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Commercial Efforts Flail to Replace Aging International Space Station
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作者 Chris Palmer 《Engineering》 2025年第5期6-8,共3页
Released in September 2024 by an oversight committee of the US National Aeronautics and Space Administration(NASA),a safety report about the International Space Station(ISS)cited,in addition to 50 other“areas of conc... Released in September 2024 by an oversight committee of the US National Aeronautics and Space Administration(NASA),a safety report about the International Space Station(ISS)cited,in addition to 50 other“areas of concern,”a troublesome leak first detected six years ago in one of the station’s modules[1].Given the persistent leak,called“a top safety risk”[2],and the fact that the space sta-tion has outlived its original life expectancy by more than 10 years,the agency’s current plans call for decommissioning the ISS in 2031 by dragging it into the Pacific Ocean[3]. 展开更多
关键词 Pacific Ocean international space station iss citedin safety report international space station space sta tion LEAK DECOMMISSIONING AGING
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Electroacupuncture improves microcirculation and neuronal morphology in the spinal cord of a rat model of intervertebral disc extrusion 被引量:10
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作者 Dai-xun Jiang Zhi-song Lu +4 位作者 Ge-bin Li Sheng-yong Sun Xiang Mu Peter Lee Wu Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第2期237-243,共7页
Most studies on spinal cord neuronal injury have focused on spinal cord tissue histology and the expression of nerve cell damage and repair-related genes. The importance of the microcirculation is often ignored in spi... Most studies on spinal cord neuronal injury have focused on spinal cord tissue histology and the expression of nerve cell damage and repair-related genes. The importance of the microcirculation is often ignored in spinal cord injury and repair research. Therefore, in this study, we established a rat model of intervertebral disc extrusion by inserting a silica gel pad into the left ventral sur-face of T13. Electroacupuncture was used to stimulate the bilateralZusanlipoint (ST36) and Neiting point (ST44) for 14 days. Compared with control animals, blood lfow in the ifrst lumbar vertebra (L1) was noticeably increased in rats given electroacupuncture. Microvessel density in the T13 segment of the spinal cord was increased significantly as well. The number of normal neurons was higher in the ventral horn of the spinal cord. In addition, vacuolation in the white matter was lessened. No obvious glial cell proliferation was visible. Furthermore, hindlimb motor function was improved signiifcantly. Collectively, our results suggest that electroacupuncture can improve neuronal morphology and microcirculation, and promote the recovery of neurological functions in a rat model of intervertebral disc extrusion. 展开更多
关键词 nerve regeneration ELECTROACUPUNCTURE intervertebral disc blood circulation inflamma-tion neuroprotection motor function neurons NSFC grants neural regeneration
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Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders A meta-analysis 被引量:8
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作者 Yingli Zhang Wei Liang +3 位作者 Shichang Yang Ping Dai Lijuan Shen Changhong Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第28期2666-2676,共11页
OBJECTIVE: This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hallucination of patients with schizophrenia spectrum disorders. DATA SOURCES: O... OBJECTIVE: This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hallucination of patients with schizophrenia spectrum disorders. DATA SOURCES: Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Controlled Trials databases from January 1985 to May 2012. Key words were "transcranial magnetic stimulation", "TMS", "repetitive tran- scranial magnetic stimulation", and "hallucination". STUDY SELECTION: Selected studies were randomized controlled trials assessing therapeutic ef- ficacy of repetitive transcranial magnetic stimulation for hallucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hallucination in schizophrenia spectrum disorders. Control groups received sham stimulation. MAIN OUTCOME MEASURES: The primary outcome was total scores of Auditory Hallucinations Rating Scale, Auditory Hallucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hallucination item, and Hallucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function. RESULTS: Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. All data were completely effective, involving 398 patients. Overall mean weighted effect size for repeti- tive transcranial magnetic stimulation versus sham stimulation was statistically significant (MD = -0.42, 95%C/: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%C/: 1.39 to 6.24, P =0.005). No significant differences were found between active repetitive transcranial magnetic stimulation and sham stimulation for positive or negative symptoms. Compared with sham stimulation, active repeti- tive transcranial magnetic stimulation had equivocal outcome in cognitive function and commonly caused headache and facial muscle twitching. CONCLUSION: Repetitive transcranial magnetic stimulation is a safe and effective treatment for auditory hallucination in schizophrenia spectrum disorders, 展开更多
