To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
In this paper, a novel multilayer substrate integrated dual-mode dielectric resonator (DR) filter is proposed. The square dual-mode DR is made of the high permittivity substrate by removing the undesired portions and the surface coppers so that the relatively high unloaded quality factor of the dominate TM11 pair can be obtained which compared to these fully dielectric-filled substrate integrated waveguides. Meanwhile, it can be easily integrated in an equivalent cavity implemented by multilayer printed circuit boards for filter design, showcasing low in-band loss, light weight, and compact size. For demonstration, a multilayer substrate integrated DR bandpass filter centered at X-band is designed and measured. Good agreement between the simulated and measured results can be observed, and the measured insertion loss at the passband center frequency (8.38 GHz) is 1.1 dB.
Compared with commercial polyolefin membranes, polyacrylonitrile (PAN) membrane prepared by electrostatic spinning has higher porosity, electrolyte uptake, thermal stability, and lithium-ion conductivity, etc. However, poor mechanical performance has largely limited the application of electrospun PAN separators. In this study, PAN/polyimide (PI) composite membrane is prepared by electrostatic spinning to improve the mechanical and electrochemical performances. Scanning electron microscopy, thermal analysis method, and electrochemical methods were used for evaluation of the electrospun composite membrane. The results show that the composite membrane possesses good thermal stability and exhibits better mechanical performance than pristine PAN membrane (increasing by 1.1 times in tension strength). The addition of PI can increase porosity and fluid absorption rate obviously. In addition, the composite membrane has high ionic conductivity (18.77 × 10−4 S/cm), wide electrochemical window (about 4.0 V), and excellent cycling performance. It can retain a discharge specific capacity of 153 mA h/g even after 50 cycles at 0.5 C. The electrospun PAN/PI membrane may be a promising candidate for lithium-ion battery separators.
Maternal dietary patterns and macronutrients intake have been shown to affect the development of gestational diabetes mellitus (GDM), but the findings are inconsistent. We aimed to identify maternal dietary patterns and examine their associations with GDM risk, and to evaluate the contributions of macronutrients intake to these associations. We included 2755 Chinese pregnant women from the Tongji Maternal and Child Health Cohort. Dietary intakes were assessed using a validated semi-quantitative FFQ 2 weeks before the diagnosis of GDM. GDM (n 248) was diagnosed based on the results of a 75-g, 2-h oral glucose tolerance test at 24–28 weeks gestation. We derived five different dietary patterns from a principal component analysis. The results showed that high fish–meat–eggs scores, which were positively related to protein intake and inversely related to carbohydrate intake, were associated with a higher risk of GDM (adjusted OR for quartile 4 v. quartile 1: 1·83; 95 % CI 1·21, 2·79; Ptrend=0·007) and higher plasma glucose levels. In contrast, high rice–wheat–fruits scores, which were positively related to carbohydrate intake and inversely related to protein intake, were associated with lower risk of GDM (adjusted OR for quartile 3 v. quartile 1: 0·54; 95 % CI 0·36, 0·83; Ptrend=0·010) and lower plasma glucose levels. In addition, dietary protein and carbohydrate intake significantly contributed to the associations between dietary patterns and GDM risk or glucose levels. These findings suggest that a dietary pattern characterised by high protein and low carbohydrate intake in pregnancy was associated with a higher risk of GDM, which may provide important clues for dietary guidance during pregnancy to prevent GDM.
A series of self-assembled WO3–BiVO4 nanostructured thin films with 17, 25, 50, 67, and 100 mol% WO3 were grown on the (001) yttria-stabilized zirconia (YSZ) substrate by pulsed laser deposition method. The microstructures including crystalline phases, epitaxial relationship, interface structures, and chemical composition distributions were investigated by a combination of various electron microscopy techniques including scanning electron microscopy, transmission electron microscopy, and X-ray energy dispersive spectroscopy. The monoclinic BiVO4 formed the matrix, in which WO3 nanopillars were embedded with specific epitaxial relationships. In BiVO4-rich sample, orthorhombic Bi2WO6 was formed. However, metastable hexagonal WO3 phase and orthorhombic WO3 phase coexisted in other composite samples. The thin amorphous layer at the film/substrate interface indicated that the mismatch strain between films and substrate is released. The hydrostatic tensile strain due to thermal expansion mismatch between BiVO4 and WO3 as well as the diffusion of Bi into the WO3 stabilized the metastable h-WO3. A WO3–BiVO4 pseudobinary phase diagram was proposed based on the magnitude of the thermal expansion mismatch and the distance of Bi diffusion, which can be applied to design the microstructures of WO3–BiVO4 heterojunctions and optimize their photoelectrochemical properties.
