超高压辅助酶法制备黑斑蛙皮抗氧化肽及其活性评估

为提高黑斑蛙加工副产物蛙皮的综合利用价值,对黑斑蛙蛙皮抗氧化肽的提取工艺及性能进行研究。采用超滤方法对黑斑蛙蛙皮的蛋白酶解液进行分离,得到不同分子量范围的小分子肽,通过体外抗氧化试验和秀丽隐杆线虫模型,评价不同分子量范围蛙皮小分子肽的抗氧化性能;以高活性小分子肽得率为目标,采用响应面方法对酶添加量、超高压压力、超高压时间、液料比四个参数优化,确定小分子肽最佳提取工艺。结果表明,1~2000 Da小分子肽具有最强的抗氧化能力,DPPH自由基、ABTS^(+)自由基清除率分别达到了76.93%、59.23%,并显著提高了秀丽隐杆线虫的抗氧化能力;在中性蛋白酶水解的基础上,二次酶解最佳工艺参数为碱性蛋白酶用量10210 U/g,超高压压力315 MPa,压力作用时间9.3 min,液料比16倍,1~2000 Da小分子肽得率为25.26%。超高压辅助双酶水解显著提高了黑斑蛙蛙皮小分子肽的得率,为黑斑蛙副产物的高值化利用提供了参考。

FROG方法诊断飞秒脉冲的振幅与相位

详细讨论了一种基于二次谐波一频谱分辨光闸法 (简称SHG_FROG方法 )的矩阵迭代算法 ,实现了对飞秒脉冲的振幅和相位的诊断 ,得出其脉冲形状为双曲正割型、相位是时间的三次幂形式。

Frog磨牙远移器的临床应用研究

目的:评价Frog磨牙远移器在治疗安氏Ⅱ类1分类牙源性错牙合畸形时的临床疗效。方法:对15例安氏Ⅱ类1分类错牙合伴上颌牙列轻中度拥挤的病例,用Frog磨牙远移器推磨牙向远中,并配合直丝弓固定矫治器进行不拔牙矫治,结合X线头影测量,评价Frog磨牙远移器的治疗效果。采用SPSSl3.0统计学软件进行配对t检验。结果:U6-Ptm(mm)、U6-PTV(mm)分别平均减少2.20mm(P<0.01),2.81mm(P<0.01),具有显著性差异,表明上颌第一磨牙明显向远中移动,同时U6-SN(°)减少2.53°(P>0.05),无显著性差异,表明上颌第一磨牙无远中向倾斜。即上颌第一磨牙发生了远中向的整体移动。结论:Frog磨牙远移器可实现磨牙整体远移,是不拔牙矫治安氏Ⅱ类1分类错牙合伴上颌牙列轻中度拥挤的有效方法之一,简便、有效且不受患者依从性的影响。

Population genetic diversity and regional differentiation of Chinese forest frog s (Rana chensinensis) in Heilongjiang Province

The Random Amplified Polymorphism DNA (RAPD) markers were used to stu dy the intra-specific diversity and regional differentiation of the Chinese fore st frogs (Rana chensinensis), which were sampled from the fields of 8 regions in Heilongjiang Province. Totally 78 polymorphic DNA loci were amplified by 10 RAP D primers. By genetic distance analysis and phylogenetic tree reconstruction wit h the Neighbor-Joining (NJ) method the results showed that the populations of Ch inese forest frogs distributed in 8 regions existed great differentiation (Avera ge Fst=0.347, SD=0.235) while there was the paradox between geographic distances and genetic distances. Based on geographic and geological data, a hypothesis wa s posed that it is very possible that the hilly lands in the downstream of the S onghua River and the Heilong River were the center of the origin of the Chinese forest frogs in Heilongjiang Province. And mainly through the Songhua River syst em, the Chinese forest frogs dispersed into the Songneng Plain from the Sanjiang Plain whereas the Fangzheng region became a sub-center for the western dispersi on.

