A fiber-optic fluorometer for measuring phytoplankton photosynthesis parameters

A fluorometer model designed at the Institute of Automatics and Control Processes and intended for measuring phytoplankton photosynthesis parameters and chlorophyll-a concentration in sea water in vivo in a wide range of depths, is described. The feature of the fluorometer is the use of fiber-optic sensors for measuring fluorescence, temperatures, and depths. The structure and design of the fluorometer is described. The measurement results of photosynthesis parameters, obtained in a series of expeditions in the Sea of Japan in autumn 2012, are discussed.     

特纳10-AU现场荧光仪吸收光谱测定套件的研发及应用

针对天然水体中溶解有机物吸收和荧光无法同时测定的问题,对特纳10-AU现场荧光仪进行了改进。通过对仪器样品室的改造,利用反射镜改变光路,设置衰减片和降低光电倍增管电压控制光通量,在不破坏原有仪器结构下实现其吸收光谱测定功能。改进后的仪器测定重铬酸钾和高锰酸钾水溶液的灵敏度较Cary100紫外可见分光光度计分别高约1倍和0．5倍,相对标准偏差分别为3．93％、2．12％（n=7）。实现了腐殖酸水溶液的吸收和荧光的同时测定,检出限分别为0．306mg／L和0．0104mg／L。实验证明改进后的10-AU现场荧光仪可用于水体中溶解有机物吸收光谱的测定,操作简便,测定结果可靠。     

10-AU便携式现场荧光仪走航测定水中CDOM

10-AU便携式现场荧光仪以其稳定的性能、简单的操作和独特的现场检测功能,得到该研究领域国际同行的认可,并在所属研究领域发挥着积极的作用。本文介绍10-AU便携式现场荧光仪在水环境参数检测中的应用。结合在国内首次将该仪器用于近岸水域水样中CDOM的大尺度连续走航在线测定工作的实际,讨论该仪器在使用过程中的一些问题、经验和体会。     

生物体液荧光在位检测仪的设计

本文介绍了一种能直接检测生物体液中荧光物质的荧光检测仪,该荧光仪带有一光纤探头,可直接插入动物体内接收荧光信号,实现在位测量。为了提高荧光接收本领,探头中输入输出用同一光纤。利用计算机的并行口输出脉冲以控制步进电机而带动色散棱镜转动,并实时采集光谱信号且实时显示。通过对光说进行分析,可以推测许多生物量。     

PHYTO-PAM对浮游植物中叶绿素的分类测定

为提高藻类生物监测的时效性,拟使用PHYTO—PAM叶绿素荧光仪对浮游植物中的叶绿素进行分类测定。本文通过PHYTO—PAM与传统方法的比较,说明前者可在短时间内对水样中的蓝藻、绿藻、硅藻／甲藻自动分类并快速测定水样叶绿素a浓度。在测定以蓝藻、绿藻、硅藻、甲藻为优势种的水样时,该法测定结果精密度和准确度较好,与分光光度法无显著性差异。     

浸没式粉末硅藻土预涂覆微滤装置过滤性能研究

浸没式粉末硅藻土预涂覆微滤装置是一种新型自来水深度处理技术设备,利用粉末硅藻土形成滤膜实现表面精细过滤,提高过滤效果,可用于新建自来水厂深度处理及已建自来水厂的达标改造。本文阐述了浸没式粉末硅藻土预涂覆微滤装置的技术原理、装置结构及试验系统组成、试验流程。通过试验,本文得出浸没式粉末硅藻土预涂覆微滤装置的运行周期、对浊度、细菌、CODMn、藻类等水中杂物的处理效果。本文也探索了滤膜厚度,粉末硅藻土在线投加量过滤阻力值等过滤工艺参数,对大型市政自来水厂采用浸没式粉末硅藻土预涂覆微滤技术设计及应用有一定参考作用。     

Measurements of the nonlinear acoustic parameter of sea water via a device using reflected pulses

A method for measuring the nonlinear acoustic parameter of sea water and a device in the form of an immersed sonde are described. The method is based on the principle of registration of waves at the difference frequencies in water at consecutive reflections of high-frequency biharmonic acoustic pumping waves between the walls of a measuring cell. Some results obtained during vertical sounding of the upper layer of the sea to a depth of 100 m are presented.     