The effect of nitrogen gas addition in Ar-based double-layer shielding gas on the impact toughness of welded ultra-ferritic stainless steel during an autogenous gas tungsten arc welding (GTAW) process was investigated. The nitrogen behavior was proposed. The microstructure, mechanical properties, and fracture surface morphology of the weld metals have been evaluated. More equiaxed crystals, refined grain, narrow HAZ width, and increased microhardness were produced with nitrogen addition. Experimental findings indicated that nitrogen diffused into HAZ and dissolved into weld pool. The solute distribution was changed thus bringing significant constitutional supercooling and decreased temperature gradient of weld pool, which contributed to fine microstructure. Impact toughness at room temperature was enhanced from 2J to 9J (welds), 5J–13J (HAZ). Ductile fracture zone was produced about 0.3–0.5 mm thickness distance from the weld surface. A significant increased impact toughness of weld metal was due to the refinement of microstructure and element addition.
Interleukin (IL)-13-associated signal pathway plays an important role in schistosomiasis hepatic fibrosis. In this study we tried to investigate the effects of corilagin to ameliorate schistosomiasis hepatic fibrosis through regulating IL-13-associated signal pathway in vitro and in vivo. Cellular model was set up with hepatic stellate cells-T6 cells stimulated by rIL-13 and male Balb/c mice were infected with Schistosoma japonicum cercariaeas as animal model. Liver histological changes were observed with haematoxylin and eosin staining. Masson staining was employed to observe the change of egg granulomas. Expression of Col (collagen) and Col III were examined with Immunohistochemistry. Western bolt was employed to detect the JAK-1 and IL13Rα1 proteins. The mRNA expression of Col I, Col III, IL-13, JAK-1 and IL13Rα1 were tested by quantitative polymerase chain reaction. As a result, less inflammatory changes were found in all corilagin groups compared with model group and praziquantel group. The mRNA levels of Col I, Col III, IL-13, JAK-1 and IL13Rα1 were significantly decreased after corilagin intervention (P < 0·01). JAK-1 and IL-13Rα1 protein levels were also greatly decreased in the corilagin groups (P < 0·01). In conclusion, corilagin could ameliorate schistosomiasis hepatic fibrosis by down-regulating the expression of IL-13 and signal molecules in IL-13 pathway.
Collagen is the most abundant protein present in the human body and found in connective tissues, bone, and tendon. It is also known as a natural resource for healing damaged skin tissues . In this study, under specific microenvironment conditions, mimetic collagen gels were successfully formed synthetically from reconstituted Bovine type I collagen monomers. This was achieved by controlling ionic strength, temperature and pH, allowing fibrils with native mimetic D periodic banding structure to assemble spontaneously within the gels. In addition, by providing appropriate aging temperatures and times, mature collagen fibril growth is also realized in the gels in vitro. Mimetic gels were subsequently formed into fibers through a wet-spinning process. These spun fibers were found to preserve the native mimetic D periodic banding and fibrillar structure formed in the initial gels. As a result, the synthetic fibers resemble native tendon. Here structural development within the gel samples and fibers as a function of processing was analyzed by scanning electron microscopy (SEM). Results in this study also show a potentially new route for the fabrication of synthetic collagen fibers mimicking tendon, which may find applications as engineered tissues or scaffolding materials.
Alkaline rock and carbonatite complexes, including the Prairie Lake complex (NW Ontario), are widely distributed in the Canadian region of the Midcontinent Rift in North America. It has been suggested that these complexes were emplaced during the main stage of rifting magmatism and are related to a mantle plume. The Prairie Lake complex is composed of carbonatite, ijolite and potassic nepheline syenite. Two samples of baddeleyite from the carbonatite yield U–Pb ages of 1157.2±2.3 and 1158.2±3.8 Ma, identical to the age of 1163.6±3.6 Ma obtained for baddeleyite from the ijolite. Apatite from the carbonatite yields the same U–Pb age of ~1160 Ma using TIMS, SIMS and laser ablation techniques. These ages indicate that the various rocks within the complex were synchronously emplaced at about 1160 Ma. The carbonatite, ijolite and syenite have identical Sr, Nd and Hf isotopic compositions with a 87Sr/86Sr ratio of ~0.70254, and positive εNd(t)1160 and εHf(t)1160 values of ~+3.5 and ~+4.6, respectively, indicating that the silicate and carbonatitic rocks are co-genetic and related by simple fractional crystallization from a magma derived from a weakly depleted mantle. These age determinations extend the period of magmatism in the Midcontinent Rift in the Lake Superior area to 1160 Ma, but do not indicate whether the magmatism is associated with passive continental rifting or the initial stages of plume-induced rifting.
