A Different Opinion on the Geological Age of the Longzhaogou and Jixi Groups of Eastern Heilongjiang, China

The age of the Longzhaogou and Jixi Groups of coal measures in eastern Heilongjiang were previouslyconsidered to be Jurassic or mainly Jurassic. But there occur Middle Barremian-Early Albian Aucellina(bivalvia) fossils in the Upper Yunshan Formation of the Longzhaogou Group and the Lower Chengzihe For-mation of the Jixi Group, and the Qihulin Formation of the Longzhaogou Group yields Early Cretaceousbivalve and ammonite fossils. Consequently, the geological ages of the two groups are mainly, or even all, Ear-ly Cretaceous.

Analyzing Differences between Online Learner Groups during the COVID-19 Pandemic through K-Prototype Clustering

Online learning is a very important means of study, and has been adopted in many countries worldwide. However, only recently are researchers able to collect and analyze massive online learning datasets due to the COVID-19 epidemic. In this article, we analyze the difference between online learner groups by using an unsupervised machine learning technique, i.e., k-prototypes clustering. Specifically, we use questionnaires designed by domain experts to collect various online learning data, and investigate students’ online learning behavior and learning outcomes through analyzing the collected questionnaire data. Our analysis results suggest that students with better learning media generally have better online learning behavior and learning result than those with poor online learning media. In addition, both in economically developed or undeveloped regions, the number of students with better learning media is less than the number of students with poor learning media. Finally, the results presented here show that whether in an economically developed or an economically undeveloped region, the number of students who are enriched with learning media available is an important factor that affects online learning behavior and learning outcomes.

Short-Term Mindfulness Intervention on Adolescents’ Negative Emotion under Global Pandemic

Objective:In this research,we tried to explore how short-term mindfulness(STM)intervention affects adoles-cents’anxiety,depression,and negative and positive emotion during the COVID-19 pandemic.Design:10 classes were divided into experiment groups(5 classes;n=238)and control(5 classes;n=244)randomly.Hospital Anxi-ety and Depression Scale(HADS)and Positive and Negative Affect Schedule(PANAS)were used to measure par-ticipants’dependent variables.In the experiment group,we conducted STM practice interventions every morning in theirfirst class from March to November 2020.No interventions were conducted in the control group.Methods:Paired-sample t-tests were used to identify if a significant difference exists between every time point of the experimental and control groups.Repeated ANOVA and Growth Mixture Model(GMM)were used to analyze the tendency of positive and negative emotions,anxiety,and depression in the experimental group.Results and Conclusions:(1)With the intervention of STM,there was a significant decrease in negative emotions and an increase in positive emotions in the experimental group,whereas there were non-significant differences in the control group.(2)To explore the heterogeneity trajectories of dependent variables,we built a GMM and found there were two latent growth classes in the trajectories.(3)The results of the models showed their trajec-tories were downward,which meant that the levels of anxiety,depression,and negative emotions of participants decreased during the STM training period.Nonetheless,the score of positive affect showed upward in three loops of intervention,which indicated that the level of the participants’positive affect increased through the STM inter-vention.(4)This research indicated that STM should be given increasing consideration to enhance mental health during the worldwide outbreak of COVID-19.

RAPD-PCR Analysis on Genetic Relationships Between Cultivars of Tree Peony

Random amplified polymorphic DNA (RAPD) was used to analyze genetic polymophism of 35 Tree Peony cultivars with 7 different color groups. Thirty four primers amplified 418 DNA fragments and 337 polymorphic bands (80.6%), including specific DNA markers for 18 cultivars that could be used to differentiate cultivars. The UPCMA method was used to analyze the genetic relationship among cultivars. The results showed that 35 Peony cultivars could be divided into 2 cluster groups when using similarity criteria of 1.5, and into 4 cluster groups when using similarity criteria of 1.0. The result confirmed that the flower color has no relation to the genetic clusters and the Tree Peony cultivars originated from the same area has close genetic relationship. Therefore, genetic background has no large effect on the genetic relationship. The sequence based on polymorphic rate from high to low was Blue groups > Yellow groups > Bark red groups > Blake groups > White groups>Green groups>Red groups.

