共查询到20条相似文献，搜索用时 31 毫秒
1.
本文介绍一种采用气敏传感器TGS203和专用集成电路FIC5401来实现气体检测的报警器。该报警器采用专用集成电路FIC5401，它是一个4位的微处理器，作为核心控制部件以形成符合传感器的间歇加热规范和要求的工作温度。本文将对报警电路、集成电路FIC5401温度补偿电路和各个电路的工作进行了分析和讨论。 相似文献
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A device and procedure have been developed for measuring tuber skin strength of Russet Burbank potatoes. Tests were designed to quantitatively measure the effects of: 1) various vine killing methods, 2) elapsed time between digging and testing, 3) tester tip hardness and 4) skin strength changes for three weeks following vine kill. Results show that no differences in skin strength can be detected between vine killing methods. Skin strength values of 2160 g-cm or greater are estimated to provide adequate resistance to harvest and handling damage. Location of the test area on the tuber influences results as well as does the elapsed time between digging and testing. Some commencai users find this testing device to be advantageous. 相似文献
3.
Three stratified clip methods for the estimation of herbage mass and its vertical distribution in grass swards were compared. The first method used a herbage-gripping device, which held a sample from a 2 × 9 cm area while it was harvested and cut into layers in the field. For the other two methods, turfs of herbage were dug and brought into the laboratory where areas defined by 10 × 10 cm or 2 × 9 cm quadrats were cut into layers. For the comparisons, two operators collected independent samples from a sward shortly before it was cut for silage, a sward grazed by cattle and a sward grazed by sheep.
The total mass of herbage dry matter collected depended on the method used, with the herbage-gripping device producing greater estimates than the turf quadrats in two of the swards. The different methods produced similar estimates of the vertical distribution of mass. The larger quadrat usually produced the least variable results, while the herbage-gripping device collected samples most quickly. There were also small differences between the estimates produced by different operators. It was concluded that because the herbage-gripping device was the most cost-effective it would often be the most appropriate method to use. However, when a higher level of precision per quadrat is required the large quadrat, following turf collection, would be more appropriate. 相似文献
The total mass of herbage dry matter collected depended on the method used, with the herbage-gripping device producing greater estimates than the turf quadrats in two of the swards. The different methods produced similar estimates of the vertical distribution of mass. The larger quadrat usually produced the least variable results, while the herbage-gripping device collected samples most quickly. There were also small differences between the estimates produced by different operators. It was concluded that because the herbage-gripping device was the most cost-effective it would often be the most appropriate method to use. However, when a higher level of precision per quadrat is required the large quadrat, following turf collection, would be more appropriate. 相似文献
4.
K.A.P. Siriwardena L.C.P. Fernando N. Nanayakkara K.F.G. Perera A.D.N.T. Kumara T. Nanayakkara 《Crop Protection》2010
Acoustic methods have been developed and used to detect insects in concealed habitats. The larvae of red palm weevil, Rynchophorus ferrugineus (Olivier), a serious pest of the coconut palm, Cocos nucifera L. feed on the soft tissues inside the stem and bud region. Detection of infested coconut palms in the early stages by the conventional method of checking for external symptoms is time consuming, labour intensive and costly. This paper describes the development of a portable and efficient acoustic device and its potential in detection of infested palms in the field. The device comprises a sensor to mount on the palm and to acquire the sounds of red palm weevil larvae, an electronic unit that processes the acquired sounds and a set of headphones to receive the output sound by the listener. It is light weight, user-friendly and powered by batteries. The highest accuracy of identifying infested palms was obtained when the palm was checked at four positions; either side of palm base and bases of the two lowermost leaves. The infested palms were detected with over 97% accuracy, while the probability of not detecting uninfested palms was over 92%. A second check increased the rate of accuracy. Many difficulties encountered with conventional methods could be overcome by the use of this device. 相似文献
5.
