Optical pulling force on nanoparticle clusters with gain due to Fano-like resonance

We demonstrate that,in a simple linearly-polarized plane wave,the optical pulling forces on nanoparticle clusters with gain can be induced by the Fano-like resonance.The numerical results based on the full-wave calculation show that the optical pulling forces can be attributed to the recoil forces for the nanoparticle clusters composed of dipolar nanoparticles with three different configurations.Interestingly,the recoil forces giving rise to optical pulling forces are exactly dominated by the coupling term between the electric and magnetic dipoles excited in the nanoparticle clusters,while other higherorder terms have a negligible contribution.In addition,the optical pulling force can be tailored by modulating the Fano-like resonance via either the particle size or the gain magnitude,offering an alternative freedom degree for optical manipulations of particle clusters.

Theoretical and experimental study of the pulling force of jet bits in radial drilling technology

Radial drilling technology, of which the jet bit is the key device, is a research focus in the field of oil drilling and production. This paper establishes mechanical equations for jet bits and analyzes the hydroseal of backward jets in bottom holes. Meanwhile this paper establishes a mechanical equation for a high pressure hose and analyzes the axial force distribution. Laboratory experiments indicate that the flow rate, the angle between the backward nozzle axis and the jet bit axis, and the hole diameter are the major influencing factors; the generation of the pulling force is mainly due to the inlet pressure of the jet bit; the backward jets can significantly increase not only the pulling force but also the stability of jet bits. The pulling force would reach 8,376 N under experimental conditions, which can steadily pull the high-pressure hose forward.

Pulling force of acoustic-vortex beams on centered elastic spheres based on the annular transducer model

To solve the difficulty of generating an ideal Bessel beam,an simplified annular transducer model is proposed to study the axial acoustic radiation force(ARF)and the corresponding negative ARF(pulling force)exerted on centered elastic spheres for acoustic-vortex(AV)beams of arbitrary orders.Based on the theory of acoustic scattering,the axial distributions of the velocity potential and the ARF for AV beams of different orders generated by the annular transducers with different physical sizes are simulated.It is proved that the pulling force can be generated by AV beams of arbitrary orders with multiple axial regions.The pulling force is more likely to exert on the sphere with a smaller k0a(product of the wave number and the radius)for the AV beam with a bigger topological charge due to the strengthened off-axis acoustic scattering.The pulling force decreases with the increase of the axial distance for the sphere with a bigger k0a.More pulling force areas with wider axial regions can be formed by AV beams using a bigger-sized annular transducer.The theoretical results demonstrate the feasibility of generating the pulling force along the axes of AV beams using the experimentally applicable circular array of planar transducers,and suggest application potentials for multi-position stable object manipulations in biomedical engineering.

Graphene-tuned threshold gain to achieve optical pulling force on microparticle

We investigate optical force on a graphene-coated gain microparticle by adopting the Maxwell's stress tensor method.It is found that there exists a threshold gain in obtaining the Fano-profile optical force which indicates the reversal of optical pushing and pulling force. And giant pushing/pulling force can be achieved if the gain value of the material is in the proximity of the threshold gain. Our results show that the threshold gain is more sensitive to the relaxation time than to the Fermi energy of the graphene. We further study the optical force on larger microparticle to demonstrate the pulling force occurring at octupole resonance with small gain value and then it will appear at quadrupole resonance by increasing gain value. Our work provides an in-depth insight into the interaction between light and gain material and gives the additional degree of freedom to optical manipulation of microparticle.

Pulling the turnip

Hare:Oh,a turnip!A big turnip!I’m hungry.I’ll pull it out.Ai-Hay-Yo,Ai-Hay-Yo.The turnip is too heavy.I can’t pull it out.Dog:I’m a dog.I’m hungry.Oh,Miss Hare,What are you doing?

