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Biological characteristics and clinical management of uveal and conjunctival melanoma
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作者 SNJEŽANA KAŠTELAN ANA DIDOVIĆPAVIČIĆ +4 位作者 DARIA PAŠALIĆ TAMARA NIKUŠEVA-MARTIĆ SAMIRČANOVIĆ PETRA KOVAČEVIĆ SUZANA KONJEVODA 《Oncology Research》 SCIE 2024年第8期1265-1285,共21页
Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very simil... Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very similar,however,the prognosis for patients with ocular melanoma remains unfavourable,primarily due to its distinctive genetic profile and tumor microenvironment.Regardless of considerable advances in understanding the genetic characteristics and biological behaviour,the treatment of uveal and conjunctival melanoma remains a formidable challenge.To enhance the prospect of success,collaborative efforts involving medical professionals and researchers in thefields of ocular biology and oncology are essential.Current data show a lack of well-designed randomized clinical trials and limited benefits in current forms of treatment for these tumors.Despite advancements in the development of effective melanoma therapeutic strategies,all current treatments for uveal melanoma(UM)and conjunctival melanoma(CoM)remain unsatisfactory,resulting in a poor long-term prognosis.Ongoing trials offer hope for positive outcomes in advanced and metastatic tumors.A more comprehensive understanding of the genetic and molecular abnormalities involved in the development and progression of ocular melanomas opens the way for the development of personalized therapy,with various potential therapeutic targets currently under consideration.Increased comprehension of the molecular pathogenesis of UM and CoM and their specificities may aid in the development of new and more effective systemic therapeutic agents,with the hope of improving the prognosis for patients with metastatic disease. 展开更多
关键词 Uveal melanoma Conjunctival melanoma Genetic characteristics Immune checkpoint inhibitors Target molecular inhibitors
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Biological Characteristics of Trehalose and Its Protective Effect on Food Fermentation Starters during Lyophilization
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作者 Yuhong YANG Yangdi ZHANG 《Agricultural Biotechnology》 CAS 2023年第4期45-48,共4页
This paper reviewed the unique biological function of trehalose and its mechanism of stabilizing biological macromolecules and the research progress in the protective effect of trehalose on lactic acid bacteria fermen... This paper reviewed the unique biological function of trehalose and its mechanism of stabilizing biological macromolecules and the research progress in the protective effect of trehalose on lactic acid bacteria fermentation starters during lyophilization in food production.The application of trehalose in food industry was prospected. 展开更多
关键词 TREHALOSE biological characteristics LYOPHILIZATION
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Comparative Study on Biological and Commercial Characteristics of Multiple Varieties of Broccoli(Brassica oleracea L.var.italica Plenck)and Vegetable Soybean(Glycine max(L.)Merr.)
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作者 Peng WANG Shengqun JIAO +5 位作者 Hongjie TANG Yanxue DANG Qingfu DU Jihui LI Bushuai ZHONG Bingguo SONG 《Agricultural Biotechnology》 CAS 2023年第2期28-31,37,共5页
[Objectives]This study was conducted to select vegetable soybean varieties(Glycine max(L.)Merr.)that are suitable for local cultivation and meet export requirements.[Methods]Through continuous years of comparative exp... [Objectives]This study was conducted to select vegetable soybean varieties(Glycine max(L.)Merr.)that are suitable for local cultivation and meet export requirements.[Methods]Through continuous years of comparative experiments on broccoli and vegetable soybean varieties,detailed biological characteristic and economic quality data of multiple varieties were obtained.[Results]Vegetable soybean variety Taiwan 75-3 had very prominent early-maturing trait,the highest quality(qualification rate),and higher yield than the control check(CK);and the early-maturing trait of vegetable soybean variety Kaohsiung 9 was also prominent,and its yield was higher than that of the CK.They could be promoted as the main vegetable soybean varieties for spring open field cultivation in this region.Among the tested broccoli varieties,Lake had a higher yield,and was relatively tolerant to cold.It had an early harvest period,and was planted as an early autumn variety in this region.Naihan Youxiu showed the highest yield,good quality,cold resistance,and strong adaptability,making it suitable for planting as a late autumn variety in this region.[Conclusions]This study provides technical guidance for the cultivation of local broccoli and vegetable soybean. 展开更多
