Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristic...Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristics and paleoenvironment in western Hubei.The lithology at the bottom of Lower Silurian Longmaxi Formationn in this study area is mainly dark carbonaceous shale,the mineral composition is mostly clay minerals,quartz and feldspar,the content of illite and kaolinite is high,but also contains a minor amount of strawberry pyrite and graptolite fossils.The test and analysishow that the total organic carbon content(TOC)of the source rock is 0.8-6.32%,the average value is 3.42%,and the vitrinite reflectance(Ro)is 1.57-2.95%.The type of organic matter is mainly typeⅡ2.The overall abundance of organic matter is high,and the degree of thermal evolution has reached the stage of high maturity and over maturity.All these have become the good material basis and conditions for the formation of shale gas.The paleoenvironment of the source rocks indicates that the organic matter is a mixed source of planktonic algae and bacteria material.The large amount of hopane also indicates that the bacterial activity is strong during the deposition of organic matter;The water of the ancient lake is almost freshwater and brackishwater in some parts;The redox property of the water is in a strong reduction environment and with a stable stratification,which is also conducive to the preservation of organic matter.The above research results will provide the application of shale gas exploration in western Hubei.展开更多
The measurement of the weak magnetic field in nanoscale resolution and at room temperature is always a significant topic in biological, physical, and material science. Such detection can be used to decide the characte...The measurement of the weak magnetic field in nanoscale resolution and at room temperature is always a significant topic in biological, physical, and material science. Such detection can be used to decide the characterization of the samples, such as cells, materials, and so on. Nitrogen-vacancy (NV) center in diamond has been proved to be able to detect a magnetic field with nano Tesla sensitivity and nanometer resolution at room temperature. Here we experimentally demonstrate an optimized NV center based single electron magnetometer in a commercial diamond and under a home-built optically detected magnetic resonance (ODMR) microscope. With current technology, we change the optically detected time window to get a better signal to noise ratio, and use dynamical decoupling to increase the slope of magnetic field amplitude versus fluorescence signal. By employing the 8-pulse XY-4 dynamical decoupling sequence we achieve a sensitivity of 18.9 nT (Hz)(1/2) , which is 1.7 times better than spin echo. We also propose a NV center based scanning diamond microscope for electron and nuclear spins detection as well as nanoscale magnetic resonance imaging. If it is realized, the NV center based magnetometry will have wide application in the future.展开更多
Quantum coherence is an important enabling feature underpinning quantum computation. However, because of couplings with its noisy surrounding environment, qubits suffer from the decoherence effects. The dynamical deco...Quantum coherence is an important enabling feature underpinning quantum computation. However, because of couplings with its noisy surrounding environment, qubits suffer from the decoherence effects. The dynamical decoupling (DD) technique uses pulse-induced qubit flips to effectively mitigate couplings between qubits and environment. Optimal DD eliminates dephasing up to a given order with the minimum number of pulses. In this paper, we first introduce our recent work on prolonging electron spin coherence in γ-irradiated malonic acid crystals and analyze different decoherence mechanisms in this solid system. Then we focus on electron spin relaxation properties in another system, phosphorous-doped silicon (Si:P) crystals. These properties have been investigated by pulse electron paramagnetic resonance (EPR). We also investigate the performance of the dynamical decoupling technique on this system. Using 8-pulse periodic DD, the coherence time can be extended to 296 μs compared with 112 μs with one-pulse control.展开更多
MicroRNAs (miRNAs) are a class of non-coding RNAs that play critical roles in post-transcriptional regulation. Their target genes are involved in a variety of biological processes such as development, metabolism, and ...MicroRNAs (miRNAs) are a class of non-coding RNAs that play critical roles in post-transcriptional regulation. Their target genes are involved in a variety of biological processes such as development, metabolism, and stress response. Panicum miliaceum L. (Panicum) is an important grain crop, but, until now, no miRNAs have been identified in this plant. Using a homology search based on expressed sequence tag (EST) analysis and miRNA precursor secondary structure, a total of 43 new miRNAs were identified. The miRNAs were found to be unevenly distributed among 11 miRNA families. Target analysis using the plant small RNA target analysis server psRNATarget showed that the newly identified miRNAs can potentially regulate 68 target genes. Ten of the 11 miRNA families were annotated as involved in RNA regulation, suggesting they may play an essential role in post-transcriptional regulation in Panicum. Selected miRNAs representing eight of the families were verified by northern blotting, indicating that the prediction method that we used to identify the miRNAs was effective.展开更多
基金Supported by project of National Natural Science Foundation of China(NSFC)(No.42072122).