Pulling growth technique towards rare earth single crystals

Pulling growth technique serves as a popular method to grow congruent melting single crystals with multiscale sizes ranging from micrometers to centimeters.In order to obtain high quality single crystals,the crystal constituents would be arranged at the lattice sites by precisely controlling the crystal growth process.Growing interface is the position where the phase transition of crystal constituents occurs during pulling growth process.The precise control of energy at the growing interface becomes a key technique in pulling growth.In this work,we review some recent advances of pulling technique towards rare earth single crystal growth.In Czochralski pulling growth,the optimized growth parameters were designed for rare earth ions doped Y_3Al_5O_(12)and Ce:(Lu_(1-x)Y_x)_2Si O_5on the basis of anisotropic chemical bonding and isotropic mass transfer calculations at the growing interface.The fast growth of high quality rare earth single crystals is realized by controlling crystallization thermodynamics and kinetics in different size zones.On the other hand,the micro pulling down technique can be used for high throughput screening novel rare earth optical crystals.The growth interface control is realized by improving the crucible bottom and temperature field,which favors the growth of rare earth crystal fibers.The rare earth laser crystal fiber can serve as another kind of laser gain medium between conventional bulk single crystal and glass fiber.The future work on pulling technique might focus on the mass production of rare earth single crystals with extreme size and with the size near that of devices.

Evaluating the clinical application and effect of acupuncture therapy in anal function rehabilitation after low-tension rectal cancer surgery

BACKGROUND According to the indexes of serum and anal function,acupuncture therapy was applied to patients with low rectal cancer in order to avoid the occurrence of anal incontinence and reduce complications.AIM To explore the clinical application and evaluate the effect of acupuncture therapy for anal function rehabilitation after low-tension rectal cancer surgery.METHODS From the anorectal surgery cases,we selected 120 patients who underwent colorectal cancer surgery between January 2020 and December 2022 and randomly divided them into a control group(n=60),observation group(n=60),and control group after surgery for lifestyle intervention(including smoking cessation and exercise),dietary factor adjustment,anal movement,and oral loperamide treatment.The serum levels of motilin,5-hydroxytryptamine,and vasoactive intestinal peptide(VIP),Wexner score for anal incontinence,and incidence of complications were compared between groups.RESULTS After treatment,the VIP and 5-hydroxytryptamine levels in the observation group were lower than those in the control group(P<0.05).The motilin level was higher than that in the control group(P<0.05).Postoperative anal incontinence was better in the observation group than in the control group(P<0.05).The incidence of complications in the observation group was 6.67%,which was significantly lower than that in the control group(21.67%;P<0.05).CONCLUSION Acupuncture therapy has a positive effect on the rehabilitation of anal function after low-tension rectal cancer surgery;it can effectively help to improve the serum indices of patients,avoid the occurrence of anal incontinence,and reduce the incidence of complications.Popularizing and applying it will be valuable.

牛CART基因核心启动子鉴定及转录调控分析

旨在筛选牛CART基因核心启动子区并鉴定调控CART表达的转录因子,探究其转录调控机制。本研究采集3头健康母牛下丘脑组织,提取基因组DNA,通过PCR扩增、测序获得牛CART启动子序列,EMBOSS、MethPrimer、New PLACE数据库分析启动子结构特征;构建4个包含不同截短长度的CART启动子报告基因载体,双荧光素酶报告基因活性检测鉴定核心启动子区;应用DNA pull down结合质谱分析(n=3),功能聚类及结合位点预测分析筛选核心启动子区候选转录因子;构建转录因子过表达载体,转染至293T细胞,分析转录因子对牛CART核心启动子区的转录调控功能(n=3)。结果表明,牛CART基因-1200 bp~+22 bp区域存在CpG岛和TATA box、CAAT box等顺式作用元件;构建的4个截短启动子报告基因载体均具有转录起始活性,-292 bp~+22 bp片段转录起始活性最强,为牛CART基因核心启动子区;转录因子RFX5、CREB、RFX1、JUND、TEAD4、TFAP2D、RELA可与牛CART基因核心启动子区特异性结合;进一步研究证实RFX5、RFX1、TEAD4抑制CART转录(P<0.01),CREB与RELA激活CART转录(P<0.001)。本研究成功扩增获得牛CART启动子区域,筛选鉴定-292 bp~+22 bp为牛CART基因的核心启动子区,证实RFX5、RFX1、TEAD4为CART转录抑制因子,CREB、RELA为CART转录激活因子。研究结论为丰富牛下丘脑CART表达调控机制,深入研究CART调控卵泡发育机理提供依据。