Motivated by a problem of characterising a family of Cayley graphs, we study a class of finite groups
which behave similarly to elementary abelian
prime, that is, there exists a subgroup
such that all elements of
are conjugate or inverse-conjugate under
. It is shown that such groups correspond to complete multipartite graphs which are normal edge-transitive Cayley graphs.
In this paper, we develop a formal framework for what a good community should look like and how strong a community is (community strength). One of the key innovations is to incorporate the concept of relative centrality into structural analysis of networks. In our framework, relative centrality is a measure that measures how important a set of nodes in a network is with respect to another set of nodes, and it is a generalization of centrality. Building on top of relative centrality, the community strength for a set of nodes is measured by the difference between its relative centrality with respect to itself and its centrality. A community is then a set of nodes with a nonnegative community strength. We show that our community strength is related to conductance that is commonly used for measuring the strength of a small community. We define the modularity for a partition of a network as the average community strength for a randomly selected node. Such a definition generalizes the original Newman's modularity and recovers the stability in as special cases. For the local community detection problem, we also develop efficient agglomerative algorithms that guarantee the community strength of the detected local community.
The rock art of Southeast Asia has been less thoroughly studied than that of Europe or Australia, and it has generally been considered to be more recent in origin. New dating evidence from Mainland and Island Southeast Asia, however, demonstrates that the earliest motifs (hand stencils and naturalistic animals) are of late Pleistocene age and as early as those of Europe. The similar form of the earliest painted motifs in Europe, Africa and Southeast Asia suggests that they are the product of a shared underlying behaviour, but the difference in context (rockshelters) indicates that experiences in deep caves cannot have been their inspiration.
The study aimed to unravel the interaction between ocean acidification and solar ultraviolet radiation (UVR) in Chaetoceros curvisetus. Chaetoceros curvisetus cells were acclimated to high CO2 (HC, 1000 ppmv) and low CO2 concentration (control, LC, 380 ppmv) for 14 days. Cell density, specific growth rate and chlorophyll were measured. The acclimated cells were then exposed to PAB (photosynthetically active radiation (PAR) + UV-A + UV-B), PA (PAR + UV-A) or P (PAR) for 60 min. Photochemical efficiency (ΦPSII), relative electron transport rate (rETR) and the recovery of ΦPSII were determined. HC induced higher cell density and specific growth rate compared with LC. However, no difference was found in chlorophyll between HC and LC. Moreover, ΦPSII and rETRs were higher under HC than LC in response to solar UVR. P exposure led to faster recovery of ΦPSII, both under HC and LC, than PA and PAB exposure. It appeared that harmful effects of UVR on C. curvisetus could be counteracted by ocean acidification simulated by high CO2 when the effect of climate change is not beyond the tolerance of cells.
A stochastic approach to conditional simulation of flow in randomly heterogeneous media is proposed with the combination of the Karhunen-Loeve expansion and the probabilistic collocation method (PCM). The conditional log hydraulic conductivity field is represented with the Karhunen-Loeve expansion, in terms of some deterministic functions and a set of independent Gaussian random variables. The propagation of uncertainty in the flow simulations is carried out through the PCM, which relies on the efficient polynomial chaos expansion used to represent the flow responses such as the hydraulic head. With the PCM, existing flow simulators can be employed for uncertainty quantification of flow in heterogeneous porous media when direct measurements of hydraulic conductivity are taken into consideration. With illustration of several numerical examples of groundwater flow, this study reveals that the proposed approach is able to accurately quantify uncertainty of the flow responses conditioning on hydraulic conductivity data, while the computational efforts are significantly reduced in comparison to the Monte Carlo simulations.
In a knowledge-based growth model where skilled workers are used in innovation and production, skill-biased technological change may lower average R&D productivity via an innovation possibilities frontier effect that eliminates scale effects. We show that skill-biased technological change increases the skill premium even if the elasticity of substitution between skilled and unskilled workers is less than two. Trade between developed countries promotes skill-biased technological change, thus raising wage inequality. Trade between developed and developing countries has differing effects: it induces relatively skill-replacing technological change and lowers wage inequality in the developed country but has the opposite effects in the developing country. Finally, we show that trade can stimulate or hurt economic growth.
