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We analyzed the effects of different combinations of organic soil amendments (OSAs) and chemical fertilizers on agrifood production, focusing on banana yields in China, the second-largest producer of bananas globally.

We computed these combinations by dividing the expenditures on OSAs by those on chemical fertilizers and called them OSA-CF ratios. First, we classified farmers based on quintiles of expenditures on chemical fertilizers. Then, we studied the association between OSA-CF ratios and banana yields for each quintile. We also considered an alternate specification in which farmers were grouped along the OSA-CF ratio continuum. The first group comprised farmers not using OSAs. Their OSA-CF ratio was zero. Farmers applying low, medium, and high OSA-CF ratios constituted groups two, three, and four; the groups were delineated based on the OSA-CF ratio tertiles, and the associations between tertiles of OSA-CF ratios and banana yields for each quintile were analyzed. The data used in this study were collected by surveying 616 households in three major banana-producing provinces (Guangdong, Hainan, and Yunnan) of China. Standard linear regressions and the two-stage predictor substitution method were employed to complete the analysis.

There were variations in the effects of OSA-CF ratios on banana yields obtained by farmers iifferent quintiles. For the first and second quintiles, low, medium, and high OSA-CF ratios improved banana yields relative to not using OSAs. For farmers in the first quintile using only chemical fertilizers, applying a low OSA-CF ratio was associated with an improvement of 792 kg/mu in banana yields. For their counterparts in the second quintile, the same transition was associated with a gain of 534 kg/mu. For the fifth quintile, comprising farmers spending 320 yuan/mu or more on chemical fertilizers, applying a high OSA-CF ratio instead of using only chemical fertilizers was associated with a 401 kg/mu decline in banana yields. Even so, for this group, no differences were observed between the yields of farmers not applying OSAs and those using low and medium OSA-CF ratios.

Banana farmers in southern China, using only chemical fertilizers, can improve yields by combining them with OSAs if their chemical fertilizer expenditures are less than 66.67 yuan/mu. Those using only chemical fertilizers and spending between 68 yuan/mu and 300 yuan/mu on them can maintain yields by applying OSAs in conjunction with chemical fertilizers. However, yields may decline for farmers using only chemical fertilizers and spending 320 yuan/mu or more on them if they incorporate OSAs such that the OSA-CF ratio reaches 0.78 or higher. Overall, combining OSAs with chemical fertilizers can improve yields while attenuating the adverse effects of chemical fertilizers on the environment. Policymakers should inform farmers of these benefits and accelerate the transition to sustainable agriculture through educational and awareness programs.

Farmers apply OSAs such as organic fertilizers and farmyard manure to adjust and remedy soil nutrition to improve farm productivity. However, little is known about how combining OSAs with chemical fertilizers affects banana yields. This study provided the first attempt to explore the associations between OSA-CF ratios and banana yields using cross-sectional data on farming households.

Three commercially available chemical substructure databases are reviewed: Chemical Abstracts, Index Chemicus, and the SANSS file (Chemical Information System). Coverage and overlap of Chemical Abstracts and Index Chemicus are studied, as well as differences between Chemical Abstracts as mounted by two different vendors (STN International and Questel). Guidelines for determining the database/system of choice are given.

Solutions of the twin plane jets HF chemical laser flow based on a turbulent kinetic theory, due to a modified Green’s function method, are presented. The calculated results of probability density function (PDF) of various chemical species in velocity space, and mass fraction concentration distributions of various reactants and products in the flow field, are revealed and discussed in this analysis. The transport phenomena of different pumping rate, collisional deactivation rate, and radiative deactivation rate in the interaction between the twin plane jets HF chemical laser show that the properties of species mass fraction concentrations, collisional reaction rate, and radiative incident intensity are the dominant factors. The present study provides the fundamentals for theoretical understanding of twin plane jets HF chemical laser and further application to multiple‐jet HF chemical laser analysis.

Focuses on, and provides a background of, the REACH Regulation, a new system of registration, evaluation and authorisation for chemicals.

In October 2003 The European Commission presented to the European parliament and the Council of the European Union (EU), a proposal for a Regulation that will radically reform Europe's existing chemical policy. The so‐called REACH Regulation will introduce a new system of Registration, Evaluation and Authorisation for Chemicals introduced on the EU market in volumes over 1 tonne per manufacturer per year. It will also establish a central Chemicals Agency to oversee the efficient operation of the new regulatory system. The implications of the draft Regulation on Europe's chemical manufacturers, importers, formulators and those sectors that either use or process chemicals, such as the electronics industry, will be manifold.

Despite a number of concessions granted to the chemical industry following an internet consultation, there remain serious doubts over the workability of the system, as well as concerns over substantial product losses and fears over the competitiveness of Europe's chemical industry.

This paper sets out to provide a background to the proposed reforms and an outline of the main components of the REACH system as well as a summary of some of the likely key impacts on the PCB industry.

