|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | IMPACTS OF CLIMATE CHANGE ON CROPPING SYSTEM AND ITS IMPLICATION FOR AGRICULTURE IN CHINA显示文摘Based on the analyses on amplitudes of historical variation of temperature and precipitation inthe past 500 years and latest 100 years,according to the regional climate change scenarios forChina estimated by composite GCM,the potential impacts of climate change on cropping systemsin China in future are simulated and assessed using the cropping system model developmentspecially for the Chinese cropping patterns.It is shown that under the projected future climatechange by 2050 the most parts of the present double cropping area would be replaced by thedifferent triple cropping patterns while the current double cropping area would shift towards thecentral part of the present single cropping area.More explicitly,the northern boundary of triplecropping area would shift from its current border at the Changjing River to the Huanghe River,ashift of more than 5 degrees of latitude.And the shift of multiple cropping areas leads to asignificant decrease of single cropping area.Furthermore,considering the changes mentioned above in combination with the likely negativebalance of precipitation and evapotranspiration and,therefore,increase of moisture stress(i.e.less water availability),as well as the possible increase of heat stress disaster and decrease of LGS(length of growing season),the potential implication of climate change for agriculture in China arealso analyzed roughly in this paper.As a result,however,it is still very difficult to reach a specific conclusion that the futureclimate change will he favorable or unfavorable to farm in China because of the complicated Chinesefarming patterns,the complex-various social and economic environment of agriculturaldevelopment and,especially,a great scientific uncertainties in the investigation/prediction ofclimate change. | 王馥棠 | 1997 | Acta meteorologica Sinica1997，11，4： | 37 |
| 2 | The relation between HLA-DQA1 genes and genetic susceptibility to duodenal ulcer in Wuhan Hans显示文摘AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wascarried out by digesting the locus specificpolymerase chain reaction amplified productswith alleles specific restriction enzymes(PCR-RFLP),i.e.,Apal Ⅰ,Bsaj Ⅰ,Hph Ⅰ,Fok Ⅰ,Mbo Ⅱ and Mnl Ⅰ.RESULTS The allele frequencies of DQA1 * 0301and DQA1 * 0102 in patients with duodenal ulcerwere significantly higher and lower respectivelythan those in healthy controls(0.40 vs 0.20,P = 0.003,mcorret = 0.024)and(0.05 vs 0.14,P = 0.012,but Pcorret>0.05),respectively.CONCLUSION DQA1 * 0301 is a susceptiblegene for duodenal ulcer in Wuhan Hans,andthere are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients andhealthy controls. | Du YP Deng CS Lu DY Huang MF Guo SF Hou W | 2000 | World Journal of Gastroenterology2000，6，1： | 37 |
| 3 | Enhanced recovery after surgery programs in patients undergoing hepatectomy:A meta-analysis显示文摘AIM:To evaluate the impact of enhanced recovery after surgery(ERAS) programs in comparison with traditional care on liver surgery outcomes.METHODS:The Pub Med,EMBASE,CNKI and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials(RCTs) comparing the ERAS program with traditional care in patients undergoing liver surgery. Studies selected for the meta-analysis met all of the following inclusion criteria:(1) evaluation of ERAS in comparison to traditional care in adult patients undergoing elective open or laparoscopic liver surgery;(2) outcome measures including complications,recovery of bowel function,and hospital length of stay; and(3) RCTs. The following exclusion criteria were applied:(1) the study was not an RCT;(2) the study did not compare ERAS with traditional care;(3) the study reported on emergency,non-elective or transplantation surgery; and(4) the study consisted of unpublished studies with only the abstract presented at a national or international meeting. The primary outcomes were complications. Secondary outcomes were length of hospital stay and time to first flatus.RESULTS:Five RCTs containing 723 patients were included in the meta-analysis. In 10/723 cases,patients presented with benign diseases,while the remaining 713 cases had liver cancer. Of the five studies,three were published in English and two were published in Chinese. Three hundred and fifty-four patients were in the ERAS group,while 369 patients were in the traditional care group. Compared with traditional care,ERAS programs were associated with significantly decreased overall complications(RR = 0.66; 95%CI:0.49-0.88; P = 0.005),grade?