检索结果-南通市图书馆

Breakup of Cavitation Bubbles within the Diesel Droplet

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2014年第1期27卷 198-204页

作者： L Ming NING Zhi YAN Kai fu juan SONG Yunchao SUN Chunhua College of Mechanical and Electrical Engineering Beijing Jiaotong University

Supercavitation in the diesel nozzle increases the instability of droplets in part due to the two-phase mixture, while the effect of cavitation bubbles on the instability of drops is still unclear. In order to investigate the breakup of cavitation bubbles within the diesel droplet, a new mathematical model describing the disturbance growth rate of the diesel bubble instability is developed. The new mathematical model is applied to predict the effects of fluids viscosity on the stability of cavitation bubbles. The predicted values reveal that the comprehensive effect of fluids viscosity makes cavitation bubbles more stable. Compared with the viscosities of air and cavitation bubble, the diesel droplet＇s viscosity plays a dominant role on the stability of cavitation bubbles. furthermore, based on the modified bubble breakup criterion, the effects of bubble growth speed, sound speed, droplet viscosity, droplet density, and bubble-droplet radius ratio on the breakup time and the breakup radius of cavitation bubbles are studied respectively. It is found that a bubble with large bubble-droplet radius ratio has the initial condition for breaking easily. For a given bubble-droplet radius ratio （0.2）, as the bubble growth speed increases （from 2 m/s to 60 m/s）, the bubble breakup time decreases（from 3.59 gs to 0.17 ps） rapidly. Both the greater diesel droplet viscosity and the greater diesel droplet density result in the increase of the breakup time. With increasing initial bubble-droplet radius ratio （from 0.2 to 0.8）, the bubble breakup radius decreases （from 8.86 trn to 6.23 tm）. There is a limited breakup radius for a bubble with a certain initial bubble-droplet radius ratio. The mathematical model and the modified bubble breakup criterion are helpful to improve the study on the breakup mechanism of the secondary diesel droplet under the condition of supercavitation.

关键词： supercavitation instability diesel droplet cavitation bubbles secondary breakup

Contact Model of Revolute Joint with Clearance Based on Fractal Theory

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2018年第6期31卷 34-44页

作者： Shi-Hua Li Xue-Yan Han Jun-Qi Wang Jing Sun fu-juan Li Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University

The contact sti ness of a mechanical bonding surface is an important parameter in determining the normal and radial contact force. To improve the calculation accuracy of the contact force model, the surface roughness of the bonding surface and the energy loss that necessarily occurs during the impact process should be considered com?prehensively. To study the normal contact force of a revolute joint with clearance more accurately in the case of dry friction, a nonlinear sti ness coe cient model considering the surface roughness was established based on fractal theory, which considers the elastic, elastic?plastic, and plastic deformations of the asperities of the contact surface during the contact process. On this basis, a modified nonlinear spring damping model was established based on the Lankarani–Nikravesh contact force model. The laws influencing the surface roughness, recovery coe cient, initial velocity, and clearance size on the impact force were revealed, and were compared with the Lankarani–Nikravesh model and a hybrid model using MATLAB. The maximum impact force was obtained using a modified contact force model under di erent initial velocities, di erent clearances, and di erent degrees of surface roughness, and the calculated results were then compared with the experiment results. This study indicates that the modified model can be used more widely than other models, and is suitable for both large and small clearances. In particular, the modified model is more accurate when calculating the contact force of a revolute joint with a small clearance.

关键词： Fractal theory Modified contact model Surface roughness Lankarani–Nikravesh model

Recent progress on anti-Candida natural products

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2021年第8期19卷 561-579页

作者： SUN fu-juan LI Min GU Liang WANG Ming-Ling YANG Ming-Hua State Key Laboratory of Natural Medicines Department of Natural Medicinal ChemistryChina Pharmaceutical UniversityNanjing 210009China

Candida is an intractable life-threatening *** infection is extremely difficult to eradicate,and thus is the major cause of morbidity and mortality in immunocompromised ***,the rapid spread of drug-resistant fungi has led to significant decreases in the therapeutic effects of clinical *** anti-Candida agents are urgently needed to solve the complicated medical *** products with intricate structures have attracted great attention of researchers who make every endeavor to discover leading compounds for antifungal *** novel mechanisms and diverse modes of action expand the variety of fungistatic agents and reduce the emergence of drug *** recent decades,considerable effort has been devoted to finding unique antifungal agents from nature and revealing their unusual mechanisms,which results in important progress on the development of new antifungals,such as the novel cell wall inhibitors YW3548 and SCY-078 which are being tested in clinical *** review will present a brief summary on the landscape of anti-Candida natural products within the last *** will also discuss in-depth the research progress on diverse natural fungistatic agents along with their novel mechanisms.

