基于光谱学和ARM的番茄叶绿素检测仪的开发

为了更加方便、简捷、快速的对温室番茄叶绿素含量进行检测,利用光谱分析技术,开发了一种用于预测温室番茄叶片叶绿素含量的新型作物长势仪。仪器选择527 nm和762 nm两个波长作为特征波长。由一个“Y”型光纤,两个硅光电池,一个信号处理单元,中心处理器及友好的人机交互界面组成。由番茄叶片反射回来的反射光经过“Y”型光纤到达硅光电池的表面,硅光电池可以将此光信号转换成电信号。然后经过信号处理单元的放大滤波转换成可以经CPU处理的电压信号。根据测量得到的光谱反射率可以计算出番茄叶片的光谱系数,再根据光谱系数预测     

基于虚拟仪器技术的风机性能自动测试系统

针对我国风机性能检测多以手工为主，存在试验手段落后，劳动量大和测试结果不准确等缺点，采用先进的虚拟仪器技术，将传感器技术、计算机技术和测试技术结合起来，建立了基于虚拟仪器技术的风机性能自动测试系统，实现了试验数据的自动采集、风机转速的自动调节、风机运行工况的自动控制、试验数据的正确处理及性能曲线的自动绘制。整个系统具有界面友好、操作方便、功能齐全等优点。试验结果表明本系统增加了试验过程的稳定性，避免了人为的读数误差、计算误差以及相关数据不能同时记录所引起的试验结果偏差，提高了测试精度和试验效率。可广泛应用于科研院所和风机生产厂家，具有较高的推广应用价值。     

Bursting tension of medium and large canine arteries sealed with ultrasonic energy or suture ligation

OBJECTIVE: To compare bursting tension of arteries > or =3 mm in diameter sealed with ultrasonic energy (UE) with arteries ligated with suture. STUDY DESIGN: Experimental, nested factorial design. SAMPLE POPULATION: Vascular segments from canine cadavers. METHODS: Arterial segments (12) were collected from each of 16 canine cadavers and equally divided into 2 groups based on vessel diameter (medium, 3.0- < 4.5 mm; large, 4.5 - < or =6.0 mm). Arterial specimens (3) from each group were sealed with either UE (Harmonic Scalpel, HS, power level 3) or suture ligation. The mean bursting pressure and tension were determined and compared. RESULTS: Bursting tension was significantly higher (P< .0001) for sutured arteries than UE-occluded arteries, irrespective of size. Bursting tension was significantly higher (P=.0013) for medium than large UE-occluded arteries, whereas there was no difference associated with size for ligated arteries. UE energy failed to seal 1 medium artery and 7 large arteries. Compared with normal blood pressure, bursting pressures were 3.5 times greater for sutured arteries irrespective of size, 1.8 times greater for medium UE-occluded arteries, and approached normal blood pressure for large UE-occluded arteries. CONCLUSION: At the power level tested, UE should not be used to seal arteries > 4.5 mm in diameter. Suture provided an optimal seal for arteries < or =6.0 mm in diameter. CLINICAL RELEVANCE: Use of UE to occlude arteries during laparoscopic surgery is advantageous because only 1 instrument is required to simultaneously cut and coagulate tissue, but care should be exercised where large arteries might be encountered.     

Validation of the Sysmex XT‐2000iV hematology system for dogs,cats, and horses. II. Differential leukocyte counts

Background: The Sysmex XT‐2000iV is a laser‐based, flow cytometric hematology system that stains nucleic acids in leukocytes with a fluorescent dye. A 4‐part differential is obtained using side fluorescence light and laser side scatter. Objective: The purpose of this study was to validate the Sysmex XT‐2000iV for determining differential leukocyte counts in blood from ill dogs, cats, and horses. Methods: Blood samples from diseased animals (133 dogs, 65 cats, and 73 horses) were analyzed with the Sysmex XT‐2000iV (Auto‐diff) and the CELL‐DYN 3500. Manual differentials were obtained by counting 100 leukocytes in Wright‐stained blood smears. Results: Leukocyte populations in the Sysmex DIFF scattergram were usually well separated in equine samples, but were not as well separated in canine and feline samples. Correlation among the Sysmex XT‐2000iV, CELL‐DYN 3500, and manual counts was excellent for neutrophil counts (r ≥.97) and good for lymphocyte counts (r ≥.87) for all three species. Systematic differences between the 3 methods were seen for lymphocyte and monocyte counts. The Sysmex reported incomplete differential counts on 18% of feline, 13% of canine, and 3% of equine samples, often when a marked left shift (>10% bands) and/or toxic neutrophils were present. Eosinophils were readily identified in cytograms from all 3 species. Neither the Sysmex nor the CELL‐DYN detected basophils in the 7 dogs and 5 cats with basophilia. Conclusions: The Sysmex XT‐2000iV automated differential leukocyte count performed well with most samples from diseased dogs, cats, and horses. Basophils were not detected. Immature neutrophils or prominent toxic changes often induced errors in samples from cats and dogs.     