Ⅰ?complications(RR = 0.51; 95%CI:0.33-0.79; P = 0.003),and hospitallength of stay [WMD =-2.77 d,95%CI:-3.87-(-1.66); P < 0.00001]. Similarly,ERAS programs were associated with decreased time to first flatus [WMD =-19.69 h,95%CI:-34.63-(-4.74); P < 0.0001]. There was no statistically significant difference in grade Ⅱ-Ⅴ complications between the two groups.CONCLUSION:ERAS is a safe and effective program in liver surgery. Future studies should define the active elements to optimize postoperative outcomes for liver surgery. | Tian-Gen Ni Han-Teng Yang Hao Zhang Hai-Peng Meng Bo Li | 2015 | World Journal of Gastroenterology2015，21，30： | 34 |
| 4 | Effects of sunspot cycle length and CO_2 on air temperature along Qinghai-Xizang railway and air temperature's trend prediction显示文摘There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (Trw) from 1935 to 2000 are constructed. The investigation is suggested that: Trw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 15-year lagged concentration of atmospheric carbon dioxide (CO2), and the correlation coefficients between them are -0.76 (SCL) and 0.88 (CO2), respectively. The future SCL is predicted by the model of average generated function constructed with its main cycles of 76a, 93a, 108a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21st century, and then it could be becoming shorter in the second half of the 21st century. Based on the natural change of SCL and the effect of double CO2 concentration, Trw in the 21st century is forecasted. It could warm up about 0.50℃ in the first half of the 21st century compared with the last decade of last century. The mean maximum air temperature could be likely about 0.20℃ in July and from 0.40℃ to 1.10℃ in January. The annual air temperature difference would likely reduce 0.3-1.00℃. The probability of above predictions ranges from 0.64 to 0.73. | LI Dongliang, QUO Hui, WANG Wen & WEI LiCold & Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, China Department of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China | 2004 | Science China Earth Sciences2004，47，z1： | 28 |
| 5 | Map and analysis of microsatellites in the genome of Populus: The first sequenced perennial plant显示文摘Environmental Sciences Division, Oak Ridge National Laboratory, TN, USA We mapped and analyzed the microsatellites throughout 284295605 base pairs of the unambiguously assembled sequence scaffolds along 19 chromosomes of the haploid poplar genome. Totally, we found 150985 SSRs with repeat unit lengths between 2 and 5 bp. The established microsatellite physical map demonstrated tr at SSRs were distributed relatively evenly across the genome of Populus. On average, These SSRs occurred every 1883 bp within the poplar genome and the SSR densities in intergenic regions, introns, exons and UTRs were 85.4%, 10.7%, 2.7% and 1.2%, respectively. We took di-, tri-, tetra-and pentamers as the four classes of repeat units and found that the density of each class of SSRs decreased with the repeat unit lengths except for the tetranucleotide repeats. It was noteworthy that the length diversification of microsatellite sequences was negatively correlated with their repeat unit length and the SSRs with shorter repeat units gained repeats faster than the SSRs with longer repeat units. We also found that the GC content of poplar sequence significantly correlated with densities of SSRs with uneven repeat unit lengths (tri-and penta-), but had no significant correlation with densities of SSRs with even repeat unit lengths (di-and tetra-). In poplar genome, there were evidences that the occurrence of different microsatellites was under selection and the GC content in SSR sequences was found to significantly relate to the functional importance of microsatellites. | LI ShuXian & YIN TongMing College of Environment and Forest Resources, Nanjing Forestry University, Nanjing 210037, China Environmental Sciences Division, Oak Ridge National Laboratory, TN, USA | 2007 | Science China(Life Sciences)2007，50，5： | 25 |
