通过诱导局域电场和电子局域化协同碱性析氢

碱性析氢反应(HER)可将间歇性可再生能源转化为可存储的清洁能源,因而备受关注.然而,水解离速度缓慢以及H中间体(*H)吸附和解吸困难限制了碱性HER的进一步发展.目前,针对碱性电解水解离缓慢问题,通常采用调整电催化剂结构降低水分解热动力学能垒,以及改变三相界面微环境加速中间产物的扩散等方法来促进水分解进行.此外,可以通过调控活性位点电子结构来优化*H的吸脱附.但是采用单一的策略很难同时促进H_(2)O的解离和*H的吸脱附,难以获得令人满意的碱性HER性能.因此,探索一种能同时促进H_(2)O的解离和*H的吸脱附协同策略对提升碱性HER的性能至关重要.本文提出了一种协同策略,通过构建高曲率二硫化钴纳米针(CoS_(2)NNs)和原子级铜(Cu)的掺杂分别实现诱导纳米尺度的局域电场和原子尺度的电子局域化,从而促进碱性HER的H_(2)O解离和*H吸脱附.首先,采用有限元法模拟和密度泛函理论计算,从理论上分别证实了纳米尺度局域电场可以加速H_(2)O解离以及原子尺度电子局域化可以促进*H吸附.受理论计算结果启发,通过一步水热法和原位硫化相结合的方法制备了高曲率的Cu掺杂CoS_(2)纳米针(Cu-CoS_(2)NNs).采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和四探针测试等技术进行表征,研究了Cu-CoS_(2)NNs的形貌、物相结构、化学组成和导电性.结果表明,在Cu原子引入后,Cu-CoS_(2)NNs依然保持着高曲率的纳米针结构,证明了Cu在CoS_(2)NNs中的原子分散状态.相较于低曲率的Cu掺杂CoS_(2)纳米线(Cu-CoS_(2)NWs),Cu-CoS_(2)NNs只存在形貌上的区别,二者的化学组成和比例均非常接近.同时,上述材料都具有很强的导电性,且电导率基本相同,这与有限元模拟结果一致.原位衰减全反射红外光谱和电响应测试结果表明,Cu-CoS_(2)NNs具有较好的解离H_(2)O和吸附*H的能力.在1 mol L^(-1)KOH溶液和10 mA cm^(-2)电流密度下,该催化剂的析氢过电位仅为64 mV,展现出较好的电化学析氢性能.催化剂还表现出非常好的碱性析氢稳定性,在标准氢电势(RHE)-0.18 V下,可在100 mA cm^(-2)电流密度下稳定工作达100 h.综上所述,本文通过诱导局域电场和电子局域化构建了一种协同策略,所制备的Cu-CoS_(2)NNs表现出很好的催化碱性HER性能和应用前景,为碱性HER电催化剂的理性设计提供了一定的参考.

甲基磺酸体系粗铅电解精炼的电沉积行为与概念验证运行

提出一种替代传统氟硅酸体系的甲基磺酸(MSA)体系,它具有挥发性低、腐蚀性低、热稳定性良好和导电性高的优点,能够实现绿色高效铅电解精炼。探讨基于MSA体系的粗铅电精炼(MPR)电沉积行为,包括其运行机理、反应可逆性、形核和生长模式。基于循环伏安法(CV)和计时电流法(CA),揭示受扩散控制且不可逆的MPR铅沉积过程,建立MPR铅沉积形核和生长的瞬态成核理论模型。MPR小规模验证性运行实现了104.22 kW·h/t Pb的能耗和99.24%的电流效率,相较于H_(2)SiF_(6)体系的120 kW·h/t Pb能耗与95%电流效率,具有竞争性。MPR小规模运行获得了纯度99.9925%且光滑致密的铅沉积层,满足铅锭纯度99.97%的标准(GB/T 469—2013)。

Phylogenetic relationships of Nemacheilidae cavefish(Heminoemacheilus,Oreonectes,Yunnanilus,Paranemachilus,and Troglonectes)revealed by analysis of mitochondrial genome and seven nuclear genes

