Qualitative indexes contained in the product standards of in-depth ecotourism development are summarized as:carrying capacity control,protection of natural environment,participation of community residents,education ab...Qualitative indexes contained in the product standards of in-depth ecotourism development are summarized as:carrying capacity control,protection of natural environment,participation of community residents,education about environment protection,enhancing standard management,clean production,green training,and overall monitoring.Based on the model of grey system theory,the improvement of in-depth ecotourism development was predicted,the construction,evaluation and monitoring model for the in-depth development of ecotourism was established,and finally the index system for the evaluation was set as the General Layer(A),the System Layer(B),the Status Layer(C),and the Variable Layer(D).展开更多
CuIn(S,Se)2 thin films were prepared by thermal crystallization of co-sputtered Cu-In alloy precursors in S/Se atmosphere. In-depth compositional uniformity is an important prereq- uisite for obtaining device-qualit...CuIn(S,Se)2 thin films were prepared by thermal crystallization of co-sputtered Cu-In alloy precursors in S/Se atmosphere. In-depth compositional uniformity is an important prereq- uisite for obtaining device-quality CuIn(S,Se)2 absorber thin films. In order to figure out the influence of heat treatments on in-depth composition uniformity of CuIn(S,Se)2 thin films, two kinds of reaction temperature profiles were investigated. One process is "one step profile", referring to formation of CuIn(S,Se)2 thin films just at elevated temperature (e.g. 500 ℃). The other is "two step profile", which allows for slow diffusion of S and Se elements into the alloy precursors at a low temperature before the formation and re-crystallization of CuIn(S,Se)2 thin films at higher temperature (e.g. first 250 ℃ then 500 ℃). X-ray diffrac- tion studies reveal that there is a discrepancy in the shape of (112) peak. Samples annealed with "one step profile" have splits on (112) peaks, while samples annealed with "two step profile" have relatively symmetrical (112) peaks. Grazing incident X-ray diffraction and en- ergy dispersive spectrum measurements of samples successively etched in bromine methanol show that CuIn(S,Se)2 thin films have better in-depth composition uniformity after "two step profile" annealing. The reaction mechanism during the two thermal processing was also investigated by X-ray diffraction and Raman spectra.展开更多
Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on th...Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the indepth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs, and the weak gels in these two cases became small gel particles after water flooding. The differences were: the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor (FRR) caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack, which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack, while in the quartz sand pack, the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water, the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.展开更多
Self-encoded spread spectrum eliminates the need for traditional pseudo noise (PN) code generators. In a self-encoded multiple access (SEMA) system, the number of users is not limited by the number of available sequen...Self-encoded spread spectrum eliminates the need for traditional pseudo noise (PN) code generators. In a self-encoded multiple access (SEMA) system, the number of users is not limited by the number of available sequences, unlike code division multiple access (CDMA) systems that employ PN codes such as m-, Gold or Kassami sequences. SEMA provides a convenient way of supporting multi-rate, multi-level grades of service in multimedia communications and prioritized heterogeneous networking systems. In this paper, we propose multiuser convolutional channel coding in SEMA that provides fewer cross-correlations among users and thereby reducing multiple access interference (MAI). We analyze SEMA multiuser convolutional coding in additive white Gaussian noise (AWGN) channels as well as fading channels. Our analysis includes downlink synchronous system as well as asynchronous system such as uplink mobile-to-base station communication.展开更多
Mankind has lived in the earth for countless years,but until now,people are not really understand the connotation of the Earth.We know that the earth composition including the lithosphere,asthenosphere,mantle,and core...Mankind has lived in the earth for countless years,but until now,people are not really understand the connotation of the Earth.We know that the earth composition including the lithosphere,asthenosphere,mantle,and core.The lithosphere supports all the life on Earth.For a long time,geoscientists trying to use all kind of methods such as geological,geophysical,and geochemical methods to detect and study the earth,but our knowledge about earth are mostly indirect.Through the direct observation to the lithosphere,people can understand and recognize the plate movement of ocean and the mainland,crustal stress,earthquakes,volcanic processes,deep resources,the origins of life,global climate change,and biodiversity.They are all the basis of a series of geoscience problems(Su et al.,2010). For our daily lives,as we all know,against landslides,mudslides and other geological disasters,people's responses can only be monitoring,prevention and countermeasures are needed.One of the most important technical means is the drilling methods.For example,through engineering investigation drilling,people can understand the overall structure of the landslide.Through anchor nails,bolt,cable,curtain grouting,soil modification,anti-slide bored piles of construction,people can prevent landslides,collapse,and other geological disasters. For geosciences,earth scientists are facing a lot of challenges.Plate tectonic theory is one of the 20th century’s major scientific achievements.The continental drift assumptions put forward in the early 20th century,but until 1968,the'Geluoma?Challenger'ocean drilling vessel belong to United States had drilled several hundred holes in the ocean,the theory of seafloor spreading and plate subduction model has been confirmed directly by drilling.However,many problems cannot be explained by'Plate theory'on land.A continental dynamics theory is initiating and developing based on the internal driving force of continent.This heralded a landmark geological revolution is coming soon. At the same time,the 21st century human survival and development resources,the environment and disaster reduction,and other issues need to be addressed urgently.All of this requires us to understand the deep Earth,and the only direct means of direct observation of the Earth's continental crust is'Continental Scientific Drilling'. Geological samples,especially those from deep of the Earth,are the most direct study subjects for geologists.But the only way to access the true