Genetic diversity and differentiation of the Dybowski's frog(Rana dybowskii) in Northeast China

The genetic diversity and population structure of the Dybowski＇s frog（Rana dybowskii） were investigated by using 11 polymorphic microsatellite loci.Total 75 individuals were sampled from six populations in Lesser Khingan Mountains and Changbai Mountains,China.Results showed that allele number of the 11 microsatellite loci was in the range of 2-10 in all populations,with the mean of 5.6.The average expected heterozygosity（HE） was 0.572,indicating a moderate polymorphism.The results of genetic differentiation coefficient（FST） showed that population genetic differentiation was significant between Changbai and Lesser Khingan Mountains（p〈0.001）.This result was verified further by Nei＇s genetic distance（DA） based on UPGMA phy-logenetic trees and by AMOVA analysis.In conclusion,the populations distributed in Lesser Khingan Mountains and Changbai Mountain are proposed to be two distinct management units（MUs） for their protection and management.

FROG飞秒脉冲脉宽重建及可视化测量

文章对在Matlab环境中实现FROG脉冲迭代算法进行了理论分析,给出了详细的矩阵数学模型推导过程。在此基础上,根据飞秒脉冲测量需求,在Matlab中编写了GUI用户界面,实现了对FROG行迹的重建和标定。采用该GUI,对实际的飞秒脉冲进行了在线测量,重建后的FROG行迹和标定后的FROG行迹吻合,可直接获取测量中的迭代次数、迭代误差、飞秒脉宽、谱宽等关键信息,可以直接应用到FROG脉宽测试仪的工程化设计中。

Experimental study and numerical analysis on bearing behaviors of super-long rock-socketed bored pile groups

A centrifuge modeling test and a three-dimensional finite element analysis（FEA）of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypical materials are simulated using different indicators in the centrifuge model.The silver sand,the shaft and the pile cap are simulated according to the natural density,the compressive stiffness and the bending stiffness,respectively.The finite element method（FEM）is implemented and analyzed in ANSYS,in which the stress field during the undisturbed soil stage,the boring stage,the concrete-casting stage and the curing stage are discussed in detail.Comparisons in terms of load-settlement,shaft axial force distribution and lateral friction between the numerical results and the test data are carried out to investigate the bearing behaviors of super-long rock-socketed bored pile groups under loading and unloading conditions.Results show that there is a good agreement between the centrifuge modeling tests and the FEM.In addition,the load distribution at the pile top is complicated,which is related to the stiffness of the cap,the corresponding assumptions and the analysis method.The shaft axial force first increases slightly with depth then decreases sharply,and the rate of decrease in rock is greater than that in sand and soil.

Sine-Gordon方程的多辛Leap-frog格式

非线性发展方程由于具有多种形式的解析解而吸引着众多的研究者,借助多辛保结构理论研究了Sine-Gordon方程的多辛算法.利用Hamilton变分原理,构造出了Sine-Gordon方程的多辛格式;采用显辛离散方法得到了leap-frog多辛离散格式,该格式满足多辛守恒律;数值结果表明leap-frog多辛离散格式能够精确地模拟Sine-Gordon方程的孤子解和周期解,模拟结果证实了该离散格式具有良好的数值稳定性.

Leap-frog格式的改进

运用待定系数法,对Leap-frog格式进行了改进,构造出一新的高精度ILF格式,新格式有非保守型和保守型两种.通过数值试验表明,ILF格式的计算结果与解析解吻合良好,与Leap-frog格式相比计算精度得到明显改善,可用于实际计算.

A Brief Analysis of the Implication in “The Celebrated Jumping Frog of Calaveras County”

The Celebrated Jumping Frog of Calaveras County is a novel first published in 1865.It tells us a story taking place in the ancient mining camp of Angel's.By using analysis,the implication hidden behind the novel is explored here.That is,the abnormal social phenomena exist in the reality,the intrigue among people to gain profits and also the immoral measures people took for panning gold at the Gold Rush Era.

