PDMS系列助剂对10%甲维盐·氯虫苯甲酰胺悬浮剂防治草地贪夜蛾的增效作用

本研究采用室内毒力测定,助剂润湿铺展性能和田间防治效果评价研究了自研“PDMS”系列助剂(PDMS-01、PDMS-02、PDMS-03、PDMS-04)对10%甲维盐·氯虫苯甲酰胺悬浮剂防治草地贪夜蛾的增效作用。结果表明,PDMS系列助剂均可提高10%甲维盐·氯虫苯甲酰胺悬浮剂的毒力;7.5~17.5 g/L处理药液中添加助剂PDMS-01,药液润湿时间降低172.84~176.59 s,药液表面张力降低15.26~16.28 mN/m,玉米叶片正、背面静态接触角分别降低13.39°~24.12°和12.02°~27.56°;10%甲维盐·氯虫苯甲酰胺悬浮剂减量30%(21 g/667m^(2))并添加PDMS-01后,无人机施药对草地贪夜蛾的3 d和14 d田间防效分别可达76.62%和82.36%,与未减量处理(30 g/667m^(2))的防效差异不显著,与添加KQ-103、凯耀高航处理差异也不显著。助剂PDMS-01可显著改善10%甲维盐·氯虫苯甲酰胺悬浮剂药液的润湿铺展性能,减少药剂用量30%对草地贪夜蛾仍有较高防效,且速效性和持效性较好。

B-PDA-G/PDMS导热绝缘材料的制备及应用

为解决可穿戴电子设备中的散热问题,开发了一种高导热、高电绝缘性能的柔性热管理材料。通过选用氮化硼(BN)和石墨烯纳米片(GNPs)作为杂化导热填料,选取聚多巴胺(PDA)对杂化导热填料表面进行改性,然后与聚二甲基硅氧烷(PDMS)混合,采用热压法制备了不同填料质量分数的B-PDA-G/PDMS导热绝缘膜。利用傅里叶变换红外光谱、X射线光电子能谱和扫描电镜等表征手段,探究填料B-PDA-G与单一BN对PDMS膜导热性能的影响,并评估其在纺织领域的应用可行性。结果表明:B-PDA-G/PDMS膜在低填料质量分数时能够保持良好的力学性能、电绝缘性和导热性能。当BN与GNPs的质量比为5∶5,填料质量分数为30%时B-PDA-G/PDMS导热绝缘膜的面内导热率最高可达7.63 W/(m·K),相较于BN/PDMS和纯PDMS膜分别提高了2.8倍和27.3倍。B-PDA-G/PDMS作为封装材料应用于电热织物中表现出良好的导热和散热性能,表明其在柔性可穿戴设备和电子器件的热管理中应用潜力巨大。

PDMS@P25复合涂层织布的制备及其光催化与自清洁性能研究

为开发具有高效光催化自清洁功能的环境友好材料,通过将聚二甲基硅氧烷(PDMS)和二氧化钛(TiO_(2),P25)在乙酸乙酯中进行光接枝反应,制备得到复合涂层,然后喷涂于织布表面得到PDMS@P25织布。采用接触角仪、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱对其进行表征,探讨了PDMS、TiO_(2)及溶剂乙酸乙酯的用量对PDMS@P25织布超疏水性能的影响,考察了PDMS@P25织布对有机染料尼罗红的紫外光降解情况。结果表明:经60 min的紫外照射后,PDMS@P25织布可将水体中尼罗红完全降解。同时PDMS@P25织布在水体中可防止其表面被泥沙和有机染料甲基蓝污染。即使PDMS@P25织布表面被有机染料尼罗红及亚甲基蓝等污染,在太阳光下仍可使其降解,实现表面的自清洁。该PDMS@P25织布具有良好的机械性能及重复使用性能,经100次摩擦后,其性能无明显变化,在10次循环使用后仍然具有稳定的光催化性能。该材料的制备工艺简单,原料均对环境友好,成本低廉,符合大规模生产的需要。

PDM管理系统在服装制造业管理中的应用设计

为设计一种能够适用于服装制造业等劳动密集型企业的PDM管理系统,全面提高服装制造企业的综合管理水平,使企业各方面资源得到充分平衡调配和优化,达到全面提高企业市场竞争力的目的。设计了用于服装制造业的PDM管理系统的整体结构,即系统层面、数据交换处理层面和用户操作层界面。为保证系统安全性,设计了用户界面的结构和功能,详细介绍用户管理模块、技术图档管理模块、项目管理、流程管理模块、数据管理模块的功能和设计要点。对提高服装制造业整体管理水平和资源共享具有重要借鉴意义。

