Compact hypersurfaces in a unit sphere Cheng, Qing-Ming; Shu, Shichang; Suh, Young Jin
Proceedings of the Royal Society of Edinburgh. Section A. Mathematics,
12/2005, Letnik:
135, Številka:
6
Journal Article
Recenzirano
We study curvature structures of compact hypersurfaces in the unit sphere Sn+1(1) with two distinct principal curvatures. First of all, we prove that the Riemannian product is the only compact ...hypersurface in Sn+1(1) with two distinct principal curvatures, one of which is simple and satisfies
where n(n − 1)r is the scalar curvature of hypersurfaces and c2 = (n − 2)/nr. This generalized the result of Cheng, where the scalar curvature is constant is assumed. Secondly, we prove that the Riemannian product is the only compact hypersurface with non-zero mean curvature in Sn+1(1) with two distinct principal curvatures, one of which is simple and satisfies
This gives a partial answer for the problem proposed by Cheng.
In order to better understand the Mesozoic tectonic evolution of Southeast China Block (SECB in short), this paper describes geological features of Mesozoic basins that are widely distributed in the ...SECB. The analyzed data are derived from a regional geological investigation on various Mesozoic basins and a recently compiled 1:1,500,000 geological map of Mesozoic–Cenozoic basins. Two types of basin are distinguished according to their tectonic settings, namely, the post-orogenic basin (Type I) and the intracontinental extensional basin (Type II); the latter includes the graben and the half-graben or faulted-depression basins. Our studies suggest that the formation of these basins connects with the evolution of geotectonics of the SECB. The post-orogenic basin (Type I) was formed in areas from the piedmont to the intraland during the interval from Late Triassic to Early Jurassic; and the formation of the intracontinental extensional basin (Type II) connects with an intracontinental crustal thinning setting in the Late Mesozoic. The graben basin was generated during the Middle Jurassic and is associated with a bimodal volcanic eruption; and the half-graben or faulted-depression basin, filled mainly by the rhyolite, tuff and sedimentary rocks during Early Cretaceous, is occupied by the Late Cretaceous–Paleogene red-colored terrestrial clastic rocks. We noticed that the modern outcrops of numerous granites and basins occur in a similar level, and the Mesozoic granitic bodies contact with the adjacent basins by large normal faults, suggesting that the modern landforms between granites and basins were yielded by the late crustal movement. The modern basin and range framework was settled down in the Cretaceous. Abundant sedimentary structures are found in the various basins, from that the deposited environments and paleo-currents are concluded; during the Late Triassic–Early Jurassic time, the source areas were situated to the north and northeast sides of the outcrop region. In this paper, we present the study results on one geological and geographical separating unit and two separating fault zones. The Wuyi orogenic belt is a Late Mesozoic paleo-geographically separating unit, the Ganjiang fault zone behaves as the western boundary of Early Cretaceous volcanic rocks, and the Zhenghe–Dapu fault zone separates the SE-China Coastal Late Mesozoic volcanic-sedimentary basins and the Wuyi orogenic belt. Finally, we discuss the geodynamic mechanisms forming various basins, proposing a three-stage model of the Mesozoic sedimentary evolution.
The adoptive transfer of tumor-sensitized T cells can eradicate disseminated malignancy in murine animal models. T cells must be sensitized to tumor antigens in vivo to acquire antitumor reactivity. ...T-cell sensitization has been demonstrated to be dependent on host antigen-presenting cells. Tumor-associated macrophages are a heterogeneous population of cells that may have both inhibitory and stimulatory influences on the sensitization of naive T cells. Here we demonstrate that a weakly immunogenic tumor, the MCA 205 sarcoma, produces substantial amounts of murine monocyte chemoattractant protein 1 (MCP-1). Neutralization of MCP-1 during in vivo T-cell sensitization resulted in T cells that possessed enhanced therapeutic activity against established pulmonary metastases. These T cells sensitized during MCP-1 depletion also exhibited enhanced production of IFN-gamma upon recognition of tumor targets. These results demonstrate that MCP-1 can have a potent inhibitory influence on the development of tumor-reactive T cells.