samples from deep of the earth is drilling.The most direct evidence always originated from the deep of the earth,such as core,cuttings,fluid samples and other physical samples.This is also true for ophiolite researches. Continental scientific drilling has been demonstrated as an efficient technique for directly obtaining information from the Earth’s surface to the deep crust,and is acknowledged as'to build a telescope inserting to the interior of the Earth',as well as'a key for opening the door of the Earth'.Over the past four decades,continental scientific drilling has achieved great success in enhancing our knowledge of the Earth,and in providing information on mineral resources,large engineering projects and global change.These benefits also relate to ophiolite research. Along with China's Brahmaputra River intermittently distributed ophiolite sets.Its distribution in Tibet is more than 1,000 kilometres long and extends along the Brahmaputra and the Indian Ocean to Myanmar and Pakistan.We have completed a number of coring holes along this ophiolite belt in recent years.The cores were collected from these holes provide geologists with real physical samples coring from the depths of the earth,which have played a significant role in deepening their ophiolite research.And the coring drilling projects along this ophiolite belt will be continue for years,to continue to provide geologists enough ophiolite real samples for their researches. No advanced drilling technology,no enough high quality samples from the deep Earth,the in-depth ophiolite research will be restricted(Zhang et al.,2013).展开更多
In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. The...In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. These decisions were adopted by American government and would also be helpful for the strategic development of Chinese power grid. It is proposed that China should take precaution,carry out security research on the overall dynamic behaviour characteristics of the UHV grid using the complexity theory,and finally provide safeguard for the Chinese UHV grid. It is also pointed out that,due to the lack of matured approaches to controll a cascading failure,the primary duty of a system operator is to work as a "watchdog" for the grid operation security,eliminate the cumulative effect and reduce the risk and losses of major cascading outages with the help of EMS and WAMS.展开更多
There exists some difficulties among high school students in understanding English monologues because some words are unfamiliar to them while some sentences are long and complex.Just by listening,reading,and translati...There exists some difficulties among high school students in understanding English monologues because some words are unfamiliar to them while some sentences are long and complex.Just by listening,reading,and translating from English into Mandarin,the students are unable to fully grasp the conveyed messages in these monologues.In the General Senior High School Curriculum Standards(2017 Edition),it clearly required candidates to be able to understand familiar short dialogues and monologues about daily life topics.Candidates should be able to understand the gist,obtain specific factual information,make simple inferences about what they are listening to,and understand the speaker^intention,views,as well as attitude.This article mainly discusses specific implementation strategies of in-depth interpretation when listening in on monologues.展开更多
Objective To identify the representative attributes of the five elements of a person with a qualitative methodology and provide the basis for the clinical diagnosis and treatment of“people with the five elements in t...Objective To identify the representative attributes of the five elements of a person with a qualitative methodology and provide the basis for the clinical diagnosis and treatment of“people with the five elements in traditional Chinese medicine(TCM).”Methods Data collected from the literature review,two sessions of brainstorming of experts with related experience in“people with the five elements in TCM”from October 2020 to December 2020,and six rounds of in-depth interviews with 30 participants who had various attributes of the five elements from March 2021 to October 2021 were analyzed.Triangulation was used in this study,and theming and synthesizing were used to analyze the data.Results A total of 31 experts and 30 interviewees participated in this study.The median age of the experts and interviewees were 48.0 and 38.5 years,respectively;51.66%and 54.8%of experts and interviewees,respectively,were men.The descriptors of facial diagrams of“people with the five elements in TCM”were complexion,shape,distribution state of facial bones,convergence trend of facial muscles,and facial expression.A theoretical model of“people with the five elements in TCM”was shaped based on these findings.Conclusion The study suggests a possibility for bridging the gap between personality and bodily state,identifying an avenue for personality research from the perspective of TCM.展开更多
Traditional three-dimensional(3D)image reconstruction method,which highly dependent on the environment and has poor reconstruction effect,is easy to lead to mismatch and poor real-time performance.The accuracy of feat...Traditional three-dimensional(3D)image reconstruction method,which highly dependent on the environment and has poor reconstruction effect,is easy to lead to mismatch and poor real-time performance.The accuracy of feature extraction from multiple images affects the reliability and real-time performance of 3D reconstruction technology.To solve the problem,a multi-view image 3D reconstruction algorithm based on self-encoding convolutional neural network is proposed in this paper.The algorithm first extracts the feature information of multiple two-dimensional(2D)images based on scale and rotation invariance parameters of Scale-invariant feature transform(SIFT)operator.Secondly,self-encoding learning neural network is introduced into the feature refinement process to take full advantage of its feature extraction ability.Then,Fish-Net is used to replace the U-Net structure inside the self-encoding network to improve gradient propagation between U-Net structures,and Generative Adversarial Networks(GAN)loss function is used to replace mean square error(MSE)to better express image features,discarding useless features to obtain effective image features.Finally,an incremental structure from motion(SFM)algorithm is performed to calculate rotation matrix and translation vector of the camera,and the feature points are triangulated to obtain a sparse spatial point cloud,and meshlab software is used to display the results.Simulation experiments show that compared with the traditional method,the image feature extraction method proposed in this paper can significantly improve the rendering effect of 3D point cloud,with an accuracy rate of 92.5%and a reconstruction complete rate of 83.6%.展开更多
