A complex longitudinal magnetoresistance （MR//） effect in the non-stoichiometric silver chaJcogenides （include the silver selenide and telluride） has been found, however the mechanism for the MR// effect is not cl...A complex longitudinal magnetoresistance （MR//） effect in the non-stoichiometric silver chaJcogenides （include the silver selenide and telluride） has been found, however the mechanism for the MR// effect is not clear now. In this work, a new random resistor network for MR// effect is proposed based on the experimental observation. The network is constructed from six-terminal resistor units and the mobility of carries within the network has a Gaussian distribution. Considering the non-zero transverse-longitudinal coupling in materials, the resistance matrix of the six- terminal resistor unit is modified. It is found that the material has the ＂chiral＂ transverse-longitudinal couplings, which is suggested a main reason for the complex MR//effect. The model predictions are compared with the experimental results. A three dimension （3D） visualization of current flow within the network demonstrates the ＂current jets＂ phenomenon in the thickness of materials dearly.展开更多
With the newly proposed Global Ocean Observing Integration, ocean observing scope has been expanded from the region to the global, therefore the need of large-scale ocean observing system integration has become more a...With the newly proposed Global Ocean Observing Integration, ocean observing scope has been expanded from the region to the global, therefore the need of large-scale ocean observing system integration has become more and more urgent. Currently, ocean observing systems enabled ocean sensor networks are commonly developed by different organizations using specific technologies and platforms, which brings several challenges in ocean observing instrument （OOI） access and ocean observing system seamless integration. Furthermore, the development of ocean observing systems often suffers from low efficiency due to the complex prograrmning and debugging process. To solve these problems, a novel model, Complex Virtual Instrument （CVI） Model, is proposed. The model provides formal definitions on observing instrument description file, CVI description file, model calculation method, development model and interaction standard. In addition, this model establishes mathematical expressions of two model calculation operations, meanwhile builds the mapping relationship between observing instrument description file and CVI description file. The CVI based on the new model can achieve automatic access to different OOIs, seamless integration and communication for heterogeneous environments, and further implement standardized data access and management for the global unified ocean observing network. Throughout the development, integration and application of such CVI, the rationality and feasibility of the model have been evaluated. The results confirm that the proposed model can effectively implement heterogeneous system integration, improve development efficiency, make full usage of reusable components, reduce development cost, and enhance overall software system quality. We believe that our new model has great significance to promote the large-scale ocean observing system integration.展开更多
In this review a series of organic-based open porous networks are discussed, in which hydrogen bonds play an important role in network formation. Using these open networks as molecular templates: 1) a wealth of functi...In this review a series of organic-based open porous networks are discussed, in which hydrogen bonds play an important role in network formation. Using these open networks as molecular templates: 1) a wealth of functional guest species can be immo- bilized; 2) fullerene molecules can be separated and recognized; 3) photoisomerization reactions can be observed by STM; 4) 1D molecular arrays can be constructed; and 5) heterogeneous bilayer structures can be formed. It is envisioned that these su- pramolecular networks might be developed into a new family of useful soft frameworks for studies toward shape-selective ca- talysis, molecular recognition and host-guest supramolecular chemistry.展开更多
Buffering exogenous perturbation is crucial to maintain transcriptional homeostasis during development.While mi RNAs have been speculated to play a role in stability maintenance, previous studies seeking to check this...Buffering exogenous perturbation is crucial to maintain transcriptional homeostasis during development.While mi RNAs have been speculated to play a role in stability maintenance, previous studies seeking to check this conjecture focused on measurements of transcript levels at steady state or involved individual mi RNA targets. We measured whole-genome expression dynamics by introducing a transient perturbation and establishing a perturbation and recovery system in Drosophila larvae. We inhibited all transcription and assayed transcriptomes at several time points during recovery from inhibition. We performed these experiments in the wild type and mi RNA-deficient genetic backgrounds. Consistent with theories about mi RNAs’ function in stabilizing the transcriptome, we find that attenuating mi RNA expression leads to weak impairment in degradation of targets but strong destabilization of target genes when transcription is re-activated. We further fitted a model that captures the essential aspects of transcription dynamics in our experiments and found that the mi RNA target transcripts uniformly overshoot the original steady state as they recover from a general inhibition of transcription if global mi RNA levels are reduced. Collectively, our results provide experimental evidence for the idea that mi RNAs act cumulatively to stabilize the transcriptional regulatory network. We therefore found a promising approach to assess the effect of these molecules on transcription dynamics.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos. 50872038 and 10675048
文摘A complex longitudinal magnetoresistance （MR//） effect in the non-stoichiometric silver chaJcogenides （include the silver selenide and telluride） has been found, however the mechanism for the MR// effect is not clear now. In this work, a new random resistor network for MR// effect is proposed based on the experimental observation. The network is constructed from six-terminal resistor units and the mobility of carries within the network has a Gaussian distribution. Considering the non-zero transverse-longitudinal coupling in materials, the resistance matrix of the six- terminal resistor unit is modified. It is found that the material has the ＂chiral＂ transverse-longitudinal couplings, which is suggested a main reason for the complex MR//effect. The model predictions are compared with the experimental results. A three dimension （3D） visualization of current flow within the network demonstrates the ＂current jets＂ phenomenon in the thickness of materials dearly.