| 6 | Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil显示文摘Vegetable oil can be used as a base oil in minimal quantity of lubrication(MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force,and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that(1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient;(2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient;(3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil;(4) viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils;(5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature;(6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and(7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force,87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7% energy ratio coefficient. | Li Benkai Li Changhe Zhang Yanbin Wang Yaogang Jia Dongzhou Yang Min | 2016 | Chinese Journal of Aeronautics2016，29，4： | 20 |
| 7 | ON CHROMATIC POLYNOMIALS OF TWO CLASSES OF GRAPHS显示文摘Up to the present, there are few classes of graphs of which chromatic polynomials can be computed with formulas. For most graphs, computing their chromatic | 刘儒英 | 1987 | Chinese Science Bulletin1987，32，16： | 19 |
| 8 | The Queue Length Distribution for M/G/1 Queue with Delay Single Server Vacation | TANG Ying\|hui,\ TANG Xiao\|woSichuan University, Chengdu 610064 University of Electronic Science & Technology of China, Chengdu 610054 | 2000 | Systems Science and Systems Engineering2000，10，2： | 16 |
| 9 | Effects of Cadmium Stress on Seed Germination, Seedling Growth and Seed Amylase Activities in Rice (Oryza sativa) | Jun-yu HE Yan-fang REN Cheng ZHU De-an JIANG | 2008 | Rice science2008，15，4： | 15 |
| 10 | Amplification and Compression of Ultrashort Fundamental Solitons in An Erbium-Doped Nonlinear Amplifying Fiber Loop Mirror显示文摘A nonlinear amplifying loop mirror constructed from erbium-doped fiber is proposed for simultaneous amplification and compression of ultrashort fundamental solitons. Numerical simulations show that, the proposed device performs efficient high-quality amplification and compression of solitons. | P. K. A. Wai | 2003 | 光学学报2003，23，S1： | 14 |
| 11 | pms3 is the locus causing the original photoperiod-sensitive male sterility mutation of‘Nongken 58S'显示文摘Photoperiod-sensitive genic male sterile (PSGMS) rice is a very useful germplasm for hybrid rice development. It was first found as a spontaneous mutant in a japonica cultivar ’Nongken 58’. pms3 on chromosome 12 was determined to be the locus where the original PSGMS mutation occurred, changing the normal cultivar Nongken 58 to PSGMS Nongken 58S. Large amounts of RAPD and AFLP analyses were also conducted for the fine mapping of the pms3 genomic region, which resulted in 4 molecular markers linked to pms3. Although these markers somewhat increased the marker density of this region, the pms3 locus is still located in a marker-sparse region. | 梅明华 陈亮 章志宏 李子银 徐才国 张启发 | 1999 | Science China(Life Sciences)1999，42，3： | 14 |
| 12 | Cavity length below chute aerators显示文摘It is proved that air entrainment is one of the efficient measures dealing with cavi-tation control for the release works of hydropower projects. There are many factors to be considered in designing a chute aerator. One of the most important factors concerns the cavity length below the aerator,which has outstanding effects on air entrainment against cavitation damage. It is crucial to determine reasonable emergence angle for the calculation of the cavity length. In the present paper the overall effects of structural and hydraulic parameters on the emergence angle of the flow from the aerator were analyzed. Four improved expressions of the emer-gence angle with weight coefficient were investigated through experimental data of 68 points observed from 12 aerators of 6 hydropower projects,of both model and prototype,on the basis of error theory. A method to calculate the cavity length be-low aerators was suggested,which considers overall effects of the above men-tioned parameters. Comparison between the method in this paper and the other five methods of calculating the cavity length showed that the present method is much more reliable than the existing methods while the mean error of the method is less than others. | WU JianHua RUAN ShiPing | 2008 | Science China(Technological Sciences)2008，51，2： | 14 |