关键词 neural regeneration META-ANALYSIS transcranial magnetic stimulation auditory hallucination schizophre-nia schizophrenia spectrum disorders schizophreniform disorder temporoparietal cortex cognitive func-tion positive symptom grants-supported paper NEUROREGENERAtion
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Existence results for unilateral contact problem with friction of thermo-electro-elasticity 被引量:1
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作者 H.BENAISSA EL-H.ESSOUFI R.FAKHAR 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第7期911-926,共16页
This work studies a mathematical model describing the static process of contact between a piezoelectric body and a thermally-electrically conductive foundation. The behavior of the material is modeled with a thermo-el... This work studies a mathematical model describing the static process of contact between a piezoelectric body and a thermally-electrically conductive foundation. The behavior of the material is modeled with a thermo-electro-elastic constitutive law. The contact is described by Signorini's conditions and Tresca's friction law including the electrical and thermal conductivity conditions. A variational formulation of the model in the form of a coupled system for displacements, electric potential, and temperature is de- rived. Existence and uniqueness of the solution are proved using the results of variational inequalities and a fixed point theorem. 展开更多
关键词 static frictional contozt thermo-piezoelectric material Signorini's condi-tion Tresca's friction frictional heat generation variational inequality fixed point process
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APPLICATIONS OF HYPERGEOMETRIC SUMMATION THEOREMS OF KUMMER AND DIXON INVOLVING DOUBLE SERIES 被引量:1
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作者 H.M.SRIVASTAVA M.I.QURESHI +1 位作者 Kaleem A.QURAISHI Ashish ARORA 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期619-628,共10页
Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust ... Using series iteration techniques identities and apply each of these identities in we derive a number of general double series order to deduce several hypergeometric reduction formulas involving the Srivastava-Daoust double hypergeometric function. The results presented in this article are based essentially upon the hypergeometric summation theorems of Kummer and Dixon. 展开更多
关键词 Pochhammer's symbol Gamma function series identities hypergeometric re-duction formulas Srivastava-Daoust double and multiple hypergeometric func-tions Legendre's duplication formula Gauss-Legendre multiplication formula Kummer's theorem Dixon's theorem
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Review on Tactile Sensory Feedback of Prosthetic Hands for the Upper-Limb Amputees by Sensory Afferent Stimulation 被引量:1
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作者 柴国鸿 隋晓红 +2 位作者 李鹏 刘小旋 蓝宁 《Journal of Shanghai Jiaotong university(Science)》 EI 2014年第5期587-591,共5页
Loss of sensory function for upper-limb amputees inevitably devastates their life qualities, and lack of reliable sensory feedback is the biggest defect to sophisticated prosthetic hands, greatly hindering their usefu... Loss of sensory function for upper-limb amputees inevitably devastates their life qualities, and lack of reliable sensory feedback is the biggest defect to sophisticated prosthetic hands, greatly hindering their usefulness and perceptual embodiment. Thus, it is extremely necessary to accomplish an intelligent prosthetic hand with effective tactile sensory feedback for an upper-limb amputee. This paper presents an overview of three kinds of existing sensory feedback approaches, including cutaneous mechanical stimulation(CMS), transcutaneous electrical nerve stimulation(TENS) and direct peripheral nerve electrical stimulation(DPNES). The emphasis concentrates on major scientific achievements, advantages and disadvantages. The TENS on the skin areas with evoked finger sensation(EFS) at upper-limb amputees' residual limbs might be one of the most promising approaches to realize natural sensory feedback. 展开更多
