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The halophyte Karelinia caspia has not only fodder and medical value but also can remediate saline-alkali soils. Our previous study showed that salt-secreting by salt glands is one of main adaptive strategies of K. caspia under high salinity. However, ROS scavenging, ion homeostasis, and photosynthetic characteristics responses to high salinity remain unclear in K. caspia. Here, physio-biochemical responses and gene expression associated with ROS scavenging and ions transport were tested in K. caspia subjected to 100–400 mM NaCl for 7 days. Results showed that both antioxidant enzymes (SOD, APX) activities and non-enzymatic antioxidants (chlorogenic acid, α-tocopherol, flavonoids, polyamines) contents were significantly enhanced, accompanied by up-regulating the related enzyme and non-enzymatic antioxidant synthesis gene (KcCu/Zn-SOD, KcAPX6, KcHCT, KcHPT1, Kcγ-TMT, KcF3H, KcSAMS and KcSMS) expression with increasing concentrations of NaCl. These responses are beneficial for removing excess ROS to maintain a stable level of H2O2 and O2− without lipid peroxidation in the K. caspia response to high salt. Meanwhile, up-regulating expression of KcSOS1/2/3, KcNHX1, and KcAVP was linked to Na+ compartmentalization into vacuoles or excretion through salt glands in K. caspia. Notably, salt can improve the function of PSII that facilitate net photosynthetic rates, which is helpful to growing normally in high saline. Overall, the findings suggested that ROS scavenging systems and Na+/K+ transport synergistically contributed to redox equilibrium, ion homeostasis, and the enhancement of PSII function, thereby conferring high salt tolerance.

Astragalus variabilis Bunge is a widespread locoweed that threatens livestock production in desert grassland. No research has reported its possible ecological functions due to focus being on its negative effect on livestock production. This study aimed to assess the effects of A. variabilis on soil properties and its possible role in improving soil quality in desert grassland. Soil samples were collected in Astragalus patches and the adjacent bare patches over two successive growing seasons in Alxa desert grassland where A. variabilis was favoured to spread. Soil properties including texture, water content, dry bulk density, porosity, available nutrients, organic matter, and soil microbial biomass were determined at 15 study sites. There was no significant difference in soil texture between Astragalus-dominant and bare patches; but organic matter (OM), available N and P, and microbial biomass in surface soil (0–30 cm) were significantly higher in Astragalus patches. Furthermore, microbial biomass showed a significantly positive correlation with available nutrients and OM. Levels of water soluble salt were significantly lower in A. variabilis surface soils under drought conditions. Results suggested that A. variabilis was associated with some positive changes in soil properties, and was potentially important in improving soil chemical and microbial properties in desert grassland ecosystems. Consequently, total elimination of locoweed should not necessarily be considered the best solution to locoweed poisoning in livestock.

The establishment, reproduction, dispersal, and distribution of alien plants are affected by various factors during the transition from being newly introduced in a habitat to being invasive. In the agro-pastoral ecotone of northern China, comprising farmlands and natural grasslands, the biological characteristics of alien plant species were the key intrinsic factors (propagation characteristics and competitive ability), followed by such extrinsic factors as human interference and environmental heterogeneity. Among biological characteristics, the life form may be an important and useful indicator of the invasive ability of a species, and the risk of invasion is greater from alien species that are poisonous, inedible, and have traits that facilitate wide dispersal. Farmlands may serve as initial shelters for alien species, from which they spread into neighbouring habitats, whereas natural grassland may act as a barrier to plant invasions. Management practices detrimental to grasslands, including overgrazing, reclamation, and road construction, often facilitate the invasions; therefore, counter measures such as reseeding and a ban on grazing need special attention. Environmental factors including precipitation, nutrients, prevailing winds, fires, and topography may be other factors that promote or block the process of invasion. In studying ways of preventing or controlling such invasions, alien plants with short life cycle, prolific seed production, and strong competitiveness, deserve particular attention and so do human activities that may damage the environment and fragile habitats.