Wear and frictional performance of polymeric composites aged in various solutions

The aim of the present work is to investigate the effect of aging process on the wear and frictional characteristics of polyester composites based on oil palm fibres. Prepared samples of treated oil palm fibre reinforced polyester (T-OPRP) composite were immersed in different types of solutions (i.e. water, salt water, diesel, petrol and engine oil) for three years. The samples were then tested on a Pin on disc (POD) machine subjected to a polished stainless steel counterface under dry adhesive wear at different sliding distances (0-6.72 km). Scanning electron microscopy (SEM) was used to observe the damage features on the worn surfaces. Results revealed that aging process has pronounced influence on the adhesive wear and frictional behaviour of the T-OPRP composite. Immersing the samples in water and salt water demonstrated poorest wear performance as compared to the ones immersed in engine oil and diesel. This was mainly due to the higher viscosities of engine oil and diesel solutions as compared to the rest.     

基于PSoC的紫外荧光法水中藻类检测系统设计

近年来我国多次大面积爆发湖泊水华,利用紫外荧光法可快速检测水中叶绿素的含量,进而监测水体中富营养化程度。本文依据叶绿素荧光检测的基本原理,设计和完成基于可编程片上芯片(PSoC)的荧光检测系统。提取湖泊中的水样,经丙酮溶液萃取后制成不同标准浓度的叶绿素溶液,实验测定其对应荧光值。实验证明,本系统可较好地应用于水质中叶绿素的检测。     

多波长LED阵列光源叶绿素荧光探测仪电路的单片机实现

构建了一种新的浮游植物分类检测仪器——多波长LED阵列光源叶绿素荧光探测仪,系统利用调制的多波长LED阵列作为激发光源,测量各个LED激发下总的叶绿素a的荧光强度信号以及水温、水深。介绍了仪器的原理,重点介绍了这个仪器的电路设计：以ADI公司的ADuC841作为微处理器,通过设计合理的光源调制电路,荧光峰值检测电路和数据的采集、处理与存储电路,实现了对浮游植物浓度进行快速、实时、原位和分类测量。系统采样速度快、精度高,而且直接利用电池供电,功耗极低。     

Application of the ultrasonic propagation imaging system to an immersed metallic structure with a crack under a randomly oscillating water surface

Ultrasound is widely used and studied to satisfy the increased demands of the Non-destructive evaluation (NDE) and testing of underwater structures. However, because of the large size and mass of underwater structures, such as submarines, ship hulls, or nuclear reactor pipe lines, it is difficult to inspect the structures during operation. This underwater NDE technology is challenging but could be highly beneficial because the time and cost of maintenance will be effectively reduced. We propose an NDE method for immersed structures using an ultrasonic propagation imaging system with a piezoelectric sensor. The underwater sensing capability of a piezoelectric sensor is experimentally demonstrated using an aluminum plate specimen. A piezoelectric sensor can compensate for the decreased signal amplitudes due to leaky waves that are generated on interfaces between structures and water, since water transmits signals better than air. Additionally, a piezoelectric sensor can be applied even if the water surface is oscillating. Using these properties, the laser induced guided Ultrasonic propagation imager (UPI) inspected a T-shaped steel structure with a 2-mm crack on the weld zone. The inspection was implemented in three cases: a specimen without water, a specimen immersed in water and a specimen immersed in water with a randomly oscillating surface. The crack was visualized and measured using the ultrasonic wave propagation imaging algorithm, the adjacent wave subtraction algorithm, and the variable time window amplitude mapping algorithm. In the case with a randomly oscillating water surface, the laser pulse was refracted randomly based on Snell’s law. This phenomenon may cause degradation of the inspecting results. However, a repeated scanning process and outlier elimination led to an improved signal-to-noise ratio such that it was able to detect the crack. These results demonstrate the possibility to apply the laser UPI to submerged structures even if the water surface is randomly oscillating.     

Laser NIR lifetime spectrometer with nanosecond time resolution

A laser lifetime spectrometer (fluorometer) for recording the luminescence kinetics in the range 950–1400 nm with a time resolution of 1 ns is described. The performance capabilities of the facility are demonstrated by an example of studying the near-IR luminescence of molecular singlet oxygen ¹O₂. The fluorometer allows measurements of quenched luminescence of ¹O₂ with a quantum yield of up to 6 × 10⁻⁹.     

