期刊文献+
共找到13,776篇文章
< 1 2 250 >
每页显示 20 50 100
Modified technical protocol for single-port laparoscopic appendectomy using needle-type grasping forceps for acute simple appendicitis:A case report
1
作者 Yang Chen Zong-Qi Fan +3 位作者 Xin-Ao Fu Xiao-Xin Zhang Jie-Qing Yuan Shi-Gang Guo 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第10期3328-3333,共6页
BACKGROUND Because of the mild inflammatory status in acute uncomplicated appendicitis,our team developed a novel technical protocol for single-port laparoscopic appendec-tomy using needle-type grasping forceps(SLAN)a... BACKGROUND Because of the mild inflammatory status in acute uncomplicated appendicitis,our team developed a novel technical protocol for single-port laparoscopic appendec-tomy using needle-type grasping forceps(SLAN)and achieved positive clinical outcomes.However,the intraoperative procedure lacked stability and fluency due to a series of problems highlighted by the small incision design of the proto-col(only 1 cm long).Therefore,there is a growing clinical demand to further opti-mize the SLAN protocol.CASE SUMMARY An adult male patient was admitted for persistent right lower abdominal pain with preoperative computed tomography findings suggestive of appendicitis accompanied by localized peritonitis.A modified technical protocol for SLAN based on minimally invasive surgical principles was used,and the patient was confirmed to have acute simple appendicitis by postoperative pathological ana-lysis.Postoperative recovery was uneventful,and no postoperative complications,such as incision infection or severe incision pain,were observed.The patient was discharged successfully on postoperative day 2.CONCLUSION The modified technical protocol of SLAN may be a new minimally invasive surgical alternative for patients with acute simple appendicitis. 展开更多
关键词 Acute appendicitis single-port laparoscopy APPENDECTOMY Minimally invasive surgery Case report
下载PDF
Design and Analysis of Power and Transmission System of Downhole Pure Electric Command Vehicle
2
作者 Md Jahangir Alam Md Shahriar Sujan +1 位作者 Md. Al Imran Tapu Joy Howlader 《Journal of Transportation Technologies》 2024年第1期31-52,共22页
Electric vehicles use electric motors, which turn electrical energy into mechanical energy. As electric motors are conventionally used in all the industry, it is an established development site. It’s a mature technol... Electric vehicles use electric motors, which turn electrical energy into mechanical energy. As electric motors are conventionally used in all the industry, it is an established development site. It’s a mature technology with ideal power and torque curves for vehicular operation. Conventional vehicles use oil and gas as fuel or energy storage. Although they also have an excellent economic impact, the continuous use of oil and gas threatened the world’s reservation of total oil and gas. Also, they emit carbon dioxide and some toxic ingredients through the vehicle’s tailpipe, which causes the greenhouse effect and seriously impacts the environment. So, as an alternative, electric car refers to a green technology of decarbonization with zero emission of greenhouse gases through the tailpipe. So, they can remove the problem of greenhouse gas emissions and solve the world’s remaining non-renewable energy storage problem. Pure electric vehicles (PEV) can be applied in all spheres, but their special implementation can only be seen in downhole operations. They are used for low noise and less pollution in the downhole process. In this study, the basic structure of the pure electric command vehicle is studied, the main components of the command vehicle power system, namely the selection of the drive motor and the power battery, are analyzed, and the main parameters of the drive motor and the power battery are designed and calculated. The checking calculation results show that the power and transmission system developed in this paper meets the design requirements, and the design scheme is feasible and reasonable. 展开更多
