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The transmission accuracy of the ball screw depends on the processing quality of the thread profile. Traditional detection method of thread profile is complicated and inefficient. When shooting the thread profile of the ball screw in the normal section, the camera axis must be tilted to the lead angle, and adjustment errors are easily introduced from both the front view and the top view. When shooting in the axial section, the spiral lines block each other, so the actual thread profile cannot be captured for detection. In order to solve the above problems, a thread profile detection method is proposed: the theoretical equation of the ball screw thread profile in the axial section is derived based on the theoretical thread profile in the normal section, and the theoretical equation of the thread profile projection curve in the axial section is solved based on helix analysis, and the differential equation between them is obtained; then, the theoretical correction value of the thread profile projection curve is obtained by Linear Search to find the boundary value; the actual thread profile in both axial section and normal section is finally obtained with the theoretical correction value, which can support accurate measurement and detection of the key parameters of the thread profile. Experiments show that the proposed method can effectively improve the accuracy of the ball screw thread profile detection.

To evaluate the role of ghrelin in cardiac fibrosis after myocardial infarction (MI) and to investigate the underlying mechanisms of ghrelin-regulated Nrf2/NADPH/ROS pathway-mediated cardioprotection, the profile of Nrf2, fibrosis markers, and oxidative stress markers were characterized in a rat model of MI and Angiotensin II (Ang II)-stimulated cardiac fibroblasts (CFs). The effects of ghrelin on cardiac function, fibrosis and oxidative stress were investigated after MI in vivo. The role of ghrelin in CF migration and proliferation was evaluated in Ang II-stimulated CFs in vitro. Inhibition of ghrelin receptors using the antagonist, d-Lys3-GHRP-6, in addition to ghrelin was employed in MI and CFs to investigate the direct effect of ghrelin on cardiac fibrosis. Loss function of Nrf2 in CFs was performed to investigate the effect of ghrelin-regulated Nrf2 on oxidative stress and cardiac fibrosis. Ghrelin improved the post-MI cardiac function and reduced cardiac fibrosis. This phenotype is associated with the upregulation of Nrf2 and downregulation of fibrotic proteins, NADPH oxidase and ROS production. In line with in vivo findings, ghrelin attenuated Ang II-stimulated CF migration, proliferation, and oxidative stress in vitro. Inhibition of the ghrelin receptor or knockdown of Nrf2 abolished the beneficial effects of ghrelin on MI or Ang II-stimulated cardiac fibroblasts. In conclusion, ghrelin ameliorates post-MI and Ang II-induced cardiac fibrosis by activating Nrf2, which in turn inhibits the NADPH/ROS pathway.

In order to prolong the service life of piston rings of heavy vehicle engine and decrease the friction and wear of piston rings and cylinder liner, CrMoN/MoS2 multilayer films were deposited on the surface of rings by magnetron sputtering and low temperature ion sulfuration. FESEM equipped with EDX was adopted to analyze the compositions and morphologies of surface, cross-section, and wear scars of the multilayer films. The nano-hardness and Young’s modulus of the films were measured by a nano tester. Tribological properties of the films were tested by an SRV®4 wear tester. The experimental results indicate that the structures of the multilayer films are dense and compact. The films possess nano hardness value of approximately 26.7 GPa and superior ability of plastic deformation resistance. The multilayer films can activate solid lubricating, and possess an excellent antifriction and wear resistance under the conditions of heavy load, high frequency, high temperature, and dynamic load.

In order to study surface structures and properties of wool fabric, plasma treatment, grafting and plasma combined grafting treatment are studied in this paper. The structure of samples was characterized by Fourier transform infrared spectroscopy (FTIR). Furthermore, wetting time, grafting ratio and whiteness were also investigated.

