747 research outputs found
Elastic model scale and material for underwater structure of cross-sea bridge
With the bridge construction gradually from inland to coast and offshore, underwater structure of cross-sea bridge can encounter more complex hydrodynamic action. When elastic model is used to simulate the hydrodynamic response of underwater structure, the model scale and model material is the first problem must be solved. Based on principle of similitude, elastic model should meet the geometric similarity, kinematic similarity and mechanical similarity. Formula derivation gives the scale conditions for elastic model are as follows, geometric scale (Lr) equals elastic modulus scale (Er) and density scale (??r) equals 1. Then, how to find a material with same density and the elastic modulus is 1/ Lr of prototype is the key to make a model
Synthesis and crystal structure of <i>N</i>-(3-benzylamino-2- cyano-3-methylthioacrylyl)-<i>N'</i>-(substituted phenyl)ureas
Phenylurea groups were introduced into the frame of traditional cyanoacrylate and a series of N-(3-benzylamino-2-cyano-3-methylthioacrylyl)-N'-(substituted phenyl)ureas were synthesized. All compounds are new and their structures were confirmed by 1H NMR, 13C NMR and mass spectral analyses
Developmental morphology of the small intestine in Yangzhou goslings
The objective of this study was to investigate the development of the weight and the morphological development of the small intestine in Yangzhou geese. The weight, length and perimeter of the small intestine, height and width of the villi, depth of the crypts were measured when geese were 1, 14, 28, 42, 56 and 70 days of age. The results revealed that the weight of the duodenum, jejunum, and ileum (relative to the BW) increased, peaked on day 14 and tended to decline thereafter with age. The weight of the duodenum, jejunum, and ileum (relative to the BW) kept steady-going on 56, 42, 42 days, respectively. A 3-fold increase in length and 2-fold increase in perimeter for the three segments during the period were obtained. The duodenum increased little in length, whereas both jejunum and ileum increased 2 and 3-folds from 1 to 70 days examined. The increase in perimeter of the duodenum, jejunum and ileum was greater from day 1 to 14 than from day 14 to 28. The length and perimeter of the intestinal segments of the gastro-intestinal of Yangzhou geese (relative to the BW) peaked on day 1, then decreased with age and kept steady-going on 42 days, except the relative perimeter of the duodenum. The villus height, surface area and crypt depth in the small intestine were positively correlated with the age of the geese. The ratio of the villus height to the crypt depth (V/C) differed among the segments of the small intestine and at the different time points. The V/C in the ileum increased from day 1 to 70, whereas in the duodenum the ratio first decreased, then rose and descended. However, in the jejunum the ratio increased first, then dropped and rose again, and descended eventually.Key words: Geese, small intestine, morphology
Creep Lifetime Assessment of Pressure-Tight PE100 Pipes Based on a Slow Fatigue Crack Growth
Polyethylene pipes are widely used in water supply, gas, and sewage systems due to their excellent mechanical properties. A slow crack growth is the primary fracture mechanism for the pipes under long-term internal pressures. If the creep loading is treated as a special case of fatigue loading, the slow crack growth kinetics of polyethylene is defined in fatigue fracture tests at different stress ratios and extrapolated to creep crack kinetics. Linear elastic fracture mechanics concepts became the basis for predicting the creep lifetime of pressure-tight pipes subjected to various hoop stresses from extrapolated (synthetic) creep crack growth curves, and the prediction is in good agreement with the standard extrapolation, in accordance with ISO 9080.ΠΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½ΠΎΠ²ΡΠ΅ ΡΡΡΠ±Ρ ΡΠΈΡΠΎΠΊΠΎ ΠΏΡΠΈΠΌΠ΅Π½ΡΡΡΡΡ Π² Π²ΠΎΠ΄ΠΎΡΠ½Π°Π±ΠΆΠ΅Π½ΠΈΠΈ, ΡΠΈΡΡΠ΅ΠΌΠ°Ρ
