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排序方式: 共有281条查询结果,搜索用时 31 毫秒
1.
The effect of trap design, trap color, and a mixture of isothiocyanates on the capture of Ceutorhynchus assimilis (Paykull) was studied in a series of field experiments. Unbaited yellow water traps, a yellow sticky box trap, and a yellow sticky card trap, mounted vertically, or at 45° to the vertical with the yellow card facing upwards were effective for capturing seed weevils, but a horizontal yellow sticky card trap caught few. White, green, and black traps were unattractive. During migratory periods, trap catch could be enhanced two to four times with a lure consisting of a mixture of allyl, 3-butenyl, 4-pentenyl, and 2-phenylethyl isothiocyanates, but this bait did not attract in a trap with ineffective design. The sticky card trap, mounted at 45° to the vertical and baited with the isothiocyanate mixture, may be useful for monitoring movement of C. assimilis during migratory periods. However, during the colonization phase, lures of either a mixture of isothiocyanates or of allyl isothiocyanate alone were not attractive. 相似文献
2.
Liu Xinke Kao Evan Haraldsson Henrik Ballweber Megan Martin Alastair Li Youxiang Wang Yuting Saloner David 《Magma (New York, N.Y.)》2021,34(5):659-666
Magnetic Resonance Materials in Physics, Biology and Medicine - To determine the intra-individual flow variation in serially acquired studies, and the influence of this variation on subsequent... 相似文献
3.
Direct Method Based Control System for an Autonomous Quadrotor 总被引:1,自引:0,他引:1
Ian D. Cowling Oleg A. Yakimenko James F. Whidborne Alastair K. Cooke 《Journal of Intelligent and Robotic Systems》2010,60(2):285-316
This paper proposes a real time control algorithm for autonomous operation of a quadrotor unmanned air vehicle. The quadrotor
is a small agile vehicle, which as well as being a excellent test bed for advanced control techniques could also be suitable
for internal surveillance, search and rescue and remote inspection. The proposed control scheme incorporates two key aspects
of autonomy; trajectory planning and trajectory following. Using the differentially-flat dynamics property of the system,
the trajectory optimization is posed as a non-linear constrained optimization within the output space in the virtual domain,
not explicitly related to the time domain. A suitable parameterization using a virtual argument as opposed to time is applied,
which ensures initial and terminal constraint satisfaction. The speed profile is optimized independently, followed by the
mapping to the time domain achieved using a speed factor. Trajectory following is achieved with a standard multi-variable
control technique and a digital switch is used to re-optimize the reference trajectory in the event of infeasibility or mission
change. The paper includes simulations using a full dynamic model of the quadrotor demonstrating the suitability of the proposed
control scheme. 相似文献
4.
Avoiding the catastrophic failure of a large structure demands the material’s microstructure be designed in such as a way as to render any crack present innocuous thereby raising the integrity of that structure. Structural integrity of a composite material embraces contributions from: materials science and engineering; processing science; design and fabrication technology. It combines a number of interacting factors: the criticality of the application; the accessibility for and ability to inspect vital parts and components; the intended use including load spectrum and time; the consequences of impact, fatigue, temperature and hostile environment; the nature of inherent flaws; the constituent properties of the material system utilized; and it takes into account human factors. 相似文献
5.
Daniela M. Ushizima Hrishikesh A. Bale E. Wes Bethel Peter Ercius Brett A. Helms Harinarayan Krishnan Lea T. Grinberg Maciej Haranczyk Alastair A. Macdowell Katarzyna Odziomek Dilworth Y. Parkinson Talita Perciano Robert O. Ritchie Chao Yang 《JOM Journal of the Minerals, Metals and Materials Society》2016,68(11):2963-2972
6.
Multimerization behaviour of single chain Fv variants for the tumour-binding antibody B72.3 总被引:2,自引:0,他引:2
Desplancq Dominique; King David J.; Lawson Alastair D.G.; Mountain Andrew 《Protein engineering, design & selection : PEDS》1994,7(8):1027-1033
A systematic study has been performed on the relationship betweenlinker length, relative orientation of variable domains, multimerizationbehaviour and antigen binding activity for single chain Fvs(scFvs) of the tumour-binding antibody B72.3. Thirteen scFvvariants with linkers comprising up to six repeats of the motifGly-Gly-Gry-Gly-Ser were studied. All these scFvs showed a tendencyto form dimers or higher molecular weight species, and thistendency decreased with increasing linker length. The dimersand higher molecular weight forms may arise from head to tailintermolecular association of VH and VL domains. For each linkerlength, scFvs with the organization VL-linker-VH showed greaterbinding activity than those with the organization VH-linker-VL.In fact, for the latter organization only the variant with a30 amino acid linker showed good binding activity, suggestingthat (0 for B72.3 the C-tenninus of VH or the N-tenninus ofVL makes a structural contribution to antigen binding, and (ii)shorter linkers interfere with this contribution. Antigen bindingstudies on scFvs should be interpreted with caution becauseof their tendency to multlmerize. Such multimerization can beminimized by using linkers longer than those in common use 相似文献
7.