非线性非一致介质二维Maxwell方程leap-frogCrank-Nicolson多区域Legendre-tau配置谱方法

该文研究了具有非线性电导率的非一致介质二维Maxwell方程的数值求解方法,提出了多区域Legendre-tau配置谱方法.该数值方法空间上达到谱精度,时间上是二阶精度.时间方向采用leap-frog Crank-Nicolson三层格式进行离散.非线性项放在中间已知层采用谱配置法显式处理,线性项采用Legendre谱方法隐式处理.利用显隐数值格式,既有较好的稳定性又方便算法实施.基于合理的弱形式,不需要使用额外附加的连接条件,以自然边界条件的方式处理交界面条件.定义不同次数多项式逼近空间,构建一致的数值格式.详细证明了半离散和全离散数值格式的稳定性和收敛性,并得到L^(2)-范数的最优误差估计.算例中,利用快速Legendre变换在Chebyshev点上计算非线性项,提高算法效率.数值结果证实了该数值方法求解此类非线性问题的有效性,并且没有因为解的间断而损失谱精度.

Biological Jumping Mechanism Analysis and Modeling for Frog Robot

This paper presents a mechanical model of jumping robot based on the biological mechanism analysis of frog. By biological observation and kinematic analysis the frog jump is divided into take-offphase, aerial phase and landing phase. We find the similar trajectories of hindlimb joints during jump, the important effect of foot during take-off and the role of forelimb in supporting the body. Based on the observation, the frog jump is simplified and a mechanical model is put forward. The robot leg is represented by a 4-bar spring/linkage mechanism model, which has three Degrees of Freedom （DOF） at hip joint and one DOF （passive） at tarsometatarsal joint on the foot. The shoulder and elbow joints each has one DOF for the balancing function of arm. The ground reaction force of the model is analyzed and compared with that of frog during take-off. The results show that the model has the same advantages of low likelihood of premature lift-off and high efficiency as the frog. Analysis results and the model can be employed to develop and control a robot capable of mimicking the jumping behavior of frog.

Circadian Rhythm of Calling Behavior in the Emei Music Frog(Babina daunchina) is Associated with Habitat Temperature and Relative Humidity

Generally, the function of vocalizations made by male anurans are to attract females or defend resources. Typically, males vocalize in choruses during one or more periods in a twenty-four-hour cycle, which varies, however, among species. Nevertheless, the causal factors influencing circadian variations of calling patterns in anuran species are not clear. In this study, male chorus vocalizations were monitored in the Emei music frog(Babina daunchina) for 17 consecutive days during the breeding season, while its habitat air temperature and relative humidity in the course of experiments were measured as well. The results revealed that the circadian calling patterns were characterized by two periods of peak vocalization, which were observed from 0500 h to 0700 h and from 1300 h to 2000 h, while the lowest activity period was found from 2100 h to 2200 h. Both calls/h and notes/h were positively correlated with air temperature and negatively with relative humidity. Overall, our data indicate that the Emei music frogs(B. daunchina) could regulate their vocal activities based on the changes of physical micro-environment(e. g., temperature or humidity) to maximize reproductive success.

Genetic Diversity and Population Structure for the Conservation of Giant Spiny Frog(Quasipaa spinosa)Using Microsatellite Loci and Mitochondrial DNA