对品种的适应性是大豆育种专用排种器技术研究的关键,主要取决于大豆种子与排种盘型孔间的关系,因此,如何精准构建排种盘型孔参数关于大豆种子物理参数的数学模型具有非常重要的意义。本研究基于东农52大豆种子的物理参数,理论分析并确定其各种型孔充填状态的型孔均径比范围(1.43~1.87)及对应状态概率。建立了大豆小区育种插装式排种器的EDEM仿真模型,并以型孔均径比及充种倒角为试验因素,漏播率及重播率为试验指标,进行了二因素五水平二次回归通用旋转组合设计试验,建立了试验指标的数学模型,以优化型孔的最佳结构参数。结果表明:对漏播率,型孔均径比极显著(P0.01),充种倒角显著(0.01P0.05);对重播率,型孔均径比极显著(P0.01),充种倒角有一定影响(0.05P0.1)。在试验范围内,随型孔均径比的增大,漏播率减小及重播率增大,随充种倒角的增大,漏播率先减小后增大,重播率无变化。型孔最佳参数为型孔均径比1.64,充种倒角1.54 mm,此时,漏播率4.95%,重播率6.49%。验证试验结果表明:优化型孔的排种盘具有相对最佳的作业性能。该研究为其它作物排种器型孔的设计研究提供了参考。 相似文献
6.
W. Aimrun M. S. M. Amin Desa Ahmad M. M. Hanafi C. S. Chan 《Paddy and Water Environment》2007,5(2):113-121
On-the-go EC sensor is a useful tool in mapping the apparent soil electrical conductivity (ECa) to identify areas of contrasting soil properties. In non-saline soils, ECa is a substitute measurement for soil texture. It is directly related to both water holding capacity and cation exchange capacity
(CEC), which are key ingredients of productivity. This sensor measures the ECa across a field quickly and gives detailed soil features (1-s interval) with few operators. Hence, a dense sampling is possible
and therefore a high resolution ECa map can be produced. This paper presents experiences in acquiring detailed ECa information that is correlated to other soil properties for precision farming of rice. The study was conducted on a 9 ha
rice plot in MARDI Seberang Prai Station, Penang. The VerisEC3100 was pulled across the field in a series of parallel transects
spaced about 15 m apart. The study showed that shallow and deep ECa had high correlation and shallow ECa had significant correlation to P. Deep ECa had significant correlation to P, K and yield. Regression equations showed that N and P could be estimated by shallow ECa but, pH, K and yield were better estimated by deep ECa. This study was able to draw some basic ideas of nutrient zone management according to precision farming technique. 相似文献
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花生中的红衣色素是一种可食用的天然色素,除具有一定的药理保健作用外、其还以安全可靠、毒副作用小、色调自然等优点而作为添加剂广泛应用于现代食品工业,因此研究花生红衣色素的提取有重要的意义遥本文对花生红衣在不同溶剂、提取时间、温度、料液比和浸提次数等条件下分别进行色素的提取,通过单因素试验确定了花生红衣色素提取的最佳工艺条件。 相似文献
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Care for diabetic wounds remains a significant clinical problem. The present study was aimed at investigating the effect of skin gelatin from Chum Salmon on defective wound repair in the skin of diabetic rats. Full-thickness excisional skin wounds were made in 48 rats, of which 32 were diabetes. The diabetic rats were orally treated daily for 14 days with skin gelatin from Chum Salmon (2 g/kg) or its vehicle. Sixteen non-diabetic control rats received the same amount of water as vehicle-treated non-diabetic rats. Rats were killed to assess the rate of wound closure, microvessel density (MVD), vascular endothelial growth factor (VEGF), hydroxyproline (HP) contents in wound tissues and nitrate in plasma and wound tissue at 7 and 14 days after wounding. Skin gelatin-treated diabetic rats showed a better wound closure, increased MVD, VEGF, hydroxyproline and NO contents and a reduced extent of inflammatory response. All parameters were significant (P < 0.05) in comparison to vehicle-treated diabetic group. In light of our finding that skin gelatin of Chum Salmon promotes skin wound repair in diabetic rats, we propose that oral administration of Chum Salmon skin gelatin might be a beneficial method for treating wound disorders associated with diabetes. 相似文献
10.
采用多点试验中同一试验点的两个重复分于同一类的可能性大小,也即重复识别率作指标,以系统聚类法中常用的最短距离法对按统一方案分布于南方稻区72个氮、磷、钾有重复肥料试验进行分类,确定了肥料试验处理产量、肥效方程常数项及偏回归系数项重复间欧氏距离的变幅、分类指标及其阈值。水稻肥料试验分类效果以肥效方程常数项分类最好,重复识别率两年平均值达73.45%;若按肥效方程氮、磷、钾一次项进行分类,重复识别率一般在65%以上,能基本满足肥料试验结果的分类要求。 相似文献
11.