关键词 sensory feedback intelligent prosthetic hand sensory substitution cutaneous mechanical stimulation(CMS) transcutaneous electrical nerve stimulation(TENS) direct peripheral nerve electrical stimulation(DPNES) evoked finger sensation(EFS)
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动词+-ion(-tion,-ation)=名词
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作者 喻安民 《语言教育》 1992年第1期40-41,共2页
英语中有大量的名词是以-tion结尾的,而这些名词绝大多数是由动词后加-ion、-tion、-ation、-ition-ution等派生而成的。其构词方法如下: 一、一般以t结尾的动词后面直接加-ion构成-tion名词:act-action 行为,作用 adopt-adoption 采用c... 英语中有大量的名词是以-tion结尾的,而这些名词绝大多数是由动词后加-ion、-tion、-ation、-ition-ution等派生而成的。其构词方法如下: 一、一般以t结尾的动词后面直接加-ion构成-tion名词:act-action 行为,作用 adopt-adoption 采用collect-collection 收集,收藏物 elect-election 选举二、一般以-te结尾的动词去e加-ion: 展开更多
关键词 tion 构词方法 ELECtion adopt COLLECtion SORPtion 吸附作用 RESOLVE simplify REVOLUtion
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Quantitative volumetric analysis of the optic radiation in the normal human brain using diffusion tensor magnetic resonance imaging-based tractography
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作者 Dong-Hoon Lee Ji-Won Park Cheol-Pyo Hong 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第3期280-284,共5页
To attain the volumetric information of the optic radiation in normal human brains, we per- formed diffusion tensor imaging examination in 13 healthy volunteers. Simultaneously, we used a brain normalization method to... To attain the volumetric information of the optic radiation in normal human brains, we per- formed diffusion tensor imaging examination in 13 healthy volunteers. Simultaneously, we used a brain normalization method to reduce individual brain variation and increase the accuracy of volumetric information analysis. In addition, tractography-based group mapping method was also used to investigate the probability and distribution of the optic radiation pathways. Our results showed that the measured optic radiation fiber tract volume was a range of about 0.16% and that the fractional anisotropy value was about 0.53. Moreover, the optic radiation probability fiber pathway that was determined with diffusion tensor tractography-based group mapping was able to detect the location relatively accurately. We believe that our methods and results are help- ful in the study of optic radiation fiber tract information. 展开更多
关键词 nerve regeneration optic radiation diffusion tensor imaging diffusion tensor tractogra-phy magnetic resonance imaging volumetric analysis probability map group mapping visualiza-tion individual variation neural regeneration
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Early rehabilitation improves neurofunctional outcome after surgery in children with spinal tumors 被引量:4
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作者 Nezire Kose Ozge Muezzinoglu +3 位作者 Sevil Bilgin Sevilay Karahan Ilkay Is kay Burcak Bilginer 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第2期129-134,共6页
To investigate the effect of early rehabilitation on neurofunctional outcome after surgery in chil- dren with spinal tumors, this study reviewed the medical charts and radiographic records of 70 pediatric patients (1... To investigate the effect of early rehabilitation on neurofunctional outcome after surgery in chil- dren with spinal tumors, this study reviewed the medical charts and radiographic records of 70 pediatric patients (1-17 years old) who received spinal tumor surgical removal. The peddiatric patients received rahabilitation treatment at 4 (range, 2-7) days after surgery for 10 (range, 7-23) days. Results from the Modified McCormick Scale, Functional Independence Measure for Chil- dren, American Spinal Injury Association Impairment Scale and Karnofsky Performance Status Scale demonstrated that the sensory function, motor function and activity of daily living of pedi- atric children who received early rehabilitation were significantly improved. Results also showed that tumor setting and level localization as well as patients's clinical symptoms have no influences on neurofunctional outcomes. 展开更多
关键词 nerve regeneration spinal cord injury spinal cord tumor CHILDREN rehabilitation func-tion SENSE motor retrospective analysis neural regeneration
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Selection of Measured Signals in the Navigation Measuring Complex 被引量:1
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作者 柯芳 Andrey PROLETARSKY Konstantin NEUSIPIN 《Journal of Measurement Science and Instrumentation》 CAS 2011年第4期346-348,共3页