Objective: The objective was to explore manager experiences using the RAFAELA system. Background: The RAFAELA system was developed in Finland during the 1990s to create a work situation where patients’ care needs wer...Objective: The objective was to explore manager experiences using the RAFAELA system. Background: The RAFAELA system was developed in Finland during the 1990s to create a work situation where patients’ care needs were balanced with personnel resources. The system is used in almost all hospitals in Finland and is implemented in several European countries. However, the system has never been evaluated outside Finland. This study, focusing on the managers’ perspective, represents the second report from a larger Norwegian evaluation project of the RAFAELA system. Methods: An explorative qualitative design was chosen. Data were collected by individual in-depth interviews at a university hospital in Norway during 2012-2013. A total of 10 informants in various management positions were interviewed. The tape-recorded interviews were transcribed verbatim, and the transcripts were analysed using Kvale’s method for content analysis. Results: Four main themes emerged from the qualitative data: making the invisible visible;a common language;a system for prospective planning;and a resource-demanding tool. Conclusions: The study indicated that the RAFAELA system provided useful information about the patients’ care needs and nursing activities. Also the system provided a common reference frame for discussing nursing, staffing and allocation. Although the managers considered the RAFAELA to be time consuming in the implementation phase, they considered the system to be an important tool.展开更多
Nodes cooperation is a significant prerequisite for the realization of the relaying Ad Hoc.While with the development of multi-hop cellular networks, how to stimulate intermediate nodes to do the packet-forwarding des...Nodes cooperation is a significant prerequisite for the realization of the relaying Ad Hoc.While with the development of multi-hop cellular networks, how to stimulate intermediate nodes to do the packet-forwarding deserves more concerning.At present research,the incentive schemes in pure Ad Hoc and multi-hop cellular networks are analyzed and compared to classify the strengths and drawbacks of each scheme.We explain in particular what the key issues are to implement incentive schemes for cooperation. Finally,an incentive scheme based on integration of reputation and charging systems is proposed not only to block the existence of selfish nodes,but to satisfy the rational requirement of nodes.展开更多
We firstly introduce development background of new collective forest tenure reform.The situations indicate that the collective forest tenure reform has already stepped into comprehensive and in-depth stage.However,due...We firstly introduce development background of new collective forest tenure reform.The situations indicate that the collective forest tenure reform has already stepped into comprehensive and in-depth stage.However,due to neglect of local demands and actual conditions,there appear problems of low operating efficiency of supporting measures and relevant policies and little effect of in-depth reform.Therefore,it is required to strictly distinguish the relation between system change of collective forest tenure and the in-depth reform.For the purpose of in-depth reform,in accordance with local situations of forest farmers and forestry organizations,requirements for system,as well as local reform conditions,we strictly divide system change of collective forest tenure into three types:induced institutional change,hidden induced institutional change and imposed institutional change.Then,we divide the imposed institutional change into weak institutional change and pure strong institutional change.展开更多
Knowledge of migration and retention mechanisms of elastic gel particles(EGPs)in pore-throats is essential for the effective application of EGPs as a smart sweep improvement and profile control agent for enhanced oil ...Knowledge of migration and retention mechanisms of elastic gel particles(EGPs)in pore-throats is essential for the effective application of EGPs as a smart sweep improvement and profile control agent for enhanced oil recovery(EOR).The matching coefficient(defined as the ratio of particle size to pore-throat size)is used to investigate its influence on migration,retention and profile control performance of EGPs.A 1-D continuous pore-throat visualization model(PTVM),a 2-D heterogeneous PTVM and a 3-D heterogeneous core model were constructed and used to investigate pore-scale migration,retention and controlling mechanism of migration and retention characteristics on EGPs profile control.The results of the 1-D continuous PTVM indicated that while the matching coefficient was in the optimal range(i.e.,0.20-0.32),the EGPs could not only smoothly migrate to the deeper pore-throats,but also form stable retention in the pores to resist the erosion of injected water,which was conducive to the effective indepth profile control.The results of the 2-D heterogeneous PTVM verified that the sweep efficiency in low-permeability regions could be significantly improved by in-depth migration and stable retention of EGPs in the pore-throats with an optimal matching coefficient(0.29),which was much better than that in cases with a smaller matching coefficient(0.17)or an excessive matching coefficient(0.39).Moreover,the NMR displacement experiments of 3-D heterogeneous cores were carried out to simulate the EGPs profile control in actual reservoir porous media.Saturation images and T2 spectrum curves of crude oil showed that EOR in the low-permeability layer was highest(56.1%)using EGPs profile control with an optimal matching coefficient,attributing to the in-depth migration and stable retention of EGPs.展开更多
In this work, we observe the behavior of block space-time code in wireless channel dynamics. The block space-time code is optimally constructed in slow fading. The block code in quasistatic fading channels provides af...In this work, we observe the behavior of block space-time code in wireless channel dynamics. The block space-time code is optimally constructed in slow fading. The block code in quasistatic fading channels provides affordable complexity in design and construction. Our results show that the performance of the block space-time code may not be as good as conventionally convolutional coding with serial transmission for some channel features. As channel approaches fast fading, a coded single antenna scheme can collect as much diversity as desired by correctly choosing the free distance of code. The results also point to the need for robust space-time code in dynamic wireless fading channels. We expect that self-encoded spread spec-trum with block space-time code will provide a robust performance in dynamic wireless fading channels.展开更多
