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Investigation of Evaporated Fragments in Intermediate Energy Heavy Ion Collisions
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作者 Liu, Fuhu Zhang, Jinjun 《Chinese journal of nuclear physics》 EI 1997年第4期216-219,共4页
The reactions induced by intermediate energy heavy ions are investigated.The evap-orated fragment multiplicity and excitation energy distributions are calculated and comparedwith the experimental data of the reaction ... The reactions induced by intermediate energy heavy ions are investigated.The evap-orated fragment multiplicity and excitation energy distributions are calculated and comparedwith the experimental data of the reaction Ar+Ag at 50 and 70 MeV/u. 展开更多
关键词 INTERMEDIATE ENERGY heavy ion Collisions evaporated fragment MULTIPLICITY Excitation ENERGY
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Multiplicity Distribution of Evaporated Fragments in Relativistic Nucleus-Nucleus Collisions
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作者 Liu, Fuhu 《Chinese journal of nuclear physics》 EI 1995年第1期17-20,共4页
The multiplicity distribtuion of evaporated fragments in relativistic nucleus-nucleus collisions are discussed.The calculated results are in agreement with the exper-imental data in the energy range from 3.7 to 200 Ge... The multiplicity distribtuion of evaporated fragments in relativistic nucleus-nucleus collisions are discussed.The calculated results are in agreement with the exper-imental data in the energy range from 3.7 to 200 GeV/N. 展开更多
关键词 Relativistic nucleus-nucleus collisions evaporated fragment MULTIPLICITY distribution
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The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries
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作者 Joseph Mayindo Mayele Jacob B. Kolleh Joel Emmanuel Saburi 《Open Journal of Ecology》 2024年第5期455-482,共28页
This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of c... This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urbanization, invaded by non-local plants, or enclosed for individual use and by subdividing farmlands into subsequent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possible. Land fragmentation is one of the key reasons why the ability of most resources in East Africa becomes scarcer, and those remaining become “privatized” by more powerful community members—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further by affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation problems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighboring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a substantial increase in population density. The study review further explores the trend in the performance of agriculture by average farm sizes within the intervals of five years by highlighting their strong linkages and found that the average farm size has declined drastically, especially for Kenya. This can only mean that small farms kept becoming smaller and smaller and that there were more small-scale farmers. The results further depicted that the major and commonly cultivated food crops among the East African countries include maize, sorghum, rice, cassava, sweet potatoes, bananas, Irish potatoes, beans, peas, etc., with maize yields (Mt/ha) in 2003 for Uganda being the highest (1.79 Mt/ha) and the lowest in Rwanda (0.77 Mt/ha) respectively. Therefore, from the review results, recommendations are being made as to how the negative impacts of land fragmentation on agricultural productivity can be reduced or mitigated. One way is by community sensitization and awareness about the importance of land consolidation and its proposition on farm productivity. 展开更多
关键词 Land fragmentation Land Consolidation Farm Productivity INDUSTRIALIZATION Impacts CAUSES Average Farm Size Population East Africa
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Frequency of Monthly Ejaculation at Sexual Intercourse, DNA Fragmentation Index and Fertilization Rate among Sperm Donors and Fertility-Challenged Men in Sub-Saharan Africa: Paper 2
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作者 Abayomi B. Ajayi Bamgboye M. Afolabi +6 位作者 Victor D. Ajayi Ifeoluwa O. Oyetunji Adedamilola Atiba Seun Saanu Ayodeji T. Adeoye Joy I. Ehichioya Ibukun I. Ayelehin 《Open Journal of Urology》 2020年第3期60-78,共19页
