Applications of cold atmospheric plasmas(CAPs)in agriculture:a brief review and the novel development of a radio-frequency CAP jet generator for plant mutation

Cold atmospheric plasmas(CAPs)have shown great applicability in agriculture.Many kinds of CAP sources have been studied in agricultural applications to promote plant growth and cure plant diseases.We briefly review the state-of-the-art stimulating effects of atmospheric-pressure dielectricbarrier-discharge(AP-DBD)plasmas,after the direct or indirect treatment of plants for growth promotion and disease control.We then discuss the special demands on the characteristics of the CAP sources for their applications in plant mutation breeding.An atmospheric and room temperature plasma(ARTP)jet generator with a large plasma irradiation area,a high enough concentration of chemically reactive species and a low gas temperature is designed for direct plant mutagenesis.Experimental measurements of the electrical,thermal and optical features of the ARTP generator are conducted.Then,an ARTP-P(ARTP for plant mutagenesis)mutation breeding machine is developed,and a typical case of plant mutation breeding by the ARTP-P mutation machine is presented using Coreopsis tinctoria Nutt.seeds.Physical and agricultural experiments show that the newly-developed ARTP-P mutation breeding machine with a large irradiation area can generate uniform CAP jets with high concentrations of chemically reactive species and mild gas temperatures,and have signiflcant mutagenesis effects on the Coreopsis tinctoria Nutt.seeds.The ARTP-P mutation breeding machine may provide a platform for systematic studies on mutation mechanisms and results for various plant seeds under different operating conditions in future research.

THE APPLICATION OF WEINSTEIN-CHIEN′S METHOD——THE UPPER AND LOWER LIMITS OF FUNDAMENTAL FREQUENCY OF RECTANGULAR PLATES WITH EDGES ARE THE MIXTURE OF SIMPLY SUPPORTED PORTIONS AND CLAMPED PORTIONS

In this paper, the method of relaxed boundary conditions is applied to rectangular plates with edges which are a sort of the mixture of simply supported portions and clamped portions, so that the lower limit of fundamental frequency of such plates is evaluated. A kind of polynomial satisfying the displacement boundary conditions is designed, os that it is enabled to evaluate the upper limit of fundamental frequency by Ritz' method. The practical calculation examples solved by these methods have given satisfactory results. At the end of this paper, it is pointed out that the socalled exact solution of such plates usually evaluated by the force superposition method is essentially a kind of lower limit of solution, if the truncated error of series which occurs in actual calculation is considered.

Application of High-frequency Electrosurgical Scalpel and Methylene Blue Staining in Endonasal Dacryocystorhinostomy

Purpose: To evaluate the application of a high-frequency electrosurgical scalpel and methylene blue staining in the endonasal dacryocystorhinostomy.Methods: This retrospective study included 37 patients(43eyes).undergoing endonasal dacryocystorhinostomy in our hospital between 2011 and 2013 using methylene blue staining of the lacrimal sac and a high-frequency electrosurgical scalpel for cutting nasal mucosa, intraoperative stanch, and fixation of lacrimal sac and nasal mucosal flaps. Surgical efficacy, intraoperative challenges, and corresponding handling methods were evaluated and summarized.Results: Among 43 eyes, 42 were successfully cured(97.7%)and the symptoms in 1 eye were improved(2.3%). Total efficacy rate was 100%. All surgeries were successfully performed. No severe intraoperative complications were observed.Conclusion: A high-frequency electrosurgical scalpel, combined with methylene blue staining of the lacrimal sac, is efficacious for nasal mucosal cutting, intraoperative stanch, and fixation of mucosal flap by cauterization, which significantly alleviates intraoperative complications and enhances surgical success rate. It deserves widespread application in clinical practice.

Analysis of cerium substitution in Co-Sr based spinel ferrites for high frequency application

Spinel ferrites exhibit exceptional magnetic properties,making them a distinctive class of magnetic materials.The sol-gel technique was utilized for the synthesis of spinel ferrites with the chemical formula Co_(0.6)Sr_(0.4)Ce_(x)Fe_(2-x)O_(4). Following that,a comprehensive X-ray diffraction analysis unveiled the crystalline cubic structure of the synthesized materials.Through the utilization of the M-H loop approach,the ferromagnetic attributes of ferrites were assessed,and the assimilation of rare earth elements led to substantial enhancements in saturation magnetization,remanence,and coercivity.Spinel ferrites with a high concentration of rare earth elements have improved direct current resistivity and activation energy.The logarithm of a material's resistance increased from 5.29 to 8.12 Ω·cm as cerium is added.With a change in the amount of cerium,the activation energy goes up from 0.19 to 0.29.By changing the frequency from 5.5 to 9.5 GHz,the dielectric characteristics were determined.As the frequency goes up,the dielectric constant goes down.Spinel ferrites that have been made better in every way can be used in high-frequency applications.