To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a select... To increase accuracy of navigation parameters,a perspective measuring complex with intellectual components is developed.Conception of synthesis optimal structure of the measuring complex is realized basing on a selective method using principles of the functional systems.Selection of measured information is finished by original numeric criterion of observation level of state vector components.Prediction is realized by algorithm of self-organization that makes synthesis of the optimal complication.Therefore mechanism of self-regulation is realized and accuracy of the selective navigation complex is increased. 展开更多
关键词 selected navigation complex functional systems intellectual components observation level selforganiza tion
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A new method of single celestial-body sun positioning based on theory of mechanisms 被引量:2
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作者 Zhang Wei Xu Xiaofeng Wu Yuanzhe 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2016年第1期248-256,共9页
Considering defects of current single celestial-body positioning methods such as discon- tinuity and long period, a new sun positioning algorithm is herein put forward. Instead of tradi- tional astronomical spherical ... Considering defects of current single celestial-body positioning methods such as discon- tinuity and long period, a new sun positioning algorithm is herein put forward. Instead of tradi- tional astronomical spherical trigonometry and celestial coordinate system, the proposed new positioning algorithm is built by theory of mechanisms. Based on previously derived solar vector equations (from a C1R2p2 series mechanism), a further global positioning method is developed by inverse kinematics. The longitude and latitude coordinates expressed by Greenwich mean time (GMT) and solar vector in local coordinate system are formulated. Meanwhile, elimination method of multiple solutions, errors of longitude and latitude calculation are given. In addition, this algo- rithm has been integrated successfully into a mobile phone application to visualize sun positioning process. Results of theoretical verification and smart phone's test demonstrate the validity of pre- sented coordinate's expressions. Precision is shown as equivalent to current works and is acceptable to civil aviation requirement. This new method solves long-period problem in sun sight running fix- ing and improves applicability of sun positioning. Its methodology can inspire development of new sun positioning device. It would be more applicable to be combined with inertial navigation systems for overcoming discontinuity of celestial navigation systems and accumulative errors of inertial nav- igation systems. 展开更多
关键词 Celestial navigation Inverse kinematics Longitude and latitude coordinates MECHANISMS Navigation systems Position measurement Single celestial-body posi-tioning SUN
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THREE SOLUTIONS FOR A FRACTIONAL ELLIPTIC PROBLEMS WITH CRITICAL AND SUPERCRITICAL GROWTH 被引量:1
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作者 张金国 刘晓春 《Acta Mathematica Scientia》 SCIE CSCD 2016年第6期1819-1831,共13页
In this paper, we deal with the existence and multiplicity of solutions to the frac- tional elliptic problems involving critical and supercritical Sobolev exponent via variational arguments. By means of the truncation... In this paper, we deal with the existence and multiplicity of solutions to the frac- tional elliptic problems involving critical and supercritical Sobolev exponent via variational arguments. By means of the truncation combining with the Moser iteration, we prove that our problem has at least three solutions. 展开更多
关键词 fractional elliptic equation variational methods three solutions Moser itera-tion
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A simulation study of water property changes using geometrical alteration in SPC/E 被引量:1
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作者 Ming-Ru Li Nan Zhang Feng-Shou Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第8期204-211,共8页
We present a systematic investigation of the impact of changing the geometry structure of the SPC/E water model by performing a series of molecular dynamic simulations at 1 bar (1 bar = 105 Pa) and 298.15 K. The geo... We present a systematic investigation of the impact of changing the geometry structure of the SPC/E water model by performing a series of molecular dynamic simulations at 1 bar (1 bar = 105 Pa) and 298.15 K. The geometric modification includes altering the H-O-H angle range from 90° to 115° and modifying the O-H length range from 0.90 A to 1.10 A in the SPC/E model. The former is achieved by keeping the dipole moment constant by modifying the O-H length, while in the latter only the O-H length is changed. With the larger bond length