An obliqued continus public space from motion: renovation of parking facilities based on the shared cars system

The sharing economy is exploding around the world thanks to three main characteristics: community-based reuse of idle resources, the extension of sharing between acquaintances to strangers, and the transformation of production into decentralized, personalized customization. Shared cars, as a very important part of it, is creating a new open community for its users, and a space should be provided to fit both the basic need of a shared cars station and the social requirements of different citizens. Garages, as the original car stockings, can be renovated to accommodate public activities. The presence of garages is researched firstly to guide following interventions. The space is designed for cars from the very beginning, and it has grown into a prototype with a series of spaces been designed to fit the different condition of the road network and functions above. No matter how impressive the inside systems are, garages, which are decorated by their facade, have sieged the motion, a new character of the 21 century. The conflict should not be the reason for hiding it. With the help of shared cars system, we can make a new public interface between man and cars. These public spaces can make diverse activities happen while providing an experience of the motion. It can generate a series of urban renovations on garages. To get started, this new public space system should be discussed in detail. Three elements are considered vital: the entrance, the machine providing the shared cars service, and the platform for connecting. Three cases are studied as possible reference: the placa de Sants, the Ford Line and the Hamburg Station. The oblique surface is a great option for the public space underground. First presented by Claude Parent and Parl Virilio, the continues surface merge the boundary between horizontal layers, making the gravity as a new clue for the organization of different activies on a single platform. Towards a total habitable space, it can be easily connected to the original structure and multiple the public value. It stimulates motion and accepts the new urban texture, which is the reason why it is different from the vertical and horizontal ones. After a field research on the public garages inside the center of Barcelona, two types of garages (a classification based on the function above): the garages besides the apartments and the ones under public squares are considered most valuable in the diversity of the crowd and the service capacity of the shared cars stations. Specific public functions are organized on a series of ramps which are interconnected like the organization of the original garages. Service line are placed besides these spaces so people can experience the beauty of motion everywhere. Oblique surfaces can create a multiple of spaces and activities and that can make these spaces totally different from the old ones

Multi-objective Optimization of Construction Project Based on Improved Ant Colony Algorithm

It is the key and difficult problem for the current project management to consider the multi-objective optimization of the four elements, such as quality, duration, cost and safety. To improve the accuracy and efficiency of project management during the engineering construction, considering the advantages and disadvantages of the traditional quality-cost-time model, the four elements were regarded as a system, and a multi-objective optimization model was established. The improved ant colony algorithm was used to carry out multi-objectives of construction projects to overcome the premature defect of the traditional method. The optimal plan of the project was found and the overall efficiency of the construction project management was improved. Results show the optimized ant colony algorithm can avoid the low efficiency of the optimal solution search and the shortcoming of the initial pheromone. The engineering practice proves that the enhanced algorithm has solved the problem of the multi-objective optimization of quality, duration, cost and safety. The obtained conclusions are of significant reference value to direct the similar engineering practice

LOW-TEMPERATURE SINTERED (ZnMg)2SiO4 MICROWAVE CERAMICS WITH TiO2 ADDITION AND CALCIUM BOROSILICATE GLASS

The low-temperature sintered (ZnMg)2SiO–TiO2 microwave ceramic using CaO–B2O3–SiO2 (CBS) as a sintering aid has been developed. Microwave properties of (Zn1-xMgx)2SiO4 base materials via sol-gel method were highly dependent on the Mg-substituted content. Further, effects of CBS and TiO2 additives on the crystal phases, microstructures and microwave characteristics of (ZnMg)2SiO4 (ZMS) ceramics were investigated. The results indicated that CBS glass could lower the firing temperature of ZMS dielectrics effectively from 1170 to 950°C due to the liquid-phase effect, and significantly improve the sintering behavior and microwave properties of ZMS ceramics. Moreover, ZMS–TiO2 ceramics showed the biphasic structure and the abnormal grain growth was suppressed by the pinning effect of second phase TiO2. Proper amount of TiO2 could tune the large negative temperature coefficient of resonant frequency (tf) of ZMS system to a near zero value. (Zn0.8Mg0.2)2SiO4 codoped with 10 wt.% TiO2 and 3 wt.% CBS sintered at 950°C exhibits the dense microstructure and excellent microwave properties: εr = 9.5, Q·f = 16 600 GHz and tf = −9.6 ppm/°C