Effects of Water and Nitrogen Application on Photosynthetic Characteristics of Flag Leaves and Grain Yield of Wheat

[Objective] The aim was to provide a scientific and rational water,nitrogen model for achieving high yield,high quality of wheat and water and fertilizer saving.[Method] Under the field conditions,the effects of irrigation frequencies and N application times on net photosynthetic rate（Pn）,chlorophyll fluorescence parameters of flag leaf and yield of wheat was studied.[Result] The differences on Pn,chlorophyll fluorescence parameters Fv/Fo,Fv/Fm,qP,qN of flag leaves and yield of wheat among different irrigation times had reached a significant level,and the difference between treatment without irrigation and irrigation treatments were relatively large;the difference on Pn,Fv/Fo,Fv/Fm,qP and qN between treatments of basal application of N fertilizer and N application（40%）in returning green stage was not significant,however,the photosynthetic parameters and yield of two treatments were obviously lower than that of N application（40%）in jointing stage or booting stage.[Conclusion] The effects of irrigation frequencies and N application times showed significant interaction effects on photosynthetic characteristics of wheat flag leaves and yield,in which W2N4 treatment combination was best.

Novel Frequency Hopping Sequences Generator Based on AES Algorithm

A novel frequency hopping(FH) sequences generator based on advanced encryption standard(AES) iterated block cipher is proposed for FH communication systems.The analysis shows that the FH sequences based on AES algorithm have good performance in uniformity, correlation, complexity and security.A high-speed, low-power and low-cost ASIC of FH sequences generator is implemented by optimizing the structure of S-Box and MixColumns of AES algorithm, proposing a hierarchical power management strategy, and applying ...

Plus Shape Slotted Fractal Antenna for Wireless Applications

Fractal antennas are characterized by space filling and self-similarity properties which results in considerable size reduction and multiband operation as compared to conventional microstrip antenna. This paper outlines a multiband antenna design based on fractal concepts. Fractal antennas show multiband behavior due to self-similarity in their structure. The plus shaped fractal antenna has been designed on a substrate of dielectric constant €r = 4.4 and thickness 1.6mm. The proposed antenna is characterized by a compact size and it is microstrip feed fractal patch of order 1/3. It is observed that the antenna is radiating at multiple resonant frequencies. The resonant frequency is reduced from 2.2 GHz to 900 MHz after I & II iterations respectively. Thus considerable size reduction of 81.77% & overall bandwidth of 12.92% are achieved. The proposed antenna is simulated using the method of moment based commercial software (IE3D) and it is found that simulated results are in good agreement with the experimental results.

RFID Applications: Prospects and Challenges in Bangladesh

Radio frequency identification (RFID) is an emerging technology, radio wave communication between a microchip and an electronic reader, consisting of data gathering, distribution, and management systems that has the ability to identify or scan information for remoting recognition of objects with increased speed and accuracy. An attempt has been made to know how using of RFID technology helps to improve services and business process efficiency in public and private sectors of Bangladesh. With this aim, we have conducted extensive literature survey. At the end of this attempt, we have come to the conclusion that the potential use of this technology includes RFID chipped passports, human implants, item-level tagging, inventory tracking and access control systems. RFID technology is at its early stage of adoption in Bangladesh with a few business applications and pilot studies. However, when tags begin to be associated with individuals, privacy is threatened. RFID is a new type of threat to personal information and must be treated as such;indeed, it must be recognized that existing privacy legislation is not adequate. This paper also explores some current and emerging applications of RFID in Bangladesh and examines the challenges including privacy and ethical issues arising from its use, as well as addressing potential means of handling those issues.

某医院2019—2022年麻醉药品使用情况分析

目的对某医院2019—2022年麻醉药品使用情况进行分析,以期加强麻醉药品的规范管理,保障麻醉药品在临床中合理使用。方法调取该医院信息系统中2019—2022年麻醉药品的使用数据,包括药品的名称、规格、数量、使用金额,计算各品规销售金额占比、用药频率(DDDs)、限定日费用(DDC)、使用金额排序与DDDs的排序比(B/A)。并对2019—2022年该医院麻醉药品的处方点评结果进行汇总分析。结果4年间,该院麻醉药品共使用18个品规;使用金额总体呈增长趋势,且每种麻醉药品的使用金额每年排序相对稳定;DDDs稳居前三位的是吗啡缓释片(30 mg)、芬太尼贴剂(8.4 mg)和芬太尼贴剂(4.2 mg);DDC相对稳定,前3名分别是羟考酮注射液、注射用瑞芬太尼(1 mg)和注射用瑞芬太尼(2 mg);所有麻醉药品的B/A处于0.1~3.5之间。该院麻醉药品处方医嘱点评合格率在97%以上。结论该院麻醉药品的临床使用基本合理,用药符合医院学科特色,能够全面、认真地贯彻并落实麻醉药品相关法律法规,符合麻醉药品的安全性、有效性、经济性和适宜性原则。

