可调眼镜

可调眼镜的原理其实很简单:透镜越厚,度数调节范围越大。眼镜两片硬塑料透镜内部各有一个填有液体的透明圆囊,分别连着各自镜腿上的小注射器。

可调式双夹线米字线组合目镜

工具显微镜类仪器一般是通过中央显微镜瞄准工件影像进行测量的。中央显微镜的瞄准系统必须设置分划板,才能实现对被测工件的瞄准测量。常见的分划板有:米字线,十字线,双夹线或其它形式的分划板等等。日常的测试工作中,首先根据不同的测量项目选择合理的分划板,即更换相应的瞄准目镜头,然后再对被测工件影像进行瞄准测量。

A novel self-alignment method for high precision silicon diffraction microlens arrays preparation and its integration with infrared focal plane arrays

Silicon(Si)diffraction microlens arrays are usually used to integrating with infrared focal plane arrays(IRFPAs)to improve their performance.The errors of lithography are unavoidable in the process of the Si diffrac-tion microlens arrays preparation in the conventional engraving method.It has a serious impact on its performance and subsequent applications.In response to the problem of errors of Si diffraction microlens arrays in the conven-tional method,a novel self-alignment method for high precision Si diffraction microlens arrays preparation is pro-posed.The accuracy of the Si diffractive microlens arrays preparation is determined by the accuracy of the first li-thography mask in the novel self-alignment method.In the subsequent etching,the etched area will be protected by the mask layer and the sacrifice layer or the protective layer.The unprotection area is carved to effectively block the non-etching areas,accurately etch the etching area required,and solve the problem of errors.The high precision Si diffraction microlens arrays are obtained by the novel self-alignment method and the diffraction effi-ciency could reach 92.6%.After integrating with IRFPAs,the average blackbody responsity increased by 8.3%,and the average blackbody detectivity increased by 10.3%.It indicates that the Si diffraction microlens arrays can improve the filling factor and reduce crosstalk of IRFPAs through convergence,thereby improving the perfor-mance of the IRFPAs.The results are of great reference significance for improving their performance through opti-mizing the preparation level of micro nano devices.

Observation and characterization of asphalt microstructure by atomic force microscopy

The microstructure of asphalt is investigated by atomic force microscopy （AFM）. In order to analyze the impacts of asphalt types on microstructures, two neat asphalts with different penetration grades （50# and 70#） and one styrene-butadiene-styrene （SBS） modified asphalt are chosen. The influence of short-term aging is also studied. Based on the knowledge of asphalt＇s microproperties, the relationship between microstructures and healing property is analyzed. The results indicate that the microstructures of three asphalts are quite different and the effects of aging on the surface characteristics for different asphalts are also different. It is proposed that the bee structure is a type of wax crystal and it has a close relationship with the ＂bridge-healing＂ mechanism. The findings may reveal the formation mechanism of microstructure and the healing property for asphalts.

Multimode Interference Optical Power Splitter in Proton-Exchange LiNbO_3 Waveguides

The self imaging effect in graded index waveguides using annealed proton exchange (APE) technique in lithium niobate (LiNbO 3) waveguides is analyzed and simulated using the three dimensional nonparaxial beam propagation method (BPM).On this basis,a 1×8 multimode interference (MMI) optical power splitter by APE technique in X cut LiNibO 3 with Y propagation substrate is fabricated.Measurements show that the device has realized eight powers splittings.