When the engine is working, the oil may be mixed with diesel once there isnt any burning diesel flowing into the crank case or there is a diesel leak in the joint of the oil atomizer and the high-pressure oil pipe. Once it happens, the oil degradation will appear, which can cause serious accidents such as drawing cylinder and tile burning when it appears to be severe. At the present moment, the quality of oil in the real vehicle cant be monitored. In this paper, a model used to monitor the quality of the oil was built by means of matching experiment, which took advantage of the neural network. Through the test of the real vehicle, it came to a conclusion that the mode could monitor the viscosity of the oil in real time and accurately calculate the volume fraction of diesel that is mixed into the oil, which could provide an effective means for the replacement of oil.

The cooling water of the large power vehicular diesel engine often got high or low and engine could not work in the adaptive thermal conditions in altitude environment. In order to solve the problem, analyzed the refrigeration requirement of the diesel engine on plateau section, suggested the amelioration program from installing the fluid operated pump-mot fan speed regulating device. Base on the coupling simulation model of the diesel engine working process and coolant system, took the 90°C water temperature of the diesel engine as the optimally target value, analyzed the change canon of cooling fan speed form the ambient conditions and the diesel engine work condition, established the cooling fan rotary speed control MAP on plateau section, and regulated the cooling fan speed by the methods of open loop preset controlling and closed loop feedback controlling. That would provide the improved method for the large power vehicular diesel engine working well on plateau section.

Using simulation software, numerical simulation and plateau tests are combined to create the plateau diesel engine process simulation model. External characteristics tests of the diesel engine, plateau simulation experiments and plateau vehicle tests are combined to verify the model. The maximum deviation of the results is less 10%. The simulation model is accurate, which provides a way to study plateau environmental adaptation of diesel engines.

For the thermal load of a heavy vehicle is too high in plateau environment, based on Hiroyasu spray model and predictive combustion model, a turbocharged diesel engine model with environmental adaptive predictive ability was established. The experimental results of 3700m revealed that the simulation result relative errors were less than 5%. The research of combustion chamber temperature field was made. This method provides a fundamental basis for further design of the combustion chamber.

Investigation on environmental adaptability of special vehicle engine is scarce and its current evaluation system is unjustifiable in our country. Based on the fuzzy evaluation theory, referenced the criterion of American army environmental adaptability experiment, the paper determined the engine environmental adaptability evaluation fuzzy sets, baseline vectors and weight coefficients by the methods of hierarchical analysis and expert scoring. Then an environmental adaptability evaluation model was established to analyze and evaluate the engine environmental adaptability of the typical areas. The results indicate that the environmental adaptability of Bange in Tibet province rank "poor", Turpan in Tibet province rank "good", and Mohe in Heilongjiang province rank "average".

An Ultrasonic water level measurement system based on GPS is presented. According to the ultrasonic principle and GPS positioning technology, the secondary ultrasonic reflection in the air and the time spent in the liquid are measured to calculate the height of the water level and the depth of the liquid. The temperature compensation circuit is designed to improve the measurement precision. The use of GPS, the specific location of measurement points can be got, and the key position multi-point level measurement, cycle monitoring, real-time monitoring and mobile monitoring can be achieved

There is a problem with non-contact measurement and detection, which reduces its measurement accuracy. Methods developed for measuring and inspecting screw thread characteristic parameters usually using a camera, which is controlled to scan the projection of thread in the parallel optical field to obtain thread images. However, with the block of screw line on the projection of the real thread form, it is impossible to acquire the real thread form from images. The traditional way is adjusting the optical axis to a suitable angle with the thread axis to acquire the real thread form projection, which has some problems, such as time consuming, high skill of operator, high-precision equipment for adjustment, inaccuracy, and so on. Hence, a new method through digital image calibration is presented. The results of relevant simulation indicated the feasibility of this new method, which improves thread measurement and detection accuracy.

A new type of reducer based on traveling wave driver principle was put forward. The initial structure of the reducer was designed and the theoretical model was built up. An initial reducer was manufactured and some performances were tested. The experiment results illustrated that the new type reducer has a feature of large ratio, and the testing results accord with the theoretical model through adjusting some test parameters.