Sporting Usefulness Potential of Nine Local Taxa of Grasses for Lawns in the Agro-Ecological Zone with Bimodal Rainfall in Cameroon

The Cameroonian flora has a very high biodiversity that remains largely unexplored. It contains many grasses that can be used for sports lawns, but are currently underutilized. In order to contribute to the improvement of the quality of sports lawns, nine local grass taxa from the agro-ecological zone with bimodal rainfall in Cameroon were evaluated for their potential for sporting use in natural lawns. The method of the Study and Control Group for Varieties and Seeds was used to evaluate the sports lawn characteristics of the taxa. The resistance to trampling and pulling, the density of the lawn, and the aesthetic appearance, which are factors in calculating the sports index, were monitored at two sites, including the experimental space at the University of Yaounde 1 in the Center region and Kagnol 2 in the East region, from January 2017 to January 2020. The monthly lawn characteristic data allowed for the differentiation between the means and the determination of the sports index of the taxa compared to commercialized lawn varieties. The sports index of the evaluated taxa varied: Cynodon dactylon (6.989), Eleusine indica (6.338), Sporobolus natalensis (6.301), Cynodon cf Cynodon dactylon (6.257), Eragrostis tremula (5.939), Sporobolus pyramidalis (5.583), Agrostis rupestris (5.335), Axonopus compressus (4.991), and Digitaria sp. (4.544). These results show that these grass taxa have potential for sporting use in lawn mixtures at different levels of sports disciplines.

Code Reviewer Intelligent Prediction in Open Source Industrial Software Project

Currently, open-source software is gradually being integrated into industrial software, while industry protocolsin industrial software are also gradually transferred to open-source community development. Industrial protocolstandardization organizations are confronted with fragmented and numerous code PR (Pull Request) and informalproposals, and differentworkflowswill lead to increased operating costs. The open-source community maintenanceteam needs software that is more intelligent to guide the identification and classification of these issues. To solvethe above problems, this paper proposes a PR review prediction model based on multi-dimensional features. Weextract 43 features of PR and divide them into five dimensions: contributor, reviewer, software project, PR, andsocial network of developers. The model integrates the above five-dimensional features, and a prediction model isbuilt based on a Random Forest Classifier to predict the review results of PR. On the other hand, to improve thequality of rejected PRs, we focus on problems raised in the review process and review comments of similar PRs.Wepropose a PR revision recommendation model based on the PR review knowledge graph. Entity information andrelationships between entities are extracted from text and code information of PRs, historical review comments,and related issues. PR revisions will be recommended to code contributors by graph-based similarity calculation.The experimental results illustrate that the above twomodels are effective and robust in PR review result predictionand PR revision recommendation.

Interfacial morphology evolution in directionally solidified Al-1.5%Cu alloy

The solid-liquid interracial morphology evolution was investigated in directional solidification （DS） of Al-1.5%Cu alloy （mass fraction）. The results show that the solidified microstructural evolution is gradual other than sharp, and the microstructure patterns are interesting and diversiform at the pulling rate ranging from 30 μm/s to 1500 μm/s. Indeed, dendrite to cell transition follows this sequence： dendrites→→banded cellular dendrites→elongated cells and part of dendrites→main elongated cells and little dendrites. Moreover, the present microstructure is not normal microstructure as we saw before. Further, according to the experimental phenomenon, the dendrite to cell transition was studied theoretically. Dendrite tip shape is an important parameter to characterize the dendrite to cell transition. As the dendrite to cell transition is far from equilibrium solidification, non-equilibrium solidification is taken into consideration in calculation. Finally, it is speculated that the dendrite to cell transition would occur at the minimum tip radius.