The Chemical Integrated Information Service Network (Chl2Net) is a comprehensive information service system which includes chemical, technical, economic, market, news and management information based on computer and modern communication technology, and built by the China National Chemical Information Centre (CNCIC). This system provides varied services for users both at home and abroad through an online service, a hotline call service, a consulting service and publishing service.

The European Commission (EC) has drafted a proposal for reforming the European Union's (EU) chemicals policy. The chemical industry has welcomed the broad political objectives of this policy, particularly those of increased protection of human health and the environment. The chemical industry also agrees that the existing process for chemicals regulation in the EU has proven to be slow and inefficient. However, it has reacted strongly to many of the finer details of the proposal, and there is a growing consensus that if the EC implements the strategy as currently outlined in the White Paper on the “Strategy for a Future Chemicals Policy” it will have very serious implications on the competitiveness of Europe's chemical industry and related sectors.

The world community has long striven for the liquidation of chemical weapons of mass destruction. The 1925 Geneva treaty “On the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacterial Methods of Warfare” was the first international accord on chemical weapons prohibition. Signed by 125 countries, the USSR ratified the treaty in December 1927. The later development of the “Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and their Destruction” (henceforth “the Convention”) followed this early step and was undertaken with Russia's active participation. The Convention was signed by the Russian Federation in January 1993 and ratified by the State Duma in November 1997 with the decision to end chemical weapons stockpiling by 2007. As a signatory, Russia accepted international responsibilities for solving many interrelated problems, paramount among them was the protection of people and the environment (The Convention…, 1994, item 4).

We examine the evolution of vertical specialization in three industries: chemicals, computers, and semiconductors. Vertical specialization is the restructuring of industry-wide value chains, such that different stages are controlled by different firms, rather than being vertically integrated within the boundaries of individual firms. In some cases, vertical specialization may span international boundaries and is associated with complex international production networks. After decades of vertical specialization, firms in the chemical industry are re-integrating stages of the value chain. By contrast, the semiconductor and computer industries have experienced significant vertical specialization during the past ten years. We examine how and why these contrasting trends in vertical specialization have co-evolved with industry maturation and decline, and underscore the importance and role of both industry factors and business strategies necessary for industries to become more specialized. We also consider the effects of vertical specialization on the sources of innovation and the geographic redistribution of production and other activities. We conclude that the evolution of vertical specialization in these three industries has both reflected and influenced the strategies of leading firms, while also displays industry-specific characteristics that are rooted in different technological and market characteristics.

The study estimates total factor productivity growth (TFPG) and its components of the 4-digit manufacturing industries of chemical and chemical products in India from 1998–1999 to 2017–2018, pre-economic crises period (from 1998–1999 to 2007–2008) and post-economic crises period (from 2008–2009 to 2017–2018) using frontier approaches, that is, data envelope analysis DEA and stochastic frontier approach (SFA). The components of TFPG are technological progress (TP), technical efficiency change (TEC) and economic scale change (SC). It is found that the growth rates of total factor productivity (TFP) in most of the 4-digit industries of chemical and chemical products in India increased during the post-economic crises period (from 2008–2009 to 2017–2018) and the increase in TFPG of them during that period is mainly accounted for by the increase in TP of the same during that period. The TEC of almost all the industries remains the same, however, declined during the post-economic crises (from 2008–2009 to 2017–2018) and SC of them remains very low or even negative during the aforementioned study periods.

The objective of this paper is to establish a solution strategy for obtaining dual solutions, namely trivial (conventional) and nontrivial (unconventional) solutions, of coupled pore-fluid flow and chemical dissolution problems in heterogeneous porous media.

Through applying a perturbation to the pore-fluid velocity, original governing partial differential equations of a coupled pore-fluid flow and chemical dissolution problem in heterogeneous porous media are transformed into perturbed ones, which are then solved by using the semi-analytical finite element method. Through switching off and on the applied perturbation terms in the resulting perturbed governing partial differential equations, both the trivial and nontrivial solutions can be obtained for the original governing partial differential equations of the coupled pore-fluid flow and chemical dissolution problem in fluid-saturated heterogeneous porous media.

When a coupled pore-fluid flow and chemical dissolution system is in a stable state, the trivial and nontrivial solutions of the system are identical. However, if a coupled pore-fluid flow and chemical dissolution system is in an unstable state, then the trivial and nontrivial solutions of the system are totally different. This recognition can be equally used to judge whether a coupled pore-fluid flow and chemical dissolution system involving heterogeneous porous media is in a stable state or in an unstable state. The proposed solution strategy can produce dual solutions for simulating coupled pore-fluid flow and chemical dissolution problems in fluid-saturated heterogeneous porous media.

A solution strategy is proposed to obtain the nontrivial solution, which is often overlooked in the computational simulation of coupled pore-fluid flow and chemical dissolution problems in fluid-saturated heterogeneous porous media. The proposed solution strategy provides a useful way for understanding the underlying dynamic mechanisms of the chemical damage effect associated with the stability of structures that are built on soil foundations.