关键词： Candida Natural products Antifungal activity Mechanisms

A PML Method for Electromagnetic Scattering from Two-dimensional Overfilled Cavities

在线全文

学校读者我要写书评

暂无评论

Communications in Mathematical Research 2009年第1期25卷 53-68页

作者： Liu juan MA fu-MING College of Mathematics Jilin University Changchun 130012

In this paper, we consider electromagnetic scattering problems for two-dimensional overfilled cavities. A half ringy absorbing perfectly matched layer （PML） is introduced to enclose the cavity, and the PML formulations for both TM and TE polarizations are presented. Existence, uniqueness and convergence of the PML solutions are considered. Numerical experiments demonstrate that the PML method is efficient and accurate for solving cavity scattering problems.

关键词： overfilled cavity scattering TM polarization TE polarization perfectly matched layer (PML) DtN operator

A hybrid method for inverse cavity scattering problem for shape

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2010年第2期25卷 127-136页

作者： LIU juan MA fu-ming School of Mathematics, Jilin University, Changchun 130012, China. School of Mathematics Jilin University Changchun China

In this paper, we give a hybrid method to numerically solve the inverse open cavity scattering problem for cavity shape, given the scattered solution on the opening of the cavity. This method is a hybrid between an iterative method and an integral equations method for solving the Cauchy problem. The idea of this hybrid method is simple, the operation is easy, and the computation cost is small. Numerical experiments show the feasibility of this method, even for cases with noise.

关键词： Open cavity Cauchy problem Helmholtz equation integral equations system method iterativehybrid method.

Venetoclax in combination with chidamide and dexamethasone in relapsed/refractory primary plasma cell leukemia without t(11;14):A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第5期9卷 1175-1183页

作者： Yang Yang Li-juan fu Chun-Mei Chen Mei-Wei Hu Department of Hematology The Second Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhou 310014Zhejiang ProvinceChina

BACKGROUND Conventional therapies for primary plasma cell leukemia(pPCL)are usually ineffective,with a short remission time with the use of multiple myeloma medications,showing aggressiveness of pPCL.B-cell lymphoma-2 inhibitor venetoclax is usually used for relapsed/refractory multiple myeloma(RRMM)with t(11;14).There are very few studies published on the use of venetoclax in pPCL without t(11;14).Similarly,histone deacetylase inhibitors are considered effective for the treatment of RRMM,but there are no reports on their use in *** SUMMARY A 57-year-old woman with severe anemia,thrombocytopenia,multiple bone destruction,impaired renal function,and 42.7%of peripheral plasma cells is *** multiple chemotherapy regimens and chimeric antigen receptor Tcell treatment,the disease progressed *** patient had very good partial response and was maintained for a long time on venetoclax in combination with chidamide and dexamethasone *** The success of venetoclax-chidamide-dexamethasone combination therapy in achieving a very good partial response suggested that it can be used for refractory/relapsed pPCL patients who have been exhausted with the use of various drug combinations and had poor survival outcomes.

关键词： Relapsed/refractory Primary plasma cell leukemia Venetoclax Chidamide Very good partial response Case report

Different Pretreatments before Application of GnRH Antagonist Protocol in Controlled Ovarian Hyperstimulation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Reproduction and Contraception 2011年第4期22卷 201-210页

作者： Ping-xiu HUANG Rong LI Min fu juan-juan WANG Reproductive Medical Centre Shenzhen Hospital of Peking University Shenzhen 518036 China

Objective To analyze the clinical features and outcome of patients who used different pretreatments before application of gonadotropin-releasing hormone antagonist protocol during in vitro fertilization - embryo transfer （IVF-ET） cycles, and to explore how effective to use the antagonist protocol. Methods A retrospective analysis was performed. All the ET cycles were divided into three groups, group A （n=125） used short acting GnRH agonist before GnRH antagonist treatment, group B （n=113） used short-acting oral contraceptives before GnRH antagonist treatment, group C （n=81） was untreated before GnRH antagonist treatment. All the patients had no tubal fluid, endometrial polyps and no anatomical abnormalities of the uterus, from April 2010 to December 2010. The patient＇s age, dose and duration of gonadotropin （Gn） treatment, the serum LH and E2 levels on the day of hCG injection, the number of oocytes retrieved, the rates of good-quality embryos, the clinical pregnancy rates were compared. At the same time, 261 GnRH agonist long protocol cycles （group D） were selected at the same period as further comparison. Results The patients in group C （32.9 ~ 4.8 years） were significantly older than those in groups A and B （31.6 ___＋3.7 years, 31.2 ___%4.1 years）（P 〈0.05）. The dose and the duration of Gn in group C were significantly lower than those in groups A and B. The serum LH level on the day of hCG injection in group A and group B was significantly lower than that in group C （P 〈0.05）, especially in group A. The endometrium was the thinnest in group B. There were no significant differences in the fertilization rates and the good-quality embryosrates among them. The clinical pregnancy rate of group B decreased significantly compared with groups A and C （P〈0. 05）. The clinical pregnancy rate of group C was the highest among them. There was no significant difference of clinical pregnancy rates between group C and group D （37% vs 40.2%,P〉0.05）. However, the dose （19.8 ±6.6 am