美的升华

催醒了 我那甜睡中的梦 当窗处 有争鸣声响起的时候 一帘的轻柔 卷起后

Fabrication and Electromechanical Characteristics of 2×2 Torsion-Mirror Optical Switch Arrays with Monolithically Integrated Fiber Self-Holding Structures

Novel 2×2 torsion-mirror optical switch arrays are fabricated by using the mixed micromachining based on the surface and bulk silicon microelectronics,then are investigated electromechanically in applied direct and alternating electric fields.When the thickness of the elastic torsion beams suspending the aluminum coated polysilicon micro-mirrors of the switches in the arrays is about 1μm,the electrostatic yielding voltages for driving the mirrors to achieve their ON-state are in the range of 270～290V,and the minimum holding voltages for mirrors ON-state are found as 55V or so.Theoretical analysis manifests that the yielding voltage is more sensitive to beam thickness than other design parameters do about the torsion-mirror switch structures.The lifetime can reach 10 8 times.The estimated shortest switching time of the switches at least lasts for less than 2ms.The force analysis on the two kinds of new fiber self-holding structures integrated monolithically in the chip of the optical switch arrays indicates that the structures can feature self-fixing and self-aligning of optical fibers.

π-Electron-Assisted Relaxation of Spin Excited States in Cobalt Phthalocyanine Molecules on Au（111） Surface

We present our investigation on the spin relaxation of cobalt phthalocyanine （CoPc） films on Au（111） （CoPc/Au（111）） surface using scanning tunneling microscopy and spectroscopy. The spin relaxation time derived from the linewidth of spin-flip inelastic electron tunneling spectroscopy is quantitatively analyzed according to the Korringa-like formula. We find that although this regime of the spin relaxation time calculation by just considering the exchange interaction between itinerant conduction electrons and localized d-shells （s-d exchange interaction） can successfully reproduce the experimental value of the adsorbed magnetic atom, it fails in our case of CoPc/Au（111）. Instead, we can obtain the relaxation time that is in good agreement with the experimental result by considering the fact that the 7c electrons in CoPc molecules are spin polarized, where the spin polarized 7c electrons extended at the Pc macrocycle may also scatter the conduction electrons in addition to the localized d spins. Our analyses indicate that the scattering by the π electrons provides an efficient spin relaxation channel in addition to the s-d interaction and thus leads to much short relaxation time in such a kind of molecular system on a metal substrate.

Natural orifice transluminal endoscopic surgery:New minimally invasive surgery come of age

Although in the past two decades,laparoscopic surgery,considered as a great revolution in the minimally inva-sive surgery field,has undergone major development worldwide,another dramatic surgical revolution has quietly appeared in recent years.Ever since Kalloo's first report on transgastric peritoneoscopy in a porcine model in 2004,interest in a new surgical procedure named natural orifice transluminal endoscopic surgery(NOTES)has blossomed worldwide.Considering that a NOTES procedure could theoretically avoid any abdomi-nal incision,operation-related pain and scarring,many surgeons and endoscopists have been enthusiastic in their study of this new technique.In recent years,sev-eral NOTES studies have been carried out on porcine models and even on humans,including transvaginal cholecystectomy,transgastric appendectomy,transvagi-nal appendectomy,and transvesical peritoneoscopy.So what is the current situation of NOTES and how many challenges do we still face?This review discusses the current research progress in NOTES.

Patient and physician perception of natural orifice transluminal endoscopic appendectomy

AIM:To investigate perception of natural orifice transluminal endoscopic surgery(NOTES)as a potential technique for appendectomy.METHODS:One hundred patients undergoing endoscopy and 100 physicians were given a questionnaire describing in detail the techniques of NOTES and laparoscopic appendectomy.They were asked about the reasons for their preference,choice of orifice,and extent of complication risk they were willing to accept.RESULTS:Fifty patients(50%)and only 21 physicians(21%)preferred NOTES(P<0.001).Patients had previously heard of NOTES less frequently(7%vs73%,P<0.001)and had undergone endoscopy more frequently(88%vs 36%,P<0.001)than physicians.Absence of hernia was the most common reason for NOTES preference in physicians(80%vs 44%,P= 0.003),whereas reduced pain was the most common reason in patients(66%vs 52%).Physicians were more likely to refuse NOTES as a novel and unsure technique(P<0.001)and having an increased risk of infection(P<0.001).The preferred access site in both groups was colon followed by stomach,with vagina being rarely preferred.In multivariable modeling,those with high-school education[odds ratio(OR):2.68,95% confidence interval(CI):1.23-5.83]and prior colonoscopy(OR:2.10,95%CI:1.05-4.19)were more likely to prefer NOTES over laparoscopic appendectomy.There was a steep decline in NOTES preference with increased rate of procedural complications.Male patients were more likely to consent to their wives vaginal NOTES appendectomy than male physicians(P=0.02).CONCLUSION:The preference of NOTES for appendectomy was greater in patients than physicians and was related to reduced pain and absence of hernia rather than lack of scarring.