关键词 pure Electric Vehicles TRANSMISSION GEARS Electronic Differential Control Algorithms
下载PDF
Stable operation of highly loaded pure Si-Fe anode under ambient pressure via carboxy silane-directed robust solid electrolyte interphase
3
作者 Guntae Lim Dong Guk Kang +6 位作者 Hyeon Gyu Lee Yen Hai Thi Tran Kihun An Junghyun Choi Kwang Chul Roh Do Youb Kim Seung-Wan Song 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期568-576,共9页
Incorporation of higher content Si anode material beyond 5 wt% to Li-ion batteries(LIBs)is challenging,owing to large volume change,swelling,and solid electrolyte interphase(SEI)instability issues.Herein,a strategy of... Incorporation of higher content Si anode material beyond 5 wt% to Li-ion batteries(LIBs)is challenging,owing to large volume change,swelling,and solid electrolyte interphase(SEI)instability issues.Herein,a strategy of diacetoxydimethylsilane(DAMS)additive-directed SEI stabilization is proposed for a stable operation of Si-0.33FeSi_(2)(named as Si-Fe)anode without graphite,which provides siloxane inorganics and organics enrichment that compensate insufficient passivation of fluoroethylene carbonate(FEC)additive and reduce a dependence on FEC.Unprecedented stable cycling performance of highly loaded(3.5 mA h cm^(-2))pure Si-Fe anode is achieved with 2 wt%DAMS combined with 9 wt%FEC additives under ambient pressure,yielding high capacity 1270 mA h g^(-1)at 0.5 C and significantly improved capacity retention of 81% after 100 cycles,whereas short circuit and rapid capacity fade occur with FEC only additive.DAMS-directed robust SEI layer dramatically suppresses swelling and particles crossover through separator,and therefore prevents short circuit,demonstrating a possible operation of pure Si or Sidominant anodes in the next-generation high-energy-density and safe LIBs. 展开更多
关键词 High-energy Li-ion battery pure Si-Fe anode without graphite Silane additive SEI layer Suppressed swelling
下载PDF
A low-frequency pure metal metamaterial absorber with continuously tunable stiffness
4
作者 Xingzhong WANG Shiteng RUI +2 位作者 Shaokun YANG Weiquan ZHANG Fuyin MA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第7期1209-1224,共16页
To address the incompatibility between high environmental adaptability and deep subwavelength characteristics in conventional local resonance metamaterials,and overcome the deficiencies in the stability of existing ac... To address the incompatibility between high environmental adaptability and deep subwavelength characteristics in conventional local resonance metamaterials,and overcome the deficiencies in the stability of existing active control techniques for band gaps,this paper proposes a design method of pure metal vibration damping metamaterial with continuously tunable stiffness for wideband elastic wave absorption.We design a dual-helix narrow-slit pure metal metamaterial unit,which possesses the triple advantage of high spatial compactness,low stiffness characteristics,and high structural stability,enabling the opening of elastic flexural band gaps in the low-frequency range.Similar to the principle of a sliding rheostat,the introduction of continuously sliding plug-ins into the helical slits enables the continuous variation of the stiffness of the metamaterial unit,achieving a continuously tunable band gap effect.This successfully extends the effective band gap by more than ten times.The experimental results indicate that this metamaterial unit can be used as an additional vibration absorber to absorb the low-frequency vibration energy effectively.Furthermore,it advances the metamaterial absorbers from a purely passive narrowband design to a wideband tunable one.The pure metal double-helix metamaterials retain the subwavelength properties of metamaterials and are suitable for deployment in harsh environments.Simultaneously,by adjusting its stiffness,it substantially broadens the effective band gap range,presenting promising potential applications in various mechanical equipment operating under adverse conditions. 展开更多
