Removal of heavy metals from mine water by cyanobacterial calcification

The influence of different illumination intensities on cyanobacterial calcification induced removal of heavy metals from contaminated mine water was studied. Cyanobacterial calcification experiments were performed using a growth medium intended to simulate contaminated mine water. The results indicate that calcification can promote the removal of heavy metal ions. As the illumination intensity became stronger calcification rates increased and the removal of Zn2+ and Cd2+ became more obvious. When the illumination intensity was 10000 lux the removal of Pb2+ was the largest observed: stronger or weaker illumination reduced the amount of lead removed. The removal of three different heavy metals complies with an index function. For identical illumination intensities different ions were removed to different degrees.

Research Progress and Prospect on the Influencing Factors of Photosynthesis in Higher Plants

Photosynthesis plays an important role in organic synthesis, solar energy storage, and environmental protection. Photosynthesis is of great theoretical and practical significance. In this paper, the main factors affecting photosynthesis of higher plants, including light, water, temperature, CO2, mineral elements and plant genotypes, were briefly reviewed and summarized, and the development prospect of photosynthesis was prospected.

Research Progress of Dendrobium officinale Kimura et Migo

The effects of light on the quality and related genes of Dendrobium officinale were summarized, and the main chemical components and pharmacological effects of D. officinale were analyzed. The biomass accumulation of D. officinale is related to light quality and light intensity. Monochromatic light quality can make polysaccharide accumulate, and mixed light quality can promote cell proliferation and component accumulation of D. officinale. Under different light intensity, the polysaccharide content of D. officinale is different, and it changes with the change of light intensity. When a certain intensity is exceeded, the polysaccharide content decreases with the increase of light intensity. The chemical components of D. officinale are polysaccharides, alkaloids, amino acids, volatile components, etc. The analysis of the growth and components of D. officinale provides reference and basis for improving the quality and chemical components of D. officinale and promotes the research and development of related products of D. officinale.

Kiwifruit recognition at nighttime using artificial lighting based on machine vision

Most researches involved so far in kiwifruit harvesting robot suggest the scenario of harvesting in daytime for taking advantage of sunlight.A robot operating at nighttime can overcome the problem of low work efficiency and would help to minimize fruit damage.In addition,artificial lights can be used to ensure constant illumination instead of the variable natural sunlight for image capturing.This paper aims to study the kiwifruit recognition at nighttime using artificial lighting based on machine vision.Firstly,an RGB camera was placed underneath the canopy so that clusters of kiwifruits could be included in the images.Next,the images were segmented using an R-G color model.Finally,a group of image processing conventional methods,such as Canny operator were applied to detect the fruits.The image processing results showed that this capturing method could reduce the background noise and overcome any target overlapping.The experimental results showed that the optimal artificial lighting ranged approximately between 30-50 lx.The developed algorithm detected 88.3%of the fruits successfully.

The influence of environment temperatures on single crystalline and polycrystalline silicon solar cell performance

The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power has been carefully studied for the Si solar cells.The results show that one of the environment temperatures plays the major role,and the temperature dependence of device performance parameters is different for single crystalline and polycrystalline Si solar cells.Furthermore,the ambient air temperature builds a bridge for the comparison of the effect between the cell temperature and the illumination intensity on solar cell performance.Based on the experimental results,the reasons which cause the difference of the environment temperatures dependence are analyzed.

Segmentation algorithm for Hangzhou white chrysanthemums based on least squares support vector machine

In order to realize the visual positioning for Hangzhou white chrysanthemums harvesting robot in natural environment,a color image segmentation method for Hangzhou white chrysanthemum based on least squares support vector machine(LS-SVM)was proposed.Firstly,bilateral filter was used to filter the RGB channels image respectively to eliminate noise.Then the pixel-level color feature and texture feature of the image,which was used as input of LS-SVM model(classifier)and SVM model(classifier),were extracted via RGB value of image and gray level co-occurrence matrix.Finally,the color image was segmented with the trained LS-SVM model(classifier)and SVM model(classifier)separately.The experimental results showed that the trained LS-SVM model and SVM model could effectively segment the images of the Hangzhou white chrysanthemums from complicated background taken under three illumination conditions such as front-lighting,back-lighting and overshadow,with the accuracy of above 90%.When segmenting an image,the SVM algorithm required 1.3 s,while the LS-SVM algorithm proposed in this paper just needed 0.7 s,which was better than the SVM algorithm obviously.The picking experiment was carried out and the results showed that the implementation of the proposed segmentation algorithm on the picking robot could achieve 81%picking success rate.