Π³Π°Π·ΠΎΡΠ½Π°Π±ΠΆΠ΅Π½ΠΈΡ ΠΈ ΠΊΠ°Π½Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ Π±Π»Π°Π³ΠΎΠ΄Π°ΡΡ ΠΈΡ
Π²ΡΡΠΎΠΊΠΈΠΌ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠΌ ΡΠ²ΠΎΠΉΡΡΠ²Π°ΠΌ. ΠΠ΅Π΄Π»Π΅Π½Π½ΡΠΉ ΡΠΎΡΡ ΡΡΠ΅ΡΠΈΠ½ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΡΠ½ΠΎΠ²Π½ΡΠΌ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠΌ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΡ ΠΏΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½ΠΎΠ²ΡΡ
ΡΡΡΠ± ΠΏΠΎΠ΄ Π΄Π»ΠΈΡΠ΅Π»ΡΠ½ΡΠΌ Π²Π½ΡΡΡΠ΅Π½Π½ΠΈΠΌ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ΠΌ. Π Π°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Ρ Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΠ΅ ΠΏΡΠΈ ΠΏΠΎΠ»Π·ΡΡΠ΅ΡΡΠΈ ΠΊΠ°ΠΊ ΠΎΡΠΎΠ±ΡΠΉ ΡΠ»ΡΡΠ°ΠΉ ΡΡΡΠ°Π»ΠΎΡΡΠ½ΠΎΠ³ΠΎ Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΡ, ΠΊΠΈΠ½Π΅ΡΠΈΠΊΠ° ΠΌΠ΅Π΄Π»Π΅Π½Π½ΠΎΠ³ΠΎ ΡΠΎΡΡΠ° ΡΡΠ΅ΡΠΈΠ½ Π² ΠΏΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½ΠΎΠ²ΠΎΠΌ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π΅ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ΅ΡΡΡ ΠΏΡΡΠ΅ΠΌ ΠΈΡΠΏΡΡΠ°Π½ΠΈΠΉ Π½Π° ΡΡΡΠ°Π»ΠΎΡΡΠ½ΠΎΠ΅ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠΈ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ°Ρ
Π°ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ ΡΠΈΠΊΠ»Π° Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ ΠΈ ΡΠΊΡΡΡΠ°ΠΏΠΎΠ»ΠΈΡΡΠ΅ΡΡΡ Π½Π° ΠΊΠΈΠ½Π΅ΡΠΈΠΊΡ ΡΡΠ΅ΡΠΈΠ½ ΠΏΠΎΠ»Π·ΡΡΠ΅ΡΡΠΈ. ΠΡΡ
ΠΎΠ΄Ρ ΠΈΠ· ΡΠ΅ΠΎΡΠΈΠΈ Π»ΠΈΠ½Π΅ΠΉΠ½ΠΎΡΠΏΡΡΠ³ΠΎΠΉ ΠΌΠ΅Ρ
Π°Π½ΠΈΠΊΠΈ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΡ Π΄ΠΎΠ»Π³ΠΎΠ²Π΅ΡΠ½ΠΎΡΡΡ ΠΏΡΠΈ ΠΏΠΎΠ»Π·ΡΡΠ΅ΡΡΠΈ ΠΏΠΎΠ»ΠΈΡΡΠΈΠ»Π΅Π½ΠΎΠ²ΠΎΠΉ ΡΡΡΠ±Ρ ΠΏΠΎΠ΄ Π΄Π°Π²Π»Π΅Π½ΠΈΠ΅ΠΌ, ΠΏΠΎΠ΄Π²Π΅ΡΠΆΠ΅Π½Π½ΠΎΠΉ Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΎΠΊΡΡΠΆΠ½ΡΡ
Π½Π°ΠΏΡΡΠΆΠ΅Π½ΠΈΠΉ, ΠΏΡΠΎΠ³Π½ΠΎΠ·ΠΈΡΡΠ΅ΡΡΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠΈΠ½ΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΊΡΠΈΠ²ΠΎΠΉ ΡΠΎΡΡΠ° ΡΡΠ΅ΡΠΈΠ½ ΠΏΠΎΠ»Π·ΡΡΠ΅ΡΡΠΈ, ΠΈ ΠΏΡΠΎΠ³Π½ΠΎΠ·Ρ Ρ
ΠΎΡΠΎΡΠΎ ΡΠΎΠ³Π»Π°ΡΡΡΡΡΡ ΡΠΎ ΡΡΠ°Π½Π΄Π°ΡΡΠ½ΠΎΠΉ ΡΠΊΡΡΡΠΎΠΏΠΎΠ»ΡΡΠΈΠ΅ΠΉ Π² ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΠΈΠΈ Ρ ISO 9080
Detection of herb-symptom associations from traditional chinese medicine clinical data
YesTraditional Chinese medicine (TCM) is an individualized medicine by observing the symptoms and signs (symptoms in brief) of patients. We aim to extract the meaningful herb-symptom relationships from large scale TCM clinical data. To investigate the correlations between symptoms and herbs held for patients, we use four clinical data sets collected from TCM outpatient clinical settings and calculate the similarities between patient pairs in terms of the herb constituents of their prescriptions and their manifesting symptoms by cosine measure. To address the large-scale multiple testing problems for the detection of herb-symptom associations and the dependence between herbs involving similar efficacies, we propose a network-based correlation analysis (NetCorrA) method to detect the herb-symptom associations. The results show that there are strong positive correlations between symptom similarity and herb similarity, which indicates that herb-symptom correspondence is a clinical principle adhered to by most TCM physicians. Furthermore, the NetCorrA method obtains meaningful herb-symptom associations and performs better than the chi-square correlation method by filtering the false positive associations. Symptoms play significant roles for the prescriptions of herb treatment. The herb-symptom correspondence principle indicates that clinical phenotypic targets (i.e., symptoms) of herbs exist and would be valuable for further investigations