DEAR EDITOR,Cave loaches within the family Nemacheilidae are among the most diverse group of cavefish in southwestern China.Although certain species have been included in previous phylogenetic studies,the intergeneric and interspecific relationships of Chinese cave loaches in Nemacheilidae remain poorly investigated due to insufficient sampling.In this study,a total of 45 samples from 37 recognized species and two unidentified species of cave loaches were collected,accounting for 87.5%of the eight recognized genera of cave loaches within the family Nemacheilidae in China.The complete mitochondrial genome(mitogenome)and seven nuclear genes were sequenced,and the phylogenetic tree of Chinese cave loaches was reconstructed.Both Bayesian inference and maximum-likelihood analyses resolved the phylogenetic relationships at the generic and species levels,suggesting the effectiveness of this multilocus marker system in determining phylogenetic relationships in Chinese cave loaches.Phylogenetic analysis not only confirmed previous taxonomic hypotheses based on morphological data but also provided new insights into the relationships of many cave loaches at the genus and species levels as well as suggestions for the current taxonomy of cave loaches within the family Nemacheilidae.

Pore evolution and shear characteristics of a soil-rock mixture upon freeze-thaw cycling

The changes in pore structure within soil-rock mixtures under freeze-thaw cycles in cold regions result in strength deterioration,leading to instability and slope failure.However,the existing studies mainly provided qualitative analysis of the changes in pore or strength of soil-rock mixture under freeze-thaw cycles.In contrast,few studies focused on the quantitative evaluation of pore change and the relationship between the freeze-thaw strength deterioration and pore change of soil-rock mixture.This study aims to explore the correlation between the micro-pore evolution characteristics and macro-mechanics of a soil-rock mixture after frequent freeze-thaw cycles during the construction and subsequent operation in a permafrost region.The pore characteristics of remolded soil samples with different rock contents(i.e.,25%,35%,45%,and 55%)subjected to various freeze-thaw cycles(i.e.,0,1,3,6,and 10)were quantitatively analyzed using nuclear magnetic resonance(NMR).Shear tests of soil-rock samples under different normal pressures were carried out simultaneously to explore the correlation between the soil strength changes and pore characteristics.The results indicate that with an increase in the number of freeze-thaw cycles,the cohesion of the soil-rock mixture generally decreases first,then increases,and finally decreases;however,the internal friction angle shows no apparent change.With the increase in rock content,the peak shear strength of the soil-rock mixture rises first and then decreases and peaks when the rock content is at 45%.When the rock content remains constant,as the number of freeze-thaw cycles rises,the shear strength of the sample reaches its peak after three freeze-thaw cycles.Studies have shown that with an increase in freeze-thaw cycles,the medium and large pores develop rapidly,especially for pores with a size of 0.2–20μm.Freeze-thaw cycling affects the internal pores of the soil-rock mixture by altering its skeleton and,therefore,impacts its macro-mechanical characteristics.

A Morphological Study of Two Young Multipolar Planetary Nebulae

We carry out an optical morphological and infrared spectral study for two young planetary nebulae(PNs)Hen2-158 and Pe 1-1 to understand their complex shapes and dust properties.Hubble Space Telescope optical images reveal that these nebulae have several bipolar-lobed structures and a faint arc with a clear boundary is located at the northwestern side of Pe 1-1.The presence of this arc-shaped structure suggests that the object interacts with its nearby interstellar medium.Spitzer IRS spectroscopic observations of these young nebulae clearly show prominent unidentified infrared emission features and a weak silicate band in Pe 1-1,indicating that Hen 2-158 is a carbonrich nebula and Pe 1-1 has a mixed chemistry dust environment.Furthermore,we construct two three-dimensional models for these PNs to realize their intrinsic structures.The simulated models of the nebulae suggest that multipolar nebulae may be more numerous than we thought.Our analyses of spectral energy distributions for Hen 2-158 and Pe 1-1 show that they have low luminosities and low stellar effective temperatures,suggesting that these nebulae are young PNs.A possible correlation between typical multipolar young PNs and nested nebulae is also discussed.

