Lattice strain induced by trace Pt single atoms in nickel for accelerating industrial hydrogen evolution

Strategically designing the electrocatalytic system and cleverly inducing strain is an effective approach to balance the cost and activity of Pt-based electrocatalysts for industrial-scale hydrogen production.Herein,we present a unipolar pulsed electrodeposition(UPED) strategy to induce strain in the Ni lattice by introducing trace amounts of Pt single atoms(SAs)(0.22 wt%).The overpotential decreased by 183 mV at 10 mA cm^(-2) in 1.0 M KOH after introducing trace amounts of Pt_(SAs).The industrial electrolyzer,assembled with Pt_(SAs)Ni cathode and a commercial NiFeO_(x) anode,requires a cell voltage of 1.90 V to attain 1 A cm^(-2) of current density and remains stable for 280 h,demonstrating significant potential for practical applications.Spherical aberration corrected scanning transmission electron microscopy(AC-STEM),X-ray absorption(XAS),and geometric phase analysis(GPA) indicate that the introduction of trace amounts of Pt SAs induces tensile strain in the Ni lattice,thereby altering the local electronic structure and coordination environment around cubic Ni for enhancing the water decomposition kinetics and fundamentally changing the reaction pathway.The doping-strain strategy showcases conformational relationships that could offer new ideas to construct efficient hydrogen evolution reaction(HER) electrocatalysts for industrial hydrogen production in the future.

Molecular cloning,characterization and promoter analysis of LbgCWIN1 and its expression profiles in response to exogenous sucrose during in vitro bulblet initiation in lily

Lily(Lilium spp.) is an important ornamental flower, which is mainly propagated by bulbs. Cell wall invertases(CWINs), which catalyze the irreversibly conversion of sucrose into glucose and fructose in the extracellular space, are key enzymes participating in sucrose allocation in higher plants. Previous studies have shown that CWINs play an essential role in bulblet initiation process in bulbous crops, but the underlying molecular mechanism remains unclear. Here, a CWIN gene of Lilium brownii var. giganteum(Lbg) was identified and amplified from genomic DNA. Quantitative RT-PCR assays revealed that the expression level of LbgCWIN1 was highly upregulated exactly when the endogenous starch degraded in non-sucrose medium during in vitro bulblet initiation in Lbg. Phylogenetic relationship, motif, and domain analysis of LbgCWIN1 protein and CWINs in other plant species showed that all sequences of these CWIN proteins were highly conserved. The promoter sequence of LbgCWIN1 possessed a number of alpha-amylase-, phytohormone-, light-and stress-responsive cis-elements. Meanwhile, β-glucuronidase(GUS) assay showed that the 459 bp upstream fragment from the translational start site displayed maximal promoter activity. These results revealed that LbgCWIN1 might function in the process of in vitro bulblet initiation and be in the response to degradation of endogenous starch.

Airfoil friction drag reduction based on grid-type and super-dense array plasma actuators

To improve the cruise flight performance of aircraft, two new configurations of plasma actuators(grid-type and super-dense array) were investigated to reduce the turbulent skin friction drag of a low-speed airfoil. The induced jet characteristics of the two actuators in quiescent air were diagnosed with high-speed particle image velocimetry(PIV), and their drag reduction efficiencies were examined under different operating conditions in a wind tunnel. The results showed that the grid-type plasma actuator was capable of producing a wall-normal jet array(peak magnitude: 1.07 m/s) similar to that generated in a micro-blowing technique, while the superdense array plasma actuator created a wavy wall-parallel jet(magnitude: 0.94 m/s) due to the discrete spanwise electrostatic forces. Under a comparable electrical power consumption level,the super-dense array plasma actuator array significantly outperformed the grid-type configuration,reducing the total airfoil friction drag by approximately 22% at a free-stream velocity of 20 m/s.The magnitude of drag reduction was proportional to the dimensionless jet velocity ratio(r), and a threshold r = 0.014 existed under which little impact on airfoil drag could be discerned.