Underwater manipulator as efficient tools plays important roles in ocean exploitation. Because of its specificity for underwater operations, the structure of an underwater manipulator should be designed compactly with light weight and small size. Structure of a 7-function underwater manipulator is designed here. Except forearm rotation and wrist rotation which use hydraulic motors, other functions are driven by hydraulic cylinders, whose parameters are determined by force analysis and limit positions. The hydraulic pipelines from the elbow joint to the end are passed through the forearm, and the hydraulic cylinder of the jaw is integrated into the wrist motor. Built-in pipelines are achieved in the designed structure and the whole weight and volume are greatly reduced by integrated and optimized design.

Micro-thermoelectric generator device (MTGD) is used to supply lasting electrical energy for Micro-electro-mechanical systems (MEMS). As an important part of MTGD, micro-combustor with high energy density has direct influence on the total electrical generating efficiency for MTG. D In this paper, Considering some parameters such as material, dimension, flux of fuel and shape of thermal conductive tunnel for micro-combustor, some simulation models such as thermal transfer, combustion for micro-combustor were built up, and some simulation results were got. Based upon, optimized micro flat combustors were designed and tested. The experiment results illustrated that the conduct efficiency of micro-combustor was well controlled by adjusting heat flux, and the combustor with shape of zigzag combustion tunnel has high thermal exchange efficiency in experiment models. By adjusting flux of fuel and the structure of micro premixed combustor, the heat loss of MTGD was reduced and output power was improved in a degree.

To explore the operative technique and clinical results of using peroneal perforator-based sural neurofasciocutaneous flaps to repair skin and soft tissue defects in lower extremities.From January 2009 to March 2012, 26 patients with skin and soft tissue defects at distal region of leg and foot were hospitalized. Among them, 9 patients suffered from tendon or bone exposure at the distal region of leg after injury due to traffic accident; 4 patients suffered from skin defects in the ankle as a result of electric injury; 8 patients suffered from chronic ulcer at the distal part of leg and foot; 5 patients suffered from plantar pressure ulcer. After debridement, soft tissue defect sizes ranged from 11 cm×5 cm to 18 cm×13 cm. According to the position and size of the defects, peroneal perforator-based sural neurofasciocutaneous flaps were designed and procured to repair the skin and soft tissue defects. The size of flaps ranged from 12 cm×6 cm to 20 cm×15 cm. Flap donor sites were closed by direct suture or skin grafting.Twenty-five flaps survived completely. Only one flap suffered partial margin necrosis in the size of 2 cm×1 cm, which was healed after dressing change. Patients were followed up for 6 to 12 months. The appearance and sensation of flaps were satisfactory; no ulcer occurred; the movement of lower extremities was normal.It is suitable to repair the skin and soft tissue defects at distal region of leg and foot with the peroneal perforator-based sural neurofasciocutaneous flap, as it possesses reliable blood supply, long and non-bulky pedicle, and sufficient available size. The operation is also easy to perform.

Background Reconstruction of lower face defects or deformity often presents as a challenge for plastic surgeons. Many methods, including skin graft, tissue expander, or free flap are introduced. Submental artery perforator flaps have been used in the reconstruction of defects or deformities of the lower face. Methods Between August 2006 and December 2008, 22 patients with lower face defects or deformity underwent reconstruction with pedicled submental artery perforator flaps. Their age ranged between 14 and 36 years. The perforator arteries were detected and labeled with a hand-held Doppler flowmeter. The size of flaps ranged from 4 × 6 to 6 × 7 cm, and the designed flaps included the perforator artery. Results All the flaps survived well, except 1 flap which resulted in partial necrosis in distal region and healed after conservative therapy. No other complication occurred with satisfactory aesthetic appearance of the donor site. Conclusions The submental artery perforator flap is a thin and reliable flap with robust blood supply. This flap can reduce donor-site morbidity significantly and is a good choice for reconstructive surgery of lower face.