关键词 Vegetable soybeans BROCCOLI biological characteristic Commercial character
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Study on Pathogeny Identification and Biological Characteristics of Anthracnose in Cassava 被引量:6
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作者 蔡吉苗 李超萍 +2 位作者 时涛 林春花 黄贵修 《Agricultural Science & Technology》 CAS 2010年第3期129-134,共6页
[Objective] The research aimed to isolate and identify the anthracnose pathogen of Cassava and study its biological charcteristics.[Method] Two isolates of anthracnose (CCGHN01 and CCGHN03) in Cassava were isolated ... [Objective] The research aimed to isolate and identify the anthracnose pathogen of Cassava and study its biological charcteristics.[Method] Two isolates of anthracnose (CCGHN01 and CCGHN03) in Cassava were isolated from the diseased leaves collected from Hainan of China.They were identified through the morphological observation of conidia and ITS sequence analysis.And the morphological characteristics were studied.[Result] The morphological observation of conidia and ITS sequence analysis indicated that the two isolates were Colletotrichum gloeosporioides.The morphological characteristics study results showed that optimum medium for the growth of two strains was PSA,the optimum temperatures were 26 ℃ and 30 ℃ respectively,the optimum pH was 8.0,the optimum light conditions were alternative light and dark and complete darkness respectively.For the conidia germination of two strains,the optimum temperatures were 28 ℃ and 30 ℃ respectively and the lethal temperature was 55 ℃ remaining 10 min.[Conclusion] The research laid the foundation for further control of anthracnose in Cassava. 展开更多
关键词 CASSAVA ANTHRACNOSE biological characteristics
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Biological Characteristics and Pathogenicities of Shewanella algae and Shewanella abalone from Babylonia 被引量:2
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作者 李淑芳 张继东 +2 位作者 邱德全 杨世平 黄子通 《Agricultural Science & Technology》 CAS 2015年第9期1845-1850,1859,共7页
[Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas... [Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas of Babylonia suffered from proboscis edema with blood agar plate. The dominant bacterial community in the ill Babylonia was identified by 16 S r DNA sequence analysis, and the bacterial cultural and biochemical characteristics and pathogenicities were studied. [Result]The Shewanella bacteria, including Shewanella algae and Shewanella abalone, are the dominant bacterial community in Babylonia suffered from proboscis edema.The colony characteristics of Shewanella algae in nutrient agar medium, TCBS agar medium and CHROMagar vibrio colored medium were similar to those of Shewanella abalone. Shewanella algae possessed β-hemolysis and Shewanella abalone possessed α-hemolysis in the blood agar plate. The biochemical reaction of Shewanella algae and Shewanella abalone was all of non-fermentation type. The results of artificial infection test showed that half lethal dose(LD50) of the test strains of Shewanella algae was 10-5.50/0.1 ml. The test strains of Shewanella algae have strong toxicity, and could cause mice and chickens to die of sepsis with mortality of100%. The mortality of Babylonia infected with Shewanella algae was 10%; while the survived Babylonia lost the ability of moving and intaking for a long time, but they were not suffered from proboscis edema. There was no death in mice or chicks infected with Shewanella abalone, but their livers and spleens were slightly hyperemic and swelling. There was also no death in Babylonia infected with Shewanella abalone, but their intaking and moving ability was lost for a short time.[Conclusion] Although Shewanella algae and Shewanella abalone were the dominant bacteria in Babylonia suffered from proboscis edema, they were not the main pathogenic bacteria for proboscis edema. Shewanella algae had strong pathogenicity to mice, chicks and Babylonia, while Shewanella abalone showed no marked pathogenicity to those experimental animals in this study. 展开更多
关键词 Shewanella algae Shewanella abalone biological characteristics PATHOGENICITY Babylonia
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Isolation and Identification of Colletotrichum gloeosporioides in Pears and Its Biological Characteristics 被引量:1
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作者 刘邮洲 陈志谊 +3 位作者 钱国良 聂亚峰 乔俊卿 刘凤权 《Agricultural Science & Technology》 CAS 2014年第2期191-195,共5页
