Revealing the impact of forest succession processes on changes in plant diversity is crucial for understanding the mechanisms that maintain plant diversity across various succession stages. While previous research has predominantly focused on the influence of environmental factors or management strategies on plant diversity within rubber plantation understories, there is a scarcity of studies examining the effects of forest succession processes on plant diversity. This study focuses on the plant diversity of the understory herbaceous layer within the rubber forest of the Yinggeling area, located in National Park of Hainan Tropical Rainforest. It employs a spatial analysis approach, rather than a temporal one, to examine the characteristics of the understory herbaceous community. The findings revealed that (1) The understory of Yinggeling rubber plantations harbors 175 plant species from 149 genera and 75 families, with Gramineae and Rubiaceae representing 46.45% of total species. And the dominant families are Rubiaceae, Gramineae, and Moraceae, with Ficus and Pteris being the dominant genera. (2) The dominant species vary with succession duration, with Tetrastigma pachyphyllum dominating in 0-year succession, Paspalum conjugatum in 3-year succession, and Microstegium fasciculatum in 7-year succession. (3) Diversity indices such as the Shannon–Wiener index, Simpson index, and Pielou index peak at 7 years of natural succession, while the species richness is highest at 3 years. (4) The similarity coefficient between understory herbaceous plant communities in rubber plantations undergoing 0 and 3 years of natural succession is highest 0.56, indicating a significant similarity, while similarity is lowest between 0 and 7 years of succession. This research shows that natural restoration helps increase species diversity in the understory herb layer of rubber forests. Succession leads to changes in the dominant families, genera, and species of the herbaceous layer. This change can be attributed to the intraspecific competition and ecological competition that occur during the succession process, leading to changes in biological and resource allocation.

Commercial gestation housing systems for sows generally fail to cater fully for their needs in terms of comfort or the ability to perform highly motivated behaviours, which can lead to chronic stress and an impairment to welfare. We compared a typical gestation system (CONTROL) with an IMPROVED one as regards oral stereotypies, aggressive behaviour, skin lesions, locomotion, and tear staining. Sows were mixed into 12 stable groups (six groups per treatment, 20 sows per group), 29 days post-service in pens with free-access, full-length individual feeding/lying stalls. CONTROL pens had fully slatted concrete floors, with two blocks of wood and two chains suspended in the group area. IMPROVED pens were the same but with rubber mats and a length of manila rope in each feeding stall, and straw provided in three racks in the group area. Direct observations of oral stereotypical (30 instantaneous scans per sow per day) and aggressive (all-occurrence sampling, 3 h per sow per day) behaviours were conducted 72 h post-mixing, in mid and late gestation. Skin lesions were counted 24 h and three weeks post-mixing, and in late gestation. Sows’ locomotion (locomotory ability) was scored using a visual analogue scale in mid and late gestation. Right and left eye tear staining was scored in late gestation. Indications of better welfare in IMPROVED sows included performance of fewer oral stereotypies in mid and late gestation, and lower tear stain scores. These sows performed more aggression in late gestation, which was associated with access to enrichment, but skin lesion counts were not affected. Thus, the changes made in the IMPROVED treatment benefitted aspects of sow welfare.

Chinese state firms are expected not only to profit but also to serve state interests. But the Chinese state is fragmented: border provinces are taking on an expanded role in China's global expansion and a broad range of firm activities could be defined as patriotic contributions. Through the case of Yunnan State Farms (YSF), a province-level state-owned enterprise, this article explores how state firms interpret and navigate multiple state interests while also pursuing profit. The firm's ability to profit depends on balancing the demands and support of different Chinese state actors while depicting itself as a development partner to the Lao state and a contributor to Sino-Lao diplomatic relations and border region stability. This case thus shows that, instead of YSF's behaviour being directed by the state, the firm exercises considerable latitude in defining its contributions to state interests through the expansion of rubber production as a driver of development.

An isolated cylindrical void is located inside an incompressible nonlinear-elastic medium whose constitutive behaviour is governed by a neo-Hookean strain energy function. In-plane hydrostatic pressure is applied in the far-field so that the void changes its radius and an inhomogeneous region of deformation arises in the vicinity of the void. We consider scattering from the void in the deformed configuration due to an incident field (of small amplitude) generated by a horizontally polarized shear (SH) line source, a distance r0 (R0) away from the centre of the void in the deformed (undeformed) configuration. We show that the scattering coefficients of this scattered field are unaffected by the pre-stress (initial deformation). In particular, they depend not on the deformed void radius a or distance r0, but instead on the original void size A and original distance R0.

The study of nonlinear dynamic behavior of laminate composed of steel and rubber layersalso referred as “Shim”, used for vibro-acoustic insulation in brake system, isinvestigated. The simulation of the vibro-acoustic nonlinear behavior of Shim depending onfrequency, taking into account the large deformations and various nonlinearhyper-viscoelastic laws of rubber are considered. This paper presents a solution tocontribute in the identification of the best design of Shim in terms of damping vibrationof brake systems, using analytical and numerical method. The choice of the best structuredepends essentially on the nature of rubber, on the stacking sequence of materials, ontheir thickness, on the number of layers and on volume fraction of rubber. An analyticalstudy, with the use of the transfer matrix method is presented. A model on the finiteelement software ANSYS is constructed. The results lead to conclusions about the beststructure and design of Shim in term of vibro-acoustic insulation.

The displacement of a plastic fluid by an elastic disc approaching a plane rigid surface oriented perpendicular to the disc axis is computed with a numerical scheme accounting for the coupled deformation of the disc and flow of plastic. The axial force to push the disc is in agreement with lubrication theory approximation. The existence of un-yielded fluid situated at the corners of the fluid region on the centre-line have been predicted, similar to the case observed for rigid disc squeeze flow.

Ce travail présente des analyses fractographiques de fissures de fatigue dans le caoutchouc naturel chargé aux noirs de carbone. Afin d'identifier les mécanismes de propagation de fissure, il est nécessaire de connaître l'état de la microstructure autour du fond de fissure. Nous avons donc mis au point une technique permettant de micro-découper le fond de fissure lors d'observations au microscope électronique à balayage (MEB). Cette technique utilise simultanément l'énergie mécanique apportée par l'étirement statique de l'éprouvette dans le MEB et l'énergie fournie par la concentration du faisceau électronique du MEB sur la zone d'observation. Les résultats de ces observations montrent que l'endommagement par fatigue au fond de fissure est dû à la cavitation engendrée par la décohésion entre la matrice polymère et les oxydes.

A case of occupational rhinitis in association with natural rubber latex hypersensitivity is presented. In the nasal provocation test for natural rubber latex glove powder the nurse experienced rhinorrhoea. A significant increase in the amount of nasal secretion and mucosal oedema could be detected. The patient also showed a positive skin prick test to natural rubber latex allergens, and an elevated natural rubber specific IgE level in her serum. This, to our knowledge, has not been previously reported in the literature.