Lower synaptic density associated with gaming disorder:an^(18)F-SynVesT-1 PET imaging study

Background Internet gaming disorder(IGD)is an ideal model to study the mechanisms underlying synaptic deficits in addiction as it eliminates the confounding effects of substance use.Synaptic loss and deficits are hypothesised to underlie the enduring maladaptive behaviours and impaired cognitive function that contribute to IGD.Aims This study aimed to determine whether subjects with IGD have lower synaptic density than control subjects and the relationship between synaptic density and IGD severity.Methods Eighteen unmedicated subjects diagnosed with current IGD according to the Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition criteria and 16 demographically matched healthy controls(HCs)participated in the study and underwent 18F-labelled difluoro-analogue of UCB-J(18F-SynVesT-1)positron emission tomography scans to assess the density of synaptic vesicle glycoprotein 2A(SV2A).The Internet Gaming Disorder Scale-Short Form(IGDS9-SF),Hamilton Rating Scale for Depression(HAMD),Hamilton Anxiety Rating Scale(HAMA),Barratt Impulsiveness Scale Version 11(BIS-11),Stroop Colour-Word Test(SCWT),stop-signal paradigms and N-back tasks were administered to all subjects.Results Patients with IGD had significantly higher scores on the IGDS9-SF,HAMD,HAMA and BIS-11 than HCs.HCs performed better on the two-back and SCWT tests as well as in terms of stop-signal reaction times(SSRTs)in the stop-signal paradigms than patients with IGD.Lower uptake was found in the bilateral putamen,right pregenual anterior cingulate cortex and Rolandic operculum of patients with IGD compared with HCs.Furthermore,in the IGD group,IGDS9-SF scores and daily gaming hours were negatively correlated with the standardised uptake value ratios of 18F-SynVesT-1 in the bilateral putamen.Longer SSRTs were significantly associated with lower SV2A density in the right pregenual anterior cingulate cortex and right Rolandic operculum.Conclusions The in vivo results in this study suggest that lower synaptic density contributes to the severity and impairments in inhibitory control of IGD.These findings may provide further incentive to evaluate interventions that restore synaptic transmission and plasticity to treat IGD.

单原子Co位点的CO_(2)还原反应路径:局部配位环境的影响

在CO_(2)还原反应(CO_(2)RR)应中,单原子催化剂被认为是很有前途的电催化剂.Co-N_(4)活性位点因其优异的CO选择性和活性而受到广泛关注.然而,Co位点的局部配位环境与CO_(2)RR途径之间的相关性尚不明确.本文采用密度泛函理论(DFT)计算,研究了含1,10-菲咯啉基底的N_(4)-大环配体(Co-N_(4)-CPY)负载的CoN_(4)位点上的CO_(2)RR路径.该模型的平面空间构型使其具有高度离域的π电子轨道,可以通过π-π相互作用更好地与底物相互作用.在相对可逆氢电极(RHE)为-0.70 V时,最大CO的法拉第效率为96%,CO的转换频率为9.59 s^(–1).众所周知,单原子位点的局部配位环境可以进一步优化电催化性能.因此,本文还研究了N被O(Co-N_(3)O-CPY)和C(Co-N_(3)C-CPY)取代的单原子Co位点的局部配位环境.计算结果表明,Co-N_(4),Co-N_(3)O和Co-N_(3)C位点的键长相差不大,而且其结合能都较大,意味着它们具有良好的稳定性.Co-N_(3)C-CPY,Co-N_(3)O-CPY和Co-N_(4)-CPY的投影态密度(PDOS)、电荷密度差分和晶体轨道哈密顿布居(COHP)显示,C和O配位均打破了初始CoN_(4)配体场的对称性,并诱发了Co原子的电荷再分布.Co原子与配位原子间的相互作用由强到弱依次为Co-C键、Co-N键和Co-O键,这与电负性O>N>C相反.通过分析CO_(2)RR过程的吉布斯自由能变化,确定了Co-N_(4)-CPY的主要产物为CO.当Co-N_(4)位点的局部配位环境改变后,Co-N_(3)O位点上有利于*COOH的形成,而Co-N_(3)C位点对碳氢化合物(CH_(3)OH或CH_(4))有更高的选择性.这是由于CO_(2)在Co-N_(3)O位点上更容易质子化形成*OCHO,从而有利于HCOOH的形成.而在Co-N_(3)C位点上时,由于*CO难以脱附,*CO将进一步质子化,最终形成CH_(3)OH或CH_(4).CO_(2)质子化形成*COOH或*OCHO的PDOS显示,在Co位上吸附之前,*OCHO的自旋密度是对称的,而*COOH的自旋密度是不对称的.对于催化剂而言,只有Co-N_(3)O-CPY的自旋密度是对称的,因此容易形成*OCHO中间体.Co-3d轨道与*COOH的C-2p轨道和*OCHO的O-2p轨道的相互作用也体现了这一关系.本工作为单原子位点的局部配位环境与CO_(2)RR途径之间的关系提供了一个新的视角.