Analysis of Vibration Attenuation and Energy Consumption of Blasting Demolition Chimney: A Case Study

Demolishing a tall chimney by directional blasting can save time and cost. However, the blasting vibration and the touchdown vibration of the parts of the chimney falling to the ground will cause noise disturbance to the local residents. To reduce the vibration effect of blasting demolition of the chimney, taking the 180 m high chimney in Jiaozuo, China, as the engineering background, the loose accumulation body with a right-angled trapezoid section 3-6 m thick was piled with three kinds of graded gravel particles as the buffer layer. According to the site restrictions, the chimney was demolished by directional blasting in two stages. The vibration propagation and attenuation rules of the blasting demolition of the chimney were analyzed and touchdown vibrations of two parts of the chimney were monitored also. Results show that the low frequency vibrations generated by the blasting and chimney touchdown have a greater impact on the surrounding environment. The vibration velocity and energy attenuation represent a form of power function. With the increase of the number of chimney touchdowns, the energy absorption rate of the loose accumulation body becomes lower. The obtained conclusions in this study can provide a reference for the similar blasting demolition practice

Analysis of Strength Characteristics and Energy Dissipation of Improved-Subgrade Soil of High-Speed Railway above Mined-Out Areas

To reveal the effect of sand content on the mechanical performance and energy dissipation of cement improved subgrade soil, using universal testing machine and SHPB test device, unconfined compressive strength (UCS) and impact compression strength under different impact load (0.2, 0.3, 0.4, and 0.5 MPa) were carried out for the cement improved subgrade soil with different sand content (0%, 5%, 10%, 15%, and 20%). Results show that the dynamic and static stress-strain curves of the cement improved soil have similar variation trend. With the increase of the sand content, the UCS and impact compressive strength of the cement improved soil both increase first, then decrease later, showing the form of a quadratic function. The strength growth rate and the dynamic increase factor (DIF) reach the maximum values when the sand content is 10%, which is 64.7% and 18.6% larger than that of ordinary improved subgrade soil, respectively. In addition, when the sand content increases from 0% to 20%, the specific dissipation energy increases first, and decreases later. Mixing 10% natural sand is the optimal proportion to obtain better energy dissipation capacity of the sand-cement-improved soil

Skewed Pressure Characteristics of Equivalent Load in Double-Arch Tunnel

It is of great importance to reasonably estimate the surrounding rock load of a double-arch tunnel for the design, construction and stability evaluation of the tunnel. Currently, the basic theory on surrounding rock pressure of double-arch tunnels is insufficient for properly making the design and calculations. Generally, simplified calculations based on experience are used, such as the calculation method of Protodyakonov\u27s theory, the building code method and others. Considering the fact that the surrounding rock pressure of double-arch tunnels has skewed distribution characteristics, a computational model of a double-arch tunnel was built using data from an actual excavation of a highway tunnel. Taking some factors into consideration, such as different stress states, different construction methods and different sizes of double-arch tunnels, the pressure evolution of the surrounding rock was analyzed during step-by-step excavation of the double-arch tunnel. The results showed that in each condition the surrounding rock pressure of the double-arch tunnel displayed skewed distribution characteristics. The skewed distribution of the surrounding rock pressure varied with changes in stress state, construction sequence and excavation size. The skewed pressure of the double-arch tunnel was converted to equivalent load. The conversion method and distribution characteristics of the equivalent load are specified. They have important theoretical significance and practical value for similar engineering practices

