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Background With the increasing fragmentation of landscape induced by rapid urbanization, the construction of ecological networks is of great significance to alleviate the degradation of urban habitats and protect natural environments. However, there is considerable uncertainty when constructing ecological networks, especially the different approaches to selecting ecological sources. We used the southern Chinese city of Shenzhen as a study area to construct and optimize ecological networks using a coupling approach. Ecological source areas were extracted using morphological spatial pattern analysis (MSPA) and the landscape index method. Ecological networks were constructed using the minimal cumulative resistance (MCR) model and the gravity model. Stepping stones and ecological fault points were added in corridors to optimize the ecological network. Results Ten core areas with maximum importance patch values were extracted by the landscape index method as ecological source areas according to MSPA, after which corridors between ecological sources were constructed based on the MCR model. The constructed ecological networks were optimized using 35 stepping stones and 17 ecological fault points. The optimized ecological networks included 11 important corridors, 34 general corridors, and seven potential corridors. The results of corridor landscape-type analysis showed that a suitable ecological corridor is 60 to 200 m wide. Conclusions Overall, our results imply that ecological source areas can be identified virtually, and that ecological networks can be significantly optimized by combining MSPA and MCR models. These results provide a methodological reference for constructing ecological networks, and they will be useful for urban planning and biodiversity protection in Shenzhen and other similar regions around the world.

Two dimensional (2D) materials have generated enormous interest in various research fields in recent years due to their fascinating properties, such as atomic thickness, distinct structures and superior characteristics. In particular, electronic and optoelectronic devices based on 2D materials have been widely investigated, which is promising for the innovation of future nanoelectronics technology. Recently, the technique of laser processing 2D materials with the advantages of facile operation, versatility and low cost has been reported to enable the fabrication of diverse 2D material electronic and optoelectronic devices, such as field-effect transistors (FETs), p–n junction diodes, bipolar junction transistors (BJTs), inverters, memory devices, photodetectors, photovoltaic devices and light-emitting devices. Here, various interactions between lasers and 2D materials are introduced, such as direct writing processing, reduction, doping, phase transition engineering, thinning, oxidation and creating defects. The current advances in laser processing-assisted 2D material electronic and optoelectronic devices are reviewed. A comprehensive outlook on the future development of 2D material nanoelectronics/optoelectronics via laser processing is also presented.

The security of quantum key distribution (QKD) usually relies on that the users’s devices are well characterized according to the security models made in the security proofs. In contrast,device-independent QKD an entanglement-based protocol permits the security even without any knowledge of the underlying devices. Despite its beauty in theory, device-independent QKD is elusive to realize with current technology. This is because a faithful realization requires ahigh-quality violation of Bell inequality without the fair-sampling assumption. Particularly, in a photonic realization, a rather high detection efficiency is needed where the threshold values depend on the security proofs; this efficiency is far beyond the current reach. Here, both theoretical and experimental innovations yield the realization of device-independent QKD based on a photonic setup. On the theory side, to relax the threshold efficiency for practical deviceindependent QKD, we exploit the random post-selection combined with adding noise for preprocessing, and compute the entropy with complete nonlocal correlations. On the experiment side, we develop a high-quality polarization-entangled photonic source and achieve state-of-theart (heralded) detection efficiency of 87.49%, which outperforms previous experiments and satisfies the threshold efficiency for the first time. Together, we demonstrate device-independent QKD at a secret key rate of 466 bits/s over 20 m standard fiber in the asymptotic limit against collective attacks. Besides, we show the feasibility of generating secret keys at a fiber length of 220 meters. Importantly, our photonic implementation can generate entangled photons at a high rate and in the telecom wavelength, which is desirable for high-speed key generation over long distances. The results not only prove the feasibility of device-independent QKD with realistic devices, but also push the security of communication to an unprecedented level.

The rapid development of urbanization has caused many ecological issues and greatly threatened the sustainable development of human society. The construction of ecological security patterns (ESPs) offers an effective way to balance ecological conservation and urbanization. This study aimed to take the highly urbanized city of Shenzhen, China, as a study area to construct an urban ESP and put forward suggestions for the urban development of ecological security. Ecological sources were identified through the Habitat Quality module in the InVEST model, and ecological corridors, strategic ecological nodes, and stepping-stone patches were extracted based on the minimum cumulative resistance (MCR) model. These elements together constituted the ESP. In particular, with the results of the continuous decline in the overall habitat quality, this study identified ten ecological sources with superior habitat quality, mainly distributed in rural woodlands, in urban green land, and in forest park patches. An optimized pattern for Shenzhen City with one axis, three belts, and four zones is proposed, with the study area divided into an ecological preservation zone, a limited development zone, an optimized development zone, and a key development zone. Moreover, forty-five ecological corridors were extracted and graded into three levels, presenting a spatial pattern of one axis and three belts. The appropriate widths of these ecological corridors were suggested to be between 30 and 60 m in Shenzhen City. In addition, we identified twenty-five ecological nodes, sixteen ecological fracture points, and sixteen stepping stones to improve the maintenance and construction of the ecological corridor network. More generally, this study demonstrates a scientific approach to identifying ESPs based on habitat quality, and can serve as a reference for the planning of urban ecological function regionalization.