Nissen fundoplication vs proton pump inhibitors for laryngopharyngeal reflux based on p H-monitoring and symptom-scale

AIM To compare the outcomes between laparoscopic Nissen fundoplication(LNF)and proton pump inhibitors(PPIs)therapy in patients with laryngopharyngeal reflux(LPR)and typeⅠhiatal hernia diagnosed by oropharyngeal p H-monitoring and symptom-scale assessment.METHODS From February 2014 to January 2015,70 patients who were diagnosed with LPR and type I hiatal hernia and referred for symptomatic assessment,oropharyngeal p H-monitoring,manometry,and gastrointestinal endoscopy were enrolled in this study.All of the patients met the inclusion criteria.All of the patients underwent LNF or PPIs administration,and completed a2-year follow-up.Patients’baseline characteristics and primary outcome measures,including comprehensive and single symptoms of LPR,PPIs independence,and satisfaction,and postoperative complications were assessed.The outcomes of LNF and PPIs therapy were analyzed and compared. RESULTS There were 31 patients in the LNF group and 39patients in the PPI group.Fifty-three patients(25 in the LNF group and 28 in the PPI group)completed reviews and follow-up.Oropharyngeal p H-monitoring parameters were all abnormal with high acid exposure,a large amount of reflux,and a high Ryan score,associated reflux symptom index(RSI)score.There was a significant improvement in the RSI and LPR symptom scores after the 2-year follow-up in both groups(P<0.05),as well as typical symptoms of gastroesophageal reflux disease.Improvement in the RSI(P<0.005)and symptom scores of cough(P=0.032),mucus(P=0.011),and throat clearing(P=0.022)was significantly superior in the LNF group to that in the PPI group.After LNF and PPIs therapy,13 and 53 patients achieved independence from PPIs therapy(LNF:44.0%vs PPI:7.14%,P<0.001)during follow-up,respectively.Patients in the LNF group were more satisfied with their quality of life than those in the PPI group(LNF:62.49±28.68 vs PPI:44.36±32.77,P=0.004).Body mass index was significantly lower in the LNF group than in the PPI group(LNF:22.2±3.1kg/m^2 vs PPI:25.1±2.9 kg/m^2,P=0.001).CONCLUSION Diagnosis of LPR should be assessed with oropharyngeal p H-monitoring,manometry,and the symptom-scale.LNF achieves better improvement than PPIs for LPR with type I hiatal hernia.

Evaluation of characteristics of left-sided colorectal perfusion in elderly patients by angiography

BACKGROUND Handling of the inferior mesenteric artery(IMA)and maintaining anastomotic perfusion are important in radical resection of left-sided colorectal cancer.However,the branching of this artery and the drainage patterns of this vein vary among individuals,and the characteristics and perfusion region of this artery in elderly patients remain unclear.AIM To evaluate the characteristics and perfusion region of the IMA in elderly patients using angiography.METHODS We enrolled 154 patients(>65 years old)who underwent digital subtraction angiography of the IMA.The characteristics,bifurcation,and distribution of the IMA and termination of the anastomotic perfusion of the left colon and rectum were examined using digital subtraction angiography.Collateral arterial arches and the IMA hemoperfusion region were also recorded.Perfusion regions were cross-referenced with clinical and anatomical features by the univariate analysis.RESULTS Of 154 patients,25(16.2%)had IMA lesions.The left colic artery arose independently from the IMA in 44.2%of patients,shared a trunk with the sigmoid artery in 35.1%,shared an opening with the sigmoid and superior rectal arteries in 16.9%,and was absent in 5.1%.The IMA perfusion region stopped at the splenic flexure in 50(32.5%)patients.The collateral circulation existed in the colonic perfusion region,including the marginal artery(Drummond’s artery),the ascending branch of the left colonic artery to supply the transverse colon,and the arc of Riolan with a frequency of 100%,22.7%,and 1.9%,respectively.The IMA perfusion region was independently associated with the comorbidity of atherosclerosis,IMA atherosclerotic lesion,branching pattern,collateral circulation,and marginal artery integrity.CONCLUSION The IMA and its branches are prone to arteriosclerosis,and IMA perfusion may be interrupted at the splenic flexure in elderly patients.The applicability and precision of preoperative angiography for evaluating the IMA branching and perfusion patterns could facilitate geriatric laparoscopic left-sided colorectal cancer surgery with suspicion of poor IMA perfusion.