Based on the empirically analysis of the data from a nationwide survey in 2010 in China, the study found. (1) The overwhelming majority of rural migrant workers in China were not willing to convert their rural house...Based on the empirically analysis of the data from a nationwide survey in 2010 in China, the study found. (1) The overwhelming majority of rural migrant workers in China were not willing to convert their rural household registration (nongye hukou) to an urban or non-rural registration Orei nong hukou). If they were required to return the rural land contract rights as precondition, only lOper cent were willing to be urban citizens. (2) For the small proportion of migrant workers who were willing to convert their rural household registration to urban household registration, 'obtaining access to better education and more opportunities for the continuation of education for their children' is the major incentive. (3) The primary reason for retaining a rural hukou, on the other hand, is to keep their rural contract land. (4) Finally, there is no significant difference between the rural migrant workers who were born before 1980 and those after 1980, in term of the attitude toward converting rural hukou to urban hukou. The policy recommendations drew from the findings are as follows: 1) In order to promote the urbanization process, the government should choose the path of 'urbanization based on the long term residence in the towns and cities' instead of the path of "urbanization based on household registration '. 2) The rural migrant workers should be converted into urban citizens without being forced to give up their contact land. 3) The government should give equal weight in policy making to the migrant workers born before 1980 and those born after 1980. Therefore, the policy emphasis of deepening the urbanization of China should focus on the 'equalization of the resource allocation of the public services and social welfare" while the characteristics of the separation of the household registration system should not be strengthened any longer.展开更多
In-depth vocabulary knowledge plays a key role in L2(second language)vocabulary acquisition,and computer English vocabulary is vital to academic performances of students majored in Computer Science.While many Chinese ...In-depth vocabulary knowledge plays a key role in L2(second language)vocabulary acquisition,and computer English vocabulary is vital to academic performances of students majored in Computer Science.While many Chinese students cannot realize computer English vocabulary acquisition due to lacking input environment of computer English.To solve this problem,with techniques of keyword search,information retrieval,and text classification,to meet the diverse learning needs of students,it built the in-depth computer English vocabulary knowledge acquisition environment for the high frequency of computer English words,providing the depth of knowledge such as polysemy,synonyms,syntax,and pragmatics.The construction of in-depth computer English vocabulary acquisition environment helps future studies on computer English teaching applications.展开更多
Herein, we developed a fractionation-free negative enriching method incorporating methylamidation, siteselective dimethylation and aldehyde resin coupling(MADMAR) for in-depth C-terminome analysis. The methylamidation...Herein, we developed a fractionation-free negative enriching method incorporating methylamidation, siteselective dimethylation and aldehyde resin coupling(MADMAR) for in-depth C-terminome analysis. The methylamidation blocked the free carboxyl group on proteins first, followed by Lys C digestion of methylamidated proteins. Then, the site-selective dimethylation blocked the N-terminal amino group of the digested peptides without affecting the amino groups of lysine. Finally, the aldehyde resin was used to capture non-C-terminal peptides containing amino groups from lysine, while leaving the C-terminal peptides without free amino group in the supernatant for its analysis. We identified 1359 database-annotated protein C-termini from 50 μg He La proteins, which was 74% more than our previous method based on aldehyde resin. Moreover, 279 protein neo-C-termini were identified.展开更多
The Second Demographic Transition(SDT)framework highlights individuals'ideational shift toward greater individualism in explaining the rise of non-marriage unions.Contemporary China has seen a substantial increase...The Second Demographic Transition(SDT)framework highlights individuals'ideational shift toward greater individualism in explaining the rise of non-marriage unions.Contemporary China has seen a substantial increase in premarital cohabitation.Drawing on 65 in-depth interviews with highly educated young urban Chinese women and men,this article examines the gendered ways in which young Chinese adults perceive and make decisions about premarital cohabitation,as they envision their ideal lives and what autonomy and self-realization mean to them.I demonstrate that while male respondents predominantly view cohabitation positively as a risk-reduction strategy for avoiding incompatible marriages,female respondents still consider cohabitation to be a risk-amplification arrangement in practice that increases the possibility of uncertain marriage prospect,unsafe sex,and reputational damages.Young women,but not men,often have to strategizethrough carefully managing information disclosureabout persistent parental expectations that discourage women's premarital cohabitation.As a result,while male respondents regard marriage to be neither the necessary precondition nor the end goal of cohabitation,female respondents,who otherwise emphasize autonomy and individualistic fulfllment,continue to desire a close linkage between cohabitation and marriage.Leveraging the unique strength of qualitative data in demographic research,this article articulates the gender asymmetry in how women and men perceive cohabitation's risks,benefits,and link to marriage.I elucidate the gendered tension between privately-held ideals of individualism vis-a-vis enduring social norms of female marriageability,as women and men differentially navigate parental expectations surrounding cohabitation.In so doing,this article makes a theoretical contribution by bringing a careful treatment of gender into the SDT framework.展开更多
基金Supported by Scientific Research Foundation of Xuchang University(2009) " Study on Livable City from the Perspective of Ecological Footprint"~~
文摘Qualitative indexes contained in the product standards of in-depth ecotourism development are summarized as:carrying capacity control,protection of natural environment,participation of community residents,education about environment protection,enhancing standard management,clean production,green training,and overall monitoring.Based on the model of grey system theory,the improvement of in-depth ecotourism development was predicted,the construction,evaluation and monitoring model for the in-depth development of ecotourism was established,and finally the index system for the evaluation was set as the General Layer(A),the System Layer(B),the Status Layer(C),and the Variable Layer(D).