and angle, we find that the liquid shows a strong quadrupole interaction and high tetrahedral structure order parameter, resulting in the enhancement of the network structure of the liquid. When the bond length or angle is reduced, the hydrogen bond lifetime and self-diffusion constant decrease due to the weakening of the intermolecular interaction. We find that modifying the water molecular bond length leading to the variation of the intermolecular interaction strength is more intensive than changing the bond angle. Through calculating the average reduced density gradient and thermal fluctuation index, it is found that the scope of vdW interaction with neighbouring water molecules is inversely proportional to the change of the bond length and angle. The effect is mainly due to a significant change of the hydrogen bond network. To study the effect of water models as a solvent whose geometry has been modified, the solutions of ions in different solvent environments are examined by introducing NaCI. During the dissolving process, NaCI ions are ideally dissolved in SPC/E water and bond with natural water more easily than with other solvent models. 展开更多
关键词 molecular dynamics simulation geometric modification intermolecular interaction ion's solva-tion
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Meteorological applications of precipitable water vapor measurements retrieved by the national GNSS network of China 被引量:10
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作者 Liang Hong Cao Yunchang +3 位作者 Wan Xiaomin Xu Zhifang Wang Haishen Hu Heng 《Geodesy and Geodynamics》 2015年第2期135-142,共8页
In this study, the Global Navigation Satellite System (GNSS) network of China is discussed, which can be used to monitor atmospheric precipitable water vapor (PWV). By the end of 2013, the network had 952 GNSS sit... In this study, the Global Navigation Satellite System (GNSS) network of China is discussed, which can be used to monitor atmospheric precipitable water vapor (PWV). By the end of 2013, the network had 952 GNSS sites, including 260 belonging to the Crustal Movement Observation Network of China (CMONOC) and 692 belonging to the China Meteorological Administration GNSS network (CMAGN). Additionally, GNSS observation collecting and data processing procedures are presented and PWV data quality control methods are investigated. PWV levels as determined by GNSS and radiosonde are compared. The results show that GNSS estimates are generally in good agreement with measurements of radio- sondes and water vapor radiometers (WVR). The PWV retrieved by the national GNSS network is used in weather forecasting, assimilation of data into numerical weather prediction models, the validation of PWV estimates by radiosonde, and plum rain monitoring. The network is also used to monitor the total ionospheric electron content. 展开更多
关键词 Precipitable water vapor (PWV) Global navigation satellite system(GNSS) Crustal Movement ObservationNetwork of China (CMONOC)China meteorological administra-tion GNSS network (CMAGN) Water vapor radiometers (WVR) Quality control Meteorological application Assimilation
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Sonoluminescence as the PeTa Radiation, Part Two 被引量:1
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作者 Vitali A. Tatartchenko 《Optics and Photonics Journal》 2017年第11期197-220,共24页
This paper is a continuation of one published in this journal nine months ago. The two papers present a model of cavitational luminescence (CL), multi-bubble sonoluminescence (MBSL), one-bubble sonoluminescence (OBSL)... This paper is a continuation of one published in this journal nine months ago. The two papers present a model of cavitational luminescence (CL), multi-bubble sonoluminescence (MBSL), one-bubble sonoluminescence (OBSL), and laser-induced bubble luminescence (LIBL). The basis of this model is the PeTa (Perel’man-Tatartchenko) effect, a nonequilibrium characteristic radiation under first-order phase transitions, especially vapour condensation. In this model, the main role is given to the liquid, where the evaporation, condensation, flash, and subsequent collapse of bubbles occur. The instantaneous vapour condensation inside the bubble is a reason for the CL/MBSL/OBSL/LIBL. Apparently, the dissolved gases and other impurities in the liquid are responsible for peaks that appear at the background of the main spectrum. They are most likely excited by a shock wave occurred during the collapse. This paper, in contrast to the previous one, presents a slightly expanded model that explains additional experimental data concerning especially the LIBL spectrum. As a result, today we are not aware of any experimental data that would contradict the PeTa model, and we continue to assert that there is no mystery to the CL/MBSL/OBSL/LIBL phenomena, as well as no reason to hope that they can be used for high-temperature chemical reactions, and even more so for a thermonuclear ones. 展开更多