A Novel CCA-NMF Whitening Method for Practical Machine Learning Based Underwater Direction of Arrival Estimation

Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical problem.Due to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based DOA estimation methods trained on simulated Gaussian noised array data cannot be directly applied to actual underwater DOA estimation tasks.In order to deal with this problem,environmental data with no target echoes can be employed to analyze the non-Gaussian components.Then,the obtained information about non-Gaussian components can be used to whiten the array data.Based on these considerations,a novel practical sonar array whitening method was proposed.Specifically,based on a weak assumption that the non-Gaussian components in adjacent patches with and without target echoes are almost the same,canonical cor-relation analysis(CCA)and non-negative matrix factorization(NMF)techniques are employed for whitening the array data.With the whitened array data,machine learning based DOA estimation models trained on simulated Gaussian noised datasets can be used to perform underwater DOA estimation tasks.Experimental results illustrated that,using actual underwater datasets for testing with known machine learning based DOA estimation models,accurate and robust DOA estimation performance can be achieved by using the proposed whitening method in different underwater con-ditions.

Utilization and Living Inheritance of Red Tourism Resources in Nanxiong City under the Background of"Baiqianwan Project"

Under the work deployment of"Double Hundred Action",Huizhou Engineering Vocational College,Nanxiong Municipal People's Government and Shaoguan College have formulated a series of plans and projects to promote the local development of Nanxiong through cooperation and in-depth research,which strengthens the role of vocational education in rural revitalization,and promotes the effective use of red tourism resources in Nanxiong City,promoted the development of local tourism and economy,provides new impetus and direction for rural revitalization,and demonstrates the positive prospects and vitality of rural revitalization,as well as the important value and potential of vocational education in rural revitalization.

太行刺皮瘿螨(Aculops taihangensis Hong＆Xue)对臭椿生长及生理生化指标的影响

研究了太行刺皮瘿螨Aculops taihangensis对臭椿生长及其叶片中光合色素、游离氨基酸、脯氨酸及可溶性蛋白质含量的影响。研究表明,试验30 d时,对照组株高平均增长23.3%,单株总叶片数平均增加252%;而该瘿螨危害的植株平均增长率仅为1%,单株总叶片数平均增长85.4%,均显著低于对照。太行刺皮瘿螨危害后可引起顶芽和叶片脱落,第61 d时顶芽脱落率达70%,第70 d时落叶率达54%。随危害时间延长,叶片中叶绿素a、叶绿素b和类胡萝卜素含量均明显低于对照组;游离氨基酸与可溶性蛋白质含量均表现为短期内含量迅速升高,随危害时间都延长逐渐降低,并最终低于对照,但脯氨酸含量始终高于对照。安全寄主测试表明,太行刺皮瘿螨仅取食臭椿,而对香椿、鸦胆子、芒果、刺槐等10几种测试寄主均无危害。

基于微信的在线生活服务的设计与实现

随着互联网的快速发展,在线生活服务迅速通过移动终端走进消费者的生活,通过微信公众号平台与原有的网络生活服务平台对接,企业、商家可利用方便快捷的微信终端为消费者提供在线生活服务的接入,已成为许多企业、商家店铺在线服务在移动终端应用的发展趋势。本文注重分析微信数据处理业务流、利用微信公共接口设计并实现与在线生活服务实现数据对接。

基板表面张力对量子点胶体及其聚氨酯复合膜荧光性能的影响

通过离子共沉积法、一锅法分别制备水相CdS@ZnS核壳结构量子点和水性聚氨酯,将量子点与聚氨酯以1:1的质量比均匀混合后,滴在具有不同表面张力的基板上,经自然干燥后形成量子点/聚氨酯薄膜。研究表明,基板的表面张力大小能直接影响量子点以及量子点薄膜的荧光性能。文中通过测量接触角来表征基板的表面张力。接触角越大,表面张力越小。表面张力较大时,会引起量子点大范围聚集,导致区域量子点浓度过大,引起浓度猝灭,所以,基板表面张力增大虽然能提升量子点的色纯度但也会导致其荧光强度下降。在365 nm紫外灯照射下可以明显看出基板与量子点分散液接触面荧光强度明显高于其它区域。通过荧光光谱仪测试量子点/聚氨酯复合膜发现,复合膜荧光强度也随表面张力的增大而减小。