基于LC谐振传感器的包装茶叶含水率无损检测 总被引：1，自引：0，他引：1
介绍一种基于经典电路理论的无线、无源LC谐振传感器设计,并将其用于包装茶叶含水率的快速、无损检测。所提出的LC谐振传感器实质上是一个印刷在湿敏绝缘衬底上的单一平面电容和螺旋电感构成的谐振电路,通过将传感器放置在茶叶包装袋内,由于包装袋内湿度变化会引起平面电容的电容值变化,进而导致传感器的并联谐振频率变化,利用连接在包装袋外部含水率测量仪上的感应线圈远程检测传感器的谐振频率值,即可通过谐振频率的变化间接确定包装茶叶的含水率;实验结果表明了该检测方法合理可行,与国标方法相比较,测量结果无明显偏差,解决了包装茶叶含水率快速、准确、无损检测的难题。 相似文献
12.
Hyeong Rok Yun Sang Woo Ahn Bomin Seol Elena A. Vasileva Natalia P. Mishchenko Sergey A. Fedoreyev Valentin A. Stonik Jin Han Kyung Soo Ko Byoung Doo Rhee Jung Eun Seol Hyoung Kyu Kim 《Marine drugs》2021,19(11)
Atopic dermatitis (AD) is a chronic inflammatory skin disease in which skin barrier dysfunction leads to dryness, pruritus, and erythematous lesions. AD is triggered by immune imbalance and oxidative stress. Echinochrome A (Ech A), a natural pigment isolated from sea urchins, exerts antioxidant and beneficial effects in various inflammatory disease models. In the present study, we tested whether Ech A treatment alleviated AD-like skin lesions. We examined the anti-inflammatory effect of Ech A on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like lesions in an NC/Nga mouse model. AD-like skin symptoms were induced by treatment with 1% DNCB for 1 week and 0.4% DNCB for 5 weeks in NC/Nga mice. The results showed that Ech A alleviated AD clinical symptoms, such as edema, erythema, and dryness. Treatment with Ech A induced the recovery of epidermis skin lesions as observed histologically. Tewameter® and Corneometer® measurements indicated that Ech A treatment reduced transepidermal water loss and improved stratum corneum hydration, respectively. Ech A treatment also inhibited inflammatory-response-induced mast cell infiltration in AD-like skin lesions and suppressed the expression of proinflammatory cytokines, such as interferon-γ, interleukin-4, and interleukin-13. Collectively, these results suggest that Ech A may be beneficial for treating AD owing to its anti-inflammatory effects. 相似文献
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Atopic dermatitis (AD) is a chronic inflammatory skin disease. Juniperus Chinensis heartwood has been known to have an excellent antibacterial and anti-inflammatory effect. This study examined the potential of the methanol extract of the Juniperus Chinensis heartwood as a natural dye with an efficacy for the treatment of atopic dermatitis. In an attempt to examine the effect of the Juniperus Chinensis heartwood extract, a skin lesion such as that of AD was induced in the NC/Nga AD mice model by topical administration. DNCB (2.4-dinitrochlorobenzene) was used to induce such AD-like skin lesions. The efficacy of the Juniperus Chinensis heartwood extract in the NC/Nga mice model was assessed by severity of skin lesion (NC mouse score), change in organ weight, serum IgE level, change in epidermal thickness, and mast cell count. The Juniperus Chinensis heartwood extract improved such skin lesions in these NC/Nga mice, and decreased spleen weight and serum IgE level. The results of histopathologic examination revealed that the treatment with the Juniperus Chinensis heartwood extract decreased epidermal thickness and mast cell count. In conclusion, the suppressive effect of local administration of the Juniperus Chinensis heartwood extract verified its potential for application as a natural dye with an efficacy of treatment for atopic dermatitis. 相似文献
15.
This study was aimed to analyze chemical components of essential oil from whole fruits of Citrus unshiu and its fragrance and to investigate its bio-functions as a skin-health finishing agent to textiles. The components of oil and fragrance were respectively determined by using both FT-IR and GC-MS. As for bioactive properties, the skin irritancy from oil was assessed by Kawai’s method and antimicrobial activity was evaluated by MIC (minimum inhibitory concentration). As results, major component of the citrus oil was identified as D1-limonene which also constituted most of its fragrance. Any skin reaction was not found by Kawai’s method, which means that the citrus oil does not cause irritancy on human skin. As for microbial activity against S. aureus, K. pneumoniae, and P. acnes, the lowest minimum inhibitory concentrations were 0.50 mg/ml, 0.28 mg/ml, and 0.23 mg/ml, respectively. These results suggest that Citrus unshiu’s essential oil could be utilized as a bioactive natural finishing agent for skin-healthcare textiles. 相似文献
16.