掺锰KLN晶体的生长及性能的研究

Potassium Lithium Niobate (KLN) crystal belongs to tetragonal system and is ferroelectric crystal,which point group is 4mm and space group is P4bm .The melt point of KLN crystal is about 1050℃.KLN crystal possesses tungsten bronze structure and its structure general expression is(A 1) 2(A 2) 4C 4(B 1) 2(B 4) 8O 3.KLN crystal is full fill up tungsten bronze structure crystal,in which the light of transmission band is 0.35-5.0μm.KLN crystal has excellent electro optical and nonlinear property and is superior double frequency crystal material for blue light.KLN crystal also is acoustic surface wave and photorefractive material.KLN crystal cracks easily during it grows.But when KLN crystal is doped in Mn 2O 3 to grow Mn∶KLN crystal,the crystal crack is reduced and the photorefractive property of the crystal is enhanced.KLN system is solid solution system and not congruent composition.The compounding ratio of Mn∶KLN crystal which we grew is 47.4mol% Nb 2O 5,17.3mol% Li 2CO 3,35mol% K 2CO 3 and 0.1mol% Mn 2O 3.The purity of Nb 2O 5,Li 2CO 3,K 2CO 3 and Mn 2O 3 is all 99.99%.Czochralski method was used to grow Mn∶KLN crystal.The technical parameters include the axial direction temperature gradient,the crystal growth rate and the rotation rate.Mn∶KLN crystal with 6mm×8mm×20mm size was grown in the condition that the axial direction temperature gradient is 30℃-40℃,the crystal growth rate is 0.5mm/h and the rotation rate is 10-15r/min.KLN crystal is one dimension ferroelectrics crystal.It has a paraelectrics ferroelectrics phase transition point curie point.So the crystal needs to be polarized in manual work.The direct current field was used to force the self polarization Ps in the same direction and the crystal turn to single domain.Before polarization,the c face needs to be confirmed exactly.The platinum pole was pasted to the two surfaces of c face and the direct current voltage about 220V was added the pole as the polarization outer electrical field.The polarization temperature is 460℃ and the polarization current density is 2mA/cm 2 .The thermal analyzer in TAS100 model was used to analyze the thermal expansion character of Mn∶KLN crystal and ascertain that the curie point of Mn∶KLN crystal is 435℃.It can be seen from the measurement result that the change of thermal expansion rate of Mn∶KLN crystal is smaller than that of pure KLN crystal. So doping Mn 2O 3 in KLN crystal to grow Mn∶KLN crystal can reduce the crack of the crystal.

Zn∶In∶Fe∶LiNbO_3晶体的生长及其二波耦合效应的研究

ZnO(4mol%),In 2O 3(1mol%)and Fe 2O 3(0.05mol%)were doped in LiNbO 3 and Czochralski method was used to grow Zn∶In∶Fe∶LiNbO 3 crystal.The diameter of the crystal we grew is 30mm.The technology parameter we took is that the axial temperature gradient is 40℃/cm,the growth rate is 1mm/h, the rotation rate is 15-25r/min,the temperature of polarization is 1220℃ and the current density of polarization is 5mA/cm 2.The wafer dimension is 10mm×10mm×3mm and was covered in Li 2CO 3 powder to reduce.The reduction temperature is 500℃ and reduction time is 30 hours. OH - stretch vibration transmission spectra were measured by Fourier infrared spectrophotometer. There are two absorption peaks in OH - spectra of Zn∶In∶Fe∶LiNbO 3,in which one is at 3534cm -1 (2.83μm) and the other is at 3505cm -1 (2.85μm).The peak at 2.85μm is far lower than that at 2.83μm. Because of the threshold effect of Zn 2+ and In 3+ ,the peak at 2.83μm is generated and the peak at 2.85μm is related with Fe 3+ .In LiNbO 3 only doped with Fe,Li + site is taken place by Fe 3+ .When doping Zn 2+ and In 3+ in high concentration,these two ions take place Nb that is at Li site and Fe 3+ substitutes for Nb 5+ at the same time.The interaction between Fe 3+ and OH - make the OH - peak shift to 2.85μm.

普鲁兰多糖的粘度性质研究

研究了温度、pH、变性剂(脲)及金属离子(Mg2+、Cu2+、Fe2+、Ca2+、Mn2+、Na+)对普鲁兰(Pull)溶液粘度的影响,发现在10～20℃时,Pull溶液的粘度略有增加,在20～70℃,其粘度基本保持不变;溶液的pH对Pull的粘度影响很小;变性剂会使Pull的粘度略有增加;而金属离子对Pull溶液的粘度有显著影响,其中Mg2+使Pull溶液的粘度增加最大,Na+的影响最小。分子量的测定表明,其粘度的增加是由于其分子量的增大造成的。