Introduction: Heterogenous sexual intercourse often produces a powerful orgasm that stimulates the pituitary function. Studies have suggested ejaculation frequency based on age. Materials and Methods: Semi-structured ... Introduction: Heterogenous sexual intercourse often produces a powerful orgasm that stimulates the pituitary function. Studies have suggested ejaculation frequency based on age. Materials and Methods: Semi-structured questionnaires were used to collect information from subjects. Semen samples were collected from sperm donors and sub-fertile men who presented for infertility challenges. Processing and analysis of semen samples were done according to World Health Organization (WHO) guidelines. Sperm deoxyribonucleic acid (DNA) fragmentation was evaluated using the Halosperm kit. Results: Among sperm donors, those aged χ2 = 0.09, P-value = 0.81, OR = 3.2, 95% CI: 0.23, 45.19) while among sub-fertile men those aged ≥40 years were approximately 2.3 times more likely to have very low frequency of MESI compared to aged χ2 = 2.11, P-value = 0.51, OR = 2.27, 95% CI: 0.74, 9.92). The frequency of all categories of MESI was highest among sub-fertile men aged χ2 = 0.03, P-value = 0.57, OR = 2.42, 95% CI: 0.41, 14.46). Sub-fertile men aged ≥40 with diastolic hypertension (≥90 mmHg) were approximately 6 times more likely to have a low (6 - 10) frequency of MESI compared to those aged χ2 = 1.97, P-value = 0.16, OR = 6.22, 95% CI: 0.69, 55.77). Overall mean fertilization rate was significantly higher (t-test = 2.44, P-value = 0.01) among sub-fertile men aged Conclusion: Cigarette smoking, more than alcohol consumption, appears to be a major factor that significantly affects the frequency of MESI among sub-fertile men in all age groups. Frequency of MESI negatively but insignificantly correlated with systolic blood pressure. 展开更多
关键词 MONTHLY EJACULATION at Sexual INTERCOURSE Systolic and Diastolic Blood Pressures DNA fragmentation INDEX Fertilization Rates Social Habits Sub-Fertile Males Sub-Sahara Black AFRICANS
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Antibiotic-Resistant Bacterial Group in Field Soil Evaluated by a Newly Developed Method Based on Restriction Fragment Length Polymorphism Analysis 被引量:1
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作者 Katsuji Watanabe Naoto Horinishi Kunimasa Matumoto 《Advances in Microbiology》 2015年第12期807-816,共10页
Spreading of antibiotic resistant bacteria into environment is becoming a major public health problem, implicating affair of the indirect transmission of antibiotic resistant bacteria to human through drinking water, ... Spreading of antibiotic resistant bacteria into environment is becoming a major public health problem, implicating affair of the indirect transmission of antibiotic resistant bacteria to human through drinking water, or vegetables, or daily products. Until now, the risk of nosocomial infection of antibiotic resistant bacteria has mainly been evaluated using clinical isolates by phenotypic method. To evaluate a risk of community-acquired infection of antibiotic resistant bacteria, a new method has been developed based on PCR-RFLP without isolation. By comparing restriction fragment lengths of the 16S rDNA gene from bacterial mixture grown under antibiotic treatment to those simulated from the DNA sequence, bacterial taxonomies were elucidated using the method of Okuda and Watanabe [1] [2]. In this study, taxonomies of polymyxin B resistant bacteria group in field soils, paddy field with organic manure and upland field without organic manure were estimated without isolation. In the both field soils, the major bacteria grown under the antibiotic were B. cereus group, which had natural resistance to this antibiotic. In field applied with organic manure, Prevotella spp., and the other Cytophagales, which were suggested to be of feces origin and to acquire resistance to the antibiotic, were detected. When numbers of each bacterial group were roughly estimated by the most probable number method, B. cereus group was enumerated to be 3.30 × 106 MPN/g dry soil in paddy field soil and 1.32 × 106 MPN/g dry soil in upland filed. Prevotella spp. and the other Cytophagales in paddy field were enumerated to be 1.31 × 106 MPN, and 1.07 × 106 MPN·g-1 dry soil. 展开更多
关键词 POLYMYXIN B Resistant Bacteria Field Soil Microchip ELECTROPHORESIS Multiple Enzyme RESTRICTION fragment Length Polymorphism Analysis the Most PROBABLE Number METHOD
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中国4个弓形虫虫株GRA6基因的比较分析 被引量:20
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作者 谢德华 翁亚彪 +4 位作者 李华文 郑唤钦 林瑞庆 张德林 朱兴全 《中国农业科学》 CAS CSCD 北大核心 2005年第7期1495-1500,共6页
通过对国内来源于不同宿主的ZS人株、SH人株、CN猪株、QH绵羊株4个弓形虫虫株,以及国际标准强毒株RH株的致密颗粒抗原(GRA6)基因进行PCR-RFLP分析,首次对中国弓形虫虫株进行了基因分型研究,旨在了解中国弓形虫基因型的分布情况,从而为... 通过对国内来源于不同宿主的ZS人株、SH人株、CN猪株、QH绵羊株4个弓形虫虫株,以及国际标准强毒株RH株的致密颗粒抗原(GRA6)基因进行PCR-RFLP分析,首次对中国弓形虫虫株进行了基因分型研究,旨在了解中国弓形虫基因型的分布情况,从而为进一步的分子遗传学研究以及弓形虫病的防制提供资料。PCR-RFLP分析显示两种带型:RH、SH、CN3株弓形虫为一种带型,QH和ZS2株弓形虫为另一种电泳带型。GRA6序列分析结果显示:RH、SH、CN3株弓形虫的GRA6基因序列上的MseΙ酶切位点与国外报道的RH株一致,同属于基因型Ι,为强毒株;QH和ZS2株弓形虫的MseΙ酶切位点与国外报道的弱毒株BEVERLEY株和ME49株一致,同属于基因型Ⅱ,与PCR-RFLP分析结果一致。除MseΙ酶切位点外,中国的几个虫株GRA6序列与GenBankTM注册的RH株及BEVERLEY和ME49两个弱毒株有个别碱基的差异。结果证明中国人源弓形虫包含了Ι、Ⅱ两种基因型,而动物源性弓形虫则因宿主和来源地不同亦有Ι、Ⅱ两个基因型。 展开更多
关键词 RFLP PCR MSe H 宿 RH