Less and shrunken pollen 1(LSP1) encodes a member of the ABC transporter family required for pollen wall development in rice(Oryza sativa L.)

Pollen fertility is an agronomic trait that strongly influences rice yield. Recent studies have revealed that the development of the pollen wall is required for pollen fertility and is regulated by several genes. However, the mechanisms underlying pollen and pollen wall development in rice remain largely unknown. In the present study, a point mutation in a gene on chromosome 1 was identified that resulted in the production of less and shrunken pollen(LSP) and led to defects in pollen wall formation. This gene was named LSP1 and was found to encode a member of the adenosine triphosphate-binding cassette(ABC)transporter G subfamily, OsABCG3. Two other loss-of-function mutants of LSP1/OsABCG3,generated using CRISPR/Cas9 technology, showed the same male sterile phenotype. The LSP1/OsABCG3 gene showed a spatio-temporal expression pattern in the developing anthers, and is an ortholog of the Arabidopsis genes At ABCG1 and At ABCG16, which play an important role in pollen wall development. Mutation of LSP1/OsABCG3 affected the expression of several genes involved in pollen and pollen wall formation. These results suggest that LSP1/OsABCG3 is critical for normal pollen fertility and shed light on the molecular mechanisms underlying rice pollen wall development.

Laser direct writing and characterizations of flexible piezoresistive sensors with microstructures

Functional materials with high viscosity and solid materials have received more and more attentions in flexible pressure sensors,which are inadequate in the most used molding method.Herein,laser direct writing(LDW)method is proposed to fabricate flexible piezoresistive sensors with microstructures on PDMS/MWCNTs composites with an 8%MWCNTs mass fraction.By controlling laser energy,microstructures with different geometries can be obtained,which significantly impacts the performances of the sensors.Subsequently,curved microcones with excellent performance are fabricated under parameters of f=40 kHz and v=150 mm·s^(-1).The sensor exhibits continuous multi-linear sensitivity,ultrahigh original sensitivity of 21.80%kPa^(-1),wide detection range of over 20 kPa,response/recovery time of~100 ms and good cycle stability for more than 1000 times.Besides,obvious resistance variation can be observed when tiny pressure(a peanut of 30 Pa)is applied.Finally,the flexible piezoresistive sensor can be applied for LED brightness controlling,pulse detection and voice recognition.

Cluster-Based Interference-Free MAC Protocol with Load Aware in Software Defined VANET

In order to reduce the interference,a novel,cluster-based medium access control(MAC)protocol with load aware for VANETs is proposed in this paper.First,all vehicles on roads are grouped into stable clusters in the light of their direction,number of neighbors,link reliability,and traffic load.By utilizing the advantages of centralized control in software defined VANETs(SDVN),cluster stability can be maintained in real-time.Second,a contention-free MAC mechanism composed of inter-cluster multi-channel allocation and intra-cluster dynamic TDMA frame allocation is proposed to prevent co-channel interference and hidden terminal interference.Simulation results show that the proposed protocol outperforms some existing protocols in cluster stability,delivery ratio,throughput and delay performance.

Dual interfacial engineering for efficient Cs_(2)AgBiBr_(6) based solar cells

The emerging lead-free halide double perovskite solar cells have attracted widespread attentions due to their long-term stability and non-toxicity, but suffer from the low device performance. One efficiencylimiting factor is the improper contacts between the halide double perovskite and anode/cathode electrodes. Here, we improve the efficiency and stability of the bismuth-halide double perovskite based solar cells by a synergistic interface design for both electron and hole transport layers(ETL/HTL). The results show that the modification of the TiO_2 ETL with a thin hydrophobic C60 layer and replacement of the lithium-doped small molecule HTL with an un-doped conjugated polymer lead to higher surface quality of perovskite film and better energy-level alignment at the contacts. As a result, the optimized device shows reduced trap density, suppressed charge recombination and enhanced charge extraction, leading to an increase of 69% in device efficiency. In addition, the device also exhibits superior stability in ambient environment, heat stress and light bias after interface optimization. This work provides an efficient strategy for the device optimization of the emerging lead-free perovskite solar cells.