[Objective] This study aimed to explore the biological characteristics of Col etotrichum gloeosporioides in pears. [Method] Twenty-five C. gloeosporioides strains were isolated and identified from the diseased samples... [Objective] This study aimed to explore the biological characteristics of Col etotrichum gloeosporioides in pears. [Method] Twenty-five C. gloeosporioides strains were isolated and identified from the diseased samples. Their pathogenicity was identified by inoculating the surface of punctured pears with fungal discs. The effects of different temperatures, pH values, carbon sources and nitrogen sources on the growth of C. gloeosporioides mycelia were explored by incubating fungal discs on the center of plates. [Result] Among the twenty-five C. gloeosporioides strains, three had strong pathogenicity, and eighteen had intermediate pathogenicity, and four strains had weak pathogenicity. Those highly-pathogenic strains had darker colonies, with dense mycelia, whereas those lowly-pathogenic ones had white colonies, with sparse mycelia. Those with fast-growing colonies showed strong pathogenicity, while those with slowly-growing colonies displayed weak pathogenicity. There was no relationship between conidia yield and pathogenicity. The optimum temperature for the growth of C. gloeosporioides mycelia was 25-30 ℃, and the optimum pH was 5.0-7.0. C. gloeosporioides could make use of various carbon sources (monosaccharide and disaccharide), inorganic and organic nitrogen sources, and the optimal carbon source and nitrogen source were sucrose and beef extract, respectively. [Conclusion] Our study benefits further understanding of C. gloeospori-oides and helps to control pear anthracnose more effectively. 展开更多
关键词 Colletotrichum gloeosporioides PATHOGENICITY biological characteristics
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Identification and Biological Characteristics of Blank Spot Pathogen from Lilium lancifolium 被引量:3
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作者 吴金平 丁自立 +3 位作者 刘晓艳 郭凤领 焦忠久 邱正明 《Agricultural Science & Technology》 CAS 2014年第11期1879-1882,共4页
With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of l... With the increasing planting area of Lilium lancifolium, the leaf fungal dis-ease of L. lancifolium is becoming more and more serious. In June and July of 2014, the excessive rainfal leads to the serious outbreak of leaf disease of L. lanci-folium. In mid-June, the wilting rate of L. lancifolium in seriously-infected field was even up to 50%-70%. In some fields, the shoots of L. lancifolium even al wilted. The pathogen was isolated from the infected leaves of L. lancifolium. Its pathogenici-ty, spore morphology, 18S rDNA sequence and biological characteristics were stud-ied. The results showed the isolated pathogen was Alternaria alternate. The lethal temperature of mycelial growth was 55 ℃. The optimum pH was 6-7. Among the tested carbon sources and nitrogen sources, the optimum carbon source was mal-tose, and the optimum nitrogen source was yeast extract. 展开更多
关键词 Lilium lancifolium Black spot biological characteristic Molecular identifi-cation
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Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases 被引量:5
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作者 Yi-Fan Chang Jia-Jing Li +4 位作者 Tao Liu Chong-Qing Wei Li-Wei Ma Vladimir N Nikolenko Wei-Long Chang 《World Journal of Gastroenterology》 SCIE CAS 2024年第11期1524-1532,共9页
Autophagy is a cellular catabolic process characterized by the formation of double-membrane autophagosomes.Transmission electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and de... Autophagy is a cellular catabolic process characterized by the formation of double-membrane autophagosomes.Transmission electron microscopy is the most rigorous method to clearly visualize autophagic engulfment and degradation.A large number of studies have shown that autophagy is closely related to the digestion,secretion,and regeneration of gastrointestinal(GI)cells.However,the role of autophagy in GI diseases remains controversial.This article focuses on the morphological and biochemical characteristics of autophagy in GI diseases,in order to provide new ideas for their diagnosis and treatment. 展开更多
关键词 AUTOPHAGY Morphological study Biochemical characteristics Subcellular structure Transmission electron microscopy Gastrointestinal diseases
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Research on the influences of motion characteristics of jetting projectile charge under water 被引量:1
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作者 Xing Chen Yong-gang Lu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期411-425,共15页