虚拟仪器技术在现代农业生产中的应用

随着科学技术的发展,由于虚拟仪器具有传统仪器不可比拟的优点而在农业生产中得到广泛的应用。介绍了虚拟仪器的概念、特点、结构、软件开发平台以及在农业生产中的应用实例,对于提高农业生产效率具有一定的指导意义。     

基于LabVIEW的液压冲击器测试系统的设计

为了简化液压冲击器性能检测方式,降低测试成本,基于LabVIEW软件和虚拟仪器开发了一个自动化测试系统。对测试系统的硬件和软件进行了设计,实现了数据采集、存储、分析和通信功能。对某型号的液压冲击器进行实验测试,通过采集的压力和流量信号得到了冲击频率和冲击能两个性能参数。进行对比试验,分析了输入流量对性能参数的影响。实验证明,该系统具备一定的可行性和可靠性。     

Chlorophyll fluorescence: A review of its practical forestry applications and instrumentation

The practical utility of chlorophyll fluorescence to forestry applications is reviewed. Major subjects include a review of past applications, sampling protocols, important fluorescence features, and instrumentation. Applications including the study of various stress effects, seasonal effects, and comparative sun/shade leaf physiology are provided. Chlorophyll fluorescence has been used mainly in applied research, rather than directly in operational forestry, but work has begun in this area. Sampling protocols include the selection and treatment of samples before assessment, and control of environmental conditions during assessment. Instrumentation is evaluated based on accuracy, versatility, ease of operation, and cost. Chlorophyll fluorescence ranks high among stress detection tests in forestry applications, because it is rapid, reliable, non‐destructive, quantitative, diagnostic, and the physiological basis of the assessment is understood.     

Comparison of home monitoring methods for feline urine pH measurement

Background — Monitoring of urine pH, often done in the patient's home, is essential for proper clinical treatment and management of conditions such as urolithiasis. Objective — The purpose of this study was to assess the agreement in pH readings between a standard laboratory method and methods readily available for home monitoring. The influence of refrigerated storage on urine pH was also examined. Methods — Urine samples were obtained by cystocentesis from 40 clinically healthy cats, and pH was measured within 2 hours of collection. Each sample was evaluated using pH paper, urinalysis reagent strip, 2 brands of portable pH meters (Chek‐Mite, Corning, Corning, NY, USA; and Checker 1, Hanna Instruments, Woonsocket, RI, USA), and a standard laboratory benchtop pH meter. Urine samples were refrigerated, and a second pH reading was obtained with the laboratory benchtop meter after 24 hours. The degree of agreement was assessed among the different methods, with the laboratory benchtop pH meter as the reference method. Results — The closest agreement was obtained with the Chek‐Mite portable pH meter and least agreement with the Checker 1 portable pH meter, which had a constant negative bias of 0.31 units due to expiration of the electrode. As expected, pH paper and reagent strips had poor and intermediate agreement, respectively. The reagent strip method had a negative bias of 0.12 units when compared with the benchtop pH meter and wide disagreement at the low pH end. The reagent strip did not agree strongly with the reference method; only 50% of values were within 0.25 pH units of each other. The difference in pH between 0 hours (6.57 ± 0.54) and 24 hours of refrigeration (6.61 ± 0.53) was not considered clinically significant. Conclusion — Portable pH meters are excellent for monitoring urine pH at home as long as attention is given to electrode maintenance. Urine can be collected at home and kept refrigerated, and pH may be measured reliably within 24 hours using the reference method or a portable pH meter.     

Measurement of ionized calcium in canine blood samples collected in prefilled and self-filled heparinized syringes using the i-STAT point-of-care analyzer

BACKGROUND: Heparinized syringes are commonly used with point-of-care analyzers (eg, i-STAT) to measure ionized calcium (iCa(2+)); however there is little information about the validity of their use in canine patients. OBJECTIVE: To examine the suitability of prefilled (40 IU heparin/mL) and self-filled (150 IU heparin/mL) heparinized syringes for iCa(2+) measurements using the i-STAT analyzer. METHODS: Forty-seven blood samples were collected from 41 canine patients. Two milliliters of blood were collected into a 2-mL nonanticoagulated (NA) syringe, a commercially available preheparinized (PH) syringe (dry calcium-balanced lithium heparin, 40 IU/mL), and a 2-mL self-filled heparinized (SH) syringe (liquid sodium heparin, 150 IU/mL). iCa(2+) was measured in the sample using the i-STAT analyzer and a wet-reagent analyzer (KoneLab 30i) used as the reference instrument. Data were analyzed using paired t-tests, Pearson correlation coefficient, and Bland-Altman difference plots. RESULTS: There was no significant difference between the results obtained from NA and PH syringes using the i-STAT analyzer, and the correlation was excellent (r =.97). The i-STAT values from the SH syringes (mean, 1.07 mmol/L) were significantly lower (P<.001) than those from the NA syringes (mean, 1.38 mmol/L). iCa(2+) was significantly higher with the i-STAT analyzer than with the KoneLab analyzer for both the PH (mean i-STAT, 1.38 mmol/L vs mean KoneLab, 1.30 mmol/L) and SH (mean i-STAT, 1.07 mmol/L vs mean KoneLab, 1.03 mmol/L) samples. CONCLUSIONS: Blood samples collected in the PH syringes used in this study can be used interchangeably with those collected in NA syringes for measuring iCa(2+) using the i-STAT analyzer. SH syringes with high-concentration heparin products (5000 IU/mL) are unsuitable for measuring iCa(2+) because they cause clinically significant underestimations. Although there was good correlation between the i-STAT and KoneLab analyzers, the results should be interpreted using analyzer-specific reference intervals.     

虚拟仪器技术及其在农业自动化中的应用

随着计算机技术的发展,基于标准个人计算机平台－－ＰＣ（包括ＰＣ／ＩＰＣ、Ｍａｃｉｎ－ｔｏｓｈ、工作站等）的虚拟仪器技术正成为测试测量与控制领域的重要应用工具。本文概括了虚拟仪器的系统构成及软件结构,简述了虚拟仪器在农业自动化领域的应用实例,介绍了用于精播机性能检测及苹果等级分选的虚拟仪器系统。