关键词 Cavitational LUMINESCENCE (CL) SONOLUMINESCENCE (SL) Multi-Bubble SONOLUMINESCENCE (MBSL) One-Bubble SONOLUMINESCENCE (OBSL) LASER-INDUCED Bubble LUMINESCENCE (LIBL) PeTa (Perel’man-Tatartchenko) Effect FIRST-ORDER Phase TRANSItionS Evapora-tion Condensation
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Fixation and Creep of Compressed Wood of Chinese Fir Irradiated with Gamma Rays 被引量:1
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作者 王洁瑛 赵广杰 《Forestry Studies in China》 CAS 2001年第1期58-65,共8页
In order to discuss the mechanisms of permanent fixation of wood compression set , compressed wood of Chinese fir (Cunninghamia lanceolata) was irradiated by gamma rays from 60 Co. The irradiation doses wer... In order to discuss the mechanisms of permanent fixation of wood compression set , compressed wood of Chinese fir (Cunninghamia lanceolata) was irradiated by gamma rays from 60 Co. The irradiation doses were 0 (for match specim ens), 10 3, 5×10 3, 10 4, 5×10 4, 10 5, 5×10 5, 10 6, 5×10 6 Gy, res pectively. Then the weight loss, the equilibrium moisture content (EMC), the rec overy of wood compression set after adsorption (RSA) and the recovery after imme rsion in water (RSW), as well as the creep behaviour under a dry specimen condit ion and under an adsorption and subsequent desorption condition were measured an d discussed. This research proves that the doses of gamma irradiation have great effect on weight loss, EMC, RSA, RSW of irradiated compressed wood of Chinese f ir. The weight loss and the EMC increase, the RSA and the RSW fall drastically w hen the irradiation doses exceed 10 6 Gy. Both the instantaneous compliance and the creep compliance of the irradiated specimens under the two measurement cond itions show the general trend of increase with the increase of gamma irradiation doses. It can be deduced that decomposition or decrystallization reactions happ en in the wood cell wall at high gamma irradiation doses, especially at doses of around 5×10 6 Gy. In addition, this research proves that decomposition of mai n components of cell wall of compressed wood will lead to fixation of compressio n set of wood to a certain degree. 展开更多
关键词 gamma irradiation compressed wood Chinese fir fixa tion CREEP
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Man-machine Function Allocation Based on Uncertain Linguistic Multiple Attribute Decision Making 被引量:13
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作者 ZHANG An TANG Zhili ZHANG Chao 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2011年第6期816-822,共7页
Function allocation is one of the necessary stages in the design course of man-machine systems since appropriate function allocation makes the whole system more effective, reliable and inexpensive. Therefore, our rese... Function allocation is one of the necessary stages in the design course of man-machine systems since appropriate function allocation makes the whole system more effective, reliable and inexpensive. Therefore, our research mainly focuses on the problems of function allocation between man and machine in man-machine systems, analyses each capability advantage of man and machine according to their respective inherent characteristics and makes a comparison between them. In view of highly uncertain characteristics of decision attribute value in the practical process, we introduce the uncertain linguistic multiple attribute decision making (ULMADM) method in the function allocation process. Meanwhile, we also use the uncertain extended weighted arithmetic averaging (UEWAA) method to determine the automation level range of the operator functions. Then, we eventually estab- lish the automation level of man-machine function allocation by using the multi-attribute decision making algorithm, which is combined by UEWAA and uncertain linguistic hybrid aggregation (ULHA) operators. Finally, an example about function allocation is given, that is, fault diagnosis in the cockpit of civil aircraft. The final result of the example demonstrates that the proposed method about function allocation is feasible and effective. 展开更多
关键词 man-machine systems function allocation uncertain linguistic multiple attribute decision making levels of automa tion fault detection cockpits RELIABILITY
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Atmospheric Deposition-Carried Pb, Zn, and Cd from a Zinc Smelter and Their Effect on Soil Microorganisms 被引量:12