Evaluating Structural, Chlorophyll-Based and Photochemical Indices to Detect Summer Maize Responses to Continuous Water Stress

his study evaluates the performance of structural, chlorophyll-based, and photochemical indices to detect maize water status and to assess production based on five years of field experiments (2013–2017) during the primary growth stages. We employed three categories of indicators, including water condition and productive and thermal indicators, to quantify the responses of summer maize under continuous water stress from drought to waterlogging conditions. Furthermore, we adopted several spectral indices to assess their sensitivity to three categories of metrics. The results showed the association is the best between the treatment level and Leaf Water Content (LWC). The waterlogging treatment influenced Leaf Water Potential (LWP) in moderate drought stress. Severe drought stress caused the strongest reduction in productivity from both Leaf Area Index (LAI) and chlorophyll content. In terms of sensitivity of various indices, red-edge-position (REP) was sensitive to maize water conditions LWP, LAI and chlorophyll content. Photochemical Reflectance Index (PRI) and Normalized Difference Vegetation Index (NDVI) were the most and second most sensitive indices to productive indicators, respectively. The results also showed that no indices were capable of capturing the information of Crop Water Stress Index (CWSI)

Perindopril and a Galectin-3 Inhibitor Improve Ischemic Heart Failure in Rabbits by Reducing Gal-3 Expression and Myocardial Fibrosis

Objective: Ventricular remodeling is considered the basis of heart failure and is involved in myocardial fibrosis. This study aimed to assess perindopril and a galectin-3 inhibitor (modified citrus pectin, MCP) for their effects on ventricular remodeling and myocardial fibrosis in rabbits with ischemic heart failure.Methods: Rabbits were divided into sham, heart failure (model), MCP, and perindopril groups, respectively. A rabbit model of ischemic heart failure was established by ligating the anterior descending coronary artery. Then, the rabbits were orally administered MCP, perindopril, or saline (all at 2 ml/kg/d) for 4 weeks. Sham animals only underwent open heart surgery without further treatment. After 4 weeks, cardiac function was examined by ultrasound, and myocardial Gal-3, collagen type I, and collagen type III expression was assessed, at the gene and protein levels, by real-time PCR and Western-Blot, respectively; serum Gal-3 was detected by ELISA, and fibrosis in the infarct zone was evaluated by H&E and Masson staining.Results: In model animals, myocardial Gal-3, collagen type I, and collagen type III gene and protein expression levels were increased compared with control values, as well as serum Gal-3 amounts. Treatment with perindopril and MCP significantly alleviated the above effects, with no significant differences between the treatment groups. Pathological analyses showed that compared with model animals, treatment with MCP or perindopril resulted in relatively neatly arranged myocardial cells in the infarct zone, with significantly decreased fibrosis.Conclusion: Perindopril and the galectin-3 inhibitor MCP comparably improve ischemic heart failure in rabbits, by downregulating Gal-3 and reducing myocardial fibrosis

Pilot Investigation of Coal Chemical Wastewater Containing Phenol by Pervaporation Process

Coal chemical wastewater contains a large number of industrial raw materials, such as phenol, resulting in difficulty as target to be treated and the resource waste as industrial raw materials. A pilot pervaporation process is investigated to separate and recycle phenols from coal chemical wastewater to reduce the follow-up biochemical processing load. Operation parameters which affect removing and recovering efficiency are studied, such as temperature, flow rate and downstream pressure. Phenol removal efficiency could reach 50% under the conditions of 70o C, 210 L/h and 3000 Pa. The system could continuously run for 20 cycles. Furthermore, the pervaporation procedure could be enhanced when pumped with gas which made the removal efficiency up to 66%

A novel small-scale self-focusing suppression method for ultrahigh peak power lasers

We proposed a novel method, using an asymmetric four grating compressor (AFGC) to improve the spatial uniformity of laser beams, to suppress the small-scale self-focusing (SSSF) during the post-compression of ultrahigh peak power lasers. The spatial uniformity is an important factor in performing post-compression, due to the spatial intensity nonuniformity will be enhanced while going through a nonlinear process. And what's more, the strong intensity spikes induced during nonlinear process can seriously damage the subsequent optical components. Moreover, the three-dimensional numerical simulations of the post-compression are implemented based on a petawatt (PW) class laser with a standard compressor and an AFGC. The results show that the post-compression with AFGC can shorten the laser pulses from 30fs to sub-10fs and meanwhile efficiently suppress SSSF. This work provides a promising scheme for the post-compression scaling to PW and even 10PW lasers