agrees with the experimental observation.Moreover,the degree of the coincidence between the ionization rate curves of the two bicircular fields decreases with the increasing field amplitude ratio and decreasing total laser intensity.With the help of the ADK theory,the above characteristics of the ionization rate curves can be well interpreted,which is related to the transition from the tunneling to multiphoton ionization mechanism. 展开更多
关键词 ABOVE-THREsHOLD ionization(ATI) bicircular laser fields length GAUGE VELOCITY GAUGE s-MATRIX theory
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Implementation and Validation of a Stride Length Estimation Algorithm,Using a Single Basic Inertial Sensor on Healthy Subjects and Patients Suffering from Parkinson’s Disease
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作者 Benoit Sijobert Mourad Benoussaad +3 位作者 Jennifer Denys Roger Pissard-Gibollet Christian Geny Christine Azevedo Coste 《Health》 2015年第6期704-714,共11页
As low cost and highly portable sensors, inertial measurements units (IMU) have become increas-ingly used in gait analysis, embodying an efficient alternative to motion capture systems. Mean-while, being able to compu... As low cost and highly portable sensors, inertial measurements units (IMU) have become increas-ingly used in gait analysis, embodying an efficient alternative to motion capture systems. Mean-while, being able to compute reliably accurate spatial gait parameters using few sensors remains a relatively complex problematic. Providing a clinical oriented solution, our study presents a gy-rometer and accelerometer based algorithm for stride length estimation. Compared to most of the numerous existing works where only an averaged stride length is computed from several IMU, or where the use of the magnetometer is incompatible with everyday use, our challenge here has been to extract each individual stride length in an easy-to-use algorithm requiring only one inertial sensor attached to the subject shank. Our results were validated on healthy subjects and patients suffering from Parkinson’s disease (PD). Estimated stride lengths were compared to GAITRite? walkway system data: the mean error over all the strides was less than 6% for healthy group and 10.3% for PD group. This method provides a reliable portable solution for monitoring the in-stantaneous stride length and opens the way to promising applications. 展开更多
关键词 Inertial Measurement Unit(IMU) stride length Gait Analysis Parkinson’s Disease BIOLOGGING
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基于DPRNN语音分离的变时长型S-T课堂教学分析法
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作者 赖文天 陈宇 《湖北第二师范学院学报》 2023年第2期86-92,共7页
在教育智能信息化的大环境下,智能且自动的教学评价体系必不可少,课堂教学分析是教育评价领域的重要环节。本文针对课堂教学分析问题,提出一种利用DPRNN分离课堂音频并使用S-T分析法进行分析的方法。该方法以DPRNN为基础,获取较精确的... 在教育智能信息化的大环境下,智能且自动的教学评价体系必不可少,课堂教学分析是教育评价领域的重要环节。本文针对课堂教学分析问题,提出一种利用DPRNN分离课堂音频并使用S-T分析法进行分析的方法。该方法以DPRNN为基础,获取较精确的教师音频,通过平均细分变时长编码法对音频进行S-T编码处理。相比基于视频的传统的S-T分析法,该方法具有成本低、方便处理、具有时间不变性及准确性较高等优点。 展开更多
关键词 课堂教学分析 DPRNN 平时细分变时长编码法 s-T分析法
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Not Relying on the Newton Gravitational Constant Gives More Accurate Gravitational Predictions