To investigate the clinical application of superior or inferior gluteal artery perforator flaps for the gluteal sores.Before operation, the perforator artery was detected by Doppler flowmeter and labeled. The perforator flap was designed, including the perforator artery, but not the gluteal maximum muscle.From Aug. 2006 to May 2009, 15 cases were treated. The flap size ranged from 6 cm x 8 cm to 7 cm x 15 cm. All the flaps survived completely without hematoma, seroma or other complication.The gluteal maximum muscle-reserved gluteal artery perforator flap is a good choice for gluteal sore with reliable blood supply and less morbidity in donor site.

To explore the vascular structure of the deep inferior epigastric artery perforator with the four-dimensional computed tomography (CT) angiography.10 abdominal specimens harvested from fresh cadavers were cannulated with trocar and injected with contrast medium in the deep inferior epigastric artery at different levels, including the deep inferior epigastric artery, its bifurcations, the lateral or medial large perforators. During the perfusion of the contrast medium in the flap, the flap was scanned by three-dimensional CT (four-dimensional defined as three dimensional CT plus time). The CT data were sent to CT workstation and the images were processed and reformatted.The deep inferior epigastric artery perforator terminates in the subdermal vascular plexus, with bifurcating superior to the Scarpa fascia and under the skin. The anastomosis in the abdominal midline occurs in the subdermal vascular plexus. The blood flow distributes in two ways, one is the subdermal vascular plexus, the other is the existed vascular structure. The zone overlying the rectus muscle in the pedicle side has the best blood supply, the other adjacent zone on the ipsilateral side of the abdomen, the zone overlying the contralateral rectus muscle and the zone lateral to the contralateral rectus muscle has declining perfusion.The four-dimensional CT is a useful method to study the vascular structure of the deep inferior epigastric artery perforator in the superficial fascia.

To analyze the clinical application of submental artery perforator flap for lower face defect and deformity.From Sep. 2006 to Mar. 2009, 22 cases with lower face defects and deformities were treated with the submental artery perforator flaps. The age of the patients ranged from 14 to 36. The perforator point was detected by Doppler flowmeter. The size of the flaps ranged from 4 cm x 5 cm to 6 cm x 7 cm.Distal partial necrosis happened in one flap, which healed through dressing. All the other flaps survived with satisfactory appearance and less morbidity in donor sites.Submental artery perforator flap is very suitable for lower face defect and deformity with reliable blood supply and less morbidity in donor site.

To analyses the clinical application of thoracodorsal artery perforator flaps (TAP).We used free or pedicled TAP flaps in 7 patients from Aug 2006 to April 2007, The age ranged from 7 to 42 years old, the perforator arteries was detected and labeled with a hand held Doppler flowmeter, the size of flaps ranged from 6 cm x 9 cm - 12 cm x 16 cm, the flaps designed with perforator artery included, all the flaps are based on the first perforator artery.All the flaps survived well, no complication occurred with lowest donor site morbidity.The thoracodorsal artery flap with latissimus dorsal muscle saved is a thin and reliable flaps with robust of blood supply, the flap can reduce significantly donor site morbidity and is a good choice for reconstructive surgery.

To observe the effect of the preoperative analgesia with Oxycodone/Acetaminophen for liposuction.In the double-blind, placebo-controlled clinical trial, 40 patients undergoing the liposuction were randomly assigned into two groups which were received a single oral dose of Oxycodone/Acetaminophen or calcium gluconate respectively before the operation. The degrees of pain were evaluated by visual analogue scale (VAS) at the beginning and the end of the operation. Adverse effects and the overall satisfaction on analgesic therapy were assessed when operation finished.The VAS scores of the experimental group were significantly lower than the control group at the beginning and the end of operation (P0.05). There were no significant differences between the two groups in side effects (P0.05).Oxycodone/Acetaminophen could produce preemptive effect. Preoperative oral administration of Oxycodone/ Acetaminophen may provide patients with good analgesia in plastic and cosmetic operation.