The gap junction blocker carbenoxolone enhances propofol and sevoflurane-induced loss of consciousness

General anesthetics induce loss of consciousness by inhibiting ascending arousal pathways, and they interfere with gap junction electrical coupling. The present study aimed to determine whether inhibition of gap junction-mediated signaling could influence general anesthetic-induced loss of consciousness. The general anesthetics sevoflurane and propofol were used. Intracerebroventricular administration of carbenoxolone, a gap junction blocker, significantly decreased the time to loss of the righting reflex （P 0.05）, but prolonged the time to recovery of the reflex （P 0.05）. Moreover, intracerebroventricular administration of carbenoxolone increased the sensitivity to sevoflurane, with a leftward shift of the loss of righting reflex dose-response curve, and decreased the 50% effective concentration of sevoflurane. These results suggest that the gap junction blocker carbenoxolone enhances propofol and sevoflurane-mediated general anesthesia.

Phylogeography and Cryptic Species Diversity of Paramesotriton caudopunctatus Species Group(Salamandridae: Paramesotriton) in Guizhou, China

The Paramesotriton caudopunctatus species group is mainly distributed in the karst mountain ecosystems of Guizhou, China. Although some species have been included in previous phylogenetic studies, the evolutionary relationships and divergence-time of members of this species group as a whole remain unexplored. In this study, we report the sequencing of one protein coding mitochondrial gene fragment(ND2) and one nuclear gene(POMC), and use a combination of phylogenetic analyses and coalescent simulations to explore the cryptic diversity and evolutionary history of the P. caudopunctatus species group. Phylogenetic relationships revealed that the P. caudopunctatus species group is composed of two major groups, i. e., East Clade and Western-South Clade. The divergence-time and ancestral area estimation suggested that the P. caudopunctatus species group likely originated in the Doupeng Mountains in Guizhou, China at 12.34 Ma(95% HPD: 8.30–14.73), and intraspecific divergence began at about 2.17 Ma(95% HPD: 1.39–2.97). This timing coincides with the orogenesis of the Miaoling Mountains during the Late Miocene to early Pleistocene. The delimitation of species in the P. caudopunctatus species group supports the existence of the currently identified species, and consensus was confirmed across methods for the existence of least to two cryptic species within what has been traditionally considered to be P. caudopunctatus species group. This study is of significance for understanding the species formation, dispersal, and diversity of the tailed amphibians in the karst mountains ecosystem of Guizhou and the role of the Miaoling Mountains as a geographical barrier to species dispersal.

A New Species of Odorous Frog Genus Odorrana(Anura,Ranidae) from Southern Guizhou Province,China

We describe Odorrana liboensis sp.nov.,a new species from the Maolan National Nature Reserve,Libo County,Guizhou Province,China.Phylogenetic analyses based on DNA sequences of the mitochondrial 12 S rRNA,16 S rRNA,and ND2 genes supported the new species as an independent lineage,closely related to O.lipuensis.The uncorrected genetic distances between the 12 S rRNA and16 S rRNA in the new species and its closest congener,O.lipuensis,were 6.06%and 5.19%,respectively.The new species is distinguished from its congeners by a combination of the following morphological characters:(1)having medium body size,with the snout-vent length(SVL)of adult females approximately 1.2 times as long as males at 56.9±1.0(55.8-58.2 mm,n=9)in females and 48.7±1.2(47.1-49.9 mm,n=5)in males;(2)head length greater than width in males and females;(3)tympanum distinctly visible,greater than one-half the diameter of the eye;(4)eyes big and prominent,width of upper eyelid(UEW)approximately3/4 of eye diameter(ED);(5)dorsolateral folds absent;(6)two metacarpal tubercles;(7)relative finger lengths:Ⅱ<Ⅰ<Ⅳ<Ⅲ;(8)subarticular tubercles on fingers prominent:1,1,2,2;(9)one metatarsal tubercle;(10)tibiotarsal articulation reaching to between the eye and nostril when the leg is stretched forward;(11)toes with entire webbing to disks;(12)subarticular tubercles on toes prominent:1,1,2,3,2;(13)dorsal surfaces of limbs with distinct brownish-black bands;(14)smooth,grass-green dorsum with irregular brown mottling;(15)venter smooth,lacking black spots;and(16)lacking pectoral spinules,lacking vocal sacs,and light white nuptial pad present on finger I in males.The new species is currently only known from the type locality.