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Assessing forest cover changes and fragmentation in the Himalayan temperate region: implications for forest conservation and management
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作者 Kaleem Mehmood Shoaib Ahmad Anees +6 位作者 Akhtar Rehman Aqil Tariq Qijing Liu Sultan Muhammad Fazli Rabbi Shao’an Pan Wesam Atef Hatamleh 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第4期128-141,共14页
This study comprehensively assessed long-term vegetation changes and forest fragmentation dynamics in the Himalayan temperate region of Pakistan from 1989 to 2019.Four satellite images,including Landsat-5 TM and Lands... This study comprehensively assessed long-term vegetation changes and forest fragmentation dynamics in the Himalayan temperate region of Pakistan from 1989 to 2019.Four satellite images,including Landsat-5 TM and Landsat-8 Operational Land Imager(OLI),were chosen for subsequent assessments in October 1989,2001,2011 and 2019.The classified maps of 1989,2001,2011 and 2019 were created using the maximum likelihood classifier.Post-classification comparison showed an overall accuracy of 82.5%and a Kappa coefficient of 0.79 for the 2019 map.Results revealed a drastic decrease in closed-canopy and open-canopy forests by 117.4 and 271.6 km^(2),respectively,and an increase in agriculture/farm cultivation by 1512.8 km^(2).The two-way ANOVA test showed statistically significant differences in the area of various cover classes.Forest fragmentation was evaluated using the Landscape Fragmentation Tool(LFT v2.0)between 1989 and 2019.The large forest core(>2.00 km^(2))decreased from 149.4 to 296.7 km^(2),and a similar pattern was observed in medium forest core(1.00-2.00 km^(2))forests.On the contrary,the small core(<1.00 km^(2))forest increased from 124.8 to 145.3 km^(2) in 2019.The perforation area increased by 296.9 km^(2),and the edge effect decreased from 458.9 to 431.7 km^(2).The frequency of patches also increased by 119.1 km^(2).The closed and open canopy classes showed a decreasing trend with an annual rate of 0.58%and 1.35%,respectively.The broad implications of these findings can be seen in the studied region as well as other global ecological areas.They serve as an imperative baseline for afforestation and reforestation operations,highlighting the urgent need for efficient management,conservation,and restoration efforts.Based on these findings,sustainable land-use policies may be put into place that support local livelihoods,protect ecosystem services,and conserve biodiversity. 展开更多
关键词 Natural catastrophes Landsat Change detection Forest fragmentation Landscape fragmentation tool(LFT) AFFORESTATION REFORESTATION
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溶剂挥发法制备萃取剂微胶囊 被引量:24
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作者 杨伟伟 骆广生 +1 位作者 伍方昱 龚行楚 《高分子学报》 SCIE CAS CSCD 北大核心 2005年第2期207-212,共6页
萃取剂微胶囊的制备是利用微囊化方法将萃取剂包覆起来 ,解决传统液液萃取中的两相相分散、相混合、相分离以及溶剂的损失和设备结构复杂等问题 .用简单易控制的溶剂挥发法成功制备了聚砜及聚苯乙烯材料包覆的多种萃取剂 (如磷酸三丁酯 ... 萃取剂微胶囊的制备是利用微囊化方法将萃取剂包覆起来 ,解决传统液液萃取中的两相相分散、相混合、相分离以及溶剂的损失和设备结构复杂等问题 .用简单易控制的溶剂挥发法成功制备了聚砜及聚苯乙烯材料包覆的多种萃取剂 (如磷酸三丁酯 ,2 乙基己基磷酸 ,三辛胺和Aliquat 336 )微胶囊 ,并考察了壁材和分散剂的选择对不同萃取剂进行包覆的影响 ,同时研究了搅拌速度和膜溶液组成对微胶囊的形态、萃取剂包覆量的影响 .结果表明 ,(1)用聚砜作壁材可以包覆磷酸三丁酯、2 乙基己基磷酸 ,而用聚苯乙烯可以包覆三辛胺、Aliquat336 ;(2 )对于不同的O W乳液体系 ,只有选择合适的分散剂 ,才能得到理想球形状、分散性好的微胶囊 ;(3)增大搅拌速度可以降低液滴尺度 ,从而减小微胶囊粒径 ;(4)膜溶液组成的影响则表现在两个方面 ,一是膜溶液的粘度和两相界面张力是除搅拌速度外微胶囊粒径的决定因素 ,二是膜溶液中壁材与萃取剂的比例优化时 ,才能得到萃取剂包覆量高的微胶囊 . 展开更多
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Prediction of rock fragmentation in a fiery seam of an open-pit coal mine in India
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作者 Mukul Sharma Bhanwar Singh Choudhary +2 位作者 Autar K.Raina Manoj Khandelwal Saurav Rukhiyar 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2879-2893,共15页
Spontaneous combustion of coal increases the temperature in adjoining overburden strata of coal seams and poses a challenge when loading blastholes.This condition,known as hot-hole blasting,is dangerous due to the inc... Spontaneous combustion of coal increases the temperature in adjoining overburden strata of coal seams and poses a challenge when loading blastholes.This condition,known as hot-hole blasting,is dangerous due to the increased possibility of premature explosions in loaded blastholes.Thus,it is crucial to load the blastholes with an appropriate amount of explosives within a short period to avoid premature detonation caused by high temperatures of blastholes.Additionally,it will help achieve the desired fragment size.This study tried to ascertain the most influencial variables of mean fragment size and their optimum values adopted for blasting in a fiery seam.Data on blast design,rock mass,and fragmentation of 100 blasts in fiery seams of a coal mine were collected and used to develop mean fragmentation prediction models using soft computational techniques.The coefficient of determination(R^(2)),root mean square error(RMSE),mean