The most important crustal growth on Earth occurred at ~2.7 Ga, but the North China Craton (NCC) is characterized by prevalent development of ~2.5 Ga juvenile crust, with relatively rare records of ~2.7 Ga crustal growth. The Fuping Complex in the middle segment of the Trans-North China Orogen (TNCO) between the Eastern and Western blocks of the NCC is composed mainly of ~2.5 Ga Fuping tonalitic–trondhjemitic–granodioritic (TTG) gneisses and Longquanguan augen gneisses, ~2.1 Ga Nanying granitic gneisses and the Wanzi supracrustal rocks. Previous studies have suggested one major phase of crustal growth at ~2.5 Ga, possible intracrustal recycling at ~2.1 Ga and the presence of older rocks in the Fuping Complex, but there has been no record of ~2.7 Ga crustal growth. The Fuping TTG gneisses are dominated by stromatic migmatite, and new U–Pb dating of magmatic zircons from two stromatic migmatite samples yielded three different ages: (1) 2.75 Ga, which is the oldest age obtained from the Fuping TTG gneisses, (2) 2.54 Ga, which just falls in the published zircon U–Pb age range of 2.53 to 2.47 Ga for the Fuping TTG gneisses, and (3) 2.11 Ga, which is almost the same as the age of the Nanying granitic gneisses. Therefore, there are two generations of TTG gneisses in the Fuping Complex. Importantly, both of the 2.75 and 2.54 Ga zircons have the highest εHf(t) values, almost equal to the contemporaneous depleted mantle. This indicates high contributions of juvenile material to the two generations of TTG gneisses. In contrast, the 2.11 Ga zircons have apparently low εHf(t) values of −0.47 to +2.04, just falling in between 2.55 and 2.75 Ga continental crust values. This strongly suggests the reworking of the two generations of TTG gneisses at 2.1 Ga. Zircon U–Pb and Hf isotopes convincingly reveal two major phases of crustal growth in the Fuping Complex at ~2.7 and ~2.5 Ga, the same as in the northern and southern segments of the TNCO, and also confirm one major phase of intracrustal recycling at ~2.1 Ga, which may be responsible for the Nanying granitic gneisses.
We characterise regular bipartite locally primitive graphs of order 2pe, where p is prime. We show that either p=2 (this case is known by previous work), or the graph is a binormal Cayley graph or a normal cover of one of the basic locally primitive graphs; these are described in detail.
Dietary isothiocyanates have been shown to possess anti-tumour activity, inhibiting several types of cultured human cancer cell growth. However, there are limited studies on their effects on cancer cell metastasis. Our previous study showed that benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC) suppressed human lung cancer cell metastasis potential. In the present study, we found BITC (7·5 and 10 μm) and PEITC (12·5 and 20 μm) induced highly metastatic human non-small cell lung cancer L9981 cell apoptosis in a dose-dependent manner. Caspase-3 was activated. They also caused cell cycle arrest at the G2/M phase, via modulation of cyclin B1 expression. The mitogen-activated protein kinase (MAPK) signalling pathway was involved. c-Jun N-terminal kinase, extracellular signal-regulated protein kinase 1/2 and p38 were activated in a dose-dependent manner; activator protein 1 (AP-1) transcriptional activation and cyclin D1 expression were repressed. Apoptosis and MAPK activation were abrogated by anti-oxidant N-acetyl cysteine (NAC), suggesting that cell death signalling was triggered by oxidative stress. Further microarray analysis evaluated the potential targeted genes related to apoptosis and the cell cycle. Our studies suggested that BITC and PEITC suppressed the metastasis potential of highly metastatic lung cancer cells by inducing apoptosis and cell cycle arrest, via targeting the MAPK/AP-1 pathway. This may provide a novel approach for metastasis therapy of lung cancer by dietary isothiocyanates and possibly other types of cancer.
In ion beam mixing, the subject on the marker evolution of Si/Pt/Si target during 300 keV Xe ion irradiation has been an interesting topic of recent years. A cottputer simulation for this system by using the Monte Carlo code TCIS-4 is reported here. Dynamic target model was employed. Some radiation-enhanced diffusion and relaxation of the displacement cascades were also considered. Results of this simulation study reveal the evolution of Pt marker profile with fluences during bombardment. The shifts of Pt marker and the dispersions evaluated from the profiles agree fairly well with experimental date, demonstrating a reslistic model of the target being irradiated is important.