关键词 elastic metamaterial absorber continuously tunable stiffness low-frequency vibration damping variable stiffness design pure metal structure
下载PDF
Strongly Coupled Ag/Sn-SnO_(2)Nanosheets Toward CO_(2)Electroreduction to Pure HCOOH Solutions at Ampere‑Level Current
5
作者 Min Zhang Aihui Cao +5 位作者 Yucui Xiang Chaogang Ban Guang Han Junjie Ding Li‑Yong Gan Xiaoyuan Zhou 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期212-226,共15页
Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance... Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance electrocatalysts.Herein,we elaborately design and develop strongly coupled nanosheets composed of Ag nanoparticles and Sn-SnO_(2) grains,designated as Ag/Sn-SnO_(2) nanosheets(NSs),which possess optimized electronic structure,high electrical conductivity,and more accessible sites.As a result,such a catalyst exhibits unprecedented catalytic performance toward CO_(2)-to-formate conversion with near-unity faradaic efficiency(≥90%),ultrahigh partial current density(2,000 mA cm^(−2)),and superior long-term stability(200 mA cm^(−2),200 h),surpassing the reported catalysts of CO_(2) electroreduction to formate.Additionally,in situ attenuated total reflection-infrared spectra combined with theoretical calculations revealed that electron-enriched Sn sites on Ag/Sn-SnO_(2)NSs not only promote the formation of*OCHO and alleviate the energy barriers of*OCHO to*HCOOH,but also impede the desorption of H*.Notably,the Ag/Sn-SnO_(2)NSs as the cathode in a membrane electrode assembly with porous solid electrolyte layer reactor can continuously produce~0.12 M pure HCOOH solution at 100 mA cm^(−2)over 200 h.This work may inspire further development of advanced electrocatalysts and innovative device systems for promoting practical application of producing liquid fuels from CO_(2). 展开更多
关键词 Electrochemical CO_(2)reduction Coupled Ag/Sn-SnO_(2)nanosheets Electronic structure Porous solid electrolyte pure
下载PDF
Underlying mechanisms of variation in yield asymmetry and strain hardening behavior of extruded pure Mg with Gd addition 被引量:1
6
作者 Gyo Myeong Lee Sung Hyuk Park 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第6期2165-2181,共17页
Effects of Gd addition on the strain hardening behavior and yield asymmetry of pure Mg are investigated by subjecting extruded pure Mg,Mg–5Gd,and Mg–15Gd(all in wt%)to tension and compression tests along the extrusi... Effects of Gd addition on the strain hardening behavior and yield asymmetry of pure Mg are investigated by subjecting extruded pure Mg,Mg–5Gd,and Mg–15Gd(all in wt%)to tension and compression tests along the extrusion direction(ED).As the amount of Gd added to pure Mg increases,the basal texture tilts toward the ED and the distribution of c-axes of grains becomes randomized.Under tension,the strain hardening rates of all the materials decrease until fracture.However,under compression,the strain hardening rate increases in the early stage of deformation in pure Mg and Mg–5Gd,whereas it continuously decreases in Mg–15Gd.Pure Mg exhibits considerably high tension-compression yield asymmetry,with a compressive yield strength(CYS)to tensile yield strength(TYS)ratio of 0.4.In contrast,Mg–5Gd exhibits excellent yield symmetry with CYS/TYS of 0.9 and Mg–15Gd exhibits reversed yield asymmetry with CYS/TYS of 1.2.Underlying mechanisms of these drastically different Gd-addition-induced deformation behaviors of the materials are discussed in terms of the crystallographic distribution of grains and the relative activation stresses of basal slip,prismatic slip,pyramidal slip,and{10–12}twinning under tension and compression. 展开更多
关键词 pure Mg Gd addition TEXTURE Yield asymmetry Activation stress
下载PDF
First 100 cases of transvesical single-port robotic radical prostatectomy
7
作者 Roxana Ramos-Carpinteyro Ethan L.Ferguson +2 位作者 Jaya S.Chavali Albert Geskin Jihad Kaouk 《Asian Journal of Urology》 CSCD 2023年第4期416-422,共7页