The giant spiny frog （Quasipaa spinosa） is an endangered species with a relatively small distribution limited to southern China and Northern Vietnam. This species is becoming increasingly threatened because of over-exploitation and habitat degradation. This study provides data on the genetic diversity and population genetic structure of the giant spiny frog to facilitate the further development of effective conservation recommendations for this economically important but threatened species. We examined 10 species-specific microsatellite loci and Cyt b genes （562 bp） collected from 13 wild populations across the entire range of this species. Results of 10 microsatellite loci analysis showed a generally high level of genetic diversity. Moreover, the genetic differentiation among all 12 populations was moderate to large （overall Fs7= 0.1057）. A total of 51 haplotypes were identified for Cyt b, which suggests high haplotype nucleotide diversities. Phylogeographic and population structure analyses using both DNA markers suggested that the wild giant spiny frog can be divided into four distinct major clades, i.e., Northern Vietnam, Western China, Central China, and Eastern China. The clades with significant genetic divergence are reproductively isolated, as evidenced by a high number of private alleles and strong incidence of failed amplification in microsatellite loci. Our research, coupled with other studies, suggests that Q. spinosa might be a species complex within which no detectable morphological variation has been revealed. The four phylogenetic clades and some subclades with distinct geographical distribution should be regarded as independent management units for conservation purposes.

Morphometric discrimination of wild from farmed Dybowski’s frog (Rana dybowskii) based on hindlimb length

Commercial farming of anuran species that are declining in the wild raises a need to discriminate wild from farmed frogs.We hypothesized wild frogs might have extended hindlimbs due to greater frequency or intensity of jumping relative to farmed frogs,highlighting a morphometric approach to discrimination of wild from farmed frogs using hindlimb length.In the present study,Dybowski＇s frog（Rana dybowskii） was used to test this hypothesis.We measured body mass（Mb） and hindlimb length（Lh） of 2-year old farmed frogs and wild frogs aged 2 to 5 years.Dybowski＇s frog demonstrated significant dimorphism in Mb and Lh.Mb was significantly greater among farmed 2-year old frogs in both sexes（p=0.000）,while only among females was Lh significantly greater for wild frogs（p=0.000）.Lh/Mb was used as an index for origin discrimination to eliminate the influence of Mb due to variation of husbandry conditions among farms.Mean Lh/Mb for farmed frogs was significantly lower than for wild frogs（p=0.000） in the 2-year old age class.Discrimination correctly classified 84.4% of farmed and 96.3% of wild male frogs.Among females,92.9% of farmed frogs and 90.1% wild frogs were correctly classified.The overall correctness of classification was 92.1% and 90.8% for males and females,respectively.However,Lh/Mb revealed variation with age,resulting in reduced discriminative power for frogs ≥3 years old.We introduced a coefficient Ce to adjust the Lh/Mb of frogs ≥3 years to the level equivalent to 2-year frogs.The adjustment achieved 89.5% for overall correctness of origin for wild males and 92.4% for wild females ≥3 years old.These results show that Lh/Mb is an effective index to discriminate wild from farmed Dybowski＇s frog.Since the physical demands of jumping are common among anurans,this index is also potentially applicable to other anuran species.

Enhanced minimum attribute reduction based on quantum-inspired shuffled frog leaping algorithm

Attribute reduction in the rough set theory is an important feature selection method, but finding a minimum attribute reduction has been proven to be a non-deterministic polynomial （NP）-hard problem. Therefore, it is necessary to investigate some fast and effective approximate algorithms. A novel and enhanced quantum-inspired shuffled frog leaping based minimum attribute reduction algorithm （QSFLAR） is proposed. Evolutionary frogs are represented by multi-state quantum bits, and both quantum rotation gate and quantum mutation operators are used to exploit the mechanisms of frog population diversity and convergence to the global optimum. The decomposed attribute subsets are co-evolved by the elitist frogs with a quantum-inspired shuffled frog leaping algorithm. The experimental results validate the better feasibility and effectiveness of QSFLAR, comparing with some representa- tive algorithms. Therefore, QSFLAR can be considered as a more competitive algorithm on the efficiency and accuracy for minimum attribute reduction.

