Measurement and temporal and spatial characteristics of agricultural eco-efficiency under climate change: a case study of Anhui, China

IntroductionAgricultural eco-efficiency is an important index to evaluate the agricultural sustainable development and ecological economics, while simultaneously providing a metric for improvements to the rural environment and the stability of agricultural ecosystems.MethodsThis study took Anhui province as a case, and applied unit survey and list analysis methodologies to quantify rural agricultural non-point source pollution (NPS). Input-oriented super-efficient DEA-SBM was used to measure agricultural eco-efficiency in the typical North-South Transition Zone, and evaluated spatial correlations and differences.ResultsThis study showed that NPS was relatively stable, with less than 5% local variation in Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorus (TP) pollutants. The environmental pressure caused by livestock breeding and the use of chemical fertilizers was very substantial, and the differences of rural agricultural NPS in Anhui Province had obvious north-south characteristics. The agricultural eco-efficiency exhibited an “inverted N” trend. Affected by the “Spatial proximity effect” and the “Matthew effect”, it presented spatial agglomeration and positive spatial correlation. The regional differences were significant, and the heterogeneity increased in our study areas. The southern region had the greatest variation, followed by the northern region, with the smallest variation in the central region, although inter-regional differences were consistent.DiscussionThough the rational allocation of resources, coordination between agricultural economic and environmental protection would be realized, and better conditions for the sustainable development of agricultural ecology and the long-term stability of agricultural ecosystem would be created

Coal roadway rapid driving technology and equipment with integrated drilling and anchoring and its application

This paper analyzes the current situation and existing problems of coal roadway driving technologies and equipment, introduces the new mode, technology, equipment of coal roadway rapid driving with integrated drilling and anchoring and its underground applications. The bolting technologies and equipment with integrated drilling and anchoring are developed which include the integrated drilling and anchoring bolt, pumpable resin, drilling boom and drill rig as well as bolts cartridge with integrated drilling and anchoring, pump unit and intelligence control system. The new technology simplifies the traditional six-step rock bolting process to one continuous step. Rock bolting can be realized automatically by pressing button once and the operation time for installing a single bolt can be reduced from 5 to 6 minutes to 3 minutes. The technologies and equipment of automatic spraying support are developed which include high-strength, rapid setting, and deformable surface supporting spraying materials with a tensile strength exceeding 9 MPa, elongation at break exceeding 100%, and a bonding strength exceeding 3 MPa. The spraying system with 6-degree-of-freedom manipulator is developed which can automatically and rapidly spray during roadway driving. The dynamic monitoring technology and system for roadway surrounding rock deformation are developed during driving which can achieve a surface deformation monitoring of roadway in environments with dust, multiple interference, and low illumination. The monitoring accuracy can meet the requirements of the surrounding rock stability evaluation. A new partitioned parallel collaborative rapid driving mode of excavation, spraying, bolting and transport is proposed and a complete set of roadway rapid driving equipment with integrated drilling and anchoring is developed. The displacement and stability of the surrounding rock during the driving process at the Caojiatan Coal Mine in Shaanxi Province are monitored. In terms of time, more than 80% of the surrounding rock displacement had already occurred in 2 to 3 hours after the excavation of the roadway. In terms of space, more than 90% of the surrounding rock displacement had already occurred at a distance equivalent to twice the width of the roadway from the excavation face. Therefore, the roadway surrounding rock displacement caused by rapid driving can be completed in a short time, requiring timely and rapid support. The nearly 6 000 m roadway driving project has been completed in the 10-metre-extra-high fully mechanized mining face of the Caojiatan Coal Mine, and over 60 000 bolts with integrated drilling and anchoring are installed. The time for installing a single bolt, the number of supporting workers, and the labor intensity of workers have been significantly reduced. The driving speed, efficiency, and automation level have been significantly improved. The displacement of the experimental roadway roof is small. The roadway surrounding rock stability is good as well as the support effect. The coal roadway rapid driving technology and equipment with integrated drilling and anchoring have achieved a success in underground field test. It has the ability to achieve a monthly driving footage of 1500 to 2000 m for ultra-large cross-section coal roadways

Profiling durable anti-tumor memory T cell responses in long-term melanoma survivors