To investigate and clarify the indications of breast reconstruction after mastectomy with various methods.A clinical analysis was made, based on 44 patients with the 45 breasts who had received breast reconstruction after mastectomy in our hospital from 2003 to 2005. The methods of breast reconstruction included in tissue expander/implant (5 cases), implants covered by latissimus dorsi flap (13 cases), latissimus dorsi flap along (3 cases), DIEP flap (6 cases), TRAN flap (10 cases) and solid double-pedicle TRAM flap (8 cases).All of the flaps survived well in total 40 patients (40 breasts) who were used a flap for breast reconstruction. Superficial skin necrosis occurred in 1 case with the method of tissue expander/implant; rupture of breast prosthesis and infection occurred in 1 case with the technique of implant with a latissimus dorsi flap; subcutaneous seroma occurred in 1 case with the method of DIEP flap; partial flap necrosis occurred in 2 cases with the method of TRAM flap. By the follow-ups of 3 - 12 months, the reconstructed breasts were well-shaped and there were no complications such as abdominal hernia.These 6 methods for breast reconstruction achieved the satisfactory results for the requirement of breast reconstruction in Chinese women. With the development of plastic surgery technique, the indications of breast reconstruction were enlarged.

To reconstruct the soft tissue defect of the hemifacial with free anterolateral thigh fascioadipose flaps or scapular dermal-adiposal flap.The free anterolateral thigh fascioadipose flaps based on the perforators of lateral circumflex femoral artery or scapular dermal-adiposal flap based on the circumflex scapular artery has been designed and reconstructed hemifacial atrophy with the donor artery and vein anastomosed to the facial artery and vein.Anterolateral thigh fascioadipose flaps were performed in 7 patients. Scapular dermal-adiposal flap was applied in 1 patient. All the flaps survived well and aesthetic appearance of reconstructed face achieved good result.The microsurgical tissue transfer, especially the free anterolateral thigh fascioadipose flap is a good and reliable choice for hemifacial reconstruction.

To evaluate a method for the reconstruction of defects of perineum and groin with pedicled anterolateral thigh fasciocutaneous flaps.From July 2003 to February 2005, 12 pedicled anterolateral thigh fasciocutaneous flap based on the perforators of lateral circumflex femoral artery had been designed and transferred to the defects of perineum and groin.Anterolateral thigh fasciocutaneous island flaps were performed in twelve patients. The size of the transferred flap ranged from 8 cm x 11 cm to 18 cm x 20 cm. Only one patient developed superficial cutaneous necrosis in the posterior aspect of the flap because of fecal contamination and infection. The wounds healed secondarily.Despite variable vascular anatomy and technical difficulties in elevating the anterolateral thigh flap, the anterolateral thigh flap is a good choice for perineum and groin reconstruction.

To analysis various complications of 30 patients of breast augmentation by injected polyacrylamide hydrogel and discuss the treatment through periareolar incision.All patients were classified according to the different complications. Open suction technique and partial mastectomies via periareolar incisions were performed in all patients, Only one patient had immediately breast reconstruction with prosthesis, five patients received secondarily breast prostheses implantation via a axillary incision.All the symptoms were relieved after remove of polyacrylamide hydrogel.Polyacrylamide hydrogel should be prohibited for injected breast augmentation at present. A double-blinded randomized clinical study, controlled animal experiments and a large sample questionnaire survey for complications are necessary. The periareolar approach is valuable technique and can remove polyacrylamide hydrogel as completely as possible.

To explore a new method to reconstruct the defect of the distal foot.A distally based dorsum pedis island flap pedicled with the first dorsal metatarsal artery was designed and transferred to the defect of the distal foot.Five patients were treated with this flap, which ranged from 2 cm x 4 cm to 6 cm x 7 cm in size. Four flaps survived completely, one flap had marginal necrosis and healed after conservative therapy.The reverse first dorsal metatarsal artery flap, with good blood circulation and easy manipulation, is a good option for the defects of the distal foot.