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作者 YANG Yuan-Gen2, JIN Zhi-Sheng, BI Xiang-Yang, LI Fei-Li, SUN Li, LIU Jie and FU Zhi-You Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China) 《Pedosphere》 SCIE CAS CSCD 2009年第4期422-433,共12页
Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years ... Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Cuizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn (508 mg kg^-1), Pb (95.6 mg kg^-1), and Cd (5.98 mg kg^-1) with low ratios of Zn/Cd (59.1-115) and Pb/Cd (12.4-23.4). Composite pollution indices (CPIs) of surface soils (2.52-15.2) were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals (SDM) in soils within 1.5 km of the smelter (averaging 1.25) was six times higher than that of the reference soils (0.209). A smaller soil microbial biomass was found more frequently in metal accumulated soils (85.1-438 μg C g^-1) than in reference soils (497 μg C g^-1), and a negative correlation (P 〈 0.01) of soil microbial biomass carbon to organic carbon ratio (Cmic/Corg) with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM (R = -0.773, P 〈 0.01). Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass . 展开更多
关键词 composite pollution index heavy metals microbial biomass saturation degree of metals sequential extrac- tion
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AN OVERVIEW ON THE URBAN-RURAL INTERACTION IN THE PAST 50 YEARS IN CHINA 被引量:4
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作者 Qi Lu Jin-yan Zhan Kang-won Lee 《Chinese Geographical Science》 SCIE CSCD 2001年第3期2-9,共8页
China is a country with a long history of agricultural development,the tr adition of bureaucratic administra-tion and economic management system s for the social development.In its t ransition from traditional society... China is a country with a long history of agricultural development,the tr adition of bureaucratic administra-tion and economic management system s for the social development.In its t ransition from traditional society to modern soci-ety during the past 50years,the rela tions between rural areas and urban a reas have been kept abnormal if considered from the point of view of the modernized co untries.Today,China still has its more than 70percent of population,bu t limited capital,lower technology and underdeveloped culture,in the rural areas.This unbalance forms not only the o bstacles to China’s modernization of social development,but also the barriers to th e society,economy and environment sustainable devel-opment.This paper focuses on the dis cussion about the coordinate develo pment of the relations between rural and urban in the past 50years,and the authors hold that only has the abnormal relation between the two areas been corrected,could China’s future development of natio nal economy be successful. 展开更多
关键词 urban-rural interaction coordin ATE DEVELOPMENT of urban-rural RELA tion DEVELOPMENT of national econo-my
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Kinetics of Asymmetric Reduction of Phenylglyoxylic Acid to R-(-)-Mandelic Acid by Saccharomyces Cerevisiae FD11b 被引量:9
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作者 肖美添 黄雅燕 +1 位作者 孟春 郭养浩 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第1期73-80,共8页
The kinetics of asymmetric production of R-(-)-mandelic acid (R-MA) from phenylglyoxylic acid (PGA) catalyzed by Saccharomyces cerevisiae sp. strain FD11b was studied by fed-batch cultures. The concentrations of... The kinetics of asymmetric production of R-(-)-mandelic acid (R-MA) from phenylglyoxylic acid (PGA) catalyzed by Saccharomyces cerevisiae sp. strain FD11b was studied by fed-batch cultures. The concentrations of glucose and PGA were controlled respectively with a dual feeding system. When the electron donor glucose was supplied at the rate of 0.0833mmol·gdw^-1·h^-1, the specific production rate (qp) and the enantiomeric excess of R-MA reached the maximum 0.353mmol·gdw^-1·h^-1 and 97.1%, respectively. The apparent reduction activity of yeast FD 11 b was obviously affected by both substrate PGA and product MA. The qp value reached the maximum 0.36-0.38mmol·gdw^-1·h^-1 when the PGA concentration was controlled between 25 and 35mmol·L^-1. The obvious substrate inhibition of bioconversion was observed at the PGA concentrations higher than 40mmol·L^-1. The accumulation of product MA also caused a severe feed-back inhibition for its production when the product concentration was above 60mmol·L^-1. The kinetic model with the inhibition effect of both substrate and product was simulated by a computer-based least-square arithrnatic. The established kinetic model was in good agreement with the experimental data. 展开更多
关键词 Saccharomyces cerevisiae asymmetric reduction R-(-)-mandelic acid substrate inhibition product inhibi- tion kinetic model
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