absolute error(MAE),mean square error(MSE),variance account for(VAF)and coefficient of efficiency in percentage(CE)were calculated to validate the results.It indicates that the random forest algorithm(RFA)outperforms the artificial neural network(ANN),response surface method(RSM),and decision tree(DT).The values of R^(2),RMSE,MAE,MSE,VAF,and CE for RFA are 0.94,0.034,0.027,0.001,93.58,and 93.01,respectively.Multiple parametric sensitivity analyses(MPSAs)of the input variables showed that the Schmidt hammer rebound number and spacing-to-burden ratio are the most influencial variables for the blast fragment size.The analysis was finally used to define the best blast design variables to achieve optimum fragment size from blasting.The optimum factor values for RFA of S/B,ld/B and ls/ld are 1.03,1.85 and 0.7,respectively. 展开更多
关键词 Fiery seam Rock fragmentation Response Surface Method(RSM) Artificial Neural Network(ANN) Random Forest Algorithm(RFA) Multiple Parametric Sensitivity Analysis (MPSA)
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Bacterial Groups Concerned with Maturing Process in Manure Production Analyzed by a Method Based on Restriction Fragment Length Polymorphism Analysis
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作者 Katsuji Watanabe Naoto Horinishi +2 位作者 Kunimasa Matumoto Akihiro Tanaka Kenichi Yakushido 《Advances in Microbiology》 2015年第13期832-841,共10页
Composting is a biological aerobic decomposition process consisted from different phases. Although the Japanese Standards for manure recommended that it took at least 6 months to complete the maturing phase, there was... Composting is a biological aerobic decomposition process consisted from different phases. Although the Japanese Standards for manure recommended that it took at least 6 months to complete the maturing phase, there was no reliable ground. In order to find out shortening method of the maturing phase, the microorganisms concerned with a progress of the maturing was determined by using the most probable number method (MPN) and PCR-RFLP of the 16S rDNA, which was found effective to provide numbers and taxonomy of polymyxin B resistant bacterial groups in the former paper [1]. Compared to the numbers after thermophilic phase, those of Actinobacteria, δ-proteobacteria, and the other gram negative bacteria increased to 50 times, 20 times, and 105 times, respectively, after maturing phase, while those of Bacillus spp., and α and β-proteobacteria decreased to 1/10, and 1/105 after maturing phase. Numbers of the other Fumicutes, and γ-proteobacteria remained in the same revel. Actinobacteria, δ-proteobacteria, and the other gram negative bacteria might be concerned with a progress of the maturing phase, because these bacterial groups were detected and enumerated due to their proliferation ability. Although number of Acitinobacteria might be underestimated because of a PCR bias, the method was found effective for the purpose to monitor bacteria actively proliferated in culture medium. 展开更多
关键词 Maturing Phase MANURE PRODUCTION Microchip ELECTROPHORESIS Multiple Enzyme RESTRICTION fragment Length Polymorphism Analysis The Most PROBABLE Number METHOD
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Frequency of Monthly Ejaculation at Sexual Intercourse, DNA Fragmentation Index and Fertilization Rate among Sperm Donors and Fertility-Challenged Men in Sub-Saharan Africa: Paper 1 被引量:1
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作者 Abayomi B. Ajayi Bamgboye M. Afolabi +6 位作者 Victor D. Ajayi Ifeoluwa O. Oyetunji Adedamilola Atiba Seun Saanu Ayodeji T. Adeoye Joy Ehichioya Ibukun I. Ayelehin 《Open Journal of Urology》 2019年第11期181-194,共14页
Introduction: In humans, the ideal ejaculation frequency depends on age, exercise and sexual potential. Natural ejaculation frequency balances the testosterone levels in the body. Materials and Methods: Semi-structure... Introduction: In humans, the ideal ejaculation frequency depends on age, exercise and sexual potential. Natural ejaculation frequency balances the testosterone levels in the body. Materials and Methods: Semi-structured questionnaire was used to collect information from subjects. Semen samples were collected from sperm donors and sub-fertile men who presented for infertility challenges. Processing and analysis of semen samples were done according to World Health Organization guidelines. Sperm DNA fragmentation was evaluated using the Halosperm&#174;?kit. Results: A total of 114 subjects, including 19 sperm donors and 95 sub-fertile males were studied. There was a significant difference (t =?&#8722;5.96, P-value = 0.00001) in the mean [±sd] age of sperm donors (30.8 [8.1]) and that of sub-fertile men (42.3 [76]). There was a significant difference (t=?&#8722;4.10, P-value = 0.0005) in the mean monthly ejaculation during sexual intercourse (MESI) among sperm donors with DNA fragmentation index &#8722;2.20, P-value = 0.02) in MESI among sub-fertile men aged ≥40 years (8.9 [4.6]) than among those aged &#8722;0.67, SE = 0.28, t = &#8722;2.40, P-value = 0.02, 95% CI: &#8722;1.24,?&#8722;0.10). Conclusion: In men < 40 years, fewer MESI did not worsen the DFI. A higher number of professionals such as doctors, lawyers and engineers, reported lower monthly frequency of sexual ejaculations compared to entrepreneurs. Entrepreneurs and non-smokers had the highest frequencies of MESI. 展开更多
