高清性色生活片

<noframes id="7nx95"><address id="7nx95"><th id="7nx95"></th></address>
<th id="7nx95"><pre id="7nx95"></pre></th>

    <listing id="7nx95"><em id="7nx95"><dfn id="7nx95"></dfn></em></listing>
      <pre id="7nx95"></pre>

          <sub id="7nx95"></sub>

          Several core issues that agricultural lighting needs to solve

          The Guangya exhibition has come to an end. Agricultural lighting has become a focus of lighting, and more and more people have shown great interest in agricultural lighting. The market potential of agricultural lighting is huge. This is an undisputed conclusion. Yang Qichang, a researcher at the Institute of Agricultural Environment and Sustainable Development of the Chinese Academy of Agricultural Sciences, has pointed out that almost all areas of modern agriculture are closely related to artificial light! Especially in the crop industry (factory horticulture, urban agriculture, etc.), livestock and poultry farming (facilities farming), aquaculture (facility farming, fish attracting, etc.), planting (open field production, plant protection, etc.), other (edible fungi, Microalgae, etc.) Demand for artificial light sources is urgent. With regard to vegetables alone, we can make a simple assumption. In 2014, the total consumption of vegetables in China alone was about 130 billion yuan. If the next 5 years, 10 years, 20 years, 30% of vegetables are passed through agriculture. Lighting to achieve, then how big the market for this agricultural lighting can be imagined.

          However, as in the salon, Yang Haifeng, an expert of the National Science and Technology Key Specialist (Semiconductor Lighting Specialist), Ding Jianhua, Senior Vice President of Beijing Century Jinshajiang Venture Capital Management Co., Ltd., and Hong Bing, General Manager of China Optical Network and Agricultural Lighting Network As mentioned, the agricultural lighting market is huge, but based on the complexity of agricultural lighting, it is not easy to grow bigger and deeper. At present, the pain points of agricultural lighting still exist, and various explorations are still going on.

          Basic level: the complexity of agricultural lighting

          Liu Muqing and Zhu Xueyu of the Institute of Electric Light Sources of Fudan University elaborated on this point from the following five levels.

          First, the multidisciplinary nature of agricultural lighting

          If plant lighting and animal lighting are included in the scope of agricultural lighting, the disciplines involved include botany, zoology, biostatistics, lighting technology, and control technology. The first three are the fields of biology, the latter two are the fields of lighting technology, and the discipline span is very wide. In these disciplines, lighting technology is a technical means, and the content of biology is the experimental process and the result evaluation. In general, knowledge in the field of biology is the most important part of agricultural lighting, but currently agricultural lighting mainly refers to the use of LED lighting technology, and the high flexibility of LED, making the agricultural lighting process, as the main agricultural Or scientists in the biological field need the high cooperation of lighting experts to achieve the best lighting conditions for various animal and plant species, and the successful improvement of the lighting discipline in the visual field is also worthy of reference for agricultural lighting. Therefore, the discipline and technological advancement of agricultural lighting requires scientists in agriculture and biology to work closely with scientists in the field of lighting.

          Second, the complexity of agricultural lighting

          As an agriculture-related science and technology, agricultural lighting inherits the complex nature of agricultural science. As mentioned earlier, it includes two aspects: agriculture and lighting.

          The former has studied a large number of species, and each of the species has a lot of conditional factors. For example, the basic elements of plant growth, sunlight, air, and water, in addition to changes in seeds, soil, and surrounding environment such as temperature, humidity, and climate, also affect plant growth. On the animal side, because it is active, it includes more factors. Even if all these conditions are consistent, the growth of individual animals and plants may be different, which determines that bio-statistical methods must be used for agricultural lighting research. the study.

          In addition, in terms of illumination, there are also a number of variables, including the spectrum, intensity, time and period of illumination, light form (steady state or pulse), and the like.

          The above two aspects determine the complexity of agricultural lighting. Although the growth of animals and plants can be optimized by adjusting the intensity of light, other conditions can be kept the same, but the interaction of various conditions that may exist will make the research problem more complication.