Partial stent-in-stent placement of biliary metallic stents using a short double-balloon enteroscopy

Endoscopic intervention is less invasive than percutaneous or surgical approaches and should be considered the primary drainage procedure in most cases with obstructive jaundice.Recently,therapeutic endoscopic retrograde cholangiopancreatography(ERCP) using double-balloon enteroscopy(DBE) has been shown to be feasible and effective,even in patients with surgically altered anatomies.On the other hand,endoscopic partial stent-in-stent(PSIS) placement of selfexpandable metallic stents(SEMSs) for malignant hilar biliary obstruction in conventional ERCP has also been shown to be feasible,safe and effective.We performed PSIS placement of SEMSs for malignant hilar biliary obstruction due to liver metastasis using a short DBE in a patient with Roux-en-Y anastomosis and achieved technical and clinical success.This procedure can result in quick relief from obstructive jaundice in a single session and with short-term hospitalization,even in patients with surgically altered anatomies.

Natural orifice transluminal endoscopic surgeryvs laparoscopic ovariectomy:Complications and inflammatory response

AIM:To compare natural orifice transluminal endoscopic surgery (NOTES) vs standard laparoscopic ovariectomy in mini pigs with respect to technical aspects,complications and parameters of systemic inflammatory response.METHODS:This was a randomized,experimental,survival study.Ten female mini pigs underwent NOTES transgastric ovariectomy (NOTES group) and ten female mini pigs underwent laparoscopic ovariectomy (LAP group).A "percutaneous endoscopic gastrostomy" approach with guidewire and sphincterotome was used for gastrotomy creation.The ovary was resected using standard biopsy forceps and a snare.The access site was closed using a "KING" closure with a single endoloop and several clips.In the laparoscopic group,a three-port laparoscopy and an ovariectomy were performed with the use of standard laparoscopic devices.C-reactive protein (CRP),white blood count and interleukin (IL)-6 plasma levels were used as indicators of systemic inflammatory response.All animals were euthanized 28 d after surgery.RESULTS:All animals survived without complications.The mean procedure time was 41.3 min ± 17.6 min (NOTES group) and 25.7 min ± 5.25 min (LAP group,P < 0.02).Postmortem examinations demonstrated that 50% and 70% of animals were free of any complications in the NOTES and LAP groups,respectively.The remaining animals developed minor complications (adhesions) in a comparable frequency between the two groups.In the NOTES group,one animal developed a small intramural gastric abscess close to the gastrotomy site.A minor serous exudate that was present in 50% and 40% of the animals in the NOTES and laparoscopy groups,respectively,was not considered a complication.In both groups CRP levels increased significantly on the 2nd and 7th postoperative days (POD) and returned to normal after 28 d.On POD 2,an increase of CRP level was significantly higher in the NOTES group compared to the LAP group.Values of IL-6 did not differ from baseline values in either of the groups postoperatively.Interestingly,the platelet count decreased significantly on POD 2,but returned close to baseline values on POD 7 and PODs 28-30.CONCLUSION:Both NOTES and laparoscopic ovariectomies had a similar frequency of minor complications.However,the NOTES technique produced an increased systemic inflammatory response on POD 2.