Objective:To describe the surgical technique and report the early outcomes of the transvesical(TV)approach to single-port(SP)robot-assisted radical prostatectomy.Methods:All procedures were performed at a single cente... Objective:To describe the surgical technique and report the early outcomes of the transvesical(TV)approach to single-port(SP)robot-assisted radical prostatectomy.Methods:All procedures were performed at a single center by one surgeon.We identified the first 100 consecutive patients with clinically localized prostate cancer that underwent SP TV robot-assisted radical prostatectomy using the da Vinci SP robotic surgical system.Data were collected prospectively and analyzed with descriptive statistics.The primary outcomes assessed were postoperative urinary continence,rate of biochemical recurrence,and sexual function.Results:All procedures were performed without extra ports or conversion.The median age was 62.1 years and 49.0%of the patients had abdominal surgery history.The preoperative median prostate-specific antigen value and prostate volume were 5.0 ng/mL and 33.0 mL,respectively.There were no intraoperative complications.The median operative time and estimated blood loss were 212.5 min and 100.0 mL,respectively.A total of 92.0%of patients were discharged within 24.0 h,with an overall median length of stay of 5.6 h.Only 4.0%of patients required opioid prescriptions at discharge.The median Foley catheter duration was 3 days.Positive margins were present in 15.0%of cases.Median follow-up was 10.4 months.Continence rate was immediate after Foley removal in 49.0%of cases,65.0%at 2 weeks,77.4%at 6 weeks,94.1%at 6 months,and 98.9%at 1 year.One case of biochemical recurrence(1.0%)was noted 3 months after surgery.Conclusion:The SP TV approach for radical prostatectomy cases is a safe and feasible technique for patients with clinically localized prostate cancer.This technique offers advantages of short hospital stay,minimal narcotic use postoperatively,and promising early return of urinary continence,without compromising oncologic outcomes. 展开更多
关键词 Prostate cancer Radical prostatectomy Robotic-assisted surgery single-port Minimally-invasive surgery
下载PDF
Effect of Soursop Puree and Gum Arabic on the Sensory Properties of Non-Dairy Coconut Milk-Based Ice Cream
8
作者 Sarah N. Mulwa Symon M. Mahungu Benard K. Muinde 《Food and Nutrition Sciences》 2023年第7期670-686,共17页
Coconut (Cocos nucifera) milk-based ice cream is one of the innovative non-dairy milk products gaining popularity among consumers. The objective was to develop coconut milk-based ice cream incorporated with soursop (A... Coconut (Cocos nucifera) milk-based ice cream is one of the innovative non-dairy milk products gaining popularity among consumers. The objective was to develop coconut milk-based ice cream incorporated with soursop (Annona muricata) fruit puree and gum Arabic from Acacia senegal var. kerensis, conduct a sensory evaluation using descriptive tests by trained panelists (n = 9) then evaluate for consumer acceptability by semi trained panelists (n = 30). A seven-point hedonic scale for colour, taste, flavour, texture and overall acceptability was used. The data obtained was subjected to analysis of variance (ANOVA) and the means were separated to determine their significance differences. Principal Component Analysis (PCA) was done for factor reduction to make it easy for the multi-dimensional descriptive data to be interpreted. PCA results indicated that unit increase in soursop and gum Arabic in the ice cream led to 83.1% increase in starchy taste, 78.3% increase in consistency and 73.6% decrease in coconut aroma. For consumer acceptability test, the obtained results showed that, soursop puree addition at successive levels led to a statistically significant effect (p < 0.05) on colour, flavour, texture, taste and overall acceptability while of gum Arabic incorporation was not significant (p > 0.05) for all attributes. The effect due to interaction between gum Arabic and soursop puree at the different levels however was significant for colour, flavour and texture but not significant for taste and overall acceptability. Our results therefore point to a potential application of soursop fruit and gum Arabic as alternative ingredients in the manufacture of a non-dairy ice cream with desirable sensory properties that would expand the variety of options consumers can choose from. 展开更多