          Third, the difficulty of testing agricultural lighting

          The complexity of agricultural lighting determines the difficulty of the research of agricultural lighting research, which is reflected in the fact that the experimental variables are too many. Despite the main experimental lighting conditions, by studying different light conditions, such as irradiation intensity, spectrum, irradiation time, irradiation period, irradiation mode, etc., it is expected to fix other agricultural conditions such as temperature, humidity, air, Moisture, nutrients, seeds, etc. However, these two kinds of factors may affect each other. Therefore, in actual experimental research, there are many experimental changes to be considered, and each condition must have a certain sample for biostatistical considerations. This makes the test conditions more, more samples, plus each test condition requires a certain growth time, and finally caused the situation of agricultural lighting research: the test sample is very large, the test time span is very long, agricultural lighting has become time-consuming and laborious Research on the cost of space. To give an example, if three kinds of illumination condition variables, such as spectrum, intensity, and illumination time, are used, and each variable uses 10 discrete values, it can be seen that there are a total of 1,000 conditions, and if there are 10 biological conditions, that is 10,000. In the case, if there are 10 samples in each case, it is 100,000 samples. If each sample is to be carried out for 2 months, then the difficulty of this test can be imagined. Therefore, the actual research is forced to reduce the number of test variables and reduce the number of variables in each test. When reading the relevant literature, I often find that the illumination conditions used are only within 10, and there may be test conditions used. Optimal, and therefore cannot find the best results.

          The Dendrobium nobile fill test, which was reported in the past, consisted of 6 seedbeds (one acre) in a greenhouse. 153 LED lamps and 8 fluorescent lamps were installed and debugged, and 644 samples were marked. The data collection was carried out for 7 months, and 3 batches of nearly 200,000 data were completed, and the best lighting conditions were obtained through analysis. The scene is shown in Figures 1, 2 and 3.

          As can be seen in Figure 3, in the 113 different light environment combinations, only the two experimental conditions showed the best growth of Dendrobium candidum, and the two growth conditions were significantly better than the rest. Under the other 111 kinds of light conditions, the growth was not much different than that of the fluorescent control group and the non-illuminated group. It is conceivable that if 10 or 20 conditions are tested, it is likely that no optimal lighting conditions can be found.

          Before the LED, a lot of research was done on the light supplementation with the traditional light source. However, due to the lack of flexibility of the traditional light source, it is difficult to achieve a variety of lighting conditions, and often only a few simple lighting conditions can be studied, as mentioned above. More than 10 kinds are often used. Therefore, in the case that LEDs are easy to implement various lighting conditions, it is of great practical significance to re-define and screen the optimal illumination conditions.

          4. Light selectivity and spectral weighting of agricultural lighting

          Agricultural lighting is generally considered to be spectrally selective, as is visual illumination, and thus there is a weighting curve similar to the spectral viewing function in visual illumination. The often cited curves are shown in Figures 4 and 5.

          The study of the human visual function has also been obtained after a large number of experiments. Due to the small difference in the existence of each race, the visual function is currently widely used. However, the weighting function of plant illumination has a limited theory at present, and more adopts the chlorophyll spectral absorption rate of the plant of Figure 5, and has been questioned a lot. In fact, looking at the differences in the spectral reflectance of the foliage of various plants, it is easy to imagine that the photosynthesis weighting functions of different plants are likely to be different, so there is a lot of research work to be done. After completing the photosynthesis spectral weighting function of various plants, the concept of "light flux" can be established with reference to visual illumination, that is, the physical quantity conversion of radiant flux to photosynthesis, and the corresponding testing means are completed.

          Animal lighting is similar to plants, and there is a corresponding research work to be done.

          V. Diversity of evaluation indicators

          In the lighting discipline, visual science is the science of studying light acting on the human eye. The main evaluation indicators are visual clarity and comfort, and include indicators such as illuminance and brightness. The latter are indicators such as glare and stroboscopic. When entering the agricultural lighting, the indicators of concern are more complicated, including the growth of plants, the content of certain components, etc. Further refinement can be the leaf area, rhizome, total height, color, etc. of the plant, including sugar, chlorophyll, etc. Indicators. In fact, there are many other indicators, such as increasing the growth of plants by supplemental light, or suppressing the growth of certain things in turn, which has another type of evaluation index.

          The evaluation indicators of animal lighting are also complex and diverse. For example, for the growth of broiler chickens, the evaluation index can be the growth rate of chickens, meat quality, protein content, etc., and the perception of chicken sales and mortality can be considered, even chickens. The situation of the feathers and so on.

          The complexity of the evaluation indicators has increased the difficulty of research on agricultural lighting. It is worth mentioning that, due to the use of multiple lighting conditions, and different growth stages may require different fill light conditions, agricultural lighting is often combined with control technology, that is, through control technology, complete control of the entire lighting.