Reversible Oxygen-Rich Functional Groups Grafted 3D Honeycomb-Like Carbon Anode for Super-Long Potassium Ion Batteries

Studies have found that oxygen-rich-containing functional groups in carbon-based materials can be used as active sites for the storage performance of K^(+),but the basic storage mechanism is still unclear.Herein,we construct and optimize 3D honeycomb-like carbon grafted with plentiful COOH/C=O functional groups(OFGC)as anodes for potassium ion batteries.The OFGC electrode with steady structure and rich functional groups can effectively contribute to the capacity enhancement and the formation of stable solid electrolyte interphase(SEI)film,achieving a high reversible capacity of 230 mAh g^(-1) at 3000 mA g^(-1) after 10,000 cycles(almost no capacity decay)and an ultra-long cycle time over 18 months at 100 mA g^(-1).The study results revealed the reversible storage mechanism between K^(+)and COOH/C=O functional groups by forming C-O-K compounds.Meanwhile,the in situ electrochemical impedance spectroscopy proved the highly reversible and rapid de/intercalation kinetics of K+in the OFGC electrode,and the growth process of SEI films.In particular,the full cells assembled by Prussian blue cathode exhibit a high energy density of 113 Wh kg^(-1) after 800 cycles(calculated by the total mass of anode and cathode),and get the light-emitting diodes lamp and ear thermometer running.

Population Variation and Food Habits of Ranid Frogs in the Rice-Based Cropping System in Gujranwala Region,Pakistan

The current study aims to investigate the population variation and food habits of ranid frogs in the rice-based cropping system in District Gujranwala,Pakistan.The population in the study area was estimated using capture,mark and release method whereas food habits of the species were studied by analysis of stomach contents.The results showed the highest average population was found during August 2009(93.10±18.64/ha) while the lowest from December 2008 to February 2009.Maximum seasonal populations existed in summer 2009,whereas winter 2008 sizes were at a minimum.Stomach content analysis of the species revealed percent frequency(% F) of occurrence of insects(80.3),earthworms(28.5),whole frogs(15.8),bone pieces(22.5),rodents(1.66),vegetation(5.0),soil particles(13.3) and some unidentified material(7.5) in all the stomach samples.Most frequently consumed prey items were insects(30% by volume),although frogs also preyed upon conspecifics and rodents.Insects recovered from the stomach contents were identified as belonging to Orthoptera,Lepidoptera,Coleoptera,Diptera,Odonata and Homoptera as well as the class Archnida.Insects recovered from the stomach contents were compared to those captured from the study area.

42号大号码道岔心轨不解锁问题研究

42号大号码道岔通常设置于高铁正线2条线路交汇处或线路所,而作为不同高铁线路的岔路口,线路所多为无人值守。当道岔出现故障后,维修人员处理时间相对较长,对行车影响较大。为此,沈阳高铁基础设施段经过近3年对京哈高速线、哈大高速线22组42号大号码道岔心轨不解锁问题进行深度分析,发现温度变化和结构因素是造成道岔心轨不解锁的主要原因。通过数据比对和研究试验,采取调整道岔框架尺寸、几何参数、道岔密贴力,以及改进外锁闭配件结构等措施,同时规范42号大号码道岔工电联合整治作业流程,可初步解决42号大号码道岔心轨不解锁问题,有益于保障高速铁路行车安全。

Membrane-inspired quantum shuffled frog leaping algorithm for spectrum allocation

To solve discrete optimization difficulty of the spectrum allocation problem,a membrane-inspired quantum shuffled frog leaping（MQSFL） algorithm is proposed.The proposed MQSFL algorithm applies the theory of membrane computing and quantum computing to the shuffled frog leaping algorithm,which is an effective discrete optimization algorithm.Then the proposed MQSFL algorithm is used to solve the spectrum allocation problem of cognitive radio systems.By hybridizing the quantum frog colony optimization and membrane computing,the quantum state and observation state of the quantum frogs can be well evolved within the membrane structure.The novel spectrum allocation algorithm can search the global optimal solution within a reasonable computation time.Simulation results for three utility functions of a cognitive radio system are provided to show that the MQSFL spectrum allocation method is superior to some previous spectrum allocation algorithms based on intelligence computing.