关键词 Consumer Acceptability Ice Cream Non-Dairy Sensory Properties Soursop puree
下载PDF
Tension-Compression Asymmetry in Ultrafine-grained Commercially Pure Ti Processed by ECAP
9
作者 刘晓燕 LI Shuaikang +1 位作者 YANG Xirong LUO Lei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第3期689-694,共6页
A homogenous microstructure of ultrafine-grained (UFG) commercially pure (CP) Ti characterized by equiaxed grains/subgrains with an average grain size of about 150 nm and strong prismatic fiber texture were obtained a... A homogenous microstructure of ultrafine-grained (UFG) commercially pure (CP) Ti characterized by equiaxed grains/subgrains with an average grain size of about 150 nm and strong prismatic fiber texture were obtained after 4 passes of equal channel angular pressing (ECAP).Tension–compression asymmetry in yield and work hardening behavior of UFG CP Ti were investigated by uniaxial tension and compression tests.The experimental results reveal that UFG CP Ti exhibits a relatively obvious tensioncompression asymmetry in yielding and work hardening behavior.The basal and prismaticslip are suppressed either for tension or compression,which is the easiest to activate.The tension twin system{1012}<1011> easily activated in compression deformation due to the prismatic fiber texture based on the Schmidt factor,consequently resulting in a lower yield strength under compression than tension.ECAP can improve the tension-compression asymmetry of CP Ti due to grain refinement.The interaction among the dislocations,grain boundaries and deformation twins are the main work hardening mechanisms for compression deformation,while the interaction between the dislocations and grain boundaries for tension deformation.Deformation twins lead to the higher work hardening under compression than tension. 展开更多
关键词 ultrafine-grained commercially pure Ti equal channel angular pressing tensioncompression asymmetry texture TWINNING
下载PDF
An Investigation of Purely Azimuthal Passive Localization and Position Adjustment in Attempted UAV Formation Flights
10
作者 Qi Zhang Keren Sun Qiaozhen Zhang 《Journal of Applied Mathematics and Physics》 2023年第10期3075-3098,共24页
When a cluster of unmanned aerial vehicles (UAVs) is flying in formation, it is crucial to maintain the formation and not to be interfered by external electromagnetic wave signals. In order to maintain the formation, ... When a cluster of unmanned aerial vehicles (UAVs) is flying in formation, it is crucial to maintain the formation and not to be interfered by external electromagnetic wave signals. In order to maintain the formation, this paper proposes to use pure azimuth passive positioning to adjust the position of UAVs, i.e., certain UAVs in the formation transmit signals, the rest of the UAVs receive the signals passively, and extract the orientation information from them to adjust the position of the UAVs [1] [2] [3]. In this paper, the position adjustment problem of UAVs in “circular” formation flight under three models is investigated. To address the problem of “how to obtain the position of the receiving UAV when there are two UAVs with known numbers and evenly distributed on the circumference in addition to the UAV transmitting at the known center of the circle, and the rest of the UAVs with slight deviations in their positions are receiving the signals”, two purely mathematical geometric methods, namely, triangular localization method and polar co-ordinate method, are proposed respectively. We have determined the position of the receiving UAV;we have used the exhaustive method and the construction and disproof method to solve the problem of “how many UAVs are needed to transmit signals in order to realize the effective positioning of the UAVs when it is known that a certain UAV with a slight deviation in its position receives the signals emitted by two UAVs