Using the published literature and records, this study investigated the historical introduction, geographical distribution, and biological characteristics of 404 alien plants in 32 provinces (including municipalities) in China. The results showed that three fifths of the alien plants was introduced for intentional purposes, and the introduction of alien plants increased with time from 139 BC to the current time, especially during historical events that played an important part in the process of introduction. The geographical distribution of alien plant species tended to decrease from the south and the east to the north and the west. Annual average precipitation (Y = 7.51X + 7.05, R2 = 0.67) and temperature (Y = 0.07X + 41.54, R2 = 0.67) had a linear relationship with alien plant introduction throughout China. Furthermore, population density and economic conditions also affected and promoted plant invasions in China. The life forms were well adapted to regional precipitation and temperature, but different life forms of alien plants were not consistent with the distribution tendency based on the quantity of alien plants. There was a higher percentage of annual and biennial plants in the northern provinces (e.g. 66.7 and 15.7% in Inner Mongolia), whereas there were more perennial and woody plant species in the southern provinces (e.g. 37.0 and 21.2% in Hainan). Family characteristics could not accurately predict plant invasions; however, predictions based on genera were acceptable. In addition, the origin of alien plants can also predict the distribution and potential risk of invasions. Thus, our study investigated the factors affecting plant invasions in order to provide information on the prevention and control of alien plants.

Austenite grain size plays an important role for quenched and tempered A517 GrQ rack steel. In order to investigate the austenite grain growth behavior, in-situ austenizing experiments were conducted at different temperatures with varied holding time. Austenite grain growth, and subsequent bainite and martensite transformation were observed by a confocal laser scanning microscope (CLSM). The average austenite grain size increased rapidly from 32.7 μm to 137.9 μm with increasing temperature from 1100 °C to 1250 °C, and abnormal grain growth occurred at 1250 °C for 15 min. While holding from 5 min to 20 min at 1200 °C, the grain size grew gradually from 70.2 μm to 84.8 μm. The grain size distributions under different conditions all obey lognormal function. After austenizing, the rate of subsequent cooling has an significant impact on transformation process. The transformation duration time decreased from over 142 s to 11 s with increasing cooling rate at 1 °C/s and 5 °C/s, which could be corresponding to bainite and martensite transformation respectively.

ZnO thin films were prepared on quartz glass substrates by different sol-gel methods using a spin-coating technique. The structural and optical properties of ZnO thin films were studied by X-ray diffraction (XRD) and transmission spectra analysis. The results show that different factors such as Zn2+ concentration, solvent, sol stabilizer, pre-heat treatment temperature, and annealing temperature have a great impact on the structural and optical properties of ZnO thin films.

The Chinese-English lexical knowledge base based on HNC is an important component of the HNC knowledge base system. As a new stage of the HNC natural language processing, the building of the knowledge base needs a deep development of the association between the target language and the source language in the concept of space. In this paper, the Chinese-English lexical knowledge base model based on the HNC theory is first put forward to provide an effective reference database for the machine translation based on the semantic content, and two examples are provided to introduce its application in the semantic distance calculation and the Chinese-English machine translation. This supplies a gap in the research about the bilingual knowledge database of the HNC theory system.

A field experiment for river restoration was carried out in Chaohe river, a second largest river in Beijing, China. The study site with an area of 2, 800 m2 was set up in the downstream zone of Miyun reservior. Multiple water quality parameters, including pH, TN, TP and COD, were used to evaluate the removal efficiency of the river restoration project. The results showed that pH of water changed in a narrow rang from 6.98 to 7.11 during the investigation period. The pH value had no significant difference between the planted treatment and the non-planted control. From April to October, 2009, TN and TP of water were reduced regularly. At the beginning, the reduction tendency was sharp, then became flat. The mean removal efficiencies of TN and TP were 5.8% and 16%, respectively. No significant difference existed between the TN content of the planted treatment and that of the control. Contrarily, the TP content difference was significant between the two treatments. The maximum removal efficiencies were 30.2% on COD, 7.8% on TN and 25.5% on TP for the aquatic plant-based remediation system. This study suggested that the restoration of aquatic vegetation could potentially be used for mitigating the degradation of water quality and improve water carrying capacity.