Shaped charge warhead is important for enhancing the damage performance of underwater weapons.This paper used finite element analysis software and based on JPC water penetration experiments to examine the influence of... Shaped charge warhead is important for enhancing the damage performance of underwater weapons.This paper used finite element analysis software and based on JPC water penetration experiments to examine the influence of liner parameters(wall thickness,material),charge aspect ratio,and stand-off distance on the movement characteristics of JPC in water.The findings reveal that the head diameter of the JPC increases and experiences significant erosion after entering the water,the effective length of the JPC in water undergoes two distinct phases:a growth phase and a decrease phase,with the velocity of the JPC decaying exponentially.Increasing the liner thickness,stand-off distance and the charge aspect ratio can improve the erosion resistance and the velocity retention capacity of the JPC.The optimal ranges for liner thickness and stand-off distance are 0.0363D_(k) to 0.0545D_(k)(D_(k) is the charge diameter),the stand-off distance should be within 1.0D_(k).After the charge aspect ratio higher than 1.25,the charge structure exerts minimal influence the movement characteristics of the JPC in water.Material density plays a crucial role in the velocity decay pattern of the JPC during penetration.JPC with higher densities exhibit superior velocity retention capabilities in water,with the velocity decay pattern converging if the densities are similar.Consequently,copper,tantalum and tungsten liners are deemed appropriate for underwater shaped charge warhead.Finally,the results will provide an important reference for the design of underwater shaped charge warhead. 展开更多
关键词 JPC Movement characteristics Underwater penetration Numerical simulation
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Isolation and Biological Characteristics of Bacteriophage of an Antibiotic-resistant Escherchia coli Strain 被引量:1
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作者 李淑芳 邓瑞玲 +3 位作者 张帅领 张智慧 梁垲珊 张继东 《Agricultural Science & Technology》 CAS 2016年第12期2692-2695,2706,共5页
In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lys... In this study, bacteriophage of an antibiotic-resistant Escherchia coil strain isolated from feces of chicken was isolated. Its host range was determined by the method of spotting sample on monolayer agar, and its lysis titer, optimal multiplicity of infection (MOI), temperature tolerance and pH tolerance were determined by the double-layer agar plate method. The results showed that the bacteriophage had a broad host range. The biological assay demonstrated that two strains of E. coil were fully lysed and one strain of E. coil was weakly lysed by the bacteriophage. The lysis titer and MOI of the bacteriophage were 1.20×10^8 PFU/ml and 1, respec- tively. Under the optimum temperature of 40℃, the Jysis titer of the bacteriophage reached 8.90×10^9 PFU/ml; however, the bacteriophage lost its infectivity at the tem- perature of 80℃. In the pH range of 5-11, the lysis titer of the bacteriophage ranged from10^6 to 10^9 PFU/mI. Under the condition of pH 4 and 12, the bacterio- phage was invalid. 展开更多
关键词 BACTERIOPHAGE Escherchia coli Antibiotic resistance biological charac-teristics
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Clinical characteristics of acute non-varicose upper gastrointestinal bleeding and the effect of endoscopic hemostasis 被引量:4
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作者 Xiao-Juan Wang Yu-Peng Shi +4 位作者 Li Wang Ya-Ni Li Li-Juan Xu Yue Zhang Shuang Han 《World Journal of Clinical Cases》 SCIE 2024年第9期1597-1605,共9页
BACKGROUND Acute non-variceal upper gastrointestinal bleeding(ANVUGIB)constitutes a prevalent emergency within Gastroenterology,encompassing 80%-90%of all gastrointestinal hemorrhage incidents.This condition is distin... BACKGROUND Acute non-variceal upper gastrointestinal bleeding(ANVUGIB)constitutes a prevalent emergency within Gastroenterology,encompassing 80%-90%of all gastrointestinal hemorrhage incidents.This condition is distinguished by its abrupt onset,swift progression,and notably elevated mortality rate.AIM To gather clinical data from patients with ANVUGIB at our hospital in order to elucidate the clinical characteristics specific to our institution and analyze the therapeutic effectiveness of endoscopic hemostasis.METHODS We retrospectively retrieved the records of 532 patients diagnosed with ANVUGIB by endoscopy at our hospital between March 2021 and March 2023,utilizing our medical record system.Data pertaining to general patient information,etiological factors,disease outcomes,and other relevant variables were meticulously collected and analyzed.RESULTS Among the 532 patients diagnosed with ANVUGIB,the male-to-female ratio was 2.91:1,with a higher prevalence among males.Notably,43.6%of patients presented with black stool as their primary complaint,while 27.4%had hematemesis as their initial symptom.Upon admission,17%of patients exhibited both hematemesis and black stool,while most ANVUGIB patients primarily complained of overt gastrointestinal bleeding.Urgent routine blood examinations at admission revealed that 75.8%of patients had