Identification of Sitobion avenae F. resistance and genetic diversity of wheat landraces from Qinling Mountains, China
The aphid Sitobion avenae F. is one of the most harmful pests of wheat growth in the world. A primary field screening test was carried out to evaluate the S. avenae resistance of 527 wheat landraces from Shaanxi. The results indicated that 25 accessions (4.74%) were resistant to S. avenae in the three consecutive seasons, of which accession S849 was highly resistant, and seven accessions were moderately resistant. The majority of S. avenae resistant accessions come from Qinling Mountains. Then, the genetic variability of a set of 33 accessions (25 S. avenae resistant and 8 S. avenae susceptible) originating from Qinling Mountains have been assessed by 20 morphological traits and 99 simple sequence repeat markers (SSRs). Morphological traits and SSRs displayed a high level of genetic diversity within 33 accessions. The clustering of the accessions based on morphological traits and SSR markers showed significant discrepancy according to the geographical distribution, resistance to S. avenae and species of accessions. The highly and moderately resistant landrace accessions were collected from the middle and the east part of Qinling Mountains with similar morphology characters, for example slender leaves with wax, lower leaf area, and high ear density. These S. avenae resistant landraces can be used in wheat aphid resistance breeding as valuable resources
Partial wave analysis of J/\psi \to \gamma \phi \phi
Using events collected in the BESII detector, the
radiative decay is
studied. The invariant mass distribution exhibits a near-threshold
enhancement that peaks around 2.24 GeV/.
A partial wave analysis shows that the structure is dominated by a
state () with a mass of
GeV/ and a width of GeV/. The
product branching fraction is: .Comment: 11 pages, 4 figures. corrected proof for journa
Measurements of the observed cross sections for exclusive light hadrons containing at , 3.650 and 3.6648 GeV
By analyzing the data sets of 17.3, 6.5 and 1.0 pb taken,
respectively, at , 3.650 and 3.6648 GeV with the BES-II
detector at the BEPC collider, we measure the observed cross sections for
, , ,
and at the three energy
points. Based on these cross sections we set the upper limits on the observed
cross sections and the branching fractions for decay into these
final states at 90% C.L..Comment: 7 pages, 2 figure
Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays
By analyzing about 33 data sample collected at and around 3.773
GeV with the BES-II detector at the BEPC collider, we directly measure the
branching fractions for the neutral and charged inclusive semimuonic decays
to be and , and determine the ratio of the two branching
fractions to be
Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV
By analyzing the data sets of 17.3 pb taken at GeV
and 6.5 pb taken at GeV with the BESII detector at the
BEPC collider, we have measured the observed cross sections for 12 exclusive
light hadron final states produced in annihilation at the two energy
points. We have also set the upper limits on the observed cross sections and
the branching fractions for decay to these final states at 90%
C.L.Comment: 8 pages, 5 figur
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