AB017.Group differences between individuals with dyslexia and normal readers while performing reading tasks

Background:Individuals with dyslexia present with a variety of reading related deficits including text comprehension,reading speed and word encoding.While previous literature addresses individual components of group differences,the present study compares individuals with dyslexia and normal readers on a variety of eye tracking components,as well as behavioural reading measures.The applied nature of this research allows for a comprehensive understanding of how individuals with dyslexia perceptually encode and process written texts.Using type font(i.e.,Times New Roman vs.OpenDyslexic;a font created to elevate visually specific characteristics of dyslexia)as a mediator,we investigated the group differences in eye movement patterns,text comprehension and reading speed between normal readers and individuals with dyslexia when reading standardized and validated texts designed for a grade six reading comprehension level.Methods:Our 73 participants included 38 normal reading controls and 35 individuals with dyslexia.Participants were administered the symbol search and coding subtests of The Wechsler Adult Scale of Intelligence.Participants then read ten texts from the International Reading Speed Texts:five texts in Times New Roman and five in OpenDyslexic,while binocular eye movements were recorded using a SR Research Eyelink 1000.Results:We found that irrespective of font type,when compared to controls,individuals with dyslexia demonstrated increased re-reading of texts[i.e.,regressions:CI(−0.99,−0.66),Hedges’s gs=−0.83]and number of saccades per trial[CI(−1.42,−1.08),gs=−1.25]as well as increased median fixation duration[CI(−1.15,−0.82),gs=−0.98].The control group had increased reading speed[words per minute:CI(1.48,1.84),gs=1.65],visited less interest areas[CI(−1.48,−1.13),gs=−1.31],and had fewer directional deviations from the horizontal-axis[CI(−0.49,−0.18),gs=−0.33].We found an interaction between text comprehension and font type,with both groups having improved performance with OpenDyslexic.However,results did not show a main effect of group with respect to text comprehension.Conclusions:The lack of group differences in text comprehension illustrates that high-functioning individuals with dyslexia are able to comprehend these elementary level texts,irrespective of font type.However,the erratic nature of their eye movements combined with a slow reading speed suggest that individuals with dyslexia read texts in a different manner;achieving the same understanding as normal readers.Our results suggest that reading speed differences act as compensatory methods in our sample of individuals with dyslexia.

Exploring the differential impacts of urban transit system on the spatial distribution of local and floating population in Beijing

The floating population has become the main driver of urban population excessive growth in China＇s mega cities. Urban transit system （UTS） is a significant factor in population spatial distributions within urban areas, especially rapid and high-capacity transit systems. This paper analyzes the causal effects of the extension of expressways and subways between 2000 and 2010 in the Beijing Metropolitan Area （BMA）, focusing on the group differences between the local residents and the floating population. Due to the endogeneity of transportation improvements and population growth, Instrumental Variable （IV） regression model is applied to avoid this problem. The results show the local residents increased in the inner suburbs but decreased in the city center, while the floating population increased in the majority areas. IV regression results show that the extension of urban transit systems had statistically significant impacts on population growth across the BMA, The results also show that the extension of urban subway system had more effects on the floating population than the local residents across the BMA. It is mainly caused by the rather low fare of urban subway system. This implies that the excessive subsidy on urban subway system could result in ex- cessive floating population growth and residential differentiation, even residential segregation Hence, it is necessary to plan and design reasonable and scientific urban transit systems in order to advance reasonable population size and promote residential integration. Moreover, the regional analysis shows that the effects of urban transportation improvements on the local residents are not statistically significant in the inner suburbs. It implies that urban transportation improvements had limited effects on inducing people to move to suburban areas and controlling center city＇s population in Beijing. Therefore, it should be stressed the differenti- ated effects of urban transportation improvements on population distribution in the process of urban planning and population control.