anemia,with 63.4%experiencing moderate to severe anemia,and 1.5%having extremely severe anemia(hemoglobin<30 g/L).With regard to etiology,53.2%of patients experienced bleeding without a definitive trigger,24.2%had a history of using gastric mucosa-irritating medications,24.2%developed bleeding after alcohol consumption,2.8%attributed it to improper diet,1.7%to emotional excitement,and 2.3%to fatigue preceding the bleeding episode.Drug-induced ANVUGIB was more prevalent in the elderly than middle-aged and young individuals,while bleeding due to alcohol consumption showed the opposite trend.Additionally,diet-related bleeding was more common among the young age group compared to the middle-aged group.Gastrointestinal endoscopy identified peptic ulcers as the most frequent cause of ANVUGIB(73.3%),followed by gastrointestinal malignancies(10.9%),acute gastric mucous lesions(9.8%),and androgenic upper gastrointestinal bleeding(1.5%)among inpatients with ANVUGIB.Of the 532 patients with gastrointestinal bleeding,68 underwent endoscopic hemostasis,resulting in an endoscopic treatment rate of 12.8%,with a high immediate hemostasis success rate of 94.1%. 展开更多
关键词 Acute non-varicose upper gastrointestinal bleeding Clinical characteristics Cause of disease Endoscopic homeostatic therapy
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Dynamic response mechanism and precursor characteristics of gneiss rockburst under different initial burial depths 被引量:1
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作者 LIU Dongqiao SUN Jie +4 位作者 MENG Wen HE Manchao ZHANG Chongyuan LI Ran CAO Binghao 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1004-1018,共15页
To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system... To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real time.The experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial depth.And then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of rockburst.What’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack evolution.Finally,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor. 展开更多
关键词 Traffic Engineering Gneiss Rockburst Crack propagation Excess energy Precursor characteristic
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Spatiotemporal deformation characteristics of Outang landslide and identification of triggering factors using data mining 被引量:1
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作者 Beibei Yang Zhongqiang Liu +1 位作者 Suzanne Lacasse Xin Liang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4088-4104,共17页
Since the impoundment of Three Gorges Reservoir(TGR)in 2003,numerous slopes have experienced noticeable movement or destabilization owing to reservoir level changes and seasonal rainfall.One case is the Outang landsli... Since the impoundment of Three Gorges Reservoir(TGR)in 2003,numerous slopes have experienced noticeable movement or destabilization owing to reservoir level changes and seasonal rainfall.One case is the Outang landslide,a large-scale and active landslide,on the south bank of the Yangtze River.The latest monitoring data and site investigations available are analyzed to establish spatial and temporal landslide deformation characteristics.Data mining technology,including the two-step clustering and Apriori algorithm,is then used to identify the dominant triggers of landslide movement.In the data mining process,the two-step clustering method clusters the candidate triggers and displacement rate into several groups,and the Apriori algorithm generates correlation criteria for the cause-and-effect.The analysis considers multiple locations of the landslide and incorporates two types of time scales:longterm deformation on a monthly basis and short-term deformation on a daily basis.This analysis shows that the deformations of the Outang landslide are driven by both rainfall and reservoir water while its deformation varies spatiotemporally mainly due to the difference in local responses to hydrological factors.The data mining results reveal different dominant triggering factors depending on the monitoring frequency:the monthly and bi-monthly cumulative rainfall control the monthly deformation,and the 10-d cumulative rainfall and the 5-d cumulative drop of water level in the reservoir dominate the daily deformation of the landslide.It is concluded that the spatiotemporal deformation pattern and data mining rules associated with precipitation and reservoir water level have the potential to be broadly implemented for improving landslide prevention and control in the dam reservoirs and other landslideprone areas. 展开更多
关键词 LANDSLIDE Deformation characteristics Triggering factor Data mining Three gorges reservoir
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Observation of Biological Characteristics of Bananamoth[Opogona sacchari (Bojer)]Larvae in Sugarcane