Autofluorescence imaging endoscopy for identifi cation and assessment of inflammatory ulcerative colitis

AIM:To validate the clinical relevance of autofluores-cence imaging(AFI)endoscopy for the assessment of inflammatory ulcerative colitis(UC).METHODS:A total of 572 endoscopic images were se-lected from 42 UC patients:286 taken with white light imaging(WLI)and 286 with AFI from the same sites.WLI images were assessed for overall mucosal inflammation according to Mayo endoscopic subscore(MES),and for seven characteristic endoscopic features.Likewise,AFI photographs were scored according to relative abundance of red,green and blue color com-ponents within each image based on an RGB additive color model.WLI and AFI endoscopic scores from the same sites were compared.Histological evaluation of biopsies was according to the Riley Index.RESULTS:Relative to red(r=0.52,P<0.01)or blue(r=0.56,P<0.01)color component,the green color component of AFI(r=-0.62,P<0.01)corresponded more closely with mucosal inflammation sites.There were signif icant differences in green color components between MES-0(0.396±0.043)and MES-1(0.340± 0.035)(P<0.01),and between MES-1 and ≥ MES-2(0.318±0.037)(P<0.01).The WLI scores for "vascu-lar patterns"(r=-0.65,P<0.01),"edema"(r=-0.62,P<0.01),histology scores for "polymorphonuclear cells in the lamina propria"(r=-0.51,P<0.01)and "crypt architectural irregularities"(r=-0.51,P<0.01)showed correlation with the green color component of AFI.There were significant differences in green color components between limited(0.399± 0.042)and extensive(0.375±0.044)(P=0.014)polymorpho-nuclear cell inf iltration within MES-0.As the severity of the mucosal inflammation increased,the green color component of AFI decreased.The AFI green color com-ponent was well correlated with the characteristic en-doscopic and histological inflammatory features of UC.CONCLUSION:AFI has application in detecting inflammatory lesions,including microscopic activity in the co-lonic mucosa of UC patients,based on the green color component of images.

Natural orifice transluminal endoscopy surgery:A review

Minimally invasive surgery started spreading worldwide in 1987,when the first laparoscopic cholecystectomy was performed.Meanwhile,improvement of endoscopic equipment and instruments allowed gastroenterologists to attempt more aggressive endoluminal interventions,even beyond the wall barrier.The first transgastric peri-toneoscopy,in 2004,brought to light the concept of natural orifice transluminal endoscopic surgery(NOTES).The idea of incisionless surgery is attractive and has become a new goal for both surgeons and other people interested in this field of investigation.The authors present a review of all developments concerning NOTES,including animal studies and human experience.

Natural orifice transluminal endoscopic wedge hepatic resection with a water-jet hybrid knife in a non-survival porcine model

AIM: To explore the feasibility of a water-jet hybrid knife to facilitate wedge hepatic resection using a natural orifice transluminal endoscopic surgery (NOTES) approach in a non-survival porcine model. METHODS: The Erbe Jet2 water-jet system allows a needleless, tissue-selective hydro-dissection with a pre-selected pressure. Using this system, wedge hepatic resection was performed through three natural routes (trans-anal, trans-vaginal and trans-umbilical) in three female pigs weighing 35 kg under general anesthesia. Entry into the peritoneal cavity was via a 15-mm incision using a hook knife. The targeted liver segment was marked by an APC probe, followed by wedge hepatic resection performed using a water-jet hybrid knife with the aid of a 4-mm transparent distance soft cap mounted onto the tip of the endoscope for holding up the desired plane. The exposed vascular and ductal structures were clipped with Endoclips. Hemostasis was applied to the bleeding cut edges of the liver parenchyma by electrocautery. After the procedure, the incision site was left open, and the animal was euthanized followed by necropsy. RESULTS: Using the Erbe Jet2 water-jet system, trans-anal and trans-vaginal wedge hepatic resection was successfully performed in two pigs without laparoscopic assistance. Trans-umbilical attempt failed due to an unstable operating platform. The incision for peritoneal entry took 1 min, and about 2 h was spent on excision of the liver tissue. The intra-operative blood loss ranged from 100 to 250 mL. Microscopically, the hydro-dissections were relatively precise and gentle, preserving most vessels. CONCLUSION: The Erbe Jet2 water-jet system can safely accomplish non-anatomic wedge hepatic resection in NOTES, which deserves further studies to shorten the dissection time.