| 13 | Laboratory pull-out tests on fully grouted rock bolts and cable bolts:Results and lessons learned显示文摘Laboratory pull-out tests were conducted on the following rock bolts and cable bolts:steel rebars,smooth steel bars,fiberglass reinforced polymer threaded bolts,flexible cable bolts,IR5/IN special cable bolts and Mini-cage cable bolts.The diameter of the tested bolts was between 16 mm and 26 mm.The bolts were grouted in a sandstone sample using resin or cement grouts.The tests were conducted under either constant radial stiffness or constant confining pressure boundary conditions applied on the outer surface of the rock sample.In most tests,the rate of displacement was about 0.02 mm/s.The tests were performed using a pull-out bench that allows testing a wide range of parameters.This paper provides an extensive database of laboratory pull-out test results and confirms the influence of the confining pressure and the embedment length on the pull-out response(rock bolts and cable bolts).It also highlights the sensitivity of the results to the operating conditions and to the behavior of the sample as a whole,which cannot be neglected when the test results are used to assess the bolt-grout or the grouterock interface. | Isabelle Thenevin Laura Blanco-Martín Faouzi Hadj-Hassen Jacques Schleifer Zbigniew Lubosik Aleksander Wrana | 2017 | Journal of Rock Mechanics and Geotechnical Engineering2017，9，5： | 14 |
| 14 | The bulk transfer coefficients and surface fluxes on the western Tibetan Plateau显示文摘On the gradient observational data of the atmospheric surface layer from September 1997 to December 1998 collected by two sets of Automatic Weather Station (AWS) installed in Gaize and Shiquanhe on the western Tibetan Plateau, mean surface roughness lengths at the two stations above are determined to be 2.7 and 2.9 cm, respectively. The bulk transfer coefficients each day are computed by the profile-flux method, means of the bulk transfer coefficient for momentum (i.e. drag coefficient) in 1998 are 4.83×10-3 and 4.75×103 at the two stations. The surface fluxes of momentum, sensible heat and latent heat each day are further estimated by the bulk formulas, annual mean of these fluxes is 3.4×10-2 and 1.8×102N/m2, 73.1 and 67.2 W/m2, 15.4 and 2.9 W/m2, respectively. The diurnal and seasonal variations are obtained by a composite method and the relationships among the heat transfers between land and atmosphere, plateau monsoon and plateau rain season are also discussed. | Guoping Li Tingyang Duan Yuanfa Gong | 2000 | Chinese Science Bulletin2000，45，13： | 13 |
| 15 | THE TRANSIENT SOLUTION FOR M/G/1 QUEUEWITH SERVER VACATIONS显示文摘In this paper, the transient solutions for M/G/1 queues with single server vacation and multiple server vacations are firstly studied, and the recursion expressions of their Laplace transform are given. Further the distribution and stochastic decomposition result of the queue length at a random point in equilibrium are directly obtained from the transient solution. As will be seen this paper provides a intuitive and elegant method for studying transient solutions for M/G/1 queues with single server. | 唐应辉 | 1997 | Acta Mathematica Scientia1997，17，3： | 13 |
| 16 | Typical Gait Analysis of a Six-legged Robot in the Context of Metamorphic Mechanism Theory显示文摘The equivalent mechanism of the system is often considered as one specific mechanism in most existing studies of multi-legged robots, however the equivalent mechanism is varying while the robot moves on the ground. Four typical tripod period gaits of a radial symmetrical six-legged robot are analyzed. Similar to the metamorphic mechanism, the locomotion of multi-legged robot is considered as a series of varying hybrid serial-parallel mechanisms by assuming the constraints of the feet on the ground with hinges. One gait cycle is divided into several periods, and in different walking period there is a specific equivalent mechanism corresponding to it, and the walking process of multi-legged robot is composed by these series of equivalent mechanisms. Walking performance can be got by analyzing these series of equivalent mechanisms. Kinematics model of the equivalent mechanism is established, workspaces of equivalent mechanisms are illustrated by simulation and a concept of static stability workspace is proposed to evaluate the static stability of these four gaits. A new method to calculate the stride length of multi-legged robots is presented by analyzing the relationship between the workspace of two adjacent equivalent parallel mechanisms in one gait cycle. The stride lengths of four gaits are given by simulations. Comparison of stride length and static stability among these four typical tripod gaits are given. It has been proved that mixed gait and insect-wave gait II have better static stability than mammal kick-off gait and insect-wave gait I. Insect-wave gait II displays its advantage on stride length while the height of robot body lower than 87 mm, mammal kick-off gait has superiority on stride length while the height of robot body higher than 115 mm, and insect-wave gait I shows its shortcoming in stride length. The proposed method based on metamorphic theory and combining the footholds and body height of robot provides a new method to comprehensive analyze the performance of multi-legged robot. | XU Kun DING Xilun | 2013 | Chinese Journal of Mechanical Engineering2013，26，4： | 12 |