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作者 魏吉利 黄诚华 +3 位作者 潘雪红 商显坤 王伯辉 黄冬发 《Plant Diseases and Pests》 CAS 2011年第2期25-27,共3页
[ Objective] The paper was to understand the biological characteristics of bananamoth [ Opogona sacchari ( Bojer ) ] larvae in sugarcane. [ Method ] Through the rearing test of bananamoth larvae with different hosts... [ Objective] The paper was to understand the biological characteristics of bananamoth [ Opogona sacchari ( Bojer ) ] larvae in sugarcane. [ Method ] Through the rearing test of bananamoth larvae with different hosts, the biological characteristics of bananamoth larvae in sugarcane were observed and analyzed. [ Result ] The mortality rate of bananamoth larvae reared with sugarcane was higher than that of the pests reared with potato. The larva had 8 instars, and the devel- opment duration of the larvae reared with sugarcane was 34.6 d longer than the pests reared with potato. The larvae needed about 98.8 d to complete a generation in average. Viewed from the observation values of head width, body length and weight of larvae, bananamoth larvae reared with sugarcane basically accorded with the growth and development law of larvae. [Condusion ] The results provided theoretical basis for the preparation of effective measures against bananamoth and the assurance of safe production of.sugarcane. 展开更多
关键词 Bananamoth SUGARCANE biological characteristics Larva
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Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction 被引量:1
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作者 Feilin Han Sheng Xue +3 位作者 Chunshan Zheng Zhongwei Chen Guofu Li Bingyou Jiang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第3期413-425,共13页
Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal... Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology. 展开更多
关键词 Clean gas extraction Chemical solvent Experimental investigation Fractal characteristics Pore fracture
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Failure mechanism and infrared radiation characteristic of hard siltstone induced by stratification effect 被引量:1
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作者 CHENG Yun SONG Zhanping +2 位作者 XU Zhiwei YANG Tengtian TIAN Xiaoxu 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1058-1074,共17页
The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and tempora... The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass. 展开更多
关键词 Hard siltstone Failure mechanism Stratification effect Infrared radiation characteristic Temporal-damage mechanism DISSIMILATION
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Grain Yield,Biomass Accumulation,and Leaf Photosynthetic Characteristics of Rice under Combined Salinity-Drought Stress 被引量:1
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作者 WEI Huanhe GENG Xiaoyu +7 位作者 ZHANG Xiang ZHU Wang ZHANG Xubin CHEN Yinglong HUO Zhongyang ZHOU Guisheng MENG Tianyao DAI Qigen 《Rice science》 SCIE CSCD 2024年第1期118-128,I0023,共12页
Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinit... Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield. 展开更多
关键词 antioxidant defense system combined salinity-drought stress drought stress photosynthetic characteristics RICE salinity stress
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Investigation of hydroxyl-terminated polybutadiene propellant breaking characteristics and mechanism impacted by submerged cavitation water jet 被引量:1
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作者 Wenjun Zhou Meng Zhao +3 位作者 Bo Liu Youzhi Ma Youzhi Zhang Xuanjun Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期559-572,共14页
A submerged cavitation water jet(SCWJ)is an effective method to recycle solid propellant from obsolete solid engines by the breaking method.Solid propellant's breaking modes and mechanical process under SCWJ impac... A submerged cavitation water jet(SCWJ)is an effective method to recycle solid propellant from obsolete solid engines by the breaking method.Solid propellant's breaking modes and mechanical process under SCWJ impact are unclear.This study aims to understand those impact breaking mechanisms.The hydroxyl-terminated polybutadiene(HTPB)propellant was chosen as the research material,and a self-designed test system was used to conduct impact tests at four different working pressures.The high-speed camera characterized crack propagation,and the DIC method calculated strain change during the impact process.Besides,micro and macro fracture morphologies were characterized by scanning electron microscope(SEM)and computed tomography(CT)scanning.The results reveal that the compressive strain concentration region locates right below the nozzle,and the shear strain region distributes symmetrically with the jet axis,which increases to 4% at first 16th ms,the compressive strain rises to 2% and 6% in the