关键词 MONTHLY Sexual EJACULATION Rate DNA fragmentation INDEX Male INFERTILITY Age Group Body Mass INDEX Social HABITS Black AFRICANS
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Comparison of microwave- and thermal-assisted rock fragmentation methods at different temperatures and loading rates
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作者 Wei Yao Shuai Wang +2 位作者 Bangbiao Wu Ying Xu Kaiwen Xia 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第6期799-819,共21页
Understanding the effects of microwave irradiation and thermal treatment on the dynamic compression and fragmentation properties of rocks is essential to quantify energy consumption in rock engineering.In this study,F... Understanding the effects of microwave irradiation and thermal treatment on the dynamic compression and fragmentation properties of rocks is essential to quantify energy consumption in rock engineering.In this study,Fangshan granite(FG)specimens were exposed to microwave irradiation and heat treatment.The damage of FG specimens induced by these two methods was compared using X-ray CT scanning and ultrasonic wave method.The temperatures of FG after microwave irradiation and thermal treatment were effectively evaluated using a newly proposed technique.A novelty method for precisely determining the geometric features of fragments is developed to estimate the fragmentation energy.Thus,the dynamic uniaxial compressive strength(UCS),the dynamic fragmentation characteristics,and the fragmentation energy of FG after these two pretreatment methods can be reasonably compared.The noticeable distinction of loading rate effect on the dynamic UCS of FG between these two pretreatment methods is first observed.A relationship is established between the dynamic UCS and the damage induced by microwave irradiation and heat treatment.Moreover,fragmentation energy fan analysis is introduced to accurately compare the fragmentation properties of FG after two pretreatment methods in dynamic compression tests. 展开更多
关键词 Fangshan granite Dynamic experiments Microwave irradiation Thermal treatment Loading rate fragmentATION
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Progressive fragmentation of granular assemblies within rockslides: Insights from discrete-continuous numerical modeling
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作者 JIANG Hui ZHOU Yuande +2 位作者 WANG Jinting DU Xiuli HUANG Hailong 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1174-1189,共16页
Rock fragmentation plays a critical role in rock avalanches,yet conventional approaches such as classical granular flow models or the bonded particle model have limitations in accurately characterizing the progressive... Rock fragmentation plays a critical role in rock avalanches,yet conventional approaches such as classical granular flow models or the bonded particle model have limitations in accurately characterizing the progressive disintegration and kinematics of multi-deformable rock blocks during rockslides.The present study proposes a discrete-continuous numerical model,based on a cohesive zone model,to explicitly incorporate the progressive fragmentation and intricate interparticle interactions inherent in rockslides.Breakable rock granular assemblies are released along an inclined plane and flow onto a horizontal plane.The numerical scenarios are established to incorporate variations in slope angle,initial height,friction coefficient,and particle number.The evolutions of fragmentation,kinematic,runout and depositional characteristics are quantitatively analyzed and compared with experimental and field data.A positive linear relationship between the equivalent friction coefficient and the apparent friction coefficient is identified.In general,the granular mass predominantly exhibits characteristics of a dense granular flow,with the Savage number exhibiting a decreasing trend as the volume of mass increases.The process of particle breakage gradually occurs in a bottom-up manner,leading to a significant increase in the angular velocities of the rock blocks with increasing depth.The simulation results reproduce the field observations of inverse grading and source stratigraphy preservation in the deposit.We propose a disintegration index that incorporates factors such as drop height,rock mass volume,and rock strength.Our findings demonstrate a consistent linear relationship between this index and the fragmentation degree in all tested scenarios. 展开更多