推进媒体多元化政策与研究:中国新闻多样性计算监测的创新

在本研究中,我们开发了一种新的计算工具,通过新闻报道中公共事务内容的比例来评估网络新闻的多样性,该工具被应用于分析微信公众号上的算法分发新闻。研究发现,一篇新闻文章的用户参与度高低与新闻标题、内容和图片使用之间存在相关性。本文认为,媒体研究的去西方化应该包括媒体多元化/多样性政策,这种方法可以增进我们对新闻媒体的理解。对中国网络新闻及其多样性的研究强调过程研究和系统研究,以及政策制定的结构、机构和路径之间的相互作用。此研究为网络新闻语料库分析提供了基于计算方法的理论框架,有助于理解和促进不同媒介系统的新闻多样性。

急性胰腺炎患者外周血CD14^+CD16^+单核细胞表达B7-H2的临床意义

背景急性胰腺炎(acute pancreatitis,AP)是常见的急腹症,不同类型预后不同.AP的免疫应答和失衡免疫与其严重程度有关,炎症因子和相关免疫细胞在AP发病机制中至关重要,因而寻找炎症细胞和新炎症免疫因子对精准治疗AP具有重要意义.目的探讨AP患者外周血CD14^+CD16^+单核细胞表达B7-H2的临床意义.方法A P患者63例[轻度A P(m i l dA P,M A P)25例、中度AP(moderately severe AP,MSAP)20例、重度AP(severe AP,SAP)18例],对照组为健康体检者20例,采用流式细胞仪检测CD14^+CD16^+细胞亚群上B7-H2表达情况,评价其与胰腺炎严重程度关联性及临床意义.结果AP患者发病24hCD14^+CD16^+细胞B7-H2出现异常高表达,显著高于健康对照组(t=11.10,P<0.001);A P各组B 7-H 2在C D 14^+C D 16^+细胞膜上表达明显高于CD14^+C D16^-细胞膜上表达(P<0.01);SAP组CD14^+C D 16^+和CD14^+C D 16^-细胞B7-H2表达(373.30±89.72和78.62±13.05)最高,M S A P组(279.55±76.95/44.92±12.44)其次,均高于M A P组(181.15±35.75/23.32±4.28),各组两两比较差异有显著性(P<0.01);MAP组、MSAP组发病24 h、48 h、72hCD14^+CD16^+和CD14^+CD16^-单核细胞膜B7-H2动态表达差异无显著性(P>0.05),然而,SAP组无论C D14^+C D16^+还是CD14^+C D16^-细胞膜B7-H2表达24h、48h、72h均呈明显上升趋势,差异有显著性(P<0.05).结论CD14^+CD16^+和CD14^+CD16^-单核细胞膜B7-H2在AP患者体内高表达,与AP严重程度密切相关,且SAP呈动态升高变化;同时B7-H2在AP患者CD14^+CD16^+单核细胞膜表达较CD14^+CD16^-单核细胞明显升高,为进一步认识AP免疫应答和失衡提供了新的线索,为AP精准靶向治疗提供参考.

The earthquake-related disturbances in ionosphere and project of the first China seismo-electromagnetic satellite

Based on the case studies and statistical analysis of earthquake-related ionospheric disturbances mainly from DEMETER satellite, ground-based GPS and ionosounding data, this paper summarizes the statisw tical characteristics of earthquake-related ionospheric disturbances, including electromagnetic emissions, plasma perturbations and variation of energetic particle flux. According to the main results done by Chinese scientists, fusing with the existed study from global researches, seismo-ionospheric disturbances usually occurred a few days or hours before earthquake occurrence. Paralleling to these case studies, lithosphere-atmosphere-ionosphere （LAI） coupling mechanisms are checked and optimized. A thermo-electric model was proposed to explain the seismo-electromagnetic effects before earthquakes. A propagation model was put forward to explain the electromagnetic waves into the ionosphere. According to the requirement of earthquake prediction research, China seismo-electromagnetic satellite, the first space-based platform of Chinese earthquake stereoscopic observation system, is proposed and planned to launch at about the end of 2014. It focuses on checking the LAI model and distinguishing earthquake-related ionospheric disturbance. The preliminary design for the satellite will adopt CAST-2000 platform with eight payloads onboard. It is believed that the satellite will work together with the ground monitoring network to improve the capability to capture seismo-electromagnetic information, which is beneficial for earthquake monitoring and prediction researches.