文摘CuIn(S,Se)2 thin films were prepared by thermal crystallization of co-sputtered Cu-In alloy precursors in S/Se atmosphere. In-depth compositional uniformity is an important prereq- uisite for obtaining device-quality CuIn(S,Se)2 absorber thin films. In order to figure out the influence of heat treatments on in-depth composition uniformity of CuIn(S,Se)2 thin films, two kinds of reaction temperature profiles were investigated. One process is "one step profile", referring to formation of CuIn(S,Se)2 thin films just at elevated temperature (e.g. 500 ℃). The other is "two step profile", which allows for slow diffusion of S and Se elements into the alloy precursors at a low temperature before the formation and re-crystallization of CuIn(S,Se)2 thin films at higher temperature (e.g. first 250 ℃ then 500 ℃). X-ray diffrac- tion studies reveal that there is a discrepancy in the shape of (112) peak. Samples annealed with "one step profile" have splits on (112) peaks, while samples annealed with "two step profile" have relatively symmetrical (112) peaks. Grazing incident X-ray diffraction and en- ergy dispersive spectrum measurements of samples successively etched in bromine methanol show that CuIn(S,Se)2 thin films have better in-depth composition uniformity after "two step profile" annealing. The reaction mechanism during the two thermal processing was also investigated by X-ray diffraction and Raman spectra.
文摘Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the indepth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs, and the weak gels in these two cases became small gel particles after water flooding. The differences were: the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor (FRR) caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack, which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack, while in the quartz sand pack, the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water, the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.
文摘Self-encoded spread spectrum eliminates the need for traditional pseudo noise (PN) code generators. In a self-encoded multiple access (SEMA) system, the number of users is not limited by the number of available sequences, unlike code division multiple access (CDMA) systems that employ PN codes such as m-, Gold or Kassami sequences. SEMA provides a convenient way of supporting multi-rate, multi-level grades of service in multimedia communications and prioritized heterogeneous networking systems. In this paper, we propose multiuser convolutional channel coding in SEMA that provides fewer cross-correlations among users and thereby reducing multiple access interference (MAI). We analyze SEMA multiuser convolutional coding in additive white Gaussian noise (AWGN) channels as well as fading channels. Our analysis includes downlink synchronous system as well as asynchronous system such as uplink mobile-to-base station communication.
文摘Mankind has lived in the earth for countless years,but until now,people are not really understand the connotation of the Earth.We know that the earth composition including the lithosphere,asthenosphere,mantle,and core.The lithosphere supports all the life on Earth.For a long time,geoscientists trying to use all kind of methods such as geological,geophysical,and geochemical methods to detect and study the earth,but our knowledge about earth are mostly indirect.Through the direct observation to the lithosphere,people can understand and recognize the plate movement of ocean and the mainland,crustal stress,earthquakes,volcanic processes,deep resources,the origins of life,global climate change,and biodiversity.They are all the basis of a series of geoscience problems(Su et al.,2010). For our daily lives,as we all know,against landslides,mudslides and other geological disasters,people's responses can only be monitoring,prevention and countermeasures are needed.One of the most important technical means is the drilling methods.For example,through engineering investigation drilling,people can understand the overall structure of the landslide.Through anchor nails,bolt,cable,curtain grouting,soil modification,anti-slide bored piles of construction,people can prevent landslides,collapse,and other geological disasters. For geosciences,earth scientists are facing a lot of challenges.Plate tectonic theory is one of the 20th century’s major scientific achievements.The continental drift assumptions put forward in the early 20th century,but until 1968,the'Geluoma?Challenger'ocean drilling vessel belong to United States had drilled several hundred holes in the ocean,the theory of seafloor spreading and plate subduction model has been confirmed directly by drilling.However,many problems cannot be explained by'Plate theory'on land.A continental dynamics theory is initiating and developing based on the internal driving force of continent.This heralded a landmark geological revolution is coming soon. At the same time,the 21st century human survival and development resources,the environment and disaster reduction,and other issues need to be addressed urgently.All of this requires us to understand the deep Earth,and the only direct means of direct observation of the Earth's continental crust is'Continental Scientific Drilling'. Geological samples,especially those from deep of the Earth,are the most direct study subjects for geologists.But the only way to access the true samples from deep of the earth is drilling.The most direct evidence always originated from the deep of the earth,such as core,cuttings,fluid samples and other physical samples.This is also true for ophiolite researches. Continental scientific drilling has been demonstrated as an efficient technique for directly obtaining information from the Earth’s surface to the deep crust,and is acknowledged as'to build a telescope inserting to the interior of the Earth',as well as'a key for opening the door of the Earth'.Over the past four decades,continental scientific drilling has achieved great