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作者 Espen Gaarder Haug 《Journal of Applied Mathematics and Physics》 2023年第10期3124-3158,共35页
The Newton gravitational constant is considered a cornerstone of modern gravity theory. Newton did not invent or use the gravity constant;it was invented in 1873, about the same time as it became standard to use the k... The Newton gravitational constant is considered a cornerstone of modern gravity theory. Newton did not invent or use the gravity constant;it was invented in 1873, about the same time as it became standard to use the kilogram mass definition. We will claim that G is just a term needed to correct the incomplete kilogram definition so to be able to make gravity predictions. But there is another way;namely, to directly use a more complete mass definition, something that in recent years has been introduced as collision-time and a corresponding energy called collision-length. The collision-length is quantum gravitational energy. We will clearly demonstrate that by working with mass and energy based on these new concepts, rather than kilogram and the gravitational constant, one can significantly reduce the uncertainty in most gravity predictions. 展开更多
关键词 Gravity Predictions Reduction of Errors Newton’s Gravitational Constant Collision space-Time Cavendish Apparatus Planck length Planck Time
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基于L_(2)灵敏度最小化的数字滤波器状态空间实现稀疏化方法
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作者 庄陵 张文静 王光宇 《电子学报》 EI CAS CSCD 北大核心 2024年第2期518-527,共10页
为解决传统数字滤波器在有限精度实现时因有限字长(Finite Word Length,FWL)效应导致滤波器性能下降的问题,提出一种L_(2)灵敏度最小化的数字滤波器状态空间实现稀疏化方法.推导前向差分算子数字滤波器结构传输函数及其等效状态空间实现... 为解决传统数字滤波器在有限精度实现时因有限字长(Finite Word Length,FWL)效应导致滤波器性能下降的问题,提出一种L_(2)灵敏度最小化的数字滤波器状态空间实现稀疏化方法.推导前向差分算子数字滤波器结构传输函数及其等效状态空间实现,根据可控及可观格莱姆矩阵得到基于相似变换矩阵的L_(2)灵敏度表达式,并进行稀疏化校准,将L_(2)灵敏度最小化问题转换为凸函数求最值问题,求导得到L_(2)灵敏度最小化表达式,代回即得前向差分算子数字滤波器的稀疏化状态空间实现.仿真结果表明,所提方法设计的数字滤波器具有更好的抗FWL效应. 展开更多
关键词 数字滤波器 有限字长效应 前向差分算子 矩阵稀疏化 L_(2)灵敏度
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Compressed H3S: Fits to the Empirical Hc2(T) Data and a Discussion of the Meissner Effect
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作者 Gulshan Prakash Malik Vijaya Shankar Varma 《World Journal of Condensed Matter Physics》 2023年第4期111-127,共17页
Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), wh... Based on μ-, T- and H-dependent pairing and number equations and the premise that μ(T) is predominantly the cause of the variation of the upper critical field H<sub>c</sub><sub>2</sub>(T), where μ, T and H denote the chemical potential, temperature and the applied field, respectively, we provide in this paper fits to the empirical H<sub>c</sub><sub>2</sub>(T) data of H<sub>3</sub>S reported by Mozaffari, et al. (2019) and deal with the issue of whether or not H<sub>3</sub>S exhibits the Meissner effect. Employing a variant of the template given by Dogan and Cohen (2021), we examine in detail the results of Hirsch and Marsiglio (2022) who have claimed that H<sub>3</sub>S does not exhibit the Meissner effect and Minkov, et al. (2023) who have claimed that it does. We are thus led to suggest that monitoring the chemical potential (equivalently, the number density of Cooper pairs N<sub>s</sub> at T = T<sub>c</sub>) should shed new light on the issue being addressed. 展开更多