Effects of confining pressure on acoustic emission and failure characteristics of sandstone

In this study,uniaxial and triaxial compression acoustic emission(AE)tests were implemented to investigate the AE effect and failure characteristics of sandstone under different confining pressures(σ3).The evolution of AE parameters in the rock failure process and fracture fractal dimension characteristics after failure were analyzed.The results revealed that the activity of the AE signal is strongly related toσ3.The evolution of the Ib value can be divided into the I-fluctuation,II-stability,and III-decrease stages.In the first stage,the Ib value of the AE was relatively high,and the AE energy was low.Then,the Ib value tended to be stable;however,the fluctuation amplitude decreased,and the AE energy rapidly increased.In the stage of decrease,the AE energy sharply increased before the load approached the peak value,and the Ib value significantly decreased and dropped to the lowest point before the peak value.Asσ3 increased,the rock’s failure mode changed from tensile failure to shear failure and became more coordinated.As the confining pressure increased,the shape dimension decreased,and the order degree of rock failure increased.The confining pressure exerted a certain control effect on the rock failure.

Tumor infiltrating lymphocytes in triple negative breast cancer receiving neoadjuvant chemotherapy

AIM To determine influence of neoadjuvant-chemotherapy(NAC) over tumor-infiltrating-lymphocytes(TIL) intriple-negative-breast-cancer(TNBC).METHODS TILs were evaluated in 98 TNBC cases who came to Instituto Nacional de Enfermedades Neoplasicas from 2005 to 2010. Immunohistochemistry staining for CD3, CD4, CD8 and FOXP3 was performed in tissue microarrays(TMA) sections. Evaluation of H/E in full-face and immunohistochemistry in TMA sections was performed in pre and post-NAC samples. STATA software was used and P value < 0.05 was considered statistically significant. RESULTS Higher TIL evaluated in full-face sections from pre-NAC tumors was associated to pathologic-complete-response(pCR)(P = 0.0251) and outcome(P = 0.0334). TIL evaluated in TMA sections showed low level of agreement with full-face sections(ICC = 0.017-0.20) and was not associated to pCR or outcome. TIL in post-NAC samples were not associated to response or outcome. PostNAC lesions with pC R had similar TIL levels than those without pCR(P = 0.6331). NAC produced a TIL decrease in full-face sections(P < 0.0001). Percentage of TIL subpopulations was correlated with their absolute counts. Higher counts of CD3, CD4, CD8 and FOXP3 in pre-NAC samples had longer disease-free-survival(DFS). Higher counts of CD3 in pre-NAC samples had longer overallsurvival. Higher ratio of CD8/CD4 counts in pre-NAC was associated with pCR. Higher ratio of CD4/FOXP3 counts in pre-NAC was associated with longer DFS. Higher counts of CD4 in post-NAC samples were associated with pCR.CONCLUSION TIL in pre-NAC full-face sections in TNBC are correlated to longer survival. TIL in full-face differ from TMA sections, absolute count and percentage analysis of TIL subpopulation closely related.

Topological analysis of plasma flow control on corner separation in a highly loaded compressor cascade

In this paper, flow behavior and topology structure in a highly loaded compressor cascade with and without plasma aerodynamic actuation （PAA） are investigated. Streamline pattern, total pressure loss coefficient, outlet flow angle and topological analysis are considered to study the effect and mechanism of the plasma flow control on corner separation. Results presented include the boundary layer flow behavior, effects of three types of PAA on separated flows and performance parameters, topology structures and sequences of singular points with and without PAA. Two separation lines, reversed flow and backflow exist on the suction surface. The cross flow on the endwall is an important element for the comer separation. PAA can reduce the undertuming and overturning as well as the total pressure loss, leading to an overall increase of flow turning and enhancement of aerodynamic performance. PAA can change the topology structure, sequences of singular points and their corresponding separation lines. Types II and III PAA are much more efficient in controlling comer separation and enhancing aerodynamic performances than type I.