自主PDM数据建模方法及CAD集成

在国产工业软件崛起的大趋势下,中国舰船研究设计中心研发了自主PDM软件(海云PDM)。文中在海云PDM内核基础上提出了一套数据建模方法,并研发了图形化数据建模管理工具,通过与Rational Rose集成,使数据建模符合UML建模规范。同时,对海云PDM与国产三维CAD设计软件SPD进行了数据集成,分析了SPD各专业的数据层次结构及数据关系,实现了三维模型数据的存储与管理。

用于人体运动姿态监测基于IL@PDMS复合膜的摩擦电纳米发电机

摩擦电纳米发电机(TENG)在自供电可穿戴领域得到了广泛关注,通过材料修饰及制备工艺优化可实现对人体运动姿态的监测。研制了一种可用于人体运动姿态监测的TENG。一方面基于聚二甲基硅氧烷(PDMS)引入高介电性离子液体(IL),制备了IL@PDMS复合膜作为摩擦层,有效提高了摩擦电输出性能;另一方面,基于光刻微电子机械系统(MEMS)工艺及模板转移技术对IL@PDMS复合膜表面进行金字塔微结构修饰,实现摩擦效应的增强。与纯PDMS膜相比,IL的引入可使摩擦电输出电流及输出电压分别提高近4倍和6倍;另外,表面微结构的修饰也使得输出电流及输出电压分别提升近1.5倍和0.7倍。此外,当工作10 000个周期后,摩擦电输出性能仍保持不变。实验表明,当将IL@PDMS-TENG贴附在手指上时,实现了对人体运动姿态的有效监测。该研究为可穿戴人体运动传感器提供了新的技术路径及应用前景。

一种稳固的SiO_(2)/PDMS超疏水涂层的制备与稳定性研究

为了提高超疏水涂层的稳定性,构筑良好的界面是关键。本研究选取并制备了一种硅烷偶联剂改性的SiO_(2)纳米粒子(KH570-SiO_(2)),不仅能在聚二甲基硅氧烷(PDMS)分散液中良好分散,还能与PDMS链之间通过共价键链接;通过一步喷涂并完全固化后在玻璃表面构筑了一个改性SiO_(2)/PDMS超疏水涂层。利用扫描电镜、红外光谱、接触角等多种方式对改性SiO_(2)/PDMS涂层的形貌、结构及表面性质进行分析;并通过划格法、砂纸摩擦及胶带剥离实验对SiO_(2)/PDMS涂层的机械稳定性进行评价,最后探讨了涂层的稳定性机制。结果表明,改性SiO_(2)/PDMS涂层具有优异的超疏水性及机械稳定性。本研究为在材料表面构筑稳定的超疏水涂层提供了一种新方法,有望扩展材料在自清洁、防腐涂层、管道运输、油水分离等领域的应用。

面向PDM系统的数据存储结构优化技术

针对当前PDM系统在航空发动机制造业应用时无法高效处理海量数据存储吞吐的问题。文中提出了一种面向PDM系统的新型NoSQL分布式数据存储方案。该方案采用NoSQL数据库搭配Ceph分布式文件处理模块作为存储结构,并设计了基于Spark的MapSearch分步查询处理方法对数据进行读取和重构。实验测试结果验证了所提方案的可靠性,且与同类研究结果的数据相比,该存储方案进行数据写存和读取的时间分别减少了约20%及41.6%,传输速度提升了约70%,数据重构完整性的均值则为92%,为先进制造业的PDM系统存储结构设计提供了一种新思路。

基于PDMS的FPI高灵敏度温度与气压传感器

为了满足生产实际对高灵敏度温度和气压测量的需要,利用聚二甲基硅氧烷(PDMS)设计了一款新型的高灵敏度温度与气压光纤传感器。传感器由两个自由光谱范围相近的法布里-珀罗干涉仪(FPI)并联构成,两个FPI由单模光纤端面涂覆PDMS制成。由于PDMS具有优良的热敏性和弹性,基于PDMS的FPI具有较好的温度和压力敏感性。将两个自由光谱范围相近的FPI并联后,形成一个光学游标效应传感器,进一步放大了传感器灵敏度。实验结果表明传感器的温度和气压灵敏度分别为2.7893 nm/℃和15.5079 nm/MPa,而单个FPI的温度与气压灵敏度分别为0.2508 nm/℃和1.5181 nm/MPa,灵敏度被分别放大了11.1和10.2倍。该传感器结构简单、制作容易、尺寸紧凑、成本低、灵敏度高、重复性和稳定性好,具有一定的实际应用价值。