While T-cell responses to cancer immunotherapy have been avidly studied, long-lived memory has been poorly characterized. Of melanoma patients who receive immunotherapy, long-term survivors are frequently found to develop melanoma-associated vitiligo. Our prior work showed in a preclinical model that vitiligo skin sustained a long-lived CD8+ resident memory T cell (TRM) population, playing key roles in perpetuating anti-tumor immunity. However, the characteristics and longevity of these memory T cells in melanoma survivors have not been defined. In the present studies, we probed both the CD8+ and CD4+ T cell responses, focusing on memory T cell responses in a cohort of metastatic melanoma survivors with exceptional responses to immunotherapy. Single-cell RNA sequencing revealed heterogenous CD8+ and CD4+ TRM subsets shared between tumors and distant vitiligo-affected skin with distinct prognostic significance. Paired T-cell receptor sequencing further identified clonotypes in tumors that co-existed as TRM in skin and as effector memory T (TEM) cells in blood. CD8+ T cell clonotypes that dispersed throughout tumor, skin and blood preferentially expressed an IFNG/TNFhigh signature, which had a strong prognostic value for patients with melanoma. An unbiased core TRM gene signature capturing the abundance of overall TRM regardless of the CD4+ and CD8+ different differentiation lineages was proved to be a better predictor for the overall survival of metastatic melanoma patients than a core circulating T cell (TCIRC) gene signature. Remarkably, the CD8+ T cell clonotypes from tumors were found in patient skin and blood up to 9 years later, with skin maintaining the most focused tumor-associated clonal repertoire. This work established that cancer survivors can maintain durable memory as functional, broadly distributed TRM and TEM compartments. Moving forward, it will be necessary to determine the tissue microenvironment factors that are required for the induction and persistence of tumor reactive TRM populations in patients for better immunotherapies

Transport Characteristics of Soil Salinity in Saline-alkali Land under Water Storage and Drainage Conditions

To test the variation and transport of soil salinity in saline-alkali land under water storage and drainage treatments, an experimental model was established in Fuping, Shaanxi Province, 2009. The variation of soil salinity during 0—160 cm soil depth under the two treatments was determined and analyzed. Results showed that the average soil water content under water storage treatment was 4.47% higher than that under drainage treatment, which means that the water storage treatment could help to improve soil moisture to satisfy the crop’s growth needs. The profile distribution of soil soluble solids (TDS), anion (Cl-, HCO3-, SO42-) and cation (Ca2+, Na+, K+) content and the variation of soil pH were also measured and analyzed. PCA (Principal Component Analysis) was used to explore the relationship between the soil salinity and its ions, which showed that the water storage treatment could significantly decrease the surface salinity of soil and accelerate the desalination of topsoils, and finally, the soil quality was improved significantly, demonstrating that the water storage treatment has a remarkable effect on soil salinity management

Using X-Ray CT Scanning to Study the Failure Mechanism of Concrete under Static and Dynamic Loadings

X-ray images can be used to nondestructively monitor the initiation, extension, and combination of cracks in concrete. In this study, real-time X-ray computed tomography (CT) scanning of concrete specimens under static and dynamic loadings was done. The CT images showed the growth, propagation, and penetration of the cracks and showed the ultimate failure of the concrete samples. Analysis of the CT images and CT numbers showed that the failure followed the structure’s areas of weakness under the static load, but for dynamic loading, the cracks formed very rapidly along straight lines through the aggregate

Landslide Susceptibility Modeling Using Integrated Ensemble Weights of Evidence with Logistic Regression and Random Forest Models

The main aim of this study was to compare the performances of the hybrid approaches of traditional bivariate weights of evidence (WoE) with multivariate logistic regression (WoE-LR) and machine learning-based random forest (WoE-RF) for landslide susceptibility mapping. The performance of the three landslide models was validated with receiver operating characteristic (ROC) curves and area under the curve (AUC). The results showed that the areas under the curve obtained using the WoE, WoE-LR, and WoE-RF methods were 0.720, 0.773, and 0.802 for the training dataset, and were 0.695, 0.763, and 0.782 for the validation dataset, respectively. The results demonstrate the superiority of hybrid models and that the resultant maps would be useful for land use planning in landslide-prone areas