Low-dose intralesional injection of 5-fluorouracil and triamcinolone reduces tissue resident memory T cells in chronic eczema

BACKGROUND Tissue resident memory T(TRM)cells have been reported to play a significant role in the pathogenesis and relapse of chronic eczema.AIM To compare the efficacy and safety of the intralesional injection of 5-fluorouracil(5-FU)and triamcinolone(TA)with those associated with TA alone for the treatment of chronic eczema.METHODS A total of 168 patients were randomized to 5-FU+TA or TA groups and received a one-time intralesional injection of 5-FU+TA or TA only.Biopsies were collected before and 2 wk after treatment for evaluation of histopathological changes.All patients were followed up monthly for up to 1 year.RESULTS No serious adverse event was observed in either group.Although the mean atopic dermatitis severity index scores and effective rates were comparable between the two groups after 2 wk of treatment,the relapse rate was significantly lower in the 5-FU+TA group than in the TA group.Histological examination showed significantly fewer CD8^(+)and CD103^(+)T cells but not CD4^(+)T cells in the 5-FU+TA group.CONCLUSION One-time intralesional injection of 5-FU+TA is effective and safe for chronic eczema treatment and can further reduce the retention of T_(RM) cells in the lesional skin and the relapse rate of chronic eczema.

Statistical analysis of distribution patterns of coal seams in fold zones in Northwest China

The mechanisms for rock bursts occurrences in fold zones are complex, and the redistribution of in-situ stresses is closely related to the complexity of the structures. Analysis of the geomorphology of fold structures and changes of coal thickness can help identify zones prone to rock bursts to improve safety and productivity in coal mines. This study investigated the distribution characteristics of fold structures in coal seams in fold zones in four mines in northwest China. Geometrical characteristics of fold structures in coal seams and changes of coal thickness were analysed, based on comprehensive evaluation indexes,such as the length–width ratio of folds, interlimb angle, ratio P1 of projected width of fold limbs to that of the hinge zone, curvature ratio P2, the maximum curvature and amplitude. The statistical analysis of the four coal mines shows that the length–width ratio of folds changed from 0.78 to 2.03 and the maximum curvature of cross sections of folds was less than 0.04. The curvature ratio of cross section of a fold in the structure was no more than 1.4 and the interlimb angles of cross sections of 89% of folds were larger than 150°. Gentle fold structures were dominant and the specific geological morphologies were domes or basins. The isopleth of coal thickness above the coal mines showed a fluctuation trend similar to the contour line of the floor of coal seams. The coal thickness in an anticline area was smaller than that in the neighboring syncline area. Therefore, the overall variation of coal thickness in the mining areas was likely to have a relation with the direction of the regional principal stress.

Amorphous iron-nickel phosphide nanocone arrays as efficient bifunctional electrodes for overall water splitting

The synthesis of low-cost and highly active electrodes for both oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is very important for water splitting.In this work,the novel amorphous iron-nickel phosphide(FeP-Ni)nanocone arrays as efficient bifunctional electrodes for overall water splitting have been in-situ assembled on conductive three-dimensional(3D)Ni foam via a facile and mild liquid deposition process.It is found that the FeP-Ni electrode demonstrates highly efficient electrocatalytic performance toward overall water splitting.In 1 M KOH electrolyte,the optimal FeP-Ni electrode drives a current density of 10 mA cm^(-2) at overpotential of 218 mV for the OER and120 mV for the HER,and can attain such current density for 25 h without performance regression.Moreover,a two-electrode electrolyzer comprising the FeP-Ni electrodes can afford 10 mA cm^(-2) electrolysis current at a low cell voltage of 1.62 V and maintain long-term stability,as well as superior to that of the coupled RuO_(2)/NFk Pt/C/NF cell.Detailed characterizations confirm that the excellent electrocatalytic performances for water splitting are attributed to the unique 3D morphology of nanocone arrays,which could expose more surface active sites,facilitate electrolyte diffusion,and benefit charge transfer and also favorable bubble detachment behavior.Our work presents a facile and cost-effective pathway to design and develop active self-supported electrodes with novel 3D morphology for water electrolysis.