Anurag Dwivedi Mark A. Rodriguez Alastair N. Cormack 《Journal of the American Ceramic Society》1992,75(7):1993-1996
Compositions of La1- x Ba x CuO3 , where x ranges from 0.0 to 0.5, were fired in air, oxygen-enriched air, and oxygen. Studies show that BaO cannot make a solid solution with LaCuO3 without changing the basic structure. The resulting phases, in all attempts, were the binary compounds La2 CuO4 , La1- x Ba x CuO3-δ ( x = 0.2 to 0.5), or their mixtures. All samples showed metallic conductivity. Extra oxygen in the reaction atmosphere appeared to encourage the formation of the LaCuO3 -based phases of La1- x Ba x CuO3-δ ( x = 0.2 or 0.5). We provide a defect-chemical and thermodynamical explanation for this observation. 相似文献
8.
9.
In vivo characterisation of a novel bioresorbable poly(lactide-co-glycolide) tubular foam scaffold for tissue engineering applications 总被引:2,自引:0,他引:2
Day RM Boccaccini AR Maquet V Shurey S Forbes A Gabe SM Jérôme R 《Journal of materials science. Materials in medicine》2004,15(6):729-734
Polylactide-co-glycolide (PLGA) foams of tubular shape were assessed for their use as soft-tissue engineering scaffolds in vitro and in vivo. Porous membranes were fabricated by a thermally induced phase separation process of PLGA solutions in dimethylcarbonate. The parameters investigated were the PLGA concentration and the casting volume of solution. Membranes produced from 5 wt/v % polymer solutions and a 6 ml casting volume of polymer solution were selected for fabricating tubes of 3 mm diameter, 20 mm length and a nominal wall thickness of 1.5 mm. Scanning electron microscopy revealed that the structure of the tubular foams consisted of radially oriented and highly interconnected pores with a large size distribution (50-300 microm). Selected tubes were implanted subcutaneously into adult male Lewis rats. Although the lumen of the tubes collapsed within one week of implantation, histological examination of the implanted scaffolds revealed that the foam tubes were well tolerated. Cellular infiltration into the foams, consisting mainly of fibrovascular tissue, was evident after two weeks and complete within eight weeks of implantation. The polymer was still evident in the scaffolds after eight weeks of implantation. The results from this study demonstrate that the PLGA tubular foams may be useful as soft-tissue engineering scaffolds with modification holding promise for the regeneration of tissues requiring a tubular shape scaffold such as intestine. 相似文献
10.
Wegner GJ Wark AW Lee HJ Codner E Saeki T Fang S Corn RM 《Analytical chemistry》2004,76(19):5677-5684
The kinetics of protein adsorption/desorption onto peptide microarrays was studied using real-time surface plasmon resonance (SPR) imaging. S protein binding interactions were examined using an array composed of five different peptides: N terminal and C terminal immobilized wild-type S peptide (S1 and S2), an alternate binding sequence derived by phage display (LB2), an NVOC-protected S peptide, and a FLAG peptide control sequence (F). Kinetic measurements of the S protein-S1 peptide interaction were analyzed to determine a desorption rate constant (k(d)) of 1.1 (+/-0.08) x 10(-2) s(-1), an adsorption rate constant (k(a)) of 1.9 (+/-0.05) x 10(5) M(-1) s(-1), and an equilibrium adsorption constant (K(Ads)) of 1.7 (+/-0.08) x 10(7) M(-1). SPR imaging equilibrium measurements of S protein to S1 peptide were performed to independently confirm the kinetically determined value of K(Ads). Rate constants for the S2 and LB2 peptides on the array were measured as follows: 1.6 (+/-0.04) x 10(5) M(-1) s(-1) (k(a)) and 1.1 (+/-0.07) x 10(-2) s(-1) (k(d)) for S2, 1.2 (+/-0.05) x 10(5) M(-1) s(-1) (k(a)) and 1.1 (+/-0.03) x 10(-2) s(-1) (k(d)) for LB2. In addition to S protein adsorption/desorption, real-time SPR imaging of peptide arrays was applied to study the surface enzymatic activities of the protease factor Xa. Enzymatic cleavage of the substrate peptide (P1) was shown to follow first-order kinetics and proceed at a rate 10 times faster than that of the mutant peptide (P2), with cleavage velocities of 5.6 (+/-0.3) x 10(-4) s(-1) for P1 and 5.7 (+/-0.3) x 10(-5) s(-1) for P2. 相似文献