success in enhancing our knowledge of the Earth,and in providing information on mineral resources,large engineering projects and global change.These benefits also relate to ophiolite research. Along with China's Brahmaputra River intermittently distributed ophiolite sets.Its distribution in Tibet is more than 1,000 kilometres long and extends along the Brahmaputra and the Indian Ocean to Myanmar and Pakistan.We have completed a number of coring holes along this ophiolite belt in recent years.The cores were collected from these holes provide geologists with real physical samples coring from the depths of the earth,which have played a significant role in deepening their ophiolite research.And the coring drilling projects along this ophiolite belt will be continue for years,to continue to provide geologists enough ophiolite real samples for their researches. No advanced drilling technology,no enough high quality samples from the deep Earth,the in-depth ophiolite research will be restricted(Zhang et al.,2013).
文摘In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. These decisions were adopted by American government and would also be helpful for the strategic development of Chinese power grid. It is proposed that China should take precaution,carry out security research on the overall dynamic behaviour characteristics of the UHV grid using the complexity theory,and finally provide safeguard for the Chinese UHV grid. It is also pointed out that,due to the lack of matured approaches to controll a cascading failure,the primary duty of a system operator is to work as a "watchdog" for the grid operation security,eliminate the cumulative effect and reduce the risk and losses of major cascading outages with the help of EMS and WAMS.
文摘There exists some difficulties among high school students in understanding English monologues because some words are unfamiliar to them while some sentences are long and complex.Just by listening,reading,and translating from English into Mandarin,the students are unable to fully grasp the conveyed messages in these monologues.In the General Senior High School Curriculum Standards(2017 Edition),it clearly required candidates to be able to understand familiar short dialogues and monologues about daily life topics.Candidates should be able to understand the gist,obtain specific factual information,make simple inferences about what they are listening to,and understand the speaker^intention,views,as well as attitude.This article mainly discusses specific implementation strategies of in-depth interpretation when listening in on monologues.
基金financially supported by the Beijing Hospital Management Center“Dengfeng”plan[DFL20191901]。
文摘Objective To identify the representative attributes of the five elements of a person with a qualitative methodology and provide the basis for the clinical diagnosis and treatment of“people with the five elements in traditional Chinese medicine(TCM).”Methods Data collected from the literature review,two sessions of brainstorming of experts with related experience in“people with the five elements in TCM”from October 2020 to December 2020,and six rounds of in-depth interviews with 30 participants who had various attributes of the five elements from March 2021 to October 2021 were analyzed.Triangulation was used in this study,and theming and synthesizing were used to analyze the data.Results A total of 31 experts and 30 interviewees participated in this study.The median age of the experts and interviewees were 48.0 and 38.5 years,respectively;51.66%and 54.8%of experts and interviewees,respectively,were men.The descriptors of facial diagrams of“people with the five elements in TCM”were complexion,shape,distribution state of facial bones,convergence trend of facial muscles,and facial expression.A theoretical model of“people with the five elements in TCM”was shaped based on these findings.Conclusion The study suggests a possibility for bridging the gap between personality and bodily state,identifying an avenue for personality research from the perspective of TCM.
基金This work is funded by Key Scientific Research Projects of Colleges and Universities in Henan Province under Grant 22A460022Training Plan for Young Backbone Teachers in Colleges and Universities in Henan Province under Grant 2021GGJS077.
文摘Traditional three-dimensional(3D)image reconstruction method,which highly dependent on the environment and has poor reconstruction effect,is easy to lead to mismatch and poor real-time performance.The accuracy of feature extraction from multiple images affects the reliability and real-time performance of 3D reconstruction technology.To solve the problem,a multi-view image 3D reconstruction algorithm based on self-encoding convolutional neural network is proposed in this paper.The algorithm first extracts the feature information of multiple two-dimensional(2D)images based on scale and rotation invariance parameters of Scale-invariant feature transform(SIFT)operator.Secondly,self-encoding learning neural network is introduced into the feature refinement process to take full advantage of its feature extraction ability.Then,Fish-Net is used to replace the U-Net structure inside the self-encoding network to improve gradient propagation between U-Net structures,and Generative Adversarial Networks(GAN)loss function is used to replace mean square error(MSE)to better express image features,discarding useless features to obtain effective image features.Finally,an incremental structure from motion(SFM)algorithm is performed to calculate rotation matrix and translation vector of the camera,and the feature points are triangulated to obtain a sparse spatial point cloud,and meshlab software is used to display the results.Simulation experiments show that compared with the traditional method,the image feature extraction method proposed in this paper can significantly improve the rendering effect of 3D point cloud,with an accuracy rate of 92.5%and a reconstruction complete rate of 83.6%.