Design of Protograph LDPC-Coded MIMO-VLC Systems with Generalized Spatial Modulation

This paper investigates the bit-interleaved coded generalized spatial modulation(BICGSM) with iterative decoding(BICGSM-ID) for multiple-input multiple-output(MIMO) visible light communications(VLC). In the BICGSM-ID scheme, the information bits conveyed by the signal-domain(SiD) symbols and the spatial-domain(SpD) light emitting diode(LED)-index patterns are coded by a protograph low-density parity-check(P-LDPC) code. Specifically, we propose a signal-domain symbol expanding and re-allocating(SSER) method for constructing a type of novel generalized spatial modulation(GSM) constellations, referred to as SSERGSM constellations, so as to boost the performance of the BICGSM-ID MIMO-VLC systems.Moreover, by applying a modified PEXIT(MPEXIT) algorithm, we further design a family of rate-compatible P-LDPC codes, referred to as enhanced accumulate-repeat-accumulate(EARA) codes,which possess both excellent decoding thresholds and linear-minimum-distance-growth property. Both analysis and simulation results illustrate that the proposed SSERGSM constellations and P-LDPC codes can remarkably improve the convergence and decoding performance of MIMO-VLC systems. Therefore, the proposed P-LDPC-coded SSERGSM-mapped BICGSMID configuration is envisioned as a promising transmission solution to satisfy the high-throughput requirement of MIMO-VLC applications.

High photoelectric conversion efficiency and fast relaxation time of FA_(0.4)MA_(0.6)PbI_(3) applied in ultrafast modulation of terahertz waves

Active control of terahertz(THz)waves is attracting tremendous attentions in terahertz communications and active photonic devices.Perovskite,due to its excellent photoelectric conversion performance and simple manufacturing process,has emerged as a promising candidate for optoelectronic applications.However,the exploration of perovskites in optically controlled THz modulators is still limited.In this work,the photoelectric properties and carrier dynamics of FA_(0.4)MA_(0.6)PbI_(3)perovskite films were investigated by optical pumped terahertz probe(OPTP)system.The ultrafast carrier dynamics reveal that FA_(0.4)MA_(0.6)PbI_(3)thin film exhibits rapid switching and relaxation time within picosecond level,suggesting that FA_(0.4)MA_(0.6)PbI_(3)is an ideal candidate for active THz devices with ultrafast response.Furthermore,as a proof of concept,a FA_(0.4)MA_(0.6)PbI_(3)-based metadevice with integrating plasma-induced transparency(PIT)effect was fabricated to achieve ultrafast modulation of THz wave.The experimental results demonstrated that the switching time of FA_(0.4)MA_(0.6)PbI_(3)-based THz modulator is near to 3.5 ps,and the threshold of optical pump is as low as 12.7μJ cm^(-2).The simulation results attribute the mechanism of ultrafast THz modulation to photo-induced free carriers in the FA_(0.4)MA_(0.6)PbI_(3)layer,which progressively shorten the capacitive gap of PIT resonator.This study not only illuminates the potential of FA_(0.4)MA_(0.6)PbI_(3)in THz modulation,but also contributes to the field of ultrafast photonic devices.

提高PDMS项目法兰连接用螺栓长度的准确性

给出了如何提高三维设计软件PDMS螺栓长度的解决方案,主要通过螺栓连接元件建模标准化、对夹元件建模标准化、螺栓集标准化、螺栓长度标准化、螺栓等级标准化,从而确保PDMS项目螺栓长度的准确。

Enhancing quantum temporal steering via frequency modulation

Various strategies have been proposed to harness and protect space-like quantum correlations in different models under decoherence.However,little attention has been given to temporal-like correlations,such as quantum temporal steering(TS),in this context.In this work,we investigate TS in a frequency-modulated two-level system coupled to a zero-temperature reservoir in both the weak and strong coupling regimes.We analyze the impact of various frequency-modulated parameters on the behavior of TS and non-Markovian.The results demonstrate that appropriate frequency-modulated parameters can enhance the TS of the two-level system,regardless of whether the system is experiencing Markovian or non-Markovian dynamics.Furthermore,a suitable ratio between modulation strength and frequency(i.e.,all zeroes of the 0th Bessel function J_(0)(δ/?))can significantly enhance TS in the strong coupling regime.These findings indicate that efficient and effective manipulation of quantum TS can be achieved through a frequency-modulated approach.