A study on fatigue crack propagation mechanism of GFRP in synthetic sea water

This paper evaluates the fatigue fracture behavior of a chopped strand glass mat/polyester composite both in air and sea water. Bending fatigue (R=−1) was performed on dry and wet specimens, that is respectively in air and sea water. Where the pH concentration of sea water was controlled to 6.0, 8.2, 10.0 and the wet specimens were immersed in the sea waters for 4 months. Throughout the tests, fatigue cracks both in the dry and wet specimens, tested in the air or sea water, occurred at the beginning of the cycle, followed by either of two regions: one decreasing and the other increasing as the crack growth rate increases.     

Video fluorometer

Details of a unique computer controlled multichannel fluorometer are given. Features include: a novel optical system enabling simultaneous acquistion of excitation and emission data over broad spectral ranges, a highly sensitive silicon intensified target (SIT) vidicon detector, and a video interface to a minicomputer allowing data acquisition at the standard television rate.     

高分子材料3DP法三维打印坯的水浸法脱黏研究

以麦芽糊精粉末和聚乙烯醇粉末为黏结剂,采用3DP法三维打印制备得到高分子材料坯件,经过加热预熔合后,采用超声波清洗机进行水浸法脱黏,采用称重法和拉曼光谱分析检测黏结剂去除情况,研究了水温、超声振动和浸泡时间对脱黏效果的影响。结果表明,水温越高,脱黏效果越好;有超声振动时,可明显提高脱黏效率;浸泡时间越长,脱黏效果越好。得到本研究试样的两种较为理想的脱黏方案,即40℃水温超声振动下浸泡9 h和50℃水温超声振动下浸泡6 h。     

A wet stage modification to a scanning electron microscope.

A modification to the vacuum system of a JSM2 scanning electron microscope has enabled hydrated specimens to be placed inside the specimen chamber of the instrument and to be surronded by water vapour at a pressure up to approximately I 3-kPa (10 Torr). The surface topography was observed by detecting the backscattered electrons using a wide angle backscattered electron detector placed close to the specimen. The microscope was operated in the normal scanning mode which allowed the examination of the surface topography of the specimens, whilst still retaining the depth of focus which is a feature of the SEM. This modification has enabled a resolution of approximately 0.2 mum to be obtained from biological specimens partially immersed in water at temperatures just above 0 degrees C.     

Writing subwavelength-sized structures into aluminium films by thermo-chemical aperture-less near-field optical microscopy

An optical near-field at the tip of an atomic force microscope probe is utilised to pattern aluminium thin films on glass substrates by photo-thermally induced corrosion in water. Aluminium forms a thin passivating oxide layer when immersed into neutral water at room temperature. Owing to the high energy density of the near-field, the metal below the probe tip can be heated to 100°C due to absorption of the light, which then provokes breakdown of the passivation and metal corrosion. The localised near-field is generated by tip-induced enhancement of an evanescent field originating from a laser beam, that is totally internally reflected at the glass–aluminium–water interface. The process is governed by surface plasmons excited in the aluminium film by the evanescent waves and the field enhancement of the probe tip. Holes of 40 nm diameter and lines below 100 nm width have been written into a 20-nm-thick aluminium film. Applications of the scanning probe lithography process may include the one-step fabrication of point contacts or contact masks for near-field optical lithography and reactive ion etching.     

强磁防蜡器工艺改进措施

针对影响强磁防蜡器两个性能指标的关键要素进行分析，设计并制造了专用的模具和采用水浸式焊接新工艺，提高了产品性能，产品质量的稳定性有了可靠的保证，同时加工成本也有较大幅度的下降。     

Note: A scanning thermal probe microscope that operates in liquids

We have developed a scanning thermal probe microscope that operates in liquid environments. The thermal sensor is a fluorescent particle glued at the end of a sharp tungsten tip. Since light emission is a strongly thermally sensitive effect, the measurement of the particle fluorescence variations allows the determination of the temperature. No electrical wiring of the probe is needed. As a demonstrative example, we have measured the temperature map of a Joule-heated microheater immersed in a water∕glycerol solution. Both topographical and thermal images are obtained with a good sensitivity.     

Phase fluorometer for measurement of picosecond processes

Time-dependent fluorescence processes can be investigated using a phase fluorometer with variable frequency. The high cutoff frequency of 500 MHz leads to a time-resolving power of about 1 ps.