文摘Objective: The objective was to explore manager experiences using the RAFAELA system. Background: The RAFAELA system was developed in Finland during the 1990s to create a work situation where patients’ care needs were balanced with personnel resources. The system is used in almost all hospitals in Finland and is implemented in several European countries. However, the system has never been evaluated outside Finland. This study, focusing on the managers’ perspective, represents the second report from a larger Norwegian evaluation project of the RAFAELA system. Methods: An explorative qualitative design was chosen. Data were collected by individual in-depth interviews at a university hospital in Norway during 2012-2013. A total of 10 informants in various management positions were interviewed. The tape-recorded interviews were transcribed verbatim, and the transcripts were analysed using Kvale’s method for content analysis. Results: Four main themes emerged from the qualitative data: making the invisible visible;a common language;a system for prospective planning;and a resource-demanding tool. Conclusions: The study indicated that the RAFAELA system provided useful information about the patients’ care needs and nursing activities. Also the system provided a common reference frame for discussing nursing, staffing and allocation. Although the managers considered the RAFAELA to be time consuming in the implementation phase, they considered the system to be an important tool.
基金supported by National "863" High Technology Research and Development Program Foundation(No.2006AA01Z208)Six Talented Eminence Foundation of Jiangsu Province+1 种基金Natural Science Foundation of Jiangsu Province(No. BK2004149)Green-Blue Academic Talented Project Foundation of Jiangsu Province
文摘Nodes cooperation is a significant prerequisite for the realization of the relaying Ad Hoc.While with the development of multi-hop cellular networks, how to stimulate intermediate nodes to do the packet-forwarding deserves more concerning.At present research,the incentive schemes in pure Ad Hoc and multi-hop cellular networks are analyzed and compared to classify the strengths and drawbacks of each scheme.We explain in particular what the key issues are to implement incentive schemes for cooperation. Finally,an incentive scheme based on integration of reputation and charging systems is proposed not only to block the existence of selfish nodes,but to satisfy the rational requirement of nodes.
文摘We firstly introduce development background of new collective forest tenure reform.The situations indicate that the collective forest tenure reform has already stepped into comprehensive and in-depth stage.However,due to neglect of local demands and actual conditions,there appear problems of low operating efficiency of supporting measures and relevant policies and little effect of in-depth reform.Therefore,it is required to strictly distinguish the relation between system change of collective forest tenure and the in-depth reform.For the purpose of in-depth reform,in accordance with local situations of forest farmers and forestry organizations,requirements for system,as well as local reform conditions,we strictly divide system change of collective forest tenure into three types:induced institutional change,hidden induced institutional change and imposed institutional change.Then,we divide the imposed institutional change into weak institutional change and pure strong institutional change.
基金supported by the National Key Research and Development Project(2019YFA0708700)the National Natural Science Foundation of China(52104061)+2 种基金the project funded by China Postdoctoral Science Foundation(2020M682264)the Shandong Provincial Natural Science Foundation(ZR2021QE075)the Fundamental Research Funds for the Central Universities(20CX06090A)。
文摘Knowledge of migration and retention mechanisms of elastic gel particles(EGPs)in pore-throats is essential for the effective application of EGPs as a smart sweep improvement and profile control agent for enhanced oil recovery(EOR).The matching coefficient(defined as the ratio of particle size to pore-throat size)is used to investigate its influence on migration,retention and profile control performance of EGPs.A 1-D continuous pore-throat visualization model(PTVM),a 2-D heterogeneous PTVM and a 3-D heterogeneous core model were constructed and used to investigate pore-scale migration,retention and controlling mechanism of migration and retention characteristics on EGPs profile control.The results of the 1-D continuous PTVM indicated that while the matching coefficient was in the optimal range(i.e.,0.20-0.32),the EGPs could not only smoothly migrate to the deeper pore-throats,but also form stable retention in the pores to resist the erosion of injected water,which was conducive to the effective indepth profile control.The results of the 2-D heterogeneous PTVM verified that the sweep efficiency in low-permeability regions could be significantly improved by in-depth migration and stable retention of EGPs in the pore-throats with an optimal matching coefficient(0.29),which was much better than that in cases with a smaller matching coefficient(0.17)or an excessive matching coefficient(0.39).Moreover,the NMR displacement experiments of 3-D heterogeneous cores were carried out to simulate the EGPs profile control in actual reservoir porous media.Saturation images and T2 spectrum curves of crude oil showed that EOR in the low-permeability layer was highest(56.1%)using EGPs profile control with an optimal matching coefficient,attributing to the in-depth migration and stable retention of EGPs.