          Other bottlenecks still faced by semiconductor light source agricultural applications

          In addition to the complexity of the above disciplines, the basic research has become the biggest constraint, the technical problems are also manifested in the lack of light formula research, the molecular mechanism is not clear, the mechanism research stays at the macro level; the LED special lamps and energy-saving control technology research and development lack; agriculture LED research talents (science and education units, enterprise level) are extremely scarce. In addition, cost price and industrialization are also the bottlenecks faced by the application and promotion of LED light sources in the agricultural field.

          Yang Qichang said that in terms of cost, the cost of artificial light LED has been greatly reduced, and it has certain advantages compared with fluorescent lamps, but one investment is high; the cost of fill light LED is still high, and there is no competitive advantage compared with high pressure sodium lamp (filled light 7 hectares) Greenhouse LED 5.9 million euros, high pressure sodium lamps 30-40 million euros).

          In terms of industry, the level of industrialization and standardization is low, and the market scale is difficult to expand; there are not many enterprises specializing in the development of agricultural LED special lamps, and domestic chip manufacturers are investing in manpower and resources to develop red light chips for agricultural lighting. There are many concurrent businesses, small scales, and it is difficult to compete with international giants; the state has no shortage of agricultural LED subsidy policies (such as agricultural machinery subsidies). Therefore, at this stage, basic research, technological breakthroughs, cost reduction, enhanced promotion, and the establishment of sustainable and profitable business models are all very important.

          Although the development of agricultural lighting still faces many difficulties, the road of LED plant lighting in China is not a€?sorrowful and sorrowfula€?. The Fifth Plenary Session of the 18th CPC Central Committee pointed out: "We must vigorously promote agricultural modernization, accelerate the transformation of agricultural development methods, and take the road of agricultural modernization with high output, product safety, resource conservation and environmental friendliness." Interpretation by industry, from high production to high efficiency, technology Prospering agriculture is the only way to modern agriculture. In addition to informatization, the 13th Five-Year Plan also pointed out that modern equipment and modern breeding technology that may be involved are the key directions for future support. The visit to the plant factory from Xia€?s time can also be a glimpse of the countrya€?s high regard for agricultural lighting.

          In short, there is still a long way to go. The development of agricultural lighting depends on the close cooperation of agricultural scientists and lighting people, the strong support of policies, and the persistence of you and me. I believe that one day, China's LED agricultural lighting will attract worldwide attention.

          Description of Heat Resistant Sleeve For Cable Management Protection

           

          High flame retardant braided sleeving is braided by UL 94 VO grade raw material PET mono filaments. It has excellent expandability, abrasive resistance and high flame retardant. Its flame rating can be up to VW-1.
          Application electronics, automobile, high-speed rail,aviation, marine and switch cabinet wire harnessing applications where cost efficiency and durability are critical. The unique braided construction and wide expandability allows quick and easy installation over large connectors and long runs.
          Ease of installation and nearly complete coverage makes fray resistance braided sleeve an ideal solution for many industrial and engineering applications.


          The Cable Wire Sleeve has smooth surface, bright color and various patterns. It is an ideal product for line management and bundle application of electronics, automobiles, airplanes, ships, industry and home. For example, DVI wire mesh sets, HDMI wire net sets, motor vehicle engine line dressing, home theater wire management, computer chassis wire layout, office line management, car wiring harness, water tube protection.

           

          PET expandable braided sleeve for cable harness is braided by environment-friendly polyester monofil. (PET,PA66), the sleeve possesses good flexibility, fire resistance, abrasive resistance and thermal insulation performance. The sleeving owns smooth surface, bright color, various patterns.




          Heat Resistant Sleeve For Cable

          304 Steel Sleeving,Heat Resistant Sleeve,Ss Braided Sleeving,Expandable Electrical Cable Sleeve

          Shenzhen Huiyunhai Tech.Co.,Ltd , https://www.hyhbraidedsleeve.com

          高清性色生活片
          <noframes id="7nx95"><address id="7nx95"><th id="7nx95"></th></address>
          <th id="7nx95"><pre id="7nx95"></pre></th>

            <listing id="7nx95"><em id="7nx95"><dfn id="7nx95"></dfn></em></listing>
              <pre id="7nx95"></pre>

                  <sub id="7nx95"></sub>