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Robot manipulation tasks by natural language instructions need common understanding of the target object between human and the robot. However, the instructions often have an interpretation ambiguity, because the instruction lacks important information, or does not express the target object correctly to complete the task. To solve this ambiguity problem, we hypothesize that "naming" the target objects in advance will reduce the ambiguity of natural language instructions. We propose a robot system and method that incorporates naming with appearance of the objects in advance, so that in the later manipulation task, instruction can be performed with its unique name to disambiguate the objects easily. To demonstrate the effectiveness of our approach, we build a system that can memorize the target objects, and show that naming the objects facilitates detection of the target objects and improves the success rate of manipulation instructions. With this method, the success rate of object manipulation task increases by 31% in ambiguous instructions., Comment: 8 pages, 7 figures

Additional file 4 : Supplementary Table S4. The Egger’s test of different subgroup.

Additional file 6 : Supplementary Figure 1. Sensitivity analysis of the effect of the individual subgroup on the pooled ORs.

Additional file 5 : Supplementary Table S5. The Egger’s test of different subgroup.

To improve the flame retardant efficiency of aromatic Schiff base (BA), and adjust the crosslinking temperature of imine groups, a cyano group, an electron-drawing group has been introduced into the chemical structure of aromatic Schiff base to obtain a third monomer for poly(ethylene terephthalate) (PET), named as dimethyl-5-[(2-cyanobenzylidene)amino]-isophthalate (CBAA). Thermogravimetry-differential scanning calorimetry (TG-DSC) and dynamic rheological results prove that the PET-based copolyester containing CBAA (CBAAnPETs) can cross-link at higher temperature than that containing BA, which will not affect the preparing and processing of PET. DSC and wide angle x-ray diffraction (WAXD) results demonstrate CBAAnPETs remain good crystallization ability. Owing to the two types of cross-linking reactions, i. e. the reactions between Schiff base ( CH N-) and cyano group (-C≡N), and among -CH N- units, CBAA plays an important role in solid phase as well as gaseous phase endowing CBAAnPETs with excellent flame retardancy. With a low CBAA content (only 6.7 mol%), the copolyesters self-extinguish in 5 s with no melt drips in UL-94 vertical test, and its LOI value also increases to 31.0%. The peak heat release rate and total smoke release of the copolyesters obtained from cone calorimetry also observably decrease.

Bonding aryl groups with carbon-nitrogen double bond is a critical structural factor for the self-crosslinking of Schiff bases at high temperature. In this study, a novel aromatic Schiff base “5-(benzylidene-amino)-isophthalic acid dimethyl ester (BA)” has been designed as a self-crosslinking monomer for poly(ethylene terephthalate) (PET) based copolyesters (BAnPETs). The cross-linking behaviors, flame retardancy and non-dripping performance of BAnPETs have been investigated by simultaneous thermal analysis (TG-DSC), dynamic rheology, limiting oxygen index (LOI), UL-94 vertical burning and cone calorimetry tests. It is found that BA units can cross-link during combustion resulting in high melting viscosity and enhance char forming for BAnPETs, which endows the copolyesters with excellent flame retardancy and non-dripping behavior. Incorporating of BA with a low content (only 7.7 mol%), the LOI value of copolyester increases from 22.0% to 31.0%, and at the same time it achieves V-0 rating in the UL-94 vertical burning test. The mode action of Schiff bases on flame retardation and anti-dripping of copolyesters also has been investigated, and the results show that the aromatic Schiff base groups can lead copolyesters to form nitrogen-containing cross-linkable networks and further transform into compact char layer during combustion. The char layer which acts as an effective barrier, cuts off oxygen, hinders the volatilization of combustible gas and isolates unburned polymer from fire resource. This work suggests that using Schiff base as a self-crosslinkable monomer is a new and effective way for fire-safe polymeric materials.

In this study, novel biobased pressure-sensitive adhesives (PSAs) derived from epoxidized soybean oils and carboxylic acid-terminated polyesters were developed with flame retardance, thermal stability, and peel strength comparable to those of current PSAs. The dynamic mechanical analysis indicated that the PSAs exhibited a dynamic mechanical response consistent with related high-performance PSAs. The thermal properties of the PSAs were investigated by thermogravimetric analysis, and the results suggested that the onset decomposition temperatures in both nitrogen and air atmospheres were improved by incorporating both 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10-phosphaphenanthrene-10-oxide (DDP) and 2-(6-oxido-6H-dibenz oxaphosphorin-6-yl)-1,4-hydroxyethoxyphenylene (DOPO-HQ-HE) as the flame-retardant monomer. Microscale combustion calorimetry, the limiting oxygen index test, UL-94, and the test method for flame resistance of PSA tapes were used to evaluate the flame retardance of the PSAs....