Experimental realization of fractal fretwork metasurface for sound anomalous modulation

Natural creatures and ancient cultures are full of potential sources to provide inspiration for applied sciences.Inspired by the fractal geometry in nature and the fretwork frame in ancient culture,here we design the acoustic metasurface to realize sound anomalous modulation,which manifests itself as an incident-dependent propagation behavior:sound wave propagating in the forward direction is allowed to transmit with high efficiency while in the backward direction is obviously suppressed.We quantitatively investigate the dependences of asymmetric transmission on the propagation direction,incident angle and operating frequency by calculating sound transmittance and energy contrast.This compact fractal fretwork metasurface for acoustic anomalous modulation would promote the development of integrated acoustic devices and expand versatile applications in acoustic communication and information encryption.

Microwave electrometry with Rydberg atoms in a vapor cell using microwave amplitude modulation

We have theoretically and experimentally studied the dispersive signal of the Rydberg atomic electromagneticallyinduced transparency(EIT)Autler–Townes(AT)splitting spectra obtained using amplitude modulation of the microwave(MW)electric field.In addition to the two zero-crossing points interval△f_(zeros),the dispersion signal has two positive maxima with an interval defined as the shoulder interval△f_(sho),which is theoretically expected to be used to measure a much weaker MW electric field.The relationship of the MW field strength E_(MW)and△f_(sho)is experimentally studied at the MW frequencies of 31.6 GHz and 9.2 GHz respectively.The results show that△f_(sho)can be used to characterize the much weaker E_(MW)than that of△f_(zeros)and the traditional EIT–AT splitting interval△f_(m);the minimum E_(MW)measured by△f_(sho)is about 30 times smaller than that by△f_(m).As an example,the minimum E_(MW)at 9.2 GHz that can be characterized by△f_(sho)is 0.056 mV/cm,which is the minimum value characterized by the frequency interval using a vapor cell without adding any auxiliary fields.The proposed method can improve the weak limit and sensitivity of E_(MW)measured by the spectral frequency interval,which is important in the direct measurement of weak E_(MW).

Systemic modulation of skeletal mineralization by magnesium implant promoting fracture healing: Radiological exploration enhanced with PCA-based machine learning in a rat femoral model

The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and sustained local release of Mg ions on bone metabolism or repair,which should not be ignored when developing Mg-based implants.Thus,it remains necessary to assess the biological effects of Mg implants in animal models relevant to clinical treatment modalities.The primary purpose of this study was to validate the beneficial effects of intramedullary Mg implants on the healing outcome of femoral fractures in a modified rat model.In addition,the mineralization parameters at multiple anatomical sites were evaluated,to investigate their association with healing outcome and potential clinical applications.Compared to the control group without Mg implantation,postoperative imaging at week 12 demonstrated better healing outcomes in the Mg group,with more stable unions in 3D analysis and high-mineralized bridging in 2D evaluation.The bone tissue mineral density(TMD)was higher in the Mg group at the non-operated femur and lumbar vertebra,while no differences between groups were identified regarding the bone tissue volume(TV),TMD and bone mineral content(BMC)in humerus.In the surgical femur,the Mg group presented higher TMD,but lower TV and BMC in the distal metaphyseal region,as well as reduced BMC at the osteotomy site.Principal component analysis(PCA)-based machine learning revealed that by selecting clinically relevant parameters,radiological markers could be constructed for differentiation of healing outcomes,with better performance than 2D scoring.The study provides insights and preclinical evidence for the rational investigation of bioactive materials,the identification of potential adverse effects,and the promotion of diagnostic capabilities for fracture healing.

Radar Signal Intra-Pulse Modulation Recognition Based on Deep Residual Network

In view of low recognition rate of complex radar intra-pulse modulation signal type by traditional methods under low signal-to-noise ratio(SNR),the paper proposes an automatic recog-nition method of complex radar intra-pulse modulation signal type based on deep residual network.The basic principle of the recognition method is to obtain the transformation relationship between the time and frequency of complex radar intra-pulse modulation signal through short-time Fourier transform(STFT),and then design an appropriate deep residual network to extract the features of the time-frequency map and complete a variety of complex intra-pulse modulation signal type recognition.In addition,in order to improve the generalization ability of the proposed method,label smoothing and L2 regularization are introduced.The simulation results show that the proposed method has a recognition accuracy of more than 95%for complex radar intra-pulse modulation sig-nal types under low SNR(2 dB).