High-precision time and frequency measurement method combining time-space conversion and different frequency phase detection

According to the time&space conversion relations and different frequency phase detection principle,an ultra-high precision time&frequency measurement method is proposed in this paper.The higher accuracy and stability of the speed of light and electromagnetic signals during the transmission in space or a specific medium enable the measurement of short time interval which uses the coincidence detection of signal’s transmission delay in length.The measurement precision better than 10 picoseconds can be easily obtained.The method develops the length vernier utilizing the stability of signal’s transmission delay,minimizes the fuzzy region of phase coincidence between the standard frequency signal and the measured signal,approaches the best phase coincidences and therefore improves the measurement precision which is higher than the precision provided by the traditional methods based on frequency processing.Besides,the method costs less than the traditional methods and can also solve the problem of the measurement of super-high frequency.Experimental results show the method can improve the measurement precision to 10 12/s in the time&frequency domain.

Heavy Metal Concentrations in Rice from Guangzhou and Associated Health Risks

In recent years, excessive levels of cadmium（Cd） in rice have been a focus of attention of the government, the public and scientists. In Guangzhou rice is a staple food for most citizens and understanding the level of Cd and other heavy metals in rice is important for food safety and health. Consumers in different income groups purchase rice from various sources at different prices but we know little about the relationship between price and safety. At the same time, the presence of zinc（Zn） can also affect the level of risk from Cd in rice and so affect food safety. This study offers a preliminary exploration of interactions between price, safety and nutritional quality. 125 rice samples were collected from markets and from the homes of high-income, middle-income and low-income groups in Guangzhou city, and were tested for the content of Cd and Zn. The results showed that 25.6% of the rice samples contained Cd in excess of the national standard, with higher levels of Cd in Indica rice than in Japonica. At the same time, we designed a questionnaire survey for groups with different incomes to assess their exposure to risks from rice with Cd and their perceptions and sources of information about risks. The survey showed that, as a whole, the low-income group faces higher risks from rice with Cd, and that there is strong public demand for scientific information about Cd in rice.

Phase group synchronization between any signals and its physical characteristics

The phase group synchronization between any signals is further revealed,which is based on proposing the new concepts of the greatest common factor frequency,the least common multiple period,quantized phase shift resolution,equivalent phase comparison frequency and so on.Then the problem of phase comparison and processing between different frequency signals is solved and shown in detail.Using the basic principle and the variation law of group phase difference,the frequency stability better than 10-14/s can be easily obtained in the time&frequency measurement and control domain,and experimental results also show the phase relations between atomic energy level transition signal and the locked crystal oscillator signal in an active hydrogen atomic clock are strict phase group synchronization,and locked precision with 10-13/s can be reached based on phase group synchronization.The phase group synchronization can provide technical support to frequency linking among radio frequency,microwave and light frequency.

Extraction of fish body oil from Sardinella longiceps by employing direct steaming method and its quantitative and qualitative assessment

Objective:To analyze the quantitative and qualitative properties of the extracted fish oil from Sardinella longiceps(S.longiceps).Methods:Four size groups of S.longiceps were examined for the extraction of fish oil based on length.The size groups included Group I(size range of 7.1-10.0 cm),Group II(size range of 10.1-13.0 cm),Group III(size range of 13.1-16.0 cm)and Group IV(size range of 16.1-19.0 cm).Fish oil was extracted from the tissues of S.longiceps by direct steaming method.The oil was then subjected to the determination of specific gravity,refractive index,moisture content,free fatty acids,iodine value,peroxide value,saponification value and observation of colour.Results:The four groups showed different yield of fish oil that Group IV recorded the highest values of(165.00±1.00)mL/kg followed by Group III[(145.66±1.15)mL/kg]and Group II[(129.33±0.58)mL/kg],whereas Group I recorded the lowest values of(78.33±0.58)mL/kg in monsoon season,and the average yield was(180.0±4.9)mL/kg fish tissues.These analytical values of the crude oil were well within the acceptable standard values for both fresh and stocked samples.Conclusions:The information generated in the present study pertaining to the quantitative and qualitative analysis of fish oil will serve as a reference baseline for entrepreneurs and industrialists in future for the successful commercial production of fish oil by employing oil sardines.