The study on restoration and rebuilding of forestry ecological system was conducted on Xianfeng Forestry Farm (N45° 03′, E129° 45′), in Yilan county, Heilongjiang province. One thousand hectare sample land...The study on restoration and rebuilding of forestry ecological system was conducted on Xianfeng Forestry Farm (N45° 03′, E129° 45′), in Yilan county, Heilongjiang province. One thousand hectare sample land was established. The research summarized the comprehensive technique measures: to managed virgin forests perfectly, to promote forest reforestation by artificial treatment, to restore the secondary forest with patch pattern; and to restorc and foster felling land on artificial forest by means of natural pattern or close hillside to facilitate afforestation. The results showed that forest ecosystem function and quality were restored and rebuilt during ten years by utilization of these technique measures.展开更多
Happiness is a treasure that everyone is longing for. But what is happiness? How can we find the genuine happiness?This essay makes a discussion of this topic and gives us an opportunity to rethink happiness by analyz...Happiness is a treasure that everyone is longing for. But what is happiness? How can we find the genuine happiness?This essay makes a discussion of this topic and gives us an opportunity to rethink happiness by analyzing the short story Bliss written by Katherine Mansfield.The essay is composed of four parts. The first part is an introduction of the topic. Chapter 1 makes a detailed discussion of what happiness is and states out the author's opinion. Chapter 2 starts with the brief account of Katherine Mansfield and her works. Then it analyzes Bliss by three stages- bliss awakening, bliss releasing and bliss searching at once, and bliss shattering and bliss rebuilding. The conclusion restates the author's point of view of what happiness is.展开更多
The electrochemical performance of lithium-ion batteries,i.e.specific capacity and cyclability,is primarily determined by chemical reversibility and structural stability of the electrodes in cycling.Here we have inves...The electrochemical performance of lithium-ion batteries,i.e.specific capacity and cyclability,is primarily determined by chemical reversibility and structural stability of the electrodes in cycling.Here we have investigated the fundamental reaction behaviors of nickel sulfide(NixSy)as lithium-ion battery anodes by in-situ TEM.We find that Ni_(3)S_(2)is the electrochemically stable phase,which appears in the first cycle of the NixSyanode.From the second cycle,conversion between Ni_(3)S_(2)and Li_(2)S/Ni is the dominant electrochemical reaction.In lithiation,the NixSynanoparticles evolve into a mixture of Ni nanocrystals embedded in Li_(2)S matrix,which form a porous structure upon full lithiation,and with the recrystallization of the Ni_(3)S_(2)phase in delithiation,a compact and interconnected network is built.Structural stability in cycles is susceptible to particle size and substrate restraint.Carbon substrate can certainly improve the tolerance for size-dependent pulverization of NixSynanoparticles.When NixSynanoparticle exceeds the critical size value,the morphology of the particle is no longer well maintained even under the constraints of the carbon substrate.This work deepens the understanding of electrochemical reaction behavior of conversiontype materials and helps to rational design of high-energy density battery anodes.展开更多
The dynamic multichannel binocular visual image modeling is studied based on Internet of Things (IoT) Perception Layer, using mobile robot self-organizing network. By employing multigroup mobile robots with binocular ...The dynamic multichannel binocular visual image modeling is studied based on Internet of Things (IoT) Perception Layer, using mobile robot self-organizing network. By employing multigroup mobile robots with binocular visual system, the real visual images of the object will be obtained. Then through the mobile self-organizing network, a three-dimensional model is rebuilt by synthesizing the returned images. On this basis, we formalize a novel algorithm for multichannel binocular visual three-dimensional images based on fast three-dimensional modeling. Compared with the method based on single binocular visual system, the new algorithm can improve the Integrity and accuracy of the dynamic three-dimensional object modeling. The simulation results show that the new method can effectively accelerate the modeling speed, improve the similarity and not increase the data size.展开更多
In this article, the author proposed guesses about memorizing, basing on the observation of hypnosis and its application on acquisition of vocabulary, and advanced the concepts of meaningful decoding and meaning rebui...In this article, the author proposed guesses about memorizing, basing on the observation of hypnosis and its application on acquisition of vocabulary, and advanced the concepts of meaningful decoding and meaning rebuilding, which are the two main courses in mem- orizing.展开更多
文摘The study on restoration and rebuilding of forestry ecological system was conducted on Xianfeng Forestry Farm (N45° 03′, E129° 45′), in Yilan county, Heilongjiang province. One thousand hectare sample land was established. The research summarized the comprehensive technique measures: to managed virgin forests perfectly, to promote forest reforestation by artificial treatment, to restore the secondary forest with patch pattern; and to restorc and foster felling land on artificial forest by means of natural pattern or close hillside to facilitate afforestation. The results showed that forest ecosystem function and quality were restored and rebuilt during ten years by utilization of these technique measures.