at the same time”, and the results show that: in addition to the known signals emitted by two UAVs, it is also necessary to transmit the signals emitted by two UAVs. The results show that in addition to the known two UAVs transmitting signals, two additional UAVs are required to transmit signals for precise po-sitioning. When the position of UAVs has deviation at the initial moment, the ideal approximation method and the target delimitation method are pro-posed, and the target of nine UAVs uniformly distributed on a circle of a spe-cific radius is achieved through several adjustments, after which the ad-vantages and disadvantages of each model are analyzed, and suggestions for improvement are put forward. The purely azimuthal passive localization method and the constructed model approach proposed in this paper can be extended to other fields, such as spacecraft formations in space and battle-ship formations at sea, as well as other formation flight position adjustment problems. 展开更多
关键词 pure Azimuth Passive Positioning Unmanned Aerial Vehicle (UAV) Position Adjustment Electromagnetic Silence
下载PDF
Effect of Strain Ratio on Fatigue Model of Ultra-fine Grained Pure Titanium
11
作者 QIANG Meng YANG Xirong +1 位作者 LIU Xiaoyan LUO Lei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第5期1169-1178,共10页
The ultra-fine grained(UFG)pure titanium was prepared by equal channel angular pressing(ECAP)and rotary swaging(RS).The strain controlled low cycle fatigue(LCF)test was carried out at room temperature.The fatigue life... The ultra-fine grained(UFG)pure titanium was prepared by equal channel angular pressing(ECAP)and rotary swaging(RS).The strain controlled low cycle fatigue(LCF)test was carried out at room temperature.The fatigue life prediction model and mean stress relaxation model under asymmetrical stress load were discussed.The results show that the strain ratio has a significant effect on the low cycle fatigue performance of the UFG pure titanium,and the traditional Manson-coffin model can not accurately predict the fatigue life under asymmetric stress load.Therefore,the SWT mean stress correction model and three-parameter power curve model are proposed,and the test results are verified.The final research shows that the threeparameter power surface model has better representation.By studying the mean stress relaxation phenomenon under the condition of R≠-1,it is revealed that the stress ratio and the strain amplitude are the factors that significantly afiect the mean stress relaxation rate,and the mean stress relaxation model with the two variables is calculated to describe the mean stress relaxation phenomenon of the UFG pure titanium under different strain ratios.The fracture morphology of the samples was observed by SEM,and it was concluded that the final fracture zone of the fatigue fracture of the UFG pure titanium was a mixture of ductile fracture and quasi cleavage fracture.The toughness of the material increases with the increase of strain ratio at the same strain amplitude. 展开更多
关键词 ultra-fine grained pure titanium low cycle fatigue life model mean stress relaxation mode strain ratio fracture morphology
下载PDF
Philosophical Matrix as a System of Categories of Pure Mind
12
作者 Yuriy Rotenfeld 《Journal of Philosophy Study》 2023年第6期269-274,共6页
The article is a study devoted to the development of the concept of the philosophical matrix as a system of categories of pure reason.The author proposes a new approach to understanding the philosophical system of cat... The article is a study devoted to the development of the concept of the philosophical matrix as a system of categories of pure reason.The author proposes a new approach to understanding the philosophical system of categories by putting forward unambiguous comparative concepts that serve as the basis for natural sciences.While the foundations of specific sciences are the concepts of“practical reason”,the author finds the categories of“pure reason”to be the foundations of philosophy,understood as“knowledge of the universal”.The article