Search

Due to the low stiffness, thin-walled part usually deforms in flank milling, resulting in a low machining precision. Error prediction is generally adopted to improve the precision of flank milling of thin-walled part as the predicted error is indispensable data for improvement. However, since cutting force and deformation will influence each other and the practical behavior of cutter and part (PBCP) in the milling is confusing, when predicting errors, iteration is always involved, which reduces prediction efficiency. Thus, in order to reveal the PBCP and improve prediction efficiency, this paper establishes the PBCP model first and then, according to the PBCP model, proposes a machining error prediction approach without iteration. First, the inspiration for the PBCP model is introduced. Then, the cutter and part are divided into differential elements and the PBCP model, which consists of the part for a single element and the part for influence between elements, is established. Subsequently, the machining error prediction approach without iteration is proposed based on the PBCP model. Finally, experiments are conducted to verify the proposed approach. The results show that most errors of prediction are within 0.03 mm and the prediction efficiency is significantly improved. Therefore, it is concluded that the PBCP model and the proposed approach are effective. Besides, based on the PBCP model, the variation tendency and value of the feed per tooth and entry angle of three sections of the part in the milling are also revealed.

An attractive isonicotinic acid-ornamented octa-CeIII-inserted phospho(III)tungstate [H2N(CH3)2]6Na8[Ce8(H2O)30W8Na2O20(INA)4][HPIIIW4O17]2[HPIIIW9O33]4·30H2O (1-Ce) (HINA = isonicotinic acid) has been isolated through the deliberately designed one-step assembly strategy, in which the HPO32–heteroanion template was introduced into the Ce3+/WO42–system in the presence of HINA. The polyoxoanion of 1-Ceconsists of two identical [Ce4(H2O)15W4NaO10(INA)2][HPIIIW4O17][HPIIIW9O33]2}7–subunits linked by Ce–O–W bonds. The polyoxoanion exhibits three kinds of polyoxotungstate building blocks [W4NaO20(INA)2]17–, [HPIIIW4O17]6–, and [HPIIIW9O33]8–, in which [W4NaO20(INA)2]17–and [HPIIIW4O17]6–building units can be considered as seeds driven by the coordination of additional Ce3+ions to induce aggregation of [HPIIIW9O33]8–fragments. Furthermore, 1-Cepossesses high peroxidase-like activity and can oxidize 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2with a turnover rate of 6.20 × 10–3s–1. Because l-cysteine (l-Cys) can reduce oxTMB to TMB, the detection of l-Cys was established based on the 1-Ce-based H2O2colorimetric biosensing platform with the linear range of 5–100 μM and the limit of detection of 4.28 μM. This work not only can expand the scientific research studies on coordination chemistry and materials chemistry of rare-earth-inserted polyoxotungstates but also can provide practical application possibility in clinical diagnosis using liquid biopsy.

The ever-growing energy demand and environmental issues have stimulated the development of sustainable energy technologies. Herein, an efficient and environmentally friendly electrochemical transformation technology was proposed to prepare highly graphitized carbon materials from an abundant natural resource - lignin (LG). The preparation process mainly includes pyrolytic carbonization of raw LG material and electrochemical conversion of amorphous carbon precursor. Interestingly, with the assistance of Co catalyst, the graphitization degree of the products was significantly improved, in which the mechanism was the removal of heteroatoms in LG and the rearrangement of carbon atoms into graphite lattice. Furthermore, tunable microstructures (nanoflakes) under catalytic effects could also be observed by controlling the electrolytic parameters. Compared with the products CN1 (without catalyst) and CN5 (with 10% catalyst), the specific surface area are158.957 and 202.246 m2/g, respectively. When used as the electrode material for lithium-ion batteries, CN5 delivered a competitive specific capacity of ∼350 mAh g−1(0.5 C) compared with commercial graphite. The strategy proposed in this work provides an effective way to extract value-added graphite materials from lignin and can be extended to the graphitization conversion of any other amorphous carbon precursor materials.

A novel tartronic acid decorated hexa-CeIII-incorporated phospho(III)tungstate aggregate (C4H12NO)6Na18H2[(HPW8O31)2[W11O39]2(H2TAD)4(H2O)4W4Ce6H2P2O14]·84H2O (1, H3TAD = tartronic acid) was synthesized by a one-step assembly strategy. Its main skeleton is constructed from two [W11O39]12–fragments, two [HPIIIW8O31]10–segments and one H2TAD–-ornamented dodecanuclear heterometallic [W4Ce6H2PIII2O14(H2TAD)4(H2O)4]18+cluster. In the structure, the [HPIIIO3]2–groups not only work as the heteroatom template to induce the formation of lacunary [HPIIIW8O31]10–segments but also function as the connector to bridge Ce3+cations. With the help of a reaction strategy of combining ultrasonication treatment with the continuous ion layer adsorption method, the 1/CdS composite was constructed and exhibits prominent photoelectrochemical activity. The 1/CdS composite was used as a photoelectrochemical sensor for oxytetracycline detection at 0 V (vs Ag/AgCl), which displays excellent properties with quick response and low limit of detection (0.042 nM). This work can provide some helpful references in the construction of novel PIII-induced polyoxometalates consisting of different building blocks and can extend the applications of polyoxometalate-based nanocomposites into photoelectrochemical detection for antibiotics as well as biomolecules.