关键词 Rock fragmentation ROCKSLIDE Numerical modelling Discrete-continuous modelling RUNOUT Cohesive zone model
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Effects of landscape fragmentation of plantation forests on carbon storage in the Loess Plateau,China
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作者 LEI Hangyu DUAN Dantong +3 位作者 CHEN Yi GUO Huifeng LI Jiangtao LI Xiang 《Journal of Arid Land》 SCIE CSCD 2024年第2期266-281,共16页
Tree plantation and forest restoration are the major strategies for enhancing terrestrial carbon sequestration and mitigating climate change.The Grain for Green Project in China has positively impacted global carbon s... Tree plantation and forest restoration are the major strategies for enhancing terrestrial carbon sequestration and mitigating climate change.The Grain for Green Project in China has positively impacted global carbon sequestration and the trend towards fragmentation of plantation forests.Limited studies have been conducted on changes in plantation biomass and stand structure caused by fragmentation,and the effect of fragmentation on the carbon storage of plantation forests remains unclear.This study evaluated the differences between carbon storage and stand structure in black locust forests in fragmented and continuous landscape in the Ansai District,China and discussed the effects of ecological significance of four landscape indices on carbon storage and tree density.We used structural equation modelling to explore the direct and indirect effects of fragmentation,edge,abiotic factors,and stand structure on above-ground carbon storage.Diameter at breast height(DBH)in fragmented forests was 53.3%thicker,tree density was 40.9%lower,and carbon storage was 49.8%higher than those in continuous forests;for all given DBH>10 cm,the trees in fragmented forests were shorter than those in continuous forests.The patch area had a negative impact on carbon storage,i.e.,the higher the degree of fragmentation,the lower the density of the tree;and fragmentation and distance to edge(DTE)directly increased canopy coverage.However,canopy coverage directly decreased carbon storage,and fragmentation directly increased carbon storage and tree density.In non-commercial forests,fragmentation reduces the carbon storage potential of plantation,and the influence of patch area,edge,and patchy connection on plantation should be considered when follow-up trees are planted and for the plantation management.Thus,expanding the area of plantation patches,repairing the edges of complex-shaped patches,enhancing the connectivity of similar patches,and applying nutrients to plantation forests at regular intervals are recommended in fragmented areas of the Loess Plateau. 展开更多
关键词 landscape fragmentation PLANTATION carbon storage tree allometry tree density structural equation modelling
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The relationship between DNA fragmentation and the intensity of morphologically abnormal human spermatozoa
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作者 Mercedes González-Martínez Pascual Sánchez-Martín +2 位作者 Carmen López-Fernández Stephen D.Johnston Jaime Gosálvez 《Asian pacific Journal of Reproduction》 CAS 2024年第1期22-27,共6页
Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal fo... Objective:To determine the relationship between teratozoospermia and sperm DNA fragmentation(SDF)in the human ejaculate.Methods:This retrospective study included 100 normozoospermic men as a control cohort(abnormal forms>14%),210 patients with a high level of abnormal forms(≤4%)and 65 patients presenting with a moderate level of abnormal forms(>4%to≤14%)based on the World Health Organization definitions.Sperm morphology was assessed using bright field microscopy.Sperm DNA fragmentation was assessed using the sperm chromatin dispersion assay.Non-parametric analyses were conducted to examine the relationship between abnormal sperm morphology and sperm DNA fragmentation;receiver operating characteristic(ROC)analyses were conducted to assess sensitivity and specificity of this relationship.Results:A correlation analysis revealed that the higher the proportion of abnormal spermatozoa in the ejaculate,the higher the level of SDF(Spearman's Rho=-0.230;P<0.001).Significant differences in the proportion of SDF were found when all cohorts were compared(P<0.001);these significant differences were also retained when the different cohorts were compared pairwise.ROC analysis showed a moderate but significant predictive value for SDF to differentiate patients with different levels of teratozoospemia.Conclusions:Although analysis of a more continuous range of values for teratozoospermia would help further clarify any causal relationship with SDF,there is clearly a synergistic or coincident affiliation between these variables that needs to be acknowledged by the clinician when interpreting the spermiogram. 展开更多