Virgilio Julius P. Manzano Jr. Masaru Mizoguchi Shoichi Mitsuishi Tetso Ito 《Paddy and Water Environment》2011,9(2):249-255
A demonstration study on Information Technology (IT) field monitoring was conducted in a rice field under the System of Rice
Intensification (SRI) environment in Shinshiro City, Aichi Prefecture, Japan. The IT system used in this study consisted of
an intelligent sensor node web-server that is equipped with in situ camera and sensor networks for agrometeorological, soil,
and plant growth monitoring. Dynamic changes in soil moisture, water level, agrometeorological, and environmental conditions
were measured and monitored. With this precision farming set-up, understanding and easy assessment of the salient field conditions
and phenomena such as cyclic soil wetting and drying as well as critical crop growth stages were made possible. Based on the
findings of the demonstration experiment, the system was effective, reliable, and efficient in monitoring soil moisture parameters
and agrometeorological information in remote rice field environment. The actual field conditions were captured well by a combination
of images, numerical, and graphical data sets. With this precise information, the frequency of irrigation was found to be
every 7 days. The rice field was irrigated up to a moisture level of 0.592 m3/m3 (~600 mV) and allowed to be depleted to a moisture level of 0.417 m3/m3 (~400 mV). With this alternate drying and wetting method (AWD), a 25.71% of irrigation water was saved. In this study, rice
production was made more scientific and more reliable. Hence, the use of IT field monitoring system represented a viable medium
for the realization of better rice productivity which leads to the ethic of sustainable agriculture. 相似文献
17.
以邻苯二胺为功能单体,伏草隆为模板分子,在金电极表面通过电聚合的方法制备对伏草隆具有特异识别能力的分子印迹膜,利用门效应原理对伏草隆进行测定。采用电化学手段对分子印迹膜进行表征,对试验条件进行优化并且考察传感器的抗干扰能力。结果发现:传感器对伏草隆具有很好的特异识别能力,在试验的最优条件下,伏草隆浓度在5×10-9~2×10-7 mol/L范围内与电流的响应信号呈良好的线性关系;方法的检出限达到1.7×10-9 mol/L。该传感器应用于实际样品的检测,加标回收率为103.0%~105.6%,结果令人满意。 相似文献
18.
For soil water and solute transport research, time domain reflectometry (TDR) has been commonly used since its introduction to soil research in 1980 by Topp and his colleagues. Although TDR seems to be very versatile for laboratory and field experiments, it requires modest user skills for accurate measurements and the instrument itself is still expensive. A new soil moisture and electrical conductivity (EC) sensor was recently developed at a reduced cost. The new sensor independently measures soil water content, and soil bulk electrical conductivity using frequency phase-shift techniques, and soil temperatures using a thermistor. We evaluated the new sensor for measurements of water content, and EC using three different sensors in variably saturated soils. There was little deviation among the units for water content measurement except at near saturation. Separate exponential curves provided good calibrations for all the soils used in the full range of water content between air-dry and saturation. In saline water up to 54 mS m?1, the mV output in the EC measurement mode was linearly related to solution EC. Although slopes were quite similar among the three sensors, the intercepts differed from the manufacturer’s calibration. The calibrations for volumetric water content and electrical conductivity provided by the manufacturer were not good enough for any use. The temperature effect on volumetric water content could be negligible or easily compensated with a simple formula. Little EC dependency of the sensor on volumetric water content was observed. 相似文献
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为改善快速测定铅电化学传感器的稳定性、灵敏度和安全性,本研究利用SDBS（十二烷基苯磺酸钠）分散羟磷灰石替代惯用的有毒汞修饰丝网印刷碳电极,并滴加Nafion膜增加稳定性,构建了一种快速测定痕量铅的新型电化学传感器。采用方波溶出伏安法,支持电解质为0.1mol/L HAc-NaAc,在优化的羟磷灰石量、测试底液pH、富集时间等工作条件下,得到2~300μg/L线性范围内的铅标准曲线,检测限为0.46µg/L（S/N=3）;其重复性好,连续5次测定后的相对标准偏差为4.59%;本方法与ICP-MS法对茶叶样本的测定结果相近。研究出的快速检测铅的新型电化学传感器具有较好的稳定性、灵敏度和安全性,且测定结果准确,具有一定的应用潜力。 相似文献