Interfacial Electronic Modulation of Dual-Monodispersed Pt–Ni_(3)S_(2) as Efficacious Bi-Functional Electrocatalysts for Concurrent H_(2) Evolution and Methanol Selective Oxidation

Constructing the efficacious and applicable bifunctional electrocatalysts and establishing out the mechanisms of organic electro-oxidation by replacing anodic oxygen evolution reaction(OER) are critical to the development of electrochemicallydriven technologies for efficient hydrogen production and avoid CO_(2) emission. Herein, the hetero-nanocrystals between monodispersed Pt(~ 2 nm) and Ni_(3)S_(2)(~ 9.6 nm) are constructed as active electrocatalysts through interfacial electronic modulation, which exhibit superior bi-functional activities for methanol selective oxidation and H_(2) generation. The experimental and theoretical studies reveal that the asymmetrical charge distribution at Pt–Ni_(3)S_(2) could be modulated by the electronic interaction at the interface of dual-monodispersed heterojunctions, which thus promote the adsorption/desorption of the chemical intermediates at the interface. As a result, the selective conversion from CH_(3)OH to formate is accomplished at very low potentials(1.45 V) to attain 100 m A cm^(-2) with high electronic utilization rate(~ 98%) and without CO_(2) emission. Meanwhile, the Pt–Ni_(3)S_(2) can simultaneously exhibit a broad potential window with outstanding stability and large current densities for hydrogen evolution reaction(HER) at the cathode. Further, the excellent bi-functional performance is also indicated in the coupled methanol oxidation reaction(MOR)//HER reactor by only requiring a cell voltage of 1.60 V to achieve a current density of 50 m A cm^(-2) with good reusability.

Nano-Au-decorated hierarchical porous cobalt sulfide derived from ZIF-67 toward optimized oxygen evolution catalysis:Important roles of microstructures and electronic modulation

Enhancing both the number of active sites available and the intrinsic activity of Co-based electrocatalysts simultaneously is a desirable goal.Herein,a ZIF-67-derived hierarchical porous cobalt sulfide decorated by Au nanoparticles(NPs)(denoted as HP-Au@CoxSy@ZIF-67)hybrid is synthesized by low-temperature sulfuration treatment.The well-defined macroporous-mesoporous-microporous structure is obtained based on the combination of polystyrene spheres,as-formed CoxSy nanosheets,and ZIF-67 frameworks.This novel three-dimensional hierarchical structure significantly enlarges the three-phase interfaces,accelerating the mass transfer and exposing the active centers for oxygen evolution reaction.The electronic structure of Co is modulated by Au through charge transfer,and a series of experiments,together with theoretical analysis,is performed to ascertain the electronic modulation of Co by Au.Meanwhile,HP-Au@CoxSy@ZIF-67 catalysts with different amounts of Au were synthesized,wherein Au and NaBH4 reductant result in an interesting“competition effect”to regulate the relative ratio of Co^(2+)/Co^(3+),and moderate Au assists the electrochemical performance to reach the highest value.Consequently,the optimized HP-Au@CoxSy@ZIF-67 exhibits a low overpotential of 340 mV at 10 mA cm^(-2)and a Tafel slope of 42 mV dec-1 for OER in 0.1 M aqueous KOH,enabling efficient water splitting and Zn-air battery performance.The work here highlights the pivotal roles of both microstructural and electronic modulation in enhancing electrocatalytic activity and presents a feasible strategy for designing and optimizing advanced electrocatalysts.

From VIB‑to VB‑Group Transition Metal Disulfides:Structure Engineering Modulation for Superior Electromagnetic Wave Absorption

The laminated transition metal disulfides(TMDs),which are well known as typical two-dimensional(2D)semiconductive materials,possess a unique layered structure,leading to their wide-spread applications in various fields,such as catalysis,energy storage,sensing,etc.In recent years,a lot of research work on TMDs based functional materials in the fields of electromagnetic wave absorption(EMA)has been carried out.Therefore,it is of great significance to elaborate the influence of TMDs on EMA in time to speed up the application.In this review,recent advances in the development of electromagnetic wave(EMW)absorbers based on TMDs,ranging from the VIB group to the VB group are summarized.Their compositions,microstructures,electronic properties,and synthesis methods are presented in detail.Particularly,the modulation of structure engineering from the aspects of heterostructures,defects,morphologies and phases are systematically summarized,focusing on optimizing impedance matching and increasing dielectric and magnetic losses in the EMA materials with tunable EMW absorption performance.Milestones as well as the challenges are also identified to guide the design of new TMDs based dielectric EMA materials with high performance.