Inherent flame-retardant semi-aromatic polyesters, containing special aryl ether and/or ketone structures (“Ar–CO–Ar”, “Ar–O–Ar”, “Ar–O–Ar–O–Ar” or “Ar–O–Ar–CO–Ar–O–Ar”) were synthesized successfully. Interestingly, these polyesters show different flame retardancy beyond our traditional knowledge that more benzene rings are beneficial to flame retardancy. The polyester containing “Ar–O–Ar–O–Ar” shows excellent flame retardancy, whose LOI value reaches 34.1% and the UL-94 rating is V-0. Meanwhile, the polyester with the “Ar–O–Ar–CO–Ar–O–Ar” structure does not perform expectedly well (31.6% and V-2 rating respectively). In order to make clear the effect of aryl ether and/or ketone structure units on the flame retardancy, the pyrolysis behaviours and the char residue are investigated by Py-GC/MS, TGA, and SEM. In the TGA test, the char residues of polyesters containing “Ar–CO–Ar”, “Ar–O–Ar” “Ar–O–Ar–O–Ar” or “Ar–O–Ar–CO–Ar–O–Ar” are 31.6%, 22.5%, 30.6% or 38.7%, respectively. These values do not match with the calculated results, which indicate that some special reactions occur during combustion. Furthermore, these polyesters show a common initial pyrolysis pathway and subsequent unique processes in the Py-GC/MS test. Their pyrolysis intermediate products can bind small-molecule free radicals, and eventually form different conjugated aromatic structures. In this way, inherent flame-retardant polyesters are obtained even without any traditional flame-retardant elements. And their flame retardant performance has great relationship with the amount of char formation, the microstructure of char, and the chemical structure of pyrolysis products.

In order to avoid potential environmental and safety problems caused by conventional flame retardants, we synthesized the flame-retardant-element-free copolyesters via chemically incorporating the structural units of bisphenol A and bisphenol F into the PET main chain via melt polymerization, respectively. The chemical structures of resulting copolyesters were confirmed by 1H NMR and 13C NMR spectroscopy. Interestingly, though there exists only a small structural difference between bisphenol A and bisphenol F, those two kinds of copolyesters show different thermal stabilities, pyrolysis behaviours and flame retardant performances. Pyrolysis-GC/MS tests were performed to investigate the pyrolysis mechanism of the copolyesters, and the results showed that the “Ar–CH2–Ar” structure units (bisphenol F) would lead to rearrangement reactions at high temperature, ultimately forming the phenanthrene ring structures; whereas “Ar–C(CH3)2−Ar” structure units (bisphenol A) could not. The corresponding specific pyrolysis processes are proposed. Thermogravimetric analysis (TGA) results indicated that these rearrangement reactions would most likely occur in the solid state of the copolyesters and made them have high residues. Cone calorimeter measurements, LOI and vertical UL-94 tests were used to characterize the flame-retardant properties of the copolyesters, and the results proved that the copolyesters containing bisphenol F had better flame retardancy, more char formation and less melt drippings than those containing bisphenol A due to the rearrangement reactions.

The solar array is an important device used in the spacecraft, which influences the quality of in-orbit operation of the spacecraft and even the launches. This paper analyzes the reliability of the mechanical system and certifies the most vital subsystem of the solar array. The fault tree analysis (FTA) model is established according to the operating process of the mechanical system based on DFH-3 satellite; the logical expression of the top event is obtained by Boolean algebra and the reliability of the solar array is calculated. The conclusion shows that the hinges are the most vital links between the solar arrays. By analyzing the structure importance(SI) of the hinge's FTA model, some fatal causes, including faults of the seal, insufficient torque of the locking spring, temperature in space, and friction force, can be identified. Damage is the initial stage of the fault, so limiting damage is significant to prevent faults. Furthermore, recommendations for improving reliability associated with damage limitation are discussed, which can be used for the redesigning of the solar array and the reliability growth planning.