文摘Happiness is a treasure that everyone is longing for. But what is happiness? How can we find the genuine happiness?This essay makes a discussion of this topic and gives us an opportunity to rethink happiness by analyzing the short story Bliss written by Katherine Mansfield.The essay is composed of four parts. The first part is an introduction of the topic. Chapter 1 makes a detailed discussion of what happiness is and states out the author's opinion. Chapter 2 starts with the brief account of Katherine Mansfield and her works. Then it analyzes Bliss by three stages- bliss awakening, bliss releasing and bliss searching at once, and bliss shattering and bliss rebuilding. The conclusion restates the author's point of view of what happiness is.
基金the support by the National Natural Science Foundation of China(11972219 and 11902185)the support of Shanghai Sailing Program(19YF1415100)+2 种基金the Young Elite Scientist Sponsorship Program by CAST(2019QNRC001)the support of the National Natural Science Foundation of China(52090022)the Natural Science Foundation for Distinguished Young Scholars of Hebei Province(E2020203085)。
文摘The electrochemical performance of lithium-ion batteries,i.e.specific capacity and cyclability,is primarily determined by chemical reversibility and structural stability of the electrodes in cycling.Here we have investigated the fundamental reaction behaviors of nickel sulfide(NixSy)as lithium-ion battery anodes by in-situ TEM.We find that Ni_(3)S_(2)is the electrochemically stable phase,which appears in the first cycle of the NixSyanode.From the second cycle,conversion between Ni_(3)S_(2)and Li_(2)S/Ni is the dominant electrochemical reaction.In lithiation,the NixSynanoparticles evolve into a mixture of Ni nanocrystals embedded in Li_(2)S matrix,which form a porous structure upon full lithiation,and with the recrystallization of the Ni_(3)S_(2)phase in delithiation,a compact and interconnected network is built.Structural stability in cycles is susceptible to particle size and substrate restraint.Carbon substrate can certainly improve the tolerance for size-dependent pulverization of NixSynanoparticles.When NixSynanoparticle exceeds the critical size value,the morphology of the particle is no longer well maintained even under the constraints of the carbon substrate.This work deepens the understanding of electrochemical reaction behavior of conversiontype materials and helps to rational design of high-energy density battery anodes.
基金supported by HiTech Researchand Development Program of China under Grant No.2007AA10Z235
文摘The dynamic multichannel binocular visual image modeling is studied based on Internet of Things (IoT) Perception Layer, using mobile robot self-organizing network. By employing multigroup mobile robots with binocular visual system, the real visual images of the object will be obtained. Then through the mobile self-organizing network, a three-dimensional model is rebuilt by synthesizing the returned images. On this basis, we formalize a novel algorithm for multichannel binocular visual three-dimensional images based on fast three-dimensional modeling. Compared with the method based on single binocular visual system, the new algorithm can improve the Integrity and accuracy of the dynamic three-dimensional object modeling. The simulation results show that the new method can effectively accelerate the modeling speed, improve the similarity and not increase the data size.
文摘In this article, the author proposed guesses about memorizing, basing on the observation of hypnosis and its application on acquisition of vocabulary, and advanced the concepts of meaningful decoding and meaning rebuilding, which are the two main courses in mem- orizing.