基金supported by the National Natural Science Foundation of China(Nos.41606112,61103196,61379127,61379128)the National High Technology Research and Development Program 863(No.2013AA09A506)
文摘With the newly proposed Global Ocean Observing Integration, ocean observing scope has been expanded from the region to the global, therefore the need of large-scale ocean observing system integration has become more and more urgent. Currently, ocean observing systems enabled ocean sensor networks are commonly developed by different organizations using specific technologies and platforms, which brings several challenges in ocean observing instrument （OOI） access and ocean observing system seamless integration. Furthermore, the development of ocean observing systems often suffers from low efficiency due to the complex prograrmning and debugging process. To solve these problems, a novel model, Complex Virtual Instrument （CVI） Model, is proposed. The model provides formal definitions on observing instrument description file, CVI description file, model calculation method, development model and interaction standard. In addition, this model establishes mathematical expressions of two model calculation operations, meanwhile builds the mapping relationship between observing instrument description file and CVI description file. The CVI based on the new model can achieve automatic access to different OOIs, seamless integration and communication for heterogeneous environments, and further implement standardized data access and management for the global unified ocean observing network. Throughout the development, integration and application of such CVI, the rationality and feasibility of the model have been evaluated. The results confirm that the proposed model can effectively implement heterogeneous system integration, improve development efficiency, make full usage of reusable components, reduce development cost, and enhance overall software system quality. We believe that our new model has great significance to promote the large-scale ocean observing system integration.
文摘In this review a series of organic-based open porous networks are discussed, in which hydrogen bonds play an important role in network formation. Using these open networks as molecular templates: 1) a wealth of functional guest species can be immo- bilized; 2) fullerene molecules can be separated and recognized; 3) photoisomerization reactions can be observed by STM; 4) 1D molecular arrays can be constructed; and 5) heterogeneous bilayer structures can be formed. It is envisioned that these su- pramolecular networks might be developed into a new family of useful soft frameworks for studies toward shape-selective ca- talysis, molecular recognition and host-guest supramolecular chemistry.
基金supported by the National Natural Science Foundation of China (31801094 to C.L. and 31771416 to X.L.)the Key Research Program of the Chinese Academy of Sciences (KFZD-SW-220-1 to X.L.)+3 种基金CAS “Light of West China” Program (to X.L.)the National Natural Science Foundation of China (31900417 to G.L.)the National Key Basic Research Program of China (2014CB542006 to C.L.)China Postdoctoral Science Foundation (2019M653162 to G.L.)。
文摘Buffering exogenous perturbation is crucial to maintain transcriptional homeostasis during development.While mi RNAs have been speculated to play a role in stability maintenance, previous studies seeking to check this conjecture focused on measurements of transcript levels at steady state or involved individual mi RNA targets. We measured whole-genome expression dynamics by introducing a transient perturbation and establishing a perturbation and recovery system in Drosophila larvae. We inhibited all transcription and assayed transcriptomes at several time points during recovery from inhibition. We performed these experiments in the wild type and mi RNA-deficient genetic backgrounds. Consistent with theories about mi RNAs’ function in stabilizing the transcriptome, we find that attenuating mi RNA expression leads to weak impairment in degradation of targets but strong destabilization of target genes when transcription is re-activated. We further fitted a model that captures the essential aspects of transcription dynamics in our experiments and found that the mi RNA target transcripts uniformly overshoot the original steady state as they recover from a general inhibition of transcription if global mi RNA levels are reduced. Collectively, our results provide experimental evidence for the idea that mi RNAs act cumulatively to stabilize the transcriptional regulatory network. We therefore found a promising approach to assess the effect of these molecules on transcription dynamics.