关键词 Compressed H<sub>3sub>s Upper and Lower Critical Fields Chemical Potential Generalized Pairing and Number Equations Coherence length Penetration Depth Meissner Effect
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On the Cosmic Evolution of the Quantum Vacuum Using Two Variable G Models and Winterberg’s Thesis
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1134-1160,共27页
We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckion... We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckions. These material particles interact indirectly, and have very strong restoring forces keeping them a finite distance apart from each other within their respective species. Because of their mass compensating effect, the vacuum appears massless, charge-less, without pressure, net energy density or entropy. In addition, we consider two varying G models, where G, is Newton’s constant, and G<sup>-1</sup>, increases with an increase in cosmological time. We argue that there are at least two competing models for the quantum vacuum within such a framework. The first follows a strict extension of Winterberg’s model. This leads to nonsensible results, if G increases, going back in cosmological time, as the length scale inherent in such a model will not scale properly. The second model introduces a different length scale, which does scale properly, but keeps the mass of the Planck particle as, ± the Planck mass. Moreover we establish a connection between ordinary matter, dark matter, and dark energy, where all three mass densities within the Friedman equation must be interpreted as residual vacuum energies, which only surface, once aggregate matter has formed, at relatively low CMB temperatures. The symmetry of the vacuum will be shown to be broken, because of the different scaling laws, beginning with the formation of elementary particles. Much like waves on an ocean where positive and negative planckion mass densities effectively cancel each other out and form a zero vacuum energy density/zero vacuum pressure surface, these positive mass densities are very small perturbations (anomalies) about the mean. This greatly alleviates, i.e., minimizes the cosmological constant problem, a long standing problem associated with the vacuum. 展开更多
关键词 Winterberg Model Planck Particles Positive and Negative Mass Planck Particles Planckions Quantum Vacuum space as a superfluid/supersolid Extended Models for space Cosmological Constant Higgs Field as a Composite Particle Higgs Boson Inherent length scale for the Vacuum Dark Energy Cosmological scaling Behavior for the Quantum Vacuum Variable G Models Extended Gravity Newton’s Constant as an Order Parameter High Energy Behavior for the Vacuum
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考虑水流路径长度的S型曲线超高段纵坡研究 被引量:10
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作者 张卓 高建平 《重庆交通大学学报(自然科学版)》 CAS 北大核心 2013年第4期594-596,691,共4页