| 17 | Energy harvesting via nonlinear energy sink for whole-spacecraft显示文摘This paper presents nonlinear energy sink with giant magnetostrictive-piezoelectric material for energy harvesting of the wholespacecraft vibration reduction system. The whole-spacecraft vibration attenuation system can effectively reduce vibration and achieve self-tuning enhanced energy harvesting range. The open-circuit voltage generated at low frequency is affected by the magnetic field force, alternating magnetic field and relative displacement. In order to acquire a steady periodic solution of the energy harvesting system, a combination of the harmonic balance method and pseudo arc length continuation technique is used.The numerical outcomes are consistent with the analytical outcomes in a certain range, which also proves the accuracy and reliability of the results. The amplitude and voltage of the energy harvesting system are analyzed by parameters such as cubic stiffness, viscous damping, and external excitation acceleration. In addition, this paper provides a new idea for broadband energy harvesting. | ZHANG YeWei LU YanNan CHEN LiQun | 2019 | Science China(Technological Sciences)2019，62，9： | 12 |
| 18 | Attributable cost of a nosocomial infection in the intensive care unit: A prospective cohort study显示文摘AIM To study the impact of hospital-acquired infections(HAIs) on cost and outcome from intensive care units(ICU) in India. METHODS Adult patients(> 18 years) admitted over 1-year, to a 24-bed medical critical care unit in India, were enrolled prospectively. Treatment cost and outcome data were collected. This cost data was merged with HAI data collected prospectively by the Hospital Infection Control Committee. Only infections occurring during ICU stay were included. The impact of HAI on treatment cost and mortality was assessed. RESULTS The mean(± SD) age of the cohort(n = 499) was42.3 ± 16.5 years. Acute physiology and chronic health evaluation-Ⅱ score was 13.9(95%CI: 13.3-14.5); 86% were ventilated. ICU and hospital length of stay were 7.8 ± 5.5 and 13.9 ± 10 d respectively. Hospital mortality was 27.9%. During ICU stay, 76(15.3%) patients developed an infection(ventilator-associated pneumonia 50; bloodstream infection 35; urinary tract infections 3), translating to 19.7 infections/1000 ICU days. When compared with those who did not develop an infection, an infection occurring during ICU stay was associated with significantly higher treatment cost [median(inter-quartile range, IQR) INR 92893(USD 1523)(IQR 57168-140286) vs INR 180469(USD 2958)(IQR 140030-237525); P < 0.001 and longer duration of ICU(6.7 ± 4.5 d vs 13.4 ± 7.0 d; P < 0.01) and hospital stay(12.4 ± 8.2 d vs 21.8 ± 13.9 d; P < 0.001)]. However ICU acquired infections did not impact hospital mortality(31.6% vs 27.2%; P = 0.49).CONCLUSION An infection acquired during ICU stay was associated with doubling of treatment cost and prolonged hospitalization but did not significantly increase mortality. | Binila Chacko Kurien Thomas Thambu David Hema Paul Lakshmanan Jeyaseelan John Victor Peter | 2017 | World Journal of Critical Care Medicine2017，6，1： | 11 |
| 19 | 长春花内生细菌多样性与柑橘黄龙病菌的相关性显示文摘【目的】分析感柑橘黄龙病长春花植株与健康长春花植株不同部位内生细菌菌群结构变化,为柑橘黄龙病菌与长春花内生细菌的相关性研究提供理论基础。【方法】本研究利用兼性厌氧可培养技术、16S rDNA限制性片段长度多态性分析(Restriction fragment length polymorphism,RFLP)以及16S rDNA序列分析相结合的方法。【结果】分别从感病和健康长春花叶、茎、根的组织中分离获得67株内生细菌,与GenBank中29种细菌的相似性达到97%-100%。其中短小杆菌属(Curtobacterium sp.)、欧文氏菌属(Erwinia sp.)、蜡样芽胞杆菌(Bacillus cereus)为感病长春花内生细菌的优势菌群,鞘胺醇单胞菌属(Brevundimonas sp.)、芽胞杆菌属(Bacillus sp.)为健康长春花内生细菌的优势菌群;马胃葡萄球菌(Staphylococcus equorum)为两者的共同优势菌群。通过RFLP方法分析,感病株得到16个、健株得到23个操作分类单元(Operational TaxonomicUnits,OTUs),感病植株中除柑橘黄龙病菌Candidatus Liberibacter asiaticus外,还有丰富的CandidatusLiberibacter sp.存在。【结论】感病与健康长春花植株中均含有丰富的内生细菌,黄龙病菌的存在改变了长春花原有内生细菌的菌群结构,且菌群多样性下降。可见长春花内生细菌在一定程度上受到柑橘黄龙病菌的抑制。 | 李佳 王中康 谢攀 吴东 殷幼平 | 2012 | 微生物学报2012，52，4： | 11 |
| 20 | 主题爬行中的隧道穿越技术显示文摘由于网络环境的复杂性和网页内容的多主题性,要想得到更多的特定主题相关网页,就要穿越那些主题不相关网页来获取更多的主题相关网页,即隧道穿越.将隧道穿越分为灰色隧道穿越和黑色隧道穿越.对于灰色隧道,在爬行过程中,将一个多主题Web页面分割成数量不多的内容块分别处理来避免由于网页整体主题不相关给该块所带来的影响.对于黑色隧道的穿越,将隧道中主题不相关网页根据其父亲页面的主题相关性赋予一个深度值,然后根据其深度值的大小进行取舍,来达到扩展主题爬行区域的目的.实验结果显示,这两种方法都达到了预期效果,所以方法是有效、稳健和实用的. | 彭涛 孟宇 左万利 王英 胡亮 | 2010 | 计算机研究与发展2010，47，4： | 11 |
您所在的机构暂未开通此部分的功能，请联系管理员