Organotemplate-free Hydrothermal Synthesis of SUZ-4 Zeolite: Influence of Synthesis Conditions

Various conditions were investigated in detail for the novel organic template-free static hydrothermal synthesis of SUZ-4 zeolite in the presence of seeds. The obtained samples were characterized by XRD （X-ray diffraction）, SEM （scanning electron microscope）, TG （thermal gravimetric analysis）, ICP （inductively coupling plasma） elemental analysis, nitrogen sorption isotherm and surface area. The results show that pure SUZ-4 zeolites with high crystallinity are obtained in a broad window of synthesis conditions： seed mass concentration 0.2%-2%, SIO2/A1203 molar ratio 21 25, KOH/SiO2 molar ratio 0.33 0.43, H20/SiO2 molar ratio 7.14-38.1, aging time 24 h, crystallization temperature 160℃, and crystallization time 6-10 d. Also, crystallinity and size of the rod-like SUZ-4 zeolite crystals are found to alter with the conditions.

Diagnosis of autoimmune gastritis by high resolution magnification endoscopy

Endoscopic visualisation of gastric atrophy is usually not feasible with conven.tional endoscopy. Magnifying endoscopy is helpful to analyze the subepithelial microvascular architecture as well as the mucosal surface microstructure without tissue biopsy. Using this technique we were able to describe the normal gastric microvasculature pattern and we also identified characteristic patterns in two cases of autoimmune atrophic gastritis.

Histologic characteristics of gastric polyps in Korea: Emphasis on discrepancy between endoscopic forceps biopsy and endoscopic mucosal resection specimen

AIM： To investigate histological characteristics of gastric polyps in the Korean population. METHODS： We reviewed endoscopic photographs and medical records of patients with gastric polyps who underwent endoscopic mucosal resection from April 1996 through February 2003. RESULTS： A total of 85 gastric polyps from 74 patients were reviewed, Male-to-female ratio was 1：1,96, Mean age was 59.9 =1：10,8 years. Multiple polyps were observed in 10,8%, Gastric polyps occurred most frequently in the antrum （58.8%）, Pathological results on resected specimens were as follows： tubular adenoma 45.9%, hyperplastic polyp 31.8%, inflammatory polyp 9.4%, hamartoma 3.5%, fundic gland polyp 2.4%, tubulovillous adenoma 2.4%, adenocarcinoma 2.4%, dysplasia 1.1%, and mucosal pseudolipomatosis 1.1%. Discrepancy rate between endoscopic biopsy and pathology of resected specimens was 27.1%. There was no relationship between the size of the polyp and concordance rate. CONCLUSION： There is considerable discrepancy in histologic findings between endoscopic forceps biopsy and resected specimens. Approaches to review of the histology of an entire polyp should be performed, especially when an adenoma is suspected.

Tailoring the Self-assembly of Melamine on Au（111） via Doping with Cu Atoms

The doping effect of Cu on the self-assembly film of melamine on an Au（111） surface has been investigated with scanning tunneling microscopy （STM）. The evaporated Cu adatoms occupy the positions underneath the amino groups and change the hydrogen bonding pat- tern between the melamine molecules. Accordingly, the self-assembly structure has changed stepwise from a well-defined honeycomb into a track-like and then a triangular structure depending on the amount of Cu adatoms. The interaction between Cu adatom and melamine is moderate thus the Cu adatoms can be released upon mild heating to around 100 ℃. These findings are different from previous observations of either the coordination assembly or the physically trapped metal adatoms.