Competitive and synergic evolution of the water-food-ecology system: A case study of the Beijing-Tianjin-Hebei region, China.

A vital approach to attaining sustainable development lies in the in-depth examination of both competition and synergy between these subsystems from a water-food-ecology (WFE) system perspective, while previous or existing studies have limitations in to quantitative characterize and evaluation the cooperative and competitive relationships between different systems. In this study, an evaluation indicator system is constructed from the two dimensions of resources and efficiency, and the WFE synergic development capacity (WFE-SDC) is proposed by integrating the order degree of the coupled system, enables a multidimensional and comprehensive quantitative assessment of the sustainable development of the WFE system. Then a synergic evolution model is constructed to explore the competitive and synergic evolution of the WFE system in the Beijing-Tianjin-Hebei region. The following key insights were obtained: (1) The WFE-SDC (range of 0-1) shows a fluctuating increase, indicating a shift from mild dysfunctional recession to intermediate synergic development (0.24 to 0.72). (2) Principal factors impeding WFE-SDC encompass diversion water, ecology water consumption, grain demand, reclaimed water consumption, and outbound water, both come from resource dimension, with a combined impediment degree of over 46 %, and the improvement of efficiency dimension may improve the WFE-SDC. (3) The water subsystem acts as a driving force for synergic development, fostering cooperation within the food and ecology subsystems, although they mainly operate in a competitive state. (4) Within the WFE system, Beijing, Tianjin, and Hebei exhibited mutual cooperation and significantly contributed to one another's development. Beijing has played a pivotal role in the progress of both Tianjin and Hebei. This study offers valuable insights for the formulation of policies and the application of technical approaches for the sustainable development of the WFE system in relevant regions.

Process Parameter Prediction and Modeling of Laser Percussion Drilling by Artificial Neural Networks.

Finding process parameters for laser-drilled blind holes often relies on an engineer's experience and the trial-and-error method. However, determining such parameters should be possible using methodical calculations. Studies have already begun to examine the use of neural networks to improve the efficiency of this situation. This study extends the field of research by applying artificial neural networks (ANNs) to predict the required parameters for drilling stainless steel with a certain depth and diameter of blind holes, and it also pre-simulates the drilling result of these predicted parameters before actual laser processing. The pre-simulated drilling results were also compared with real-world observations after drilling the stainless steel. These experimental findings confirmed that the proposed method can be used to accurately select laser drilling parameters and predict results in advance. Being able to make these predictions successfully reduces time spent, manpower, and the number of trial-and-error shots required in the pre-processing phase. In addition to providing specific data for engineers to use, this method could also be used to develop a set of reference parameters, greatly simplifying the laser drilling process.

Impact damage visualization in a honeycomb composite panel through laser inspection using zero-lag cross-correlation imaging condition.

A fully non-contact laser-based nondestructive inspection (NDI) system is developed to detect and visualize damage in structures. The study focuses on the size quantification and characterization of a barely visible impact damage (BVID) in a honeycomb composite panel. The hardware consists of a Q-switched Nd:YAG pulse laser that probes the panel by generating broadband guided waves via thermo-elastic expansion. The laser, in combination with a set of galvano-mirrors is used to raster scan over a two-dimensional surface covering the damaged region of an impacted quasi-isotropic [60/0/-60]s honeycomb composite panel. The out-of-plane velocities are measured at a fixed location normal to the surface by a laser Doppler vibrometer (LDV). An ultrasonic full wavefield assembled from the three-dimensional space-time data matrix in the interrogated area is first acquired and then processed for imaging the impacted damage area. A wavenumber filtering technique in terms of wave vectors is applied to distinguish the forward and backward wavefields in the wavenumber-frequency domain. A zero-lag cross correlation (ZLCC) imaging condition is then employed in the space-frequency domain for damage imaging. The ZLCC imaging condition consists of cross correlating the incident and reflected wavefields in the entire scanned region. The condition not only images the damage boundary between incident and reflected waves outside the damage region but also, for longer time windows, enables to capture the momentary standing waves formed within the damaged region. The ZLCC imaging condition imaged two delaminated region: a main delamination, which was a skewed elliptic with major and minor axis lengths roughly 17 mm and 10 mm respectively, and a secondary delamination region approximately 6 mm by 4 mm, however, which can only be shown at higher frequency range around 80-95 kHz. To conclude, the ZLCC results were in very good agreement with ultrasonic C-scan and X-ray computed tomographic (X-ray CT) scan results. Since the imaging condition is performed in the space-frequency domain, the imaging from ZLCC can also reveal resonance modes which are shown in the main delaminated area by windowing a narrow frequency band sequentially.

A modified method for pesticide transport and fate in subsurface environment of a winter wheat field of Yangling, China.

The Guanzhong region is one of the water resources shortage areas and also an important food producing area in Chinese Loess Plateau. The unreasonable application of irrigation and pesticide not only reduces the utilization rate of pesticides, but also is a potential threat to aquatic environments. In order to explore the reasonable application pattern of irrigation and pesticide, a modified method considering crop water requirement and pesticide transport was established to simulate transport and fate of Triadimefon in subsurface environment of a winter wheat field in Yangling, China. Results indicate that: (1) the modified method introduces the concepts of crop water requirement and irrigation schedule, which can estimate irrigation amount more accurately and achieve the goal of water saving and agricultural diffuse pollution control more efficiently. The method shows good potential applications and implications in predicting pesticide exposure levels of different crops and in reducing pesticide pollution. (2) The changing trends of soil pesticide levels under different pesticide applications are various. The Triadimefon concentration level in surface soil layer (0.005m) was directly affected by pesticide application and irrigation. The Triadimefon peak below the soil depth of 0.035m has prominently delayed effects and it is mainly affected by irrigations. The concentration of pesticides decays rapidly with the increase of soil depth, and it can be ignored below the depth of 0.5m. (3) The soil pesticide levels under different pesticide and irrigation modes show considerable differences, the irrigation is still the most significant factor affecting the level of soil pesticide residues under different time intervals between pesticide application and irrigation. The irrigation scheme of one-day interval and five-divided irrigation can effectively reduce deep soil pollution without affecting the normal growth of crops. Results may provide theoretical basis and guide farmers to choose appropriate irrigation and pesticide application patterns.

Theranostic mesoporous silica nanoparticles biodegrade after pro-survival drug delivery and ultrasound/magnetic resonance imaging of stem cells.

Increasing cell survival in stem cell therapy is an important challenge for the field of regenerative medicine. Here, we report theranostic mesoporous silica nanoparticles that can increase cell survival through both diagnostic and therapeutic approaches. First, the nanoparticle offers ultrasound and MRI signal to guide implantation into the peri-infarct zone and away from the most necrotic tissue. Second, the nanoparticle serves as a slow release reservoir of insulin-like growth factor (IGF)-a protein shown to increase cell survival. Mesenchymal stem cells labeled with these nanoparticles had detection limits near 9000 cells with no cytotoxicity at the 250 µg/mL concentration required for labeling. We also studied the degradation of the nanoparticles and showed that they clear from cells in approximately 3 weeks. The presence of IGF increased cell survival up to 40% (p<0.05) versus unlabeled cells under in vitro serum-free culture conditions.