Study on fault mechanism of shaft hoist steelwork

AbstractSome achievements have been made in detecting the vibration faults in shaft hoist steelwork, but very little information is currently available to help study the faults mechanism. The faults during the run-ups stage are different from the faults during even speed stage. This paper deals with the fault mechanism through establishing the vibration model as the conveyance moves in shaft. By simulation we can see different vibrating instances correspond to different steelwork faults, and then we put forward suitable fault diagnosis methods

Reinforcement Learning Ramp Metering without Complete Information

This paper develops a model of reinforcement learning ramp metering (RLRM) without complete information, which is applied to alleviate traffic congestions on ramps. RLRM consists of prediction tools depending on traffic flow simulation and optimal choice model based on reinforcement learning theories. Moreover, it is also a dynamic process with abilities of automaticity, memory and performance feedback. Numerical cases are given in this study to demonstrate RLRM such as calculating outflow rate, density, average speed, and travel time compared to no control and fixed-time control. Results indicate that the greater is the inflow, the more is the effect. In addition, the stability of RLRM is better than fixed-time control

(4-Carb­oxy-2-sulfonato­benzoato-κ2 O 1,O 2)bis­(1,10-phenanthroline-κ2 N,N′)manganese(II)

In the title complex, [Mn(C8H4O7S)(C12H8N2)2], the MnII atom is chelated by one 4-carb­oxy-2-sulfonato­benzoate anion and two phenathroline (phen) ligands in a distorted octa­hedral MnN4O2 geometry. The benzene ring of the 4-carb­oxy-2-sulfonato­benzoate anion is twisted with respect to the two phen ring systems at dihedral angles of 66.38 (9) and 53.56 (9)°. In the crystal, inter­molecular O—H⋯O and C—H⋯O hydrogen bonding links the mol­ecules into chains running parallel to [100]. Inter­molecular π–π stacking is also observed between parallel phen ring systems, the face-to-face distance being 3.432 (6) Å

Short-term power generation scheduling rules for cascade hydropower stations based on hybrid algorithm

AbstractPower generation dispatching is a large complex system problem with multi-dimensional and nonlinear characteristics. A mathematical model was established based on the principle of reservoir operation. A large quantity of optimal scheduling processes were obtained by calculating the daily runoff process within three typical years, and a large number of simulated daily runoff processes were obtained using the progressive optimality algorithm (POA) in combination with the genetic algorithm (GA). After analyzing the optimal scheduling processes, the corresponding scheduling rules were determined, and the practical formulas were obtained. These rules can make full use of the rolling runoff forecast and carry out the rolling scheduling. Compared with the optimized results, the maximum relative difference of the annual power generation obtained by the scheduling rules is no more than 1%. The effectiveness and practical applicability of the scheduling rules are demonstrated by a case study. This study provides a new perspective for formulating the rules of power generation dispatching

Bis[[aqua­(1H-imidazo[4,5-f][1,10]phenanthroline-κ2 N 6,N 7)cadmium]bis­(μ-pyridine-2,3-dicarboxyl­ato)-κ3 N,O 2:O 3;κ3 O 3:N,O 2]

In the title compound, [Cd2(C7H3NO4)2(C13H8N4)2(H2O)2], the CdII ion is six-coordinated by two N atoms from a 1H-imidazo[4,5-f][1,10]phenanthroline (IP) ligand, one N atom and one O atom from a pyridine-2,3-dicarboxyl­ate (pdc) ligand, one O atom from another pdc ligand and one water mol­ecule in a distorted octa­hedral geometry. Two CdII ions are bridged by a pair of pdc ligands, forming a centrosymmetric dinuclear structure. Neighboring dinuclear units are linked by the coordinated water mol­ecules through O—H⋯N and O—H⋯O hydrogen bonds, forming a layer parallel to (011). The layers are further linked into a three-dimensional network through N—H⋯O hydrogen bonds. π–π inter­actions between the IP ligands further stabilize the supra­molecular structure [centroid–centroid distances = 3.579 (3), 3.686 (3), 3.710 (3), 3.766 (3) and 3.841 (3) Å]

Treatment of osteonecrosis of femoral head with BMSCs-seeded bio-derived bone materials combined with rhBMP-2 in rabbits

ObjectiveTo evaluate the effect of autologous bone marrow mesenchymal stem cells (BMSCs) seeded bio-derived bone materials (BBM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in repairing defect of osteonecrosis of femoral head (ONFH).MethodsEarly-stage osteonecrosis in the left hip was induced in 36 adult New Zealand white rabbits (provided by the Animal Center of Guangxi Medical University, Nanning, China) after core decompression and delivery of liquid nitrogen into the femoral head. Then the animals were divided into three groups according to the type of implants for bone repair: 12 rabbits with nothing (Group I, the blank control group), 12 with BBM combined with rhBMP-2 (Group II), and 12 with BMSCs-seeded BBM combined with rhBMP-2 (Group III). At 4, 8, and 12 weeks after surgery, X-ray of the femoral head of every 4 rabbits in each group was taken, and then they were killed and the femoral heads were collected at each time point, respectively. Gross observation was made on the femoral heads. After hematoxylin and eosin staining, Lane-sandhu scores of X-ray and bone densitometry were calculated and the histomorphometric measurements were made for the new bone trabeculae.ResultsAt 12 weeks after surgery, two femoral heads collapsed in Group I, but none in Group II or Group III. X-ray examination showed that the femoral heads in Group I had defect shadow or collapsed while those in Group II had a low density and those in Group III presented with a normal density. Histologically, the defects of femoral heads were primarily filled with no new bone but fibrous tissues in Group I. In contrast, new bone regeneration and fibrous tissues occurred in Group II and only new bone regeneration occurrd in Group III. Lane-sandhu scores of X-ray, bone mineral density and rate of new bone in trabecular area in Group III were higher significantly than those of the other two groups.ConclusionsOur findings indicate a superior choice of repairing the experimental defect of ONFH with BMSCs-seeded BBM combined with rhBMP-2