文摘Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristics and paleoenvironment in western Hubei.The lithology at the bottom of Lower Silurian Longmaxi Formationn in this study area is mainly dark carbonaceous shale,the mineral composition is mostly clay minerals,quartz and feldspar,the content of illite and kaolinite is high,but also contains a minor amount of strawberry pyrite and graptolite fossils.The test and analysishow that the total organic carbon content(TOC)of the source rock is 0.8-6.32%,the average value is 3.42%,and the vitrinite reflectance(Ro)is 1.57-2.95%.The type of organic matter is mainly typeⅡ2.The overall abundance of organic matter is high,and the degree of thermal evolution has reached the stage of high maturity and over maturity.All these have become the good material basis and conditions for the formation of shale gas.The paleoenvironment of the source rocks indicates that the organic matter is a mixed source of planktonic algae and bacteria material.The large amount of hopane also indicates that the bacterial activity is strong during the deposition of organic matter;The water of the ancient lake is almost freshwater and brackishwater in some parts;The redox property of the water is in a strong reduction environment and with a stable stratification,which is also conducive to the preservation of organic matter.The above research results will provide the application of shale gas exploration in western Hubei.
基金supported by the National Basic Research Program of China (2013CB921800)the National Natural Science Foundation of China (11227901, 91021005, 10834005, 11104262) and the Chinese Academy of Sciences
文摘The measurement of the weak magnetic field in nanoscale resolution and at room temperature is always a significant topic in biological, physical, and material science. Such detection can be used to decide the characterization of the samples, such as cells, materials, and so on. Nitrogen-vacancy (NV) center in diamond has been proved to be able to detect a magnetic field with nano Tesla sensitivity and nanometer resolution at room temperature. Here we experimentally demonstrate an optimized NV center based single electron magnetometer in a commercial diamond and under a home-built optically detected magnetic resonance (ODMR) microscope. With current technology, we change the optically detected time window to get a better signal to noise ratio, and use dynamical decoupling to increase the slope of magnetic field amplitude versus fluorescence signal. By employing the 8-pulse XY-4 dynamical decoupling sequence we achieve a sensitivity of 18.9 nT (Hz)(1/2) , which is 1.7 times better than spin echo. We also propose a NV center based scanning diamond microscope for electron and nuclear spins detection as well as nanoscale magnetic resonance imaging. If it is realized, the NV center based magnetometry will have wide application in the future.
基金supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences, the Ministry of Education of PRC, the National Basic Research Program of China (2007CB925200)
文摘Quantum coherence is an important enabling feature underpinning quantum computation. However, because of couplings with its noisy surrounding environment, qubits suffer from the decoherence effects. The dynamical decoupling (DD) technique uses pulse-induced qubit flips to effectively mitigate couplings between qubits and environment. Optimal DD eliminates dephasing up to a given order with the minimum number of pulses. In this paper, we first introduce our recent work on prolonging electron spin coherence in γ-irradiated malonic acid crystals and analyze different decoherence mechanisms in this solid system. Then we focus on electron spin relaxation properties in another system, phosphorous-doped silicon (Si:P) crystals. These properties have been investigated by pulse electron paramagnetic resonance (EPR). We also investigate the performance of the dynamical decoupling technique on this system. Using 8-pulse periodic DD, the coherence time can be extended to 296 μs compared with 112 μs with one-pulse control.
基金supported by the National Natural Science Foundation of China (Grant No. 30600384)Outstanding Younger Scholar Foundation of Northwest A & F University
基金supported by the National Natural Science Foundation of China (Grant Nos. 30600384 and 50809068)the Young Outstanding Scholar Foundation of Northwest A & F University, China
文摘MicroRNAs (miRNAs) are a class of non-coding RNAs that play critical roles in post-transcriptional regulation. Their target genes are involved in a variety of biological processes such as development, metabolism, and stress response. Panicum miliaceum L. (Panicum) is an important grain crop, but, until now, no miRNAs have been identified in this plant. Using a homology search based on expressed sequence tag (EST) analysis and miRNA precursor secondary structure, a total of 43 new miRNAs were identified. The miRNAs were found to be unevenly distributed among 11 miRNA families. Target analysis using the plant small RNA target analysis server psRNATarget showed that the newly identified miRNAs can potentially regulate 68 target genes. Ten of the 11 miRNA families were annotated as involved in RNA regulation, suggesting they may play an essential role in post-transcriptional regulation in Panicum. Selected miRNAs representing eight of the families were verified by northern blotting, indicating that the prediction method that we used to identify the miRNAs was effective.