关键词 TERATOZOOSPERMIA Sperm morphology Sperm DNA fragmentation Male factor Human reproduction Human fertility
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Double casing warhead with sandwiched charge:The axial distribution of fragments velocities
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作者 Ping Ye Yongxiang Dong +5 位作者 Qitian Sun Peizhuo Shi Wang Yao Yongnan Li Yujing Li Mingze Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期201-216,共16页
The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine... The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings. 展开更多
关键词 Double casing warhead Sandwiched charge fragment velocity Rarefaction wave Gurney formula Explosive loading
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Sonoluminescence as the PeTa Radiation, Part Three 被引量:1
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作者 Vitali A. Tatartchenko 《Optics and Photonics Journal》 2018年第6期187-200,共14页
This paper is the third in a series published in this journal during 2017-2018. These three papers present various stages in the development of the PeTa model for phenomena of the same physical nature: cavitational lu... This paper is the third in a series published in this journal during 2017-2018. These three papers present various stages in the development of the PeTa model for phenomena of the same physical nature: cavitational luminescence (CL), multi-bubble sonoluminescence (MBSL), single-bubble sonoluminescence (SBSL), 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, for instance, vapour condensation. The third iteration of this model “Vapour bubble luminescence” (VBL) is presented in this paper. The essence of this model is as follows: with a local decrease of pressure or an increase of temperature in a tiny volume of the liquid, one or several bubbles filled with vapour will appear. Subsequently, a very rapid increase in pressure or a decrease in temperature of the bubble leads to super-saturation of the vapour inside the bubble, followed by its instantaneous condensation with the emission of condensation energy (this is the PeTa effect). A sharp decrease in pressure causes the collapse of the bubble accompanied by a shock wave in the liquid. VBL model is conveniently represented on the solid-liquid-vapour phase diagram. A better understanding of the physical nature of the phenomena under consideration could help to find their useful applications. To develop this idea further, we propose a design of a cavity-free pulsed laser on the basis of CL/MBSL/SBSL. An analysis of LIBL in cryogenic liquids is also given in this paper. 展开更多
关键词 Cavitational LUMINESCENCE (CL) SONOLUMINESCENCE (SL) Multi-Bubble SONOLUMINESCENCE (MBSL) Single-Bubble SONOLUMINESCENCE (SBSL) Laser-Induced BUBBLE LUMINESCENCE (LIBL) LIBL in Cryogenic Liquids VAPOUR BUBBLE LUMINESCENCE (VBL) PeTa (Perelman-Tatartchenko) Effect FIRST-ORDER Phase Transitions Evaporation Condensation Crystallization Cavity-Free Pulsed Laser
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^(99m)Tc-labeled HAb18 McAb Fab fragment for radioimmunoimaging in nude mice bearing human hepatocellular carcinoma 被引量:8
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作者 Qiu K Wang BC +4 位作者 Chen ZN Fang P Liu CG Wan WX Liu YF 《World Journal of Gastroenterology》 SCIE CAS CSCD 1998年第2期25-28,共4页
AIM To establish a method of labeling anti hepatoma McAb (HAb18) Fab fragment modifier with 99m Tc. METHODS HAb18 Fab was modified with 2 iminotholane and labeled with 99m Tc by transchelation f... AIM To establish a method of labeling anti hepatoma McAb (HAb18) Fab fragment modifier with 99m Tc. METHODS HAb18 Fab was modified with 2 iminotholane and labeled with 99m Tc by transchelation from 99m Tc GH. Labeling yield, radiochemical purity and immunoreactivity were determined by thin layer chromatography (TLC SG), paper chromatography (PC), gel chromatography (GC) and cell binding assay, respectively. The nude mice bearing human hepatoma were used for radioimmunoimaging (RII). RESULTS A radiolabeling yield of 50%-80% was obtained, and immunoreactivity (IR) was 30%-40%. Radioimaging results showed that 99m Tc HAb18 McAb Fab fragment was concentrated in the tumor 4-8 hours after injection, and the maximum concentration was seen in 12-24 hours, and the T/NT value was 5 18 and 7 48 at 6h and 8h after the injection. CONCLUSION 99m Tc HAb18 McAb Fab fragment could be specifically localized in the tumor of nude mice bearing human hepatocellular carcinoma within 24 hours and this method might be effectively used for labeling McAb Fab fragment with 展开更多
关键词 liver neoplasms carcinoma HEPATOCELLULAR HAB18 autibodies monoclonal radioimmunodetection FAB fragments 99m Tc NUDE MICE 99m Tc.