雨天公路S型曲线超高缓和路段易形成积水,影响行车安全。以力学为基础,运用有限差分,建立了超高渐变段的水流路径长度与纵坡的关系模型;考虑车辆发生滑水的危险状态,得到水流路径控制长度。以公路单路拱S型曲线为研究对象,对3组不同车... 雨天公路S型曲线超高缓和路段易形成积水,影响行车安全。以力学为基础,运用有限差分,建立了超高渐变段的水流路径长度与纵坡的关系模型;考虑车辆发生滑水的危险状态,得到水流路径控制长度。以公路单路拱S型曲线为研究对象,对3组不同车道数和7种不同纵坡工况下的±2%超高渐变段的水流路径长度进行分析。结果表明:纵坡由0.5%增加到6%,水流路径长度平均增大2.83倍,纵坡越大,水流路径越长;当纵坡大于4%时,不同车道的水流路径都超过了限定值。以水流路径长度为控制指标,给出了不同车道数S型曲线平缓超高路段最大纵坡建议值。 展开更多
关键词 s型曲线 超高 缓和曲线 纵坡 水流路径长度
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广东部分地区健康人群GSTP1基因多态性研究 被引量:3
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作者 杨淋清 杨杏芬 +4 位作者 林忠宁 赵敏 魏青 马文军 凌文华 《卫生毒理学杂志》 CSCD 北大核心 2004年第1期12-14,共3页
目的 了解谷胱甘肽 S 转移酶P1(GSTP1)基因多态性在广东省部分地区健康人群中的分布规律。方法 应用聚合酶链式反应 限制性片段长度多态性 (PCR RFLP)的方法检测广东省粤语言地区 2 2 4名健康人GSTP1基因型。应用SPSS软件进行统计... 目的 了解谷胱甘肽 S 转移酶P1(GSTP1)基因多态性在广东省部分地区健康人群中的分布规律。方法 应用聚合酶链式反应 限制性片段长度多态性 (PCR RFLP)的方法检测广东省粤语言地区 2 2 4名健康人GSTP1基因型。应用SPSS软件进行统计分析。结果 在所调查人群中野生纯合子GSTP1 A A基因型的频率为 66 5 % (14 9 2 2 4) ;杂合子GSTP1 A G在人群占 2 6 8% ,突变纯合子GSTP1 G G占 6 7%。经检验这种分布在不同性别、职业、地区以及生活方式人群中的分布均衡。结论 二分类Logistic回归分析结果显示 ,高血压、冠心病、脑卒中、肺癌及鼻咽癌等家族史在人群中的发生与人群GSTP1不同基因型的分布无显著相关关系。 展开更多
关键词 广东 健康人群 GsTP1 基因多态性 谷胱甘肽-s-转移酶P1 遗传学
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葡萄VJyGST全长cDNA克隆及其在果实着色过程中的表达 被引量:2
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作者 于淼 刘海峰 +1 位作者 杨成君 王军 《果树学报》 CAS CSCD 北大核心 2010年第6期887-891,共5页
以京优葡萄果皮为试材,利用RT-PCR、SMARTTMRACE技术克隆了1个全长为851bp的GST基因,Genebank的登录号为GU370062,命名为VJyGST。该基因包括开放阅读框(ORF)642bp,编码213个氨基酸,推导其分子量为24.25ku,等电点为5.52。氨基酸同源性分... 以京优葡萄果皮为试材,利用RT-PCR、SMARTTMRACE技术克隆了1个全长为851bp的GST基因,Genebank的登录号为GU370062,命名为VJyGST。该基因包括开放阅读框(ORF)642bp,编码213个氨基酸,推导其分子量为24.25ku,等电点为5.52。氨基酸同源性分析表明,VJyGST与山葡萄GST(FJ645770)、甜橘GST(DQ198153)、荔枝GST(EF613493)相似性分别达到了99%、77%、67%。实时荧光定量PCR分析显示,在果实着色过程中,GST基因在果肉中表达较低且相对稳定;在果皮中表达较高,表达量随花色苷的合成递增,90%着色时到达最高,表明GST的表达与花色苷生物合成密切相关。 展开更多
关键词 葡萄 谷胱甘肽转移酶(GsT) 全长CDNA
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番茄斑萎病毒属病毒SRNA序列比对 被引量:3
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作者 徐小刚 刘雅婷 +3 位作者 李永忠 何婷婷 韩毅 孙文涛 《湖南农业大学学报(自然科学版)》 CAS CSCD 北大核心 2010年第2期142-146,共5页
从生物信息数据库NCBI中搜索并下载最新有关番茄萎斑病毒属Tospovirus各种间SRNA片段全长序列以及该片段上NSs、N的核酸和蛋白质序列着手,运用DNAstar和DNAMAN以及NPSA等生物信息软件对其进行比对分析,结果发现,以NSs蛋白序列建立的系... 从生物信息数据库NCBI中搜索并下载最新有关番茄萎斑病毒属Tospovirus各种间SRNA片段全长序列以及该片段上NSs、N的核酸和蛋白质序列着手,运用DNAstar和DNAMAN以及NPSA等生物信息软件对其进行比对分析,结果发现,以NSs蛋白序列建立的系统进化树显示CCSV和TZSV之间的同源性为85.8%,IYSV和TYRV之间的同源性达90%,MYSV和PSMV间的同源性为97.5%;通过N蛋白序列分析显示,Tospovirus属中有7组同源性较高的种;在Tospovirus属病毒中非极性氨基酸含量最高,极性酸性氨基酸最少,比较TSWV中抗性破坏RB株系与普通株系在NSs、N核酸、蛋白质序列、氨基酸含量和蛋白质二级结构之间的差异,发现差异不显著. 展开更多
关键词 番茄斑萎病毒属 核壳体序列 s RNA上的非结构蛋白序列 抗性破坏
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基于VISSIM仿真的平面交叉口信号配时方案比选分析 被引量:2
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作者 张鹏 赵静 +2 位作者 安慧姝 王占宇 吕岩峰 《交通科技与经济》 2013年第5期9-12,16,共5页
信号交叉口是城市路网的节点和交通关键,它的配时方法对缓解交通拥挤起到决定作用。首先介绍国内外信号配时模型,在对哈尔滨实际交叉口交通调查的基础上,运用4种模型进行配时方案设计,应用VISSIM软件进行仿真分析,得出美国HCM配时方法... 信号交叉口是城市路网的节点和交通关键,它的配时方法对缓解交通拥挤起到决定作用。首先介绍国内外信号配时模型,在对哈尔滨实际交叉口交通调查的基础上,运用4种模型进行配时方案设计,应用VISSIM软件进行仿真分析,得出美国HCM配时方法是最优配时模型。 展开更多
关键词 交叉口 信号配时 周期时长 延误 美国HCM算法
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