A Linear Frequency Principle Model to Understand the Absence of Overfitting in Neural Networks

Why heavily parameterized neural networks(NNs) do not overfit the data is an important long standing open question. We propose a phenomenological model of the NN training to explain this non-overfitting puzzle. Our linear frequency principle(LFP) model accounts for a key dynamical feature of NNs: they learn low frequencies first, irrespective of microscopic details. Theory based on our LFP model shows that low frequency dominance of target functions is the key condition for the non-overfitting of NNs and is verified by experiments. Furthermore,through an ideal two-layer NN, we unravel how detailed microscopic NN training dynamics statistically gives rise to an LFP model with quantitative prediction power.

A novel primary culture method for high-purity satellite glial cells derived from rat dorsal root ganglion

Satellite glial cells surround neurons within dorsal root ganglia. Previous studies have focused on single-cell suspensions of cultured neurons derived from rat dorsal root ganglia. At present, the primary culture method for satellite glial cells derived from rat dorsal root ganglia requires no digestion skill. Hence, the aim of the present study was to establish a novel primary culture method for satellite glial cells derived from dorsal root ganglia. Neonatal rat spine was collected and an incision made to expose the transverse protrusion and remove dorsal root ganglia. Dorsal root ganglia were freed from nerve fibers, connective tissue, and capsule membranes, then rinsed and transferred to 6-well plates, and cultured in a humidified 5% CO_2 incubator at 37°C. After 3 days in culture, some cells had migrated from dorsal root ganglia. After subculture, cells were identified by immunofluorescence labeling for three satellite glial cell-specific markers: glutamine synthetase, glial fibrillary acidic protein, and S100β. Cultured cells expressed glutamine synthetase, glial fibrillary acidic protein, and S100β, suggesting they are satellite glial cells with a purity of > 95%. Thus, we have successfully established a novel primary culture method for obtaining high-purity satellite glial cells from rat dorsal root ganglia without digestion.

Transmission Capacity Analysis for Linear VANET under Physical Model

In this study, the transmission capacity of VANETs in a highway scenario is analysed on the basis of a 1D line model and the carrier sense multiple access with collision avoidance(CSMA/CA) protocol. We describe the CSMA/CA protocol used in IEEE802.11 p from the perspective of the geometric relationship amongst simultaneous transmitters. The desired channel and interfering channels are assumed to experience the same amount of path-loss and Rayleigh fading. On the basis of the proposed model, we analyse the attempted transmission probability of each road segment and the maximum intensity of active transmitters, including their theoretical values. Then, we employ the physical model to obtain the outage probability and derive the upper bound of the transmission capacity of a VANET, which is defined as the average spatial density of successful transmissions in the network. Simulation results indicate that the theoretical value offers a good bound on network capacity.

Tandem catalysis on adjacent active motifs of copper grain boundary for efficient CO_(2) electroreduction toward C2 products

Copper (Cu) is a special electrocatalyst for CO_(2) reduction reaction (CO_(2)RR) to multi-carbon products.Experimentally introducing grain boundaries (GBs) into Cu-based catalysts is an efficient strategy to improve the selectivity of C^(2+) products.However,it is still elusive for the C^(2+) product generation on Cu GBs due to the complex active sites.In this work,we found that the tandem catalysis pathway on adjacent active motifs of Cu GB is responsible for the enhanced activity for C^(2+)production by first principles calculations.By electronic structure analysis shows,the d-band center of GB site is close to the Fermi level than Cu(100) facet,the Cu atomic sites at grain boundary have shorter bond length and stronger bonding with*CO,which can enhance the adsorption of*CO at GB sites.Moreover,CO_(2)protonation is more favorable on the region Ⅲ motif (0.84 e V) than at Cu(100) site (1.35 e V).Meanwhile,the region Ⅱ motif also facilitate the C–C coupling (0.72 e V) compared to the Cu(100) motif (1.09 e V).Therefore,the region Ⅲ and Ⅱ motifs form a tandem catalysis pathway,which promotes the C^(2+)selectivity on Cu GBs.This work provides new insights into CO_(2)RR process.