Experimental study on energy characteristics and ignition performance of recessed multichannel plasma igniter

In the extreme conditions of high altitude,low temperature,low pressure,and high speed,the aircraft engine is prone to flameout and difficult to start secondary ignition,which makes reliable ignition of combustion chamber at high altitude become a worldwide problem.To solve this problem,a kind of multichannel plasma igniter with round cavity is proposed in this paper,the three-channel and five-channel igniters are compared with the traditional ones.The discharge energy of the three igniters was compared based on the electric energy test and the thermal energy test,and ignition experiments was conducted in the simulated high-altitude environment of the component combustion chamber.The results show that the recessed multichannel plasma igniter has higher discharge energy than the conventional spark igniter,which can increase the conversion efficiency of electric energy from 26%to 43%,and the conversion efficiency of thermal energy from 25%to 73%.The recessed multichannel plasma igniter can achieve greater spark penetration depth and excitation area,which both increase with the increase of height.At the same height,the inlet flow helps to increase the penetration depth of the spark.The recessed multichannel plasma igniter can widen the lean ignition boundary,and the maximum enrichment percentage of lean ignition boundary can reach 31%.

Effects of pre-oxidant(KMnO4)on structure and performance of PVDF and PES membranes

The structure and performance of membrane materials are very important to the efficient and stable operation in membrane drinking water purification technology. Potassium permanganate(KMnO_4), which can change the characteristics of organic matters and control membrane surface fouling, has been widely used as pre-oxidant in the front of membrane drinking water process. This study investigates the evolution of membrane surface structure and performance when polyvinylidene fluoride(PVDF) and polyethersulfone(PES) were exposed to10, 100 and 1000 mg·L^(-1) KMnO_4 solution for 6 and 12 d, respectively. The aged membrane physicochemical characteristics such as membrane surface morphology, chemical composition, hydrophilicity, porosity and zeta potential were evaluated by modern analytical and testing instruments. The anti-fouling property of membrane surface was also investigated by the filtration-backwash experiment. The results indicated that the different concentrations and exposure time of KMnO_4 led to a different variation on PVDF and PES membrane surface structure and performance, which could further affect the membrane separation performance and the membrane fouling behaviors. The membrane surface pore size and porosity increased due to the dislodgment and degradation of membrane additive(PVP), which improved membrane permeability and enhanced the adsorption and deposition of pollutants in the membrane pores. With the increase of exposure time, the membrane surface pore size and porosity reduced for the reactions of chain scission and crosslinking on membrane materials, and the backwashing efficiency declined, leading to a more serious irreversible fouling. Compared with PVDF membranes, the formation of sulfonic group for PES membranes increased the negative charge on membrane surface due to the oxidation of KMnO_4. The present study provides some new insights for the regulation of the pre-oxidant dose and the selection of the membrane materials in KMnO_4 pre-oxidation combined with membrane filtration system.

Species composition and influencing factors of understory woody species in Robinia pseudoacacia plantations on the Loess Plateau

Black locust(Robinia pseudoacacia L.)plantations have contributed significantly to soil and water conservation and ecological reconstruction on China’s Loess Plateau.Understanding the impact of stand and environment on species composition of understory woody plants will improve the stability of existing black locust plantations.Ten stands were selected in second-generation black locust plantations in tableland and gully areas of the Loess Plateau.The number of understory tree species in the tablelands was significantly lower than in the gully stands.Regenerated black locust(19.76%)and Rubus corchorifolius L.f.(64.85%)were the most abundant understory tree and shrub species,respectively,in the tableland stands;Broussonetia papyrifera(L.)L’Hér.ex Vent.(6.77%)and Acanthopanax senticosus(Rupr.Maxim.)Harms.(37.22%)were most abundant in the gully stands.Species richness(S),Shannon diversity(H),and evenness index(J)of the understory plants were significantly lower in the tableland stands than in the gully stands.More diverse understory species and community structures occurred in the gully stands.Differences in species diversity among landform positions may be attributed to differences in soil moisture.In addition,77.57%of the variation in understory species composition was explained,among which shrub and herb coverage,stand age,leaf area index,slope and total soil phosphorus in the 10-20 cm layer were the main factors.Soil organic carbon and total potassium significantly impacted S,H and J.Considering the environmental conditions and the biological characteristics of the plants investigated,R.corchorifolius should be given priority in the development of tableland stands,while B.papyrifera and Celtis sinensis Pers.should form mixed forests with black locust in gully stands.This management could promote biodiversity and stability of the existing black locust plantations but also optimize regional landscape patterns.