Based on the full-scale test results of 29 shaft anchors installed in the silty alluvial soil of the Taipei basin, the anchorage behaviors of anchors having two different types of tendon assemblies, ...namely the singly anchored type and the multiple anchored type, are evaluated in this paper. Test results indicate that the benefits of the multiple anchored anchor system is not obvious in terms of the residual movement and the ultimate anchorage capacity when compared with the traditional singly anchored anchor. A critical fixed length of 20 m is observed regarding the ultimate anchorage capacity for both singly anchored tension anchors and triply anchored compression anchors. This critical fixed length is considerably longer than the upper fixed length limit proposed by the major anchorage specifications. For those anchors with fixed length shorter than the critical length, the anchorage capacity increases linearly with the fixed length. However, if the fixed length is extended beyond this critical length, up to 70% falloff in anchorage resistance per unit fixed length increment was found.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
The role of semiochemicals in host location by the parasitoid Pteromalus cerealellae (Boucek) was investigated in Y-tube and three-way olfactometers, by measuring responses to stimuli ...associated with the cowpea weevil, Callosobruchus maculatus. Orientation of mated parasitoid females was measured in response to five stimuli: live virgin female bruchid beetles, solvent extracts of whole body virgin female bruchids, solvent extracts of the oviposition marking pheromone from a glass substrate, previously infested cowpea seeds with adult emergence holes, and uninfested cowpea seeds. All stimuli elicited significantly better responses than those to blank controls. Female parasitoids that had previous exposure to live, virgin beetles and infested seeds exhibited shorter latency and response times to the stimuli than did naïve females. Live, virgin female bruchids and whole body solvent extracts of virgin female bruchids elicited the strongest responses. Comparison of responses in a three-way olfactometer of whole body solvent extracts of virgin female bruchids, infested seeds, and solvent extracts of bruchid oviposition marker pheromone showed that whole body extracts of virgin female bruchids elicited the strongest response by both host-experienced and naïve female parasitoids. The potential for innate responses to host-specific chemical cues and the possibility of female parasitoids using chemical cues from adult hosts are discussed.
Pregnancy in a cesarean scar is the rarest form of an ectopic pregnancy. The treatment for cesarean scar pregnancy mainly includes systemic methotrexate and uterine artery embolization. Here, we ...reported a case of cesarean scar pregnancy treated by curettage and aspiration guided by laparoscopy. The treatment plan included two phases. Three days after a combination of methotrexate and mifepristone was administered, the gestational sac was removed under laparoscopy, which enabled a successful treatment for the unruptured ectopic pregnancy in a previous cesarean scar and made it possible to preserve the reproductive capability of the patient.
The Tianshan range could have been built by both late Early Paleozoic accretion and Late Paleozoic collision events. The late Early Paleozoic Aqqikkudug-Weiya suture is marked by Ordovician ...ophiolitic mélange and a Silurian flysch sequence, high-pressure metamorphic relics, and mylonitized rocks. The Central Tianshan belt could principally be an Ordovician volcanic arc; whereas the South Tianshan belt, a back-arc basin. Macro- and microstructures, along with unconformities, provide some kinematic and chronological constraints on 2-phase ductile deformation. The earlier ductile deformation occurring at ca. 400 Ma was marked by north-verging ductile shearing, yielding granulite-bearing ophiolitic mélange blocks and garnet-pyroxene-facies ductile deformation, and the later deformation, a dextral strike-slip tectonic process, occurred during the Late Carboniferous(Early Permian. Early Carboniferous molasses were deposited unconformably on pre-Carboniferous metamorphic and ductilely sheared rocks, implying the end of the early orogeny. The large-scale ductile strike-slip along the Aqqikkudug-Weiya zone was possibly caused by the second tectonic event, the Hercynian collision between the northern Tarim block and the southern Siberian block. Late Paleozoic granitic magmatism and superimposed structures overprinted this Early Paleozoic deformation belt. Results of geometric and kinematic studies suggest that the primary framework of the Southern-Central Tianshan belt, at least the eastern part of the Tianshan belt, was built by these two phases of accretion events.
Action against bullying in schools has been quite extensive over the last decade. The article reports a survey of 2308 pupils aged 10-14 years, from 19 schools across England. Frequencies of being ...bullied and of bullying others suggest some decline from earlier findings, which may reflect positive results achieved by schools concerned about the issue. Victims report a variety of coping strategies, varying with age. Bullies report often feeling that the victim deserved it, a response especially marked in older boys. A `culture of silence' still persists in that 30 percent of victims had told no one of the bullying. However, for those who had told, the outcome was usually seen as positive, although there was a small risk of things getting worse especially when teachers were told. Findings are discussed in terms of the opportunities and challenges facing schools as they work to develop effective anti-bullying policies and strategies.
Effects of carbon sources, i.e. carbon nanotubes (CNTs), graphite, carbon black (C-black), on synthesised TiC
x
size, shape and compressive properties of in situ 40–60 vol.-% TiC
x
/2009Al composites ...were investigated. When CNTs and C-black were used, the synthesised TiC
x
with particle sizes of 0.08–1 and 0.9–5 µm, respectively, was spherical or nearly spherical in shape, while graphite was used, the synthesised TiC
x
with particles sizes of 0.2–2 µm was octahedral or spherical in shape. The yield strength (σ0.2), ultimate compression strength (σUCS) and hardness of TiC
x
/2009Al composites all increased with increasing TiC
x
content, while the plastic strain (ε) decreased. The σ0.2, σUCS, ε and hardness of 60 vol.-% TiC
x
/2009Al composites fabricated by using CNTs were 722 MPa, 946 MPa, 3.2% and 260 ± 10 Hv, respectively. The strength increase of the composites resulted from finer-sized TiC
x
particles with spherical shape.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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