一种可模态分离的高分辨率频率-波数法及其工程应用

高分辨率频率-波数法是通过计算F-K谱从能量角度获取主导表面波频散信息的一种常用方法。然而,由于高模态瑞利波的能量通常低于基阶波的能量,因此难以分离多模态频散信息。本文通过建立多模态瑞利波模型,并讨论其相速度、波数和能量特性,提出一种可模态分离的高分辨率频率-波数法。通过增强F-K谱上的高模态能量,提取其多模态能量的局部极值,进而得到相速度点,对所有相速度点进行概率分布并拟合,得到多模态频散曲线。工程应用表明,改进的高分辨率频率-波数法能够较好地还原多模态瑞利波信息,通过对提取的多模态频散曲线进行联合反演,可以得到与工程钻孔结果匹配较好的剪切波速度结构。

一种分布式会议管理系统的设计与实现

基于现代会议管理的需求,设计和实现一种C/S和B/S混合部署的会议管理系统。包括会议管理服务中心和若干个会议现场,会议管理服务中心包括数据服务器、应用服务器、Web服务器、通信网关和出口路由器;会议现场包括若干个便携式电脑、RFID(Radio Frequency Identification)读卡器、二维码阅读器、信息显示发布设备、现场WLAN设备及用户终端。使用RIA(Rich Internet Application)技术优化了B/S界面,应用RFID对会议过程中的细节进行监控,借助SAAS(Software as a Service)模式实现会议管理按需配置和快速部署。该系统显著提高了会议管理效率。

岳阳市市树市花的城市绿地应用现状与发展

课题组通过资料查阅、网络调查、街头调查、现场勘察等方法对岳阳市主城区居住绿地、单位绿地、道路与广场绿地、公园绿地和湖滨绿地等绿地的本市市树市花的应用现状和生长势进行了调查研究。调研结果显示,杜英和栀子花在岳阳市城市建设中的应用频率较低、生长状态较差,杜英日灼病严重,栀子花黄化病严重。基于此,应加强市树市花的应用推广,改善市树市花的种植环境,加强市树市花后期的培育管理,以实现城市风貌和人文环境的进一步优化。

基于声学多普勒频差法的自动测流设备应用

实现流量在线监测是提高水文测报现代化水平的重要前提,目前水文自动测流技术研究中多普勒频差原理广泛应用,自动测流设备适用程度较高,能够实现自动化监测,但不同设备又都有其局限性与应用范围,具体自动测流方案的选择要充分考虑测流断面的特性,同时必须根据历史数据与资料进行充分论证和精准分析。结合石梁河水文站测流断面,从技术方面对垂直式声学多普勒流速剖面仪和侧扫雷达设备进行充分论证和精准分析。

飞轮储能辅助火电一次调频技术与应用

大规模新能源并网造成电网频率波动增大,使得火电机组调频任务繁重、动作频繁,加剧了机组老化,飞轮储能辅助火电机组调频能提升机组的调频性能。论述了飞轮储能辅助机组一次调频原理,分析了飞轮储能的出力特性,结合世界最大容量飞轮储能,提出了飞轮储能满功率辅助机组一次调频的控制策略,并应用于我国第一套飞轮储能辅助火电机组一次调频的调试中,验证了控制策略有效性。现场测试结果表明,飞轮储能辅助火电机组一次调频性能良好,采取所提一次调频策略后该机组一次调频动作合格率提升21.26%,一次调频积分电量贡献指数提升3.45倍。飞轮储能辅助火电机组一次调频模式对解决此类问题具有一定指导意义。