Background of Land Development and Opportunity of Land Use Transition

In order to ease the contradiction between people and land and ensure the needs of construction land and farmland, this paper analyzes the demand and regional land development background, and points out the problems of the development of the land in China: late start of land development and utilization practices; declining back-up resources and sharply increasing costs; new resources and environmental problems brought about by development and utilization of land in some areas. This paper presents a new opportunity and strategy for land use transition: giving full play to the agricultural and geographical advantages of farming-pastoral area; carrying out water-saving technologies and intensive use of agricultural land in water-deficient areas, in order to achieve reasonable and efficient development and utilization

Sedimentary succession and recognition marks of lacustrine gravel beach-bars, a case study from the Qinghai Lake, China

The present is the key to the past. Based on the dissection of modern beach-bars in the Qinghai Lake, Qinghai-Tibet Plateau, China, including two profiles parallelly to the shoreline, two profiles vertically to the shoreline and one plane-view profile, the sedimentary succession and recognition marks of lacustrine gravel beach-bars have been summarized. Vertically, the lacustrine gravel beach-bars develop with the “ABC” succession. The A interval, the B interval, and the C interval respectively correspond with the gravelly sand facies, the well-sorted gravel facies, and the graded sand facies. The lacustrine gravel beach-bars is composed of several combinations of the “ABC” succession, such as “ABAB”, “ABCABC”, “BCBC”. The main recognition marks of lacustrine gravel beach-bars is the following: the bottom contact is distinct and with the “ABC” succession; and the lacustrine beach-bars develop the swash bedding and sheet-like parallelly to the lakeshore. These viewpoints have significant contributions to the reconstruction of paleoenvironments and paleoshorelines and to the reservoir interpretation within lacustrine beach-bar clastic bodies

Response of the characteristics of organic carbon mineralization of soft rock and soil composed of sand to soil depth

The addition of soft rock to aeolian sandy soil can improve the level of fertility and ability of the soil to sequester carbon, which is of substantial significance to improve the ecological environment of the Mu Us sandy land and supplement newly added cultivated land. S oft rock and sand were combined using the ratio (v/v) of 0:1 (CK), 1:5 (S1), 1:2 (S2), and 1:1 (S3). The process of mineralization of organic carbon at different depths (0–10 cm, 10–20 cm, and 20–30 cm) in the combined soil was studied by 58 days of incubation indoors at a constant temperature. The content of soil nutrient s increased significantly under the S2 and S3 treatments and was higher in the 0–10 cm soil depth. The mineralization of rate of soil organic carbon (SOC) of different combination ratios can be divided into three time periods: the stress mineralization stage (1–7 d), the rapid mineralization stage (7–9 d) and the slow mineralization stage (9–58 d). At the end of incubation, the rates of mineralization of SOC and accumulated mineralization amount (Ct) were relatively large in the 0–10 cm soil depth, followed by the 10–20 cm and 20–30 cm soil layers , indicating that the stability of SOC in the surface layer was poor, which is not conducive to the storage of carbon. The content of potentially mineralizable organic carbon (C0) in the soil was consistent with the trend of change of Ct. Compared with the CK treatment, the cumulative organic carbon mineralization rate (Cr) of the S2 and S3 treatment s decreased by 7.77% and 6.05%, respectively; and the C0/SOC decreased by 22.84% and 15.55%, respectively. Moreover, the Cr and C0/SOC values in the 10–20 cm soil depth were small, which indirectly promoted the storage of organic carbon. With the process of SOC mineralization, the contents of soil microbial biomass carbon (SMBC) and dissolved organic carbon (DOC) tended to decrease compared with the initial contents, with larger amplitudes in the 20–30 cm and 10–20 cm soil depth s, respectively. SOC, total nitrogen, available potassium, SMBC and DOC were all closely related to the process of mineralization of organic carbon. Therefore, the accumulation of soil carbon could be enhanced when the proportion of soft rock and sand composite soil was between 1:2 and 1:1, and the 10–20 cm soil depth was relatively stable. These results provide a theoretical basis for the improvement of desertified land