axial and transverse direction,respectively.The two tensile cracks formed first at the compression strain concentrate region,and there generate many shear cracks around the tensile cracks,and those shear cracks that develop and aggregate cause the cracks to become wider and cut through the tensile cracks,forming the tensile-shear cracks and the impact parts eventually fail.The HTPB propellant forms a breaking hole shaped conical after impact 10 s.The mass loss increases by 17 times at maximum,with the working pressure increasing by three times.Meanwhile,the damage value of the breaking hole remaining on the surface increases by 7.8 times while 2.9 times in the depth of the breaking hole.The breaking efficiency is closely affected by working pressures.The failure modes of HTPB impacted by SCWJ are classified as tensile crack-dominated and tensile-shear crack-dominated damage mechanisms. 展开更多
关键词 Submerged cavitation water jet Hydroxyl-terminated polybutadiene propellant Breaking characteristics Failure modes
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Biological Characteristics and Pathogenicity of Verticillium lecanii Isolated from Naturally Died Boettcherisca peregrine
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作者 王凌超 高熹 +3 位作者 王松田 刘小文 叶敏 吴国星 《Plant Diseases and Pests》 CAS 2010年第2期28-31,40,共5页
[Objective] In order to find the pathogenic microorganisms suitable for biological control of filth flies, the pathogenic microorganism was isolated from the dead fly, Boettcherisca peregrine. [Method] The conidia and... [Objective] In order to find the pathogenic microorganisms suitable for biological control of filth flies, the pathogenic microorganism was isolated from the dead fly, Boettcherisca peregrine. [Method] The conidia and mycelia were observed by optical microscope. The pathogenic microorganism was identified on the basis of its culture characters and the optical morphologies of the conidia and mycelia, and its biological characteristics and pathogenicity were preliminarily studied. [Result] The pathogenic microorganism isolated from the dead fly was a new strain of Verticillium lecanii. The new strain of V. lecanii was numbered as KMZW-1. The colonies of V. lecanii KMZW-1 grew fastest on potato dextrose agar medium (PDA) at 29 ℃ and pH 6.0. The LC50 of its spore suspension to the adults of B. peregrine, Lucilia sericata, Musca domestic, Piophila casei and Drosophila melanogaster were 9.50×10^5, 4.58×10^7, 4.06×10^7, 4.10×10^3 and 1.05×10^7 conidia/ml, respectively. The LT50 were 6.86, 8.17, 8.16, 8.12 and 3.22 d, respectively. [Conclusion] V. lecanii KMZW-1 is an active pathogenic microorganism to control the adults of five fly species. 展开更多
关键词 Boettcherisca peregrine Verticillium lecanii biological characteristic PATHOGENICITY
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A dynamic soil freezing characteristic curve model for frozen soil 被引量:1
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作者 Xiaokang Li Xu Li Jiankun Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3339-3352,共14页
The soil freezing characteristic curve(SFCC)plays a fundamental role in comprehending thermohydraulic behavior and numerical simulation of frozen soil.This study proposes a dynamic model to uniformly express SFCCs ami... The soil freezing characteristic curve(SFCC)plays a fundamental role in comprehending thermohydraulic behavior and numerical simulation of frozen soil.This study proposes a dynamic model to uniformly express SFCCs amidst varying total water contents throughout the freezing-thawing process.Firstly,a general model is proposed,wherein the unfrozen water content at arbitrary temperature is determined as the lesser of the current total water content and the reference value derived from saturated SFCC.The dynamic performance of this model is verified through test data.Subsequently,in accordance with electric double layer(EDL)theory,the theoretical residual and minimum temperatures in SFCC are calculated to be-14.5℃to-20℃for clay particles and-260℃,respectively.To ensure that the SFCC curve ends at minimum temperature,a correction function is introduced into the general model.Furthermore,a simplified dynamic model is proposed and investigated,necessitating only three parameters inherited from the general model.Additionally,both general and simplified models are evaluated based on a test database and proven to fit the test data exactly across the entire temperature range.Typical recommended parameter values for various types of soils are summarized.Overall,this study provides not only a theoretical basis for most empirical equations but also proposes a new and more general equation to describe the SFCC. 展开更多
关键词 Frozen soils Unsaturated soils Soil freezing characteristic curve(SFCC) Mathematic models
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