关键词： in vitro fertilization-embryo transfer (IVF-ET) gonadotropin-releasing hormone antagonist short-acting oral contraceptives short-acting agonist

Properties and nucleotide sequence of linear plasmid-like DNA pC4 from mitochondria of Cucumis sativus

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第15期46卷 1288-1291页

作者： Junying Li Yingda Wen Yanling Bai juan fu Xiuming Zhang Caichang Gao Nankai Univ Inst Mol Biol Tianjin 300071 Peoples R China

Four kinds of mitochondrial plasmid-like DNAs, designated pC1, pC2, pC3 and pC4, were detected in Cucumis sativus Jinyan No. 4. The electron microscopy observation showed that pC4 was linear conformation. Complete sequence of pC4 was cloned into pUC19 with E. coli JM109 as host. Sequence analysis revealed that pC4 was 370 bp long, the shortest one among all the reported mitochondrial plasmid-like DNAs. pC4 was AT rich. It contained terminal direct repeat sequence (35 bp in length)as well as many short direct and inverted repeats. ORFs in pC4 were short. pC4 was found to be homologous to nuclear DNAs, but lack homology with main mitochondrial and chloroplast DNAs. pC4-homologous sequence also occurred in nuclear genome of Jinyan No. 7 which contained no mitochondrial plasmid-like DNAs. The hybridization pattern of Jinyan No. 7 was slightly different from that of Jinyan No. 4. This suggested that pC4 occurred at the forepart of Cucumis sativus species divergence and integrated into the nuclear genome,

关键词： Cucumis sativus linear mitochondrial plasmid-like DNAs nucleotide sequence homology.

Geology, geochronology and geochemistry of large Duobaoshan Cu-Mo-Au orefield in NE China: Magma genesis and regional tectonic implications

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第1期12卷 265-292页

作者： Wen-yan Cai Ke-yong Wang Jian Li Li-juan fu Chun-kit Lai Han-lun Liu College of Earth Sciences Jilin UniversityChangchun 130061China College of Geology and Mining Engineering Xinjiang UniversityUrumqi 830047China Key Laboratory of Mineral Resources Evaluation in Northeast Asia Ministry of Land and Resources of ChinaChangchun 130061China Technical Information Department Inner Mongolia Shandong Gold Geological Minerals Survey Co.Ltd.Chifeng 024000China Faculty of Science Universiti Brunei DarussalamGadongBrunei Darussalam

Duobaoshan is the largest porphyry-related Cu-Mo-Au orefield in northeastern(NE)Asia,and hosts a number of large-medium porphyry Cu(PCDs),epithermal Au and Fe-Cu skarn *** ages of these deposits,from the oldest(Ordovician)to youngest(Jurassic),have spanned across over 300 *** similar orefields of such size and geological complexity are found in NE Asia,which reflects its metallogenic uniqueness in forming and preserving porphyry-related *** this study,we explore the actual number and timing of magmatic/mineralization phases,their respective magma genesis,fertility,and regional tectonic connection,together with the preservation of *** present new data on the magmatic/mineralization ages(LA-ICP-MS zircon U-Pb,pyrite and molybdenite Re-Os dating),whole-rock geochemistry,and zircon trace element compositions on four representative deposits in the Duobaoshan orefield,i.e.,Duobaoshan PCD,Tongshan PCD,Sankuanggou Fe-Cu skarn,and Zhengguang epithermal Au deposits,and compiled published ones from these and other mineral occurrences in the *** terms of geochronology,we have newly summarized seven magmatic phases in the orefield:(1)Middle-Late Cambrian(506-491 Ma),(2)Early and Middle Ordovician(485-471 Ma and~462 Ma),(3)Late Ordovician(450-447 Ma),(4)Early Carboniferous and Late-Carboniferous to Early Permian(351-345 and 323-291 Ma),(5)Middle-Late Triassic(244-223 Ma),(6)Early-Middle and Late Jurassic(178-168 Ma and~150 Ma),and(7)Early Cretaceous(~112 Ma).Three of these seven major magmatic phases were coeval with ore formation,including(1)Early Ordovician(485-473 Ma)porphyry-type Cu-Mo-(Au),(2)Early-Middle Triassic(246-229 Ma)porphyry-related epithermal Au-(Cu-Mo),and(3)Early Jurassic(177-173 Ma)Fe-Cu skarn *** deposits in the orefield,notably Tongshan and Zhengguang,were likely formed by more than one mineralization *** terms of geochemistry,ore-causative granitoids in the orefield exhibit adakite-like or adakite-nor

关键词： Duobaoshan Cu-Mo-Au orefield(NE China) Porphyry Cu deposit Epithermal Au deposit Paleo-Asian Ocean Central Asian Orogenic Belt(CAOB)