shows that relying on the senses and the concepts of“practical reason”allows for the verification of knowledge,while their generalization,removed from knowledge obtained empirically,gives categories of“pure reason”,which are accepted as the building material of the matrix.In this way,the author proposes a new system of philosophical categories that describes the fundamental aspects of human reasoning and its interaction with the world.At the same time,the categories of the philosophical matrix are not related to such ambiguous classificatory concepts as space,time,being,existence,consciousness,and others.The article draws attention to the fact that the matrix can be used not only to analyze philosophical theories but also to develop new concrete scientific approaches,for example,for the intellectual development of children.In addition,the article suggests the possibility of applying the philosophical matrix in other areas of the humanities,including psychology,linguistics,and sociology.As a result of the conducted research,the human intellect is divided into three ascending stages,designated by me in the following words-reason,mind,and wisdom,with the subsequent use of these concepts in philosophy and other fields of knowledge. 展开更多
关键词 REASON MIND wisdom CONTRADICTORY correlated opposite philosophical matrix practical mind pure mind
下载PDF
Optimization of Process Parameters of Continuous Microwave Drying Raspberry Puree Based on RSM and ANN-GA 被引量:1
13
作者 Zheng Xian-zhe Gao Feng +2 位作者 Fu Ke-sen Lu Tian-lin Zhu Chong-hao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第1期69-84,共16页
To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexe... To improve drying uniformity and anthocyanin content of the raspberry puree dried in a continuous microwave dryer,the effects of process parameters(microwave intensity,air velocity,and drying time)on evaluation indexes(average temperature,average moisture content,average retention rate of the total anthocyanin content,temperature contrast value,and moisture dispersion value)were investigated via the response surface method(RSM)and the artificial neural network(ANN)with genetic algorithm(GA).The results showed that the microwave intensity and drying time dominated the changes of evaluation indexes.Overall,the ANN model was superior to the RSM model with better estimation ability,and higher drying uniformity and anthocyanin retention rate were achieved for the ANN-GA model compared with RSM.The optimal parameters were microwave intensity of 5.53 W•g^(-1),air velocity of 1.22 m·s^(-1),and drying time of 5.85 min.This study might provide guidance for process optimization of microwave drying berry fruits. 展开更多
关键词 raspberry puree continuous microwave drying response surface method(RSM) artificial neural network(ANN) genetic algorithm(GA)CLC number:TG376 Document code:A Article ID:1006-8104(2023)-01-0069-16
下载PDF
基于宏基因组测序和纯培养技术解析胀袋生抽酱油的微生物类群 被引量:1
14
作者 王玉荣 席啦 +3 位作者 易宗伟 付彩霞 葛东颖 郭壮 《食品与发酵工业》 CAS CSCD 北大核心 2024年第4期165-170,177,共7页
该研究采用宏基因组测序技术对胀袋生抽酱油微生物类群进行了解析,对其微生物菌株进行了分离鉴定,并对分离株是否可导致酱油胀气进行了验证。宏基因组结果表明,胀袋生抽酱油样品中平均相对含量大于1.0%的微生物主要由嗜盐四联球菌(Tetra... 该研究采用宏基因组测序技术对胀袋生抽酱油微生物类群进行了解析,对其微生物菌株进行了分离鉴定,并对分离株是否可导致酱油胀气进行了验证。宏基因组结果表明,胀袋生抽酱油样品中平均相对含量大于1.0%的微生物主要由嗜盐四联球菌(Tetragenococcus halophilus)、酸鱼联合乳杆菌(Ligilactobacillus acidipiscis)、植物乳植物杆菌(Lactiplantibacillus plantarum)、耐酸乳杆菌(Lactobacillus acetotolerans)、棒状腐败乳杆菌(Loigolactobacillus coryniformis)、短促生乳杆菌(Levilactobacillus brevis)和屎肠球菌(Enterococcus faecium)构成,平均相对含量分别为28.01%、25.50%、9.45%、2.49%、1.83%、1.53%和1.33%;采用纯培养技术,分离出的49株细菌被鉴定为6个属下的11个种,其中枯草芽孢杆菌(Bacillus subtilis)、破布子联合乳杆菌(Ligilactobacillus pobuzihii)、蛋白原酶腐败乳杆菌(Loigolactobacillus rennini)和L.acidipiscis分离株占总分离株数的39.22%、19.61%、11.76%和9.80%,分离出的2株酵母菌均被鉴定为扣囊复膜酵母(Saccharomycopsis fibuligera);产气验证实验发现,所有分离株均不能单独引起生抽酱油的胀袋现象。由此可见,胀袋生抽酱油具有较高的微生物多样性,在后续研究引入培养组学策略以获得更多的分离株,亦或考虑多菌株的协同作用,对酱油涨袋这一产业问题的解决可能具有积极的意义。 展开更多
关键词 生抽酱油 胀气 宏基因组测序 纯培养 微生物
下载PDF
基于精密切削和抛光的铸态软金属的金相表征
15
作者 孙明艳 张永皞 +1 位作者 张晓峰 黄姝珂 《热加工工艺》 北大核心 2024年第7期147-150,154,共5页
