China’s Mega Supply Chains

This chapter explains the development and significance of China’s mega supply chains and their position in the global division of labour. It explains the importance of modularity, standardization, and complementarity in supply chains. It analyses how efficiencies and resilience are achieved and balanced in supply chains and the importance of platforms, both geographical clusters, such as industrial bases in Shenzhen, Chengdu, and Suzhou, and digital platforms, such as Alibaba and Pinduoduo. The chapter also argues that China’s mega supply chains have become regional hubs supplying intermediate products to manufacturing facilities in countries with lower labour costs. It discusses the extent to which China is progressing towards Industry 4.0, with smart supply chains, and how the country is responding to the challenges from growing global trade tensions.

High Efficiency for Methanol Electrooxidation of Self-Supporting 3D Nanoporous PdAg Alloy Foams

The self-supporting three-dimensional (3D) nanoporous PdAg alloy (NP–PdAg) foams have been prepared by a simple one-step dealloying melt-spun Al–Pd–Ag ribbons in a 20[Formula: see text]wt.% NaOH aqueous solution at 90∘C for 1.5[Formula: see text]h. The structure is advantageous to the diffusion and removal of the intermediate products and the transmission of the methanol molecules. The NP–PdAg foams exhibit better electrocatalytic performance than the NP-Pd foam toward the methanol oxidation in potassium hydroxide (KOH) solution. The optimal atomic ratio of Pd to Ag in the NP–PdAg foams is 1:1, and its electrocatalytic activity is about 2.6 times that of the NP–Pd foam. The significant improvement in the electrocatalytic performance is attributed to the addition of a moderate amount of Ag. In the whole electrocatalytic process, Ag can provide OHads to oxidize the intermediate products on the surface of active Pd sites into carbon dioxide or other cleaning products. Also, the Ag can increase electrochemical active surface area and the adsorption energy of Pd to methanol molecules and OHads. These significantly prevent the accumulation of poisoning intermediates on the surface of Pd and quickly release more active Pd sites.

Reactive Molecular Dynamics Simulations On Thermal Decomposition of 3-Methyl-2,6-Dinitrophenol

The decomposition mechanism of 3-methyl-2,6-dinitrophenol (MDNP) was simulated by reaction molecular dynamics using ReaxFF force field. The evolution of some main products with time at different heating rates (10, 15 and 20 K·ps-1) were obtained as well. The simulation outcomes reveal that with the elevation of the heating rate, the shorter the time required for the system to reach equilibrium, and the more products are produced. At three heating rates, the main intermediate products are C7H7O5N2, C7H6O4N2, C7H5O5N2, C7H5O4N2, HON, NO, NO2 and the primary final products are N2, CO2, H2O, H2, NH3, amongst which C7H5O5N2 is the first produced intermediate product and H2O is the first produced final product with the biggest abundance. The intermediate products first increase and then decrease to zero. Moreover, the primary chemistry reactions in the MDNP pyrolysis are acquired by ReaxFF MD simulations.

Experimental proof of thiophene hydrodesulfurization reaction steps by isotope (14C) labeled thiophene

Hydrodesulfurization of thiophene has been studied over alumina supported sulfided molybdena, nickel-promoted molybdena and over nickel (Mo, NiMo and Ni) catalysts. The experiments were carried out with a mixture of thiophene, labeled with radioactive carbon (thiophene-[G-]-14C) and of non-radioactive tetrahydrothiophene (1:1 mol ratio) in a micro catalytic system. It was established, that the main products were tetrahydrothiophene-14C, 1-butene-14C, 2-butene-14C, butane-14C. Tetrahydrothiophene-14C was a major intermediate in the conversion of thiophene—14C in the experimental condition applied. The amounts of converted tetrahydrothiophene on the catalysts were substantially higher than those of thiophene under the same conditions. Hydrothiophene and dihydrothiophene—14C were intermediate products in the hydrodesulfurization of thiophene and tetrahydrothiophene. The hydrodesulphurization of tetrahydrothiophene was paired with dehydrogenation, producing small amounts of thiophene. The experimental results have been considered in the discussion of the mechanism of thiophene and tetrahydrothiophene desulfurization reaction pathway.