两种水稻GDP解离抑制蛋白基因的分离及特征分析

以Rho家族成员OsRacD为诱饵 ,采用酵母双杂交体系 ,分离到两种与OsRacD互作的水稻RhoGDP解离抑制蛋白的基因 ,分别命名为OsRhoGDI1和OsRhoGDI2 .酵母体内结合和GSTpulldown分析结果显示 ,OsRhoGDI1和OsRhoGDI2与野生型和组成型激活的OsRacD都能结合 ,且不依赖GDI的N端部分序列 ;GDI和Rho的结合具有一定的特异性 .两种GDI在水稻根、地上组织和幼穗等多种组织和器官都有表达 ,但在表达特征上存在明显差异 .研究证实 ,在水稻中存在着调控RhoGTPases的GDP解离抑制蛋白基因家族 。

Push/Pull和CONWIP/Pull生产控制模式对比分析

针对制造企业如何有效地进行生产控制的问题,对Push/Pull、CONWIP、CONWIP/Pull生产控制模式作了详细介绍,对比分析了Push/Pull、CONWIP/Pull两种混合生产控制,对混合生产控制方法做出了研究展望。

蛋白质相互作用实验技术的最新进展

蛋白质相互作用的研究,是揭示生物体正常生长发育及其应对各种生物或(和)非生物胁迫的分子机制及其调控网络的重要途径。文章综述了近年来发展起来的研究蛋白质相互作用的常用实验性方法,如酵母双杂交系统、串联亲和纯化、免疫共沉淀、GST Pull-down、双分子荧光互补、荧光共振能量转移、表面等离子共振分析,介绍了其原理、发展进程,并分析了其优缺点。

基于Android C2DM服务的云端推送研究与实现

在基于Android平台上的应用中,保持其Android终端与服务器端的数据同步十分关键。传统的信息pull方法实现了保持Android终端与服务器端数据同步,它需要每个Android终端定时的去服务器上扫描,查看服务器是否发布或有更新数据,与最新的数据同步,需要客户端大量的网络流量和手机电量。针对pull方法的不足,文中实现了一种基于An-droid的C2DM服务来进行消息的云端推送的方法。运用该方法成功地让客户端接收到了服务器端发送过来的数据更新消息,大量地节省了Android客户端的网络流量和手机电量。

GST Pull-down实验鉴定NF-κB相互作用多肽

目的体外鉴定NF-κB相互作用多肽与p50和p65间的相互作用。方法首先构建GST-作用多肽融合蛋白的原核表达载体pET-42a/polypeptide及NF-κB p50和p65亚基保守结构域的原核表达载体pET22b/p50和pET22b/p65,并在大肠杆菌E.coliBL-21中诱导表达,后进行GST pull-down实验验证多肽与NF-κB p50和p65的结合效应。结果经诱导表达获得了可溶性的GST-多肽融合蛋白和具有DNA结合活性的p50p、65蛋白,GST pull-down实验证实3条多肽与p50发生特异地相互作用。结论证实3条多肽在体外能与p50发生物理性的相互作用,这为获得靶向NF-κB的功能拮抗多肽工作奠定了基础。

PreIQ及其突变体载体构建表达纯化和活性鉴定

目的构建心肌L型钙通道片段PreIQ及其突变体与谷胱甘肽转移酶(GST)重组的融合蛋白原核表达载体并进行表达纯化和活性鉴定。方法将PreIQ及其突变体的cDNA插入pGEX-6p-1质粒载体后,转化大肠杆菌BL21感受态细胞,大量培养并利用异丙基硫代-β-D半乳糖苷(IPTG)诱导PreIQ及其突变体的GST融合蛋白表达,GS-4B beads进行分离纯化。采用SDS-PAGE鉴定目的蛋白分子质量和相对纯度。采用Bradford方法测定纯化后蛋白浓度。采用pull-down法检测纯化后蛋白的活性。结果 PreIQ及其突变体融合蛋白得到了大量表达;纯化的PreIQ及其突变体具有较高的纯度;纯化后蛋白能与钙调蛋白(CaM)结合,具有生物活性。结论本研究成功构建了PreIQ及其突变体融合蛋白原核表达载体,获得具有生物活性的PreIQ及其突变体融合蛋白,为深入研究PreIQ的生能学功能奠定基础。