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A new framework for evaluation of rock fragmentation in open pit mines 被引量:4
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作者 Mohammad Babaeian Mohammad Ataei +2 位作者 Farhang Sereshki Farzad Sotoudeh Sadjad Mohammadi 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2019年第2期325-336,共12页
The main purpose of blasting in open pit mines is to produce the feed for crushing stage with the optimum dimensions from in situ rocks. The size distribution of muck pile indicates the efficiency of blasting pattern ... The main purpose of blasting in open pit mines is to produce the feed for crushing stage with the optimum dimensions from in situ rocks. The size distribution of muck pile indicates the efficiency of blasting pattern to reach the required optimum sizes. Nevertheless, there is no mature model to predict fragmentation distribution to date that can be used in various open pit mines. Therefore, a new framework to evaluate and predict fragmentation distribution is presented based on the image analysis approach. For this purpose, the data collected from Jajarm bauxite mine in Iran were used as the sources in this study. The image analysis process was performed by Split-Desktop software to find out fragmentation distribution, uniformity index and average size of the fragmented rocks. Then, two different approaches including the multivariate regression method and the decision-making trial and evaluation laboratory(DEMATEL) technique were incorporated to develop new models of the uniformity index and the average size to improve the Rosin-Rammler function. The performances of the proposed models were evaluated in four blasting operation sites. The results obtained indicate that the regression model possesses a better performance in prediction of the uniformity index and the average size and subsequently the fragmentation distribution in comparison with DEMATEL and conventional Rosin-Rammler models. 展开更多
关键词 Rock fragmentATION Image analysis Open PIT mine Split-desktop software package Decision-making TRIAL and EVALUATION laboratory(DEMATEL)technique
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Determination of Fragmentation Schemes and Metabolites of Fluorinated Histone Deacetylase Inhibitors for Use as Positron Emission Tomography Imaging Agents Using HPLC-MS/MS
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作者 Wei-Hsi Chen Yu-Chieh Hsiao +5 位作者 Ming-Hsin Li Mu-Chen Tsai Chun-Fang Feng Han-Chih Chang Hung-Wen Yu Chyng-Yann Shiue 《International Journal of Analytical Mass Spectrometry and Chromatography》 2018年第1期1-19,共19页
High performance liquid chromatography coupled with tandem mass spectrometry was developed and validated as a method for the analysis of fluorinated histone deacetylase inhibitors (F-HDACi), and then employed to study... High performance liquid chromatography coupled with tandem mass spectrometry was developed and validated as a method for the analysis of fluorinated histone deacetylase inhibitors (F-HDACi), and then employed to study their metabolism in biosystems. Four HDACi analogs labeled with the positron emission nuclide 18F constitute a group of potential positron emission tomography imaging agents, which were developed by the Institute of Nuclear Energy Research (INER) and coded as INER-1577 #1, #2, #3, and #4 during animal studies for the diagnosis of dementia. The performance of the method was found to be suitable for the determination of analog #3, and it was employed to determine the structures and fragmentation mechanisms of all four analogs and to study the biotransformations of analogs #3 and #4. The results indicated that the method used for the determination of analog #3 was suitable for determining the abundance of the analogs in chemical and biochemical tests with high precision, accuracy, reproducibility, and recovery. Weaknesses in the chemical bonding of the analogs were found to involve the fluoro, dimethylamino, and benzamide groups in a fragmentation mechanism deduced via tandem mass spectrometry. The metabolites of analogs #3 and #4 in rat liver microsomes and rat plasma were also identified to clarify their characteristic behaviors in biosystems. The major product of analogs #3 in liver microsomes was produced by hydroxylation of the benzylic carbon atom, but in rat plasma the metabolites of analog #3 were produced by hydrolysis of the benzamide group to give a diaminobiphenyl compound with the simultaneous replacement of a fluorine atom by a hydroxyl group. The metabolites of analog #4 in liver microsomes were produced by hydroxylation of the benzylic carbon atom and hydrolysis of the benzamide bond. The results of the studies characterized the chemical and biochemical behaviors of the series F-HADCi analogs. 展开更多
关键词 HISTONE DEACETYLASE Inhibitors POSITRON Emission Tomography Imaging Agent Dementia LC-Tandem MS fragmentATION Mechanism Metabolism Pathways EPIGENETICS
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