Application of high-performance liquid chromatography in porphyrias diagnostics

Porphyrias are distinguished by the stage of heme synthesis at which a failure occurs, leading to the accumulation of intermediate products – porphyrins. Due to the low specificity of clinical manifestations of porphyria and the latent course of the disease, their timely diagnosis is difficult. This article substantiates the effectiveness of high-performance liquid chromatography method in the determination of porphyrins. The method is suitable for porphyrin determination in urine, blood and feces of patients. Examples of its work are shown.

The Electrochemical Mechanism of Preparing Mn from LiMn2O4 in Waste Batteries in Molten Salt

The electrochemical reduction mechanism of Mn in LiMn2O4 in molten salt was studied. The results show that in the NaCl-CaCl2 molten salt, the process of reducing from Mn (IV) to manganese is: Mn (IV)→Mn (III)→Mn (II)→Mn. LiMn2O4 reacts with molten salt to form CaMn2O4 after being placed in molten salt for 1 h. The reaction of reducing CaMn2O4 to Mn is divided into two steps: Mn (III)→Mn (II)→Mn. The results of constant voltage deoxidation experiments under different conditions show that the intermediate products of LiMn2O4 reduction to Mn are CaMn2O4, MnO, and (MnO)x(CaO)(1−x). As the reaction progresses, x gradually decreases, and finally the Mn element is completely reduced under the conditions of 3 V for 9 h. The CaO in the product can be removed by washing the sample with deionized water at 0 °C.

Price Markups and Upstreamness in World Input-Output Data

This research uses the publicly available World Input-Output Database (WIOD) to investigate the relationship between an industry’s markup and its upstreamness, the industry’s position in the vertical chain of production; the research also identifies common attributes among high-markup industrial sectors: higher-markup industries display a higher level of capital compensation and a lower share of labour and other inputs in the value of output. Finally, it is found that upstream industries, those producing mostly raw materials and intermediate products enjoy higher market power than their downstream counterparts. This result could be among the first in the literature to find evidence of double marginalization at an industry level of aggregation. It also suggests that virtually all final product prices may incorporate substantial markups through their inputs.

Study on the Removal Performance of Phenol and Lead by Vernadite Synthesized via a New Method

Vernadite has excellent oxidation and adsorption performance, suggesting that it has good application prospects for the removal of phenolic substances and heavy metals from wastewater. In this study, after vernadite was synthesized by two different methods, the removal performance difference between the samples synthesized by the new and traditional methods (Ver-H and Ver-OH, respectively) was explored by sample characterization, phenol degradation, and Pb2+ adsorption experiments. The results show that, compared with Ver-OH, Ver-H has a larger particle size, specific surface areas, and total organic carbon (TOC) degradation capacity; the equilibrium degradation capacity of TOC of Ver-H was increased by 31.3%. The difference in the amount of TOC degradation may be attributed to more Mn(IV) oxygen vacancies in Ver-H, which facilitate the removal of intermediate products formed during phenol degradation. In addition, the larger specific surface areas provide the mineral surface with a larger number of active sites; Ver-H can therefore adsorb more intermediate products to promote their mineralization into CO2. The adsorptions of Pb2+ by Ver-H and Ver-OH are both consistent with Langmuir isothermal adsorption, and the maximum adsorption capacities are 569.79 g/kg and 623.10 g/kg, respectively. The lack of significant difference indicates that both vernadites have strong adsorption capacities for Pb2+.

Examining sub-daily tornado warning performance and associated environmental characteristics

Increasing tornado warning skill in terms of the probability of detection and false alarm ratio remains an important operational goal. Although many studies have examined tornado warning performance in a broad sense, less focus has been placed on warning performance within sub-daily convective events. In this study, we use the NWS tornado verification database to examine tornado warning performance by order-of-tornado within each convective day. We combine this database with tornado reports to relate warning performance to environmental characteristics. On convective days with multiple tornadoes, the first tornado is warned significantly less often than the middle and last tornadoes. More favorable kinematic environmental characteristics, like increasing 0–1-km shear and storm-relative helicity, are associated with better warning performance related to the first tornado of the convective day. Thermodynamic and composite parameters are less correlated to warning performance. During tornadic events, over half of false alarms occur after the last tornado of the day decays, and false alarms are twice as likely to be issued during this time than before the first tornado forms. These results indicate that forecasters may be better “primed” (or more prepared) to issue warnings on middle and last tornadoes of the day, and must overcome a higher threshold to warn on the first tornado of the day. To overcome this challenge, using kinematic environmental characteristics and intermediate products on the watch-to-warning scale may help.