基于超精密、精密切削和抛光技术,介绍了两种表征铸态软金属材料金相组织的新方法。该方法摒弃了常规金相组织表征在试样制备过程中的磨制步骤。采用超精密切削,或者精密切削与抛光相结合的方法,解决了铸态软金属材料金相试样制备困难... 基于超精密、精密切削和抛光技术,介绍了两种表征铸态软金属材料金相组织的新方法。该方法摒弃了常规金相组织表征在试样制备过程中的磨制步骤。采用超精密切削,或者精密切削与抛光相结合的方法,解决了铸态软金属材料金相试样制备困难、重复性和稳定性差的难题,提高了制样效率和金相组织形貌显示的真实性。 展开更多
关键词 精密切削 软金属 纯锡 纯铅 金相组织
下载PDF
超声对乳腺单纯黏液癌与纤维腺瘤鉴别诊断的价值
16
作者 王红莉 胡越 +5 位作者 谭翠 顾然 梅静思 余玥幸 陈丽莉 龚畅 《中山大学学报(医学科学版)》 CAS CSCD 北大核心 2024年第4期631-636,共6页
【目的】探讨乳腺单纯黏液癌(PMC)和纤维腺瘤(FA)的超声表现差异,为临床鉴别诊断提供参考。【方法】回顾性搜集2012年1月至2021年1月间在中山大学孙逸仙纪念医院就诊的连续乳腺PMC初诊患者50例及2018年6月至2019年1月间的连续乳腺FA初... 【目的】探讨乳腺单纯黏液癌(PMC)和纤维腺瘤(FA)的超声表现差异,为临床鉴别诊断提供参考。【方法】回顾性搜集2012年1月至2021年1月间在中山大学孙逸仙纪念医院就诊的连续乳腺PMC初诊患者50例及2018年6月至2019年1月间的连续乳腺FA初诊患者100例超声资料。依据2013年版乳腺影像报告与数据系统(BI-RADS)评估两组病变的超声图像特征,并比较两组患者年龄、病变的长径及超声图像特征的差异。【结果】PMC患者中位年龄为47岁,而FA为33岁,PMC患者年龄较FA偏大,两者差异具有统计学意义(P<0.001)。PMC患者病变中位长径2.4 cm大于FA的1.8 cm,差异有统计学意义(P=0.001)。PMC中,70%(35/50)表现为不规则形,82%(41/50)与皮肤平行,92%(46/50)边缘不清晰,72%(36/50)内部呈低回声,68%(34/50)后方回声增强;FA中,69%(69/100)表现为卵圆形或圆形,98%(98/100)与皮肤平行,54%(54/100)边缘清晰,98%(98/100)内部呈低回声,75%(75/100)后方回声未见变化,PMC与FA相应超声表现的差异有统计学意义(P<0.001,P=0.001,P<0.001,P<0.001,P<0.001),而病变内是否存在钙化、病变的血流表现在两者间差异无统计学意义。【结论】与FA相比,PMC患者年龄及病变长径偏大,并且在超声上,大部分乳腺PMC的形态及边缘仍表现为浸润性癌的生长特点,同时,PMC的后方回声增强,是其独特的表现。 展开更多
关键词 乳腺 黏液癌 单纯黏液癌 纤维腺瘤 超声
下载PDF
热轧变形对纯钴显微组织和力学性能的影响
17
作者 徐仰涛 魏江龙 南宏强 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第6期2019-2029,共11页
为研究不同热轧变形量对纯钴的显微组织和力学性能的影响,对高纯钴(99.95%)进行500℃下的热轧处理,将试样水冷后进行XRD、EBSD表征。结果表明:初始态试样中HCP相、FCC相两相共存,且以HCP相为主;随轧制进行,最大晶粒尺寸从28.08μm细化到... 为研究不同热轧变形量对纯钴的显微组织和力学性能的影响,对高纯钴(99.95%)进行500℃下的热轧处理,将试样水冷后进行XRD、EBSD表征。结果表明:初始态试样中HCP相、FCC相两相共存,且以HCP相为主;随轧制进行,最大晶粒尺寸从28.08μm细化到12.35μm,∑3退火孪晶和相变孪晶的含量降低,残余应变增加,两相含量发生改变,FCC相含量上升,HCP相含量降低;不同相中大小角度晶界呈现相同的变化趋势,小角度晶界(LAGB)含量上升,大角度晶界(HAGB)含量降低;压下量27%的试样性能最好,其屈服强度、抗拉强度、硬度和伸长率(657.18 MPa、964.05 MPa、298.2HV_(0.5)和42.87%)相较于初始态(408.34 MPa、862.53 MPa、214.4HV_(0.5)和38.07%)均有提升;塑性随强度的增加不降反升,主要是由FCC相含量上升、大尺寸片层状HCP相晶粒发生细化和均匀化所致。 展开更多
关键词 纯钴 热轧 显微组织 力学性能
下载PDF
敦煌莫高窟隋至初唐洞窟西壁所绘图像的功能 被引量:1
18
作者 八木春生 牛源(译) 《敦煌研究》 CSSCI 北大核心 2024年第2期38-50,共13页
敦煌莫高窟第57窟是唐前期第一期的代表洞窟。外层龛正面左右下部绘有树下两脚合并坐式菩萨像和树下坐于藤座上呈半跏思惟姿势的菩萨像。这种菩萨坐像的组合以及与其类似的组合,在隋代第二期洞窟中就已出现,它们与弥勒像密切相关。但在... 敦煌莫高窟第57窟是唐前期第一期的代表洞窟。外层龛正面左右下部绘有树下两脚合并坐式菩萨像和树下坐于藤座上呈半跏思惟姿势的菩萨像。这种菩萨坐像的组合以及与其类似的组合,在隋代第二期洞窟中就已出现,它们与弥勒像密切相关。但在第57窟中,与隋代第二期洞窟有所不同的是人们憧憬的往生净土画在窟顶。阿弥陀如来作为过去佛,由阿弥陀、释迦、弥勒构成的新三世佛在唐前期第一期完成了转变。重要的是南北壁所表现的树下说法图不仅仅表现了三世佛,还表现了当时人们所憧憬的往生世界的情景。另外,唐前期第一期出现了将弥勒以如来表现且坐于宝池中。但是,初唐第一期末期的第322窟仅北壁阿弥陀如来坐在宝池中,南壁的弥勒如来未见宝池,这是因为弥勒净土本来就没有宝池。这种阿弥陀如来和弥勒如来都拥有配备宝池的净土的模糊印象,也显示了净土之间的不同。第57窟与第322窟一样,北壁如来坐像坐于宝池中伸出的莲花座上、南壁如来坐像周围未见表现其坐于宝池中的莲花和荷叶,那么第57窟南壁主尊虽然不是如来倚坐像,但下意识地作为弥勒如来而绘制的可能性很高。 展开更多
关键词 第57窟 第322窟 两脚合并菩萨坐像 半跏思惟菩萨像 净土往生思想
下载PDF
华南锑矿带单锑型锑矿床“两层楼”二元成矿模型——以滇东南木利锑矿床为例 被引量:1
19
作者 王加昇 付浩 +3 位作者 侯德发 王永瑞 李海明 赵建华 《地球学报》 CAS CSCD 北大核心 2024年第4期502-514,共13页
华南锑矿带是我国乃至世界上最重要的锑成矿带,分布有众多大型-超大型单锑型锑矿床。本文以滇东南木利锑矿床作为主要研究对象,并与华南锑矿带内单锑型矿床中最典型的锡矿山和独山锑矿田(床)进行详细的基础地质特征对比研究。发现对于... 华南锑矿带是我国乃至世界上最重要的锑成矿带,分布有众多大型-超大型单锑型锑矿床。本文以滇东南木利锑矿床作为主要研究对象,并与华南锑矿带内单锑型矿床中最典型的锡矿山和独山锑矿田(床)进行详细的基础地质特征对比研究。发现对于单锑型锑矿田(床)而言,无论是矿田尺度还是矿床尺度,普遍具有“石英-辉锑矿”和“方解石-辉锑矿”两种矿石类型。同一矿田内,部分矿床(段)以“石英-辉锑矿”的矿物组合为主,部分以“方解石-辉锑矿”的矿物组合为主;而矿床(段)尺度内,又往往表现为上部“石英-辉锑矿”型矿物组合,下部为“方解石-辉锑矿”型矿物组合的两层楼模式。该模型的提出对于华南锑矿带单锑型矿床成因研究和找矿勘查具有重要意义。 展开更多
关键词 华南锑矿带 “两层楼”二元成矿模型 木利 单锑型锑矿床
下载PDF
基于纯培养和超高深宏基因组测序技术分析茅台镇两企业高温大曲微生物多样性差异
20
作者 王玉荣 侯强川 +3 位作者 田龙新 刘菊珍 周加平 郭壮 《食品科学》 EI CAS CSCD 北大核心 2024年第4期108-115,共8页
以茅台镇不同酒厂高温大曲为研究对象,采用纯培养技术和宏基因组测序对高温大曲中微生物多样性进行解析。结果发现,分离的212株芽孢杆菌主要为77株索诺拉沙漠芽孢杆菌(Bacillus sonorensis)、39株地衣芽孢杆菌(B. licheniformis)和19株... 以茅台镇不同酒厂高温大曲为研究对象,采用纯培养技术和宏基因组测序对高温大曲中微生物多样性进行解析。结果发现,分离的212株芽孢杆菌主要为77株索诺拉沙漠芽孢杆菌(Bacillus sonorensis)、39株地衣芽孢杆菌(B. licheniformis)和19株解淀粉芽孢杆菌(B. amyloliquefaciens)等。通过宏基因组Binning技术共获得55个高质量基因组,其中有18个疑似新菌株,分别为Bacillus sp.、Lactobacillus sp.和Weissella sp.等。菌群结构分析表明,高温大曲中的主要菌属分别为Desmospora sp. 8437、B. sonorensis和B. amyloliquefaciens等,其中A酒厂在B. sonorensis和B. amyloliquefaciens等的相对丰度显著较低(P<0.05)。A酒厂高温大曲中微生物的多样性和丰富度均显著低于B酒厂(P<0.05),且两者的菌群结构存在明显的差异。在功能方面,A酒厂高温大曲中丰度较高的差异代谢通路主要与氨基酸的生物合成相关,而B酒厂高温大曲中丰度较高的差异代谢通路主要与L-鼠李糖的降解相关。由此可见,本研究对后续发酵工艺的改良和优良菌株的筛选具有积极意义。 展开更多
关键词 高温大曲 纯培养技术 宏基因组 芽孢杆菌 生物信息学
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部