Human beings have entered the stage of big data in the information age. How to use big data to serve all walks of life is a very worthy of discussion. This article thought that the mine well under - ground real-time monitoring data and mining production, living and ecological water demands as the research object, from the large data set up, management, analysis, and maintain the four aspects, combining the reality of mine work, using the large system decomposition-coordination principle and fuzzy hierarchy comprehensive evaluation method, the multi-objective dynamic programming model for nonlinear iterative simulation optimization, determine coal water - coordinate the development of new pattern and the underground water source water coal mining technology, mine Wells under - ground multi-objective efficient mixing technology, realizing the accurate, intelligent mine water utilization. Research method, this paper USES “Knowledgediscovery from GIS” and “Simonett rubik’s cube” concept, cyber GIS method is applied to build the mine Wells under - ground real-time monitoring to the big data is discussed, at the same time points out the characteristics of the coal mining situation of real-time, and possible problems are derived, which provide reference for other mines to establish large data.

Coal is China’s main energy, and this situation in the future in a long period of time is unlikely to have fundamental changes. As an underground activity, coal mining inevitably causes local damage and pollution to underground water cut system due to improper application of coal mining technology. And a large number of mine drainage, not only need to spend a lot of drainage costs, increase the cost of coal production, but also waste very valuable water resources. In this paper, based on the water - coal, on the basis of coordination development, through big data analysis methods, proposes the establishment process of coal mining and mine water quality, and the whole life cycle of the coal - water coordination development precision control technology system, through a series of research on the laws of the evolution of time and space and nonlinear multiobjective model building and simulation development plan, research and development of the evaluation method of mine water resource utilization efficiency and benefit, help to realize the coordinated development of the coal - water control in whole life cycle of technology. So as to realize the exploitation and utilization of mine drainage and turn waste into treasure, it can not only relieve the tight situation of water supply in coal mines, but also reduce the environmental pollution caused by coal mining to the mining areas and surrounding cities, and realize the unity of economic and environmental benefits.

Quantum computing has seen tremendous progress in the past years. Due to the implementation complexity and cost, the future path of quantum computation is strongly believed to delegate computational tasks to powerful quantum servers on cloud. Universal blind quantum computing (UBQC) provides the protocol for the secure delegation of arbitrary quantum computations, and it has received significant attention. However, a great challenge in UBQC is how to transmit quantum state over long distance securely and reliably. Here, we solve this challenge by proposing and demonstrating a resource-efficient remote blind qubit preparation (RBQP) protocol with weak coherent pulses for the client to produce, using a compact and low-cost laser. We demonstrate the protocol in field, experimentally verifying the protocol over 100-km fiber. Our experiment uses a quantum teleportation setup in telecom wavelength and generates $1000$ secure qubits with an average fidelity of $(86.9\pm1.5)\%$, which exceeds the quantum no-cloning fidelity of equatorial qubit states. The results prove the feasibility of UBQC over long distances, and thus serving as a key milestone towards secure cloud quantum computing., 11 pages, 9 figures

The present study was undertaken to further investigate the spinal anti-allodynic effects of endomorphins (EMs) and their C-terminal hydrazide modified analogs EM-1-NHNH2 and EM-2-NHNH2 in the spared nerve injury (SNI) model of neuropathic pain in mice. Our results demonstrated that intrathecal (i.t.) administration of endomorphin-1 (EM-1), endomorphin-2 (EM-2), EM-1-NHNH2 and EM-2-NHNH2 produced potent anti-allodynic effects ipsilaterally in neuropathic pain model. Judging from the area under the curve (AUC) values, these two analogs exhibited higher antinociception than their parent peptides. Moreover, they also displayed significant antinociceptive effects in the contralateral paw administered intrathecally. Interestingly, EM-1 and its analog EM-1-NHNH2 displayed their antinociception probably by μ2-opioid receptor subtype since the μ1-opioid receptor antagonist naloxonazine didn't significantly block the anti-allodynia of EM-1 and EM-1-NHNH2, which implied a same opioid mechanism. However, the anti-allodynia induced by EM-2, but not EM-2-NHNH2 was significantly reduced by both μ1-opioid antagonist, naloxonazine and κ-antagonist, nor-binaltorphamine (nor-BNI), indicating multiple opioid receptors were involved in the anti-allodynic effects of EM-2. Most importantly, EM-1-NHNH2 decreased the antinociceptive tolerance, and EM-2-NHNH2 displayed non-tolerance-forming antinociception. Therefore, C-terminal amide to hydrazide conversion changed the spinal antinociceptive profiles of EMs in neuropathic pain. The present investigation is of great value in the development of novel opioid therapeutics against neuropathic pain.