不同水氮配施对北疆膜下滴灌棉花生长发育的影响

研究灌水频率、灌溉定额和施氮量对膜下滴灌棉花生长、产量和水分利用效率的影响,探明灌水频率、灌溉定额和施氮量的最优组合模式,为膜下滴灌棉花的水氮管理提供科学合理的灌溉技术依据.试验设置3个灌水频率:7 d(D1),10 d(D2),13 d(D3),2个灌溉定额:4400 m^(3)/hm^(2)(W1),3300 m^(3)/hm^(2)(W2)和2个施氮水平:300 kg/hm^(2)(F1),225 kg/hm^(2)(F2),共12个处理,每个处理3次重复.结果表明:D1的株高较D2,D3分别降低2.90%和7.96%;叶面积指数与灌水频率呈正相关,D1的叶面积指数较D2,D3分别提高1.96%和7.28%;蕾铃生物量和地上部生物量之比随灌水频率的增加而增加;D1的产量较D2和D3分别增加3.84%和11.76%;W1的产量较W2增加5.56%;F1的产量较F2增加13.49%;D1的水分利用效率WUE较D2和D3分别增加2.75%和9.80%;W2的WUE较W1增加22.71%;F1的WUE较F2增加11.37%.说明D1水平避免棉花过度生长,提高棉花群体发展,增强群体光合作用和物质生产能力,确保地上部生物量的生殖生长,并且随着灌溉定额和施氮量的增加,棉花株高、叶面积指数和地上部生物量也显著增加,从而提高棉花产量.此外,高频减水能够保持根层水分的适宜程度,满足棉花水分需求,高氮能够满足棉花生长的需氮量,减少水分蒸发损失,提高水分利用效率.所以,综合考虑棉花产量和水分利用效率,得出灌水频率7 d,灌溉定额3300 m^(3)/hm^(2),施氮量300 kg/hm^(2)为较优管理模式.

施氮量和施氮频次对野牛草种子产量和氮肥利用效率的影响

为探究野牛草(Buchloe dactyloides(Nutt.)Engelm.)种子产量生产的最佳施氮量和施氮频次,本研究于2023年在河北涿州开展田间试验,采用随机区组设计,以不施肥为对照,以施氮量和施氮次数为试验因素,其中施氮量设置6个水平(60,90,120,150,180,210 kg·hm^(-2)),施氮频次设置1次和2次。结果表明:随施氮量的增加,株高差值、生殖枝数、种子产量和氮肥农学利用率(Nitrogen Agronomic Efficiency,NAE)均呈先增后减的趋势;相同施氮量条件下,分2次施肥比1次施肥显著提高了(P<0.05)种子产量与NAE,其增幅分别为2%~65%和11%~159%。根据施氮量、施氮频次与野牛草和NAE的回归模型分析,将总施氮量为165.50 kg·hm^(-2)分两次施入时,能够获得最佳种子产量。本研究为河北地区野牛草的高产制种及肥料的高效管理提供参考依据。

基于数字检测的磁通门电流传感器

传统的自激式磁通门电流传感器通常基于平均电流法测量电流,结构复杂且测量带宽和响应时间均受滤波器截止频率的限制。文中基于占空比采样的数字检测法设计了一款面向复杂漏电流测量的传感器,使用单片机直接测量激磁信号占空比,并通过数字算法完成信号的解调与处理。文中的传感器采用开环设计,节省了滤波电路与AD转换器,降低了成本。实验表明:该传感器的带宽和响应时间性能均优于基于平均电流法的传感器。

聚氨酯涤纶复合人工血管顺应性研究

目的分析不同应用环境对聚氨酯涤纶复合人工血管顺应性的影响。方法通过改变测试中的频率和压力模拟人工血管不同应用环境,对3种不同直径的聚氨酯涤纶复合人工血管在恒定压力不同频率,以及恒定频率不同压力下的顺应性进行测试,使用t检验分析测试结果的差异性。结果本研究中使用的3种直径的聚氨酯涤纶复合人工血管,在恒定压力不同频率的测试中,顺应性测试值均随着频率的增大而减小(P<0.05);在恒定频率不同压力的测试中,顺应性测试值随着压力的增大而减小(P<0.05)。结论聚氨酯涤纶复合人工血管的顺应性结果明显受到应用环境的影响,并且这种影响呈规律性变化。在人工血管的生产、质控以及临床使用中应充分考虑预期使用部位的特性,以提高临床使用过程中人工血管与人体的适配性。

A Selective‑Response Hypersensitive Bio‑Inspired Strain Sensor Enabled by Hysteresis Effect and Parallel Through‑Slits Structures

Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into one flexible strain sensor remains a huge challenge.Herein,inspired by the hysteresis strategy of the scorpion slit receptor,a bio-inspired flexible strain sensor(BFSS)with parallel through-slit arrays is designed and fabricated.Specifically,BFSS consists of conductive monolayer graphene and viscoelastic styrene–isoprene–styrene block copolymer.Under the synergistic effect of the bio-inspired slit structures and flexible viscoelastic materials,BFSS can achieve both hypersensitivity and highly selective frequency response.Remarkably,the BFSS exhibits a high gage factor of 657.36,and a precise identification of vibration frequencies at a resolution of 0.2 Hz through undergoing different morphological changes to high-frequency vibration and low-frequency vibration.Moreover,the BFSS possesses a wide frequency detection range(103 Hz)and stable durability(1000 cycles).It can sense and recognize vibration signals with different characteristics,including the frequency,amplitude,and waveform.This work,which turns the hysteresis effect into a"treasure,"can provide new design ideas for sensors for potential applications including human–computer interaction and health monitoring of mechanical equipment.