文摘In this work, we observe the behavior of block space-time code in wireless channel dynamics. The block space-time code is optimally constructed in slow fading. The block code in quasistatic fading channels provides affordable complexity in design and construction. Our results show that the performance of the block space-time code may not be as good as conventionally convolutional coding with serial transmission for some channel features. As channel approaches fast fading, a coded single antenna scheme can collect as much diversity as desired by correctly choosing the free distance of code. The results also point to the need for robust space-time code in dynamic wireless fading channels. We expect that self-encoded spread spec-trum with block space-time code will provide a robust performance in dynamic wireless fading channels.
文摘Based on the empirically analysis of the data from a nationwide survey in 2010 in China, the study found. (1) The overwhelming majority of rural migrant workers in China were not willing to convert their rural household registration (nongye hukou) to an urban or non-rural registration Orei nong hukou). If they were required to return the rural land contract rights as precondition, only lOper cent were willing to be urban citizens. (2) For the small proportion of migrant workers who were willing to convert their rural household registration to urban household registration, 'obtaining access to better education and more opportunities for the continuation of education for their children' is the major incentive. (3) The primary reason for retaining a rural hukou, on the other hand, is to keep their rural contract land. (4) Finally, there is no significant difference between the rural migrant workers who were born before 1980 and those after 1980, in term of the attitude toward converting rural hukou to urban hukou. The policy recommendations drew from the findings are as follows: 1) In order to promote the urbanization process, the government should choose the path of 'urbanization based on the long term residence in the towns and cities' instead of the path of "urbanization based on household registration '. 2) The rural migrant workers should be converted into urban citizens without being forced to give up their contact land. 3) The government should give equal weight in policy making to the migrant workers born before 1980 and those born after 1980. Therefore, the policy emphasis of deepening the urbanization of China should focus on the 'equalization of the resource allocation of the public services and social welfare" while the characteristics of the separation of the household registration system should not be strengthened any longer.
基金This research is partly supported by the Ministry of Education’s Humanities and Social Science Project No.11YJC740048,Scientific planning issues of education in Heilongjiang Province No.GBC1211062,research fund for the program of new century excellent talents in Heilongjiang provincial university No.1155-ncet-008 and the National Natural Science Foundation of China under grant Nos.60903083,61502123.
文摘In-depth vocabulary knowledge plays a key role in L2(second language)vocabulary acquisition,and computer English vocabulary is vital to academic performances of students majored in Computer Science.While many Chinese students cannot realize computer English vocabulary acquisition due to lacking input environment of computer English.To solve this problem,with techniques of keyword search,information retrieval,and text classification,to meet the diverse learning needs of students,it built the in-depth computer English vocabulary knowledge acquisition environment for the high frequency of computer English words,providing the depth of knowledge such as polysemy,synonyms,syntax,and pragmatics.The construction of in-depth computer English vocabulary acquisition environment helps future studies on computer English teaching applications.
基金supported by the National Key Research and Development Program of China (No. 2017YFA0505001)National Natural Science Foundation of China (No. 21974025)the project of Shanghai Key Laboratory of Kidney and Blood Purification。
文摘Herein, we developed a fractionation-free negative enriching method incorporating methylamidation, siteselective dimethylation and aldehyde resin coupling(MADMAR) for in-depth C-terminome analysis. The methylamidation blocked the free carboxyl group on proteins first, followed by Lys C digestion of methylamidated proteins. Then, the site-selective dimethylation blocked the N-terminal amino group of the digested peptides without affecting the amino groups of lysine. Finally, the aldehyde resin was used to capture non-C-terminal peptides containing amino groups from lysine, while leaving the C-terminal peptides without free amino group in the supernatant for its analysis. We identified 1359 database-annotated protein C-termini from 50 μg He La proteins, which was 74% more than our previous method based on aldehyde resin. Moreover, 279 protein neo-C-termini were identified.
文摘The Second Demographic Transition(SDT)framework highlights individuals'ideational shift toward greater individualism in explaining the rise of non-marriage unions.Contemporary China has seen a substantial increase in premarital cohabitation.Drawing on 65 in-depth interviews with highly educated young urban Chinese women and men,this article examines the gendered ways in which young Chinese adults perceive and make decisions about premarital cohabitation,as they envision their ideal lives and what autonomy and self-realization mean to them.I demonstrate that while male respondents predominantly view cohabitation positively as a risk-reduction strategy for avoiding incompatible marriages,female respondents still consider cohabitation to be a risk-amplification arrangement in practice that increases the possibility of uncertain marriage prospect,unsafe sex,and reputational damages.Young women,but not men,often have to strategizethrough carefully managing information disclosureabout persistent parental expectations that discourage women's premarital cohabitation.As a result,while male respondents regard marriage to be neither the necessary precondition nor the end goal of cohabitation,female respondents,who otherwise emphasize autonomy and individualistic fulfllment,continue to desire a close linkage between cohabitation and marriage.Leveraging the unique strength of qualitative data in demographic research,this article articulates the gender asymmetry in how women and men perceive cohabitation's risks,benefits,and link to marriage.I elucidate the gendered tension between privately-held ideals of individualism vis-a-vis enduring social norms of female marriageability,as women and men differentially navigate parental expectations surrounding cohabitation.In